LIBGNUTLS_VERSION

#define     LIBGNUTLS_VERSION

LIBGNUTLS_VERSION_MAJOR

#define     LIBGNUTLS_VERSION_MAJOR

LIBGNUTLS_VERSION_MINOR

#define     LIBGNUTLS_VERSION_MINOR

LIBGNUTLS_VERSION_PATCH

#define     LIBGNUTLS_VERSION_PATCH

LIBGNUTLS_VERSION_NUMBER

#define     LIBGNUTLS_VERSION_NUMBER

HAVE_SSIZE_T

#define     HAVE_SSIZE_T

GNUTLS_CIPHER_RIJNDAEL_128_CBC

#define     GNUTLS_CIPHER_RIJNDAEL_128_CBC

GNUTLS_CIPHER_RIJNDAEL_256_CBC

#define     GNUTLS_CIPHER_RIJNDAEL_256_CBC

GNUTLS_CIPHER_RIJNDAEL_CBC

#define     GNUTLS_CIPHER_RIJNDAEL_CBC

GNUTLS_CIPHER_ARCFOUR

#define     GNUTLS_CIPHER_ARCFOUR

enum gnutls_cipher_algorithm_t

  typedef enum gnutls_cipher_algorithm
  {
    GNUTLS_CIPHER_NULL = 1,
    GNUTLS_CIPHER_ARCFOUR_128,
    GNUTLS_CIPHER_3DES_CBC,
    GNUTLS_CIPHER_AES_128_CBC,
    GNUTLS_CIPHER_AES_256_CBC,
    GNUTLS_CIPHER_ARCFOUR_40,
    GNUTLS_CIPHER_RC2_40_CBC = 90,
    GNUTLS_CIPHER_DES_CBC
  } gnutls_cipher_algorithm_t;

enum gnutls_kx_algorithm_t

  typedef enum
  {
    GNUTLS_KX_RSA = 1,
    GNUTLS_KX_DHE_DSS,
    GNUTLS_KX_DHE_RSA,
    GNUTLS_KX_ANON_DH,
    GNUTLS_KX_SRP,
    GNUTLS_KX_RSA_EXPORT,
    GNUTLS_KX_SRP_RSA,
    GNUTLS_KX_SRP_DSS,
    GNUTLS_KX_PSK,
    GNUTLS_KX_DHE_PSK
  } gnutls_kx_algorithm_t;

enum gnutls_params_type_t

  typedef enum
  {
    GNUTLS_PARAMS_RSA_EXPORT = 1,
    GNUTLS_PARAMS_DH
  } gnutls_params_type_t;

enum gnutls_credentials_type_t

  typedef enum
  {
    GNUTLS_CRD_CERTIFICATE = 1,
    GNUTLS_CRD_ANON,
    GNUTLS_CRD_SRP,
    GNUTLS_CRD_PSK,
    GNUTLS_CRD_IA
  } gnutls_credentials_type_t;

GNUTLS_MAC_SHA

#define     GNUTLS_MAC_SHA

GNUTLS_DIG_SHA

#define     GNUTLS_DIG_SHA

enum gnutls_mac_algorithm_t

  typedef enum
  {
    GNUTLS_MAC_UNKNOWN = 0,
    GNUTLS_MAC_NULL = 1,
    GNUTLS_MAC_MD5,
    GNUTLS_MAC_SHA1,
    GNUTLS_MAC_RMD160,
    GNUTLS_MAC_MD2
  } gnutls_mac_algorithm_t;

enum gnutls_digest_algorithm_t

  typedef enum
  {
    GNUTLS_DIG_NULL = GNUTLS_MAC_NULL,
    GNUTLS_DIG_MD5 = GNUTLS_MAC_MD5,
    GNUTLS_DIG_SHA1 = GNUTLS_MAC_SHA1,
    GNUTLS_DIG_RMD160 = GNUTLS_MAC_RMD160,
    GNUTLS_DIG_MD2 = GNUTLS_MAC_MD2
  } gnutls_digest_algorithm_t;

GNUTLS_MAX_ALGORITHM_NUM

#define     GNUTLS_MAX_ALGORITHM_NUM

GNUTLS_COMP_ZLIB

#define     GNUTLS_COMP_ZLIB

enum gnutls_compression_method_t

  typedef enum
  {
    GNUTLS_COMP_NULL = 1,
    GNUTLS_COMP_DEFLATE,
    GNUTLS_COMP_LZO		/* only available if gnutls-extra has
				   been initialized
				 */
  } gnutls_compression_method_t;

enum gnutls_connection_end_t

  typedef enum
  {
    GNUTLS_SERVER = 1,
    GNUTLS_CLIENT
  } gnutls_connection_end_t;

enum gnutls_alert_level_t

  typedef enum
  {
    GNUTLS_AL_WARNING = 1,
    GNUTLS_AL_FATAL
  } gnutls_alert_level_t;

enum gnutls_alert_description_t

  typedef enum
  {
    GNUTLS_A_CLOSE_NOTIFY,
    GNUTLS_A_UNEXPECTED_MESSAGE = 10,
    GNUTLS_A_BAD_RECORD_MAC = 20,
    GNUTLS_A_DECRYPTION_FAILED,
    GNUTLS_A_RECORD_OVERFLOW,
    GNUTLS_A_DECOMPRESSION_FAILURE = 30,
    GNUTLS_A_HANDSHAKE_FAILURE = 40,
    GNUTLS_A_SSL3_NO_CERTIFICATE = 41,
    GNUTLS_A_BAD_CERTIFICATE = 42,
    GNUTLS_A_UNSUPPORTED_CERTIFICATE,
    GNUTLS_A_CERTIFICATE_REVOKED,
    GNUTLS_A_CERTIFICATE_EXPIRED,
    GNUTLS_A_CERTIFICATE_UNKNOWN,
    GNUTLS_A_ILLEGAL_PARAMETER,
    GNUTLS_A_UNKNOWN_CA,
    GNUTLS_A_ACCESS_DENIED,
    GNUTLS_A_DECODE_ERROR = 50,
    GNUTLS_A_DECRYPT_ERROR,
    GNUTLS_A_EXPORT_RESTRICTION = 60,
    GNUTLS_A_PROTOCOL_VERSION = 70,
    GNUTLS_A_INSUFFICIENT_SECURITY,
    GNUTLS_A_INTERNAL_ERROR = 80,
    GNUTLS_A_USER_CANCELED = 90,
    GNUTLS_A_NO_RENEGOTIATION = 100,
    GNUTLS_A_UNSUPPORTED_EXTENSION = 110,
    GNUTLS_A_CERTIFICATE_UNOBTAINABLE = 111,
    GNUTLS_A_UNRECOGNIZED_NAME = 112,
    GNUTLS_A_UNKNOWN_SRP_USERNAME = 120,
    GNUTLS_A_MISSING_SRP_USERNAME = 121,
    GNUTLS_A_INNER_APPLICATION_FAILURE = 208,
    GNUTLS_A_INNER_APPLICATION_VERIFICATION = 209
  } gnutls_alert_description_t;

enum gnutls_handshake_description_t

  typedef enum
  { GNUTLS_HANDSHAKE_HELLO_REQUEST,
    GNUTLS_HANDSHAKE_CLIENT_HELLO,
    GNUTLS_HANDSHAKE_SERVER_HELLO,
    GNUTLS_HANDSHAKE_CERTIFICATE_PKT = 11,
    GNUTLS_HANDSHAKE_SERVER_KEY_EXCHANGE,
    GNUTLS_HANDSHAKE_CERTIFICATE_REQUEST,
    GNUTLS_HANDSHAKE_SERVER_HELLO_DONE,
    GNUTLS_HANDSHAKE_CERTIFICATE_VERIFY,
    GNUTLS_HANDSHAKE_CLIENT_KEY_EXCHANGE,
    GNUTLS_HANDSHAKE_FINISHED = 20
  } gnutls_handshake_description_t;

enum gnutls_certificate_status_t

  typedef enum
  {
    GNUTLS_CERT_INVALID = 2,	/* will be set if the certificate
				 * was not verified.
				 */
    GNUTLS_CERT_REVOKED = 32,	/* in X.509 this will be set only if CRLs are checked
				 */

    /* Those are extra information about the verification
     * process. Will be set only if the certificate was 
     * not verified.
     */
    GNUTLS_CERT_SIGNER_NOT_FOUND = 64,
    GNUTLS_CERT_SIGNER_NOT_CA = 128,
    GNUTLS_CERT_INSECURE_ALGORITHM = 256
  } gnutls_certificate_status_t;

enum gnutls_certificate_request_t

  typedef enum
  {
    GNUTLS_CERT_IGNORE,
    GNUTLS_CERT_REQUEST = 1,
    GNUTLS_CERT_REQUIRE
  } gnutls_certificate_request_t;

enum gnutls_openpgp_key_status_t

  typedef enum
  { GNUTLS_OPENPGP_KEY,
    GNUTLS_OPENPGP_KEY_FINGERPRINT
  } gnutls_openpgp_key_status_t;

enum gnutls_close_request_t

  typedef enum
  {
    GNUTLS_SHUT_RDWR = 0,
    GNUTLS_SHUT_WR = 1
  } gnutls_close_request_t;

GNUTLS_TLS1

#define     GNUTLS_TLS1

enum gnutls_protocol_t

  typedef enum
  {
    GNUTLS_SSL3 = 1,
    GNUTLS_TLS1_0,
    GNUTLS_TLS1_1,
    GNUTLS_VERSION_UNKNOWN = 0xff
  } gnutls_protocol_t;

enum gnutls_certificate_type_t

  typedef enum
  {
    GNUTLS_CRT_X509 = 1,
    GNUTLS_CRT_OPENPGP
  } gnutls_certificate_type_t;

enum gnutls_x509_crt_fmt_t

  typedef enum
  {
    GNUTLS_X509_FMT_DER,
    GNUTLS_X509_FMT_PEM
  } gnutls_x509_crt_fmt_t;

enum gnutls_pk_algorithm_t

  typedef enum
  {
    GNUTLS_PK_UNKNOWN = 0,
    GNUTLS_PK_RSA = 1,
    GNUTLS_PK_DSA
  } gnutls_pk_algorithm_t;

gnutls_pk_algorithm_get_name ()

const char* gnutls_pk_algorithm_get_name    (gnutls_pk_algorithm_t algorithm);

GNUTLS_SIGN_RSA_SHA

#define     GNUTLS_SIGN_RSA_SHA

GNUTLS_SIGN_DSA_SHA

#define     GNUTLS_SIGN_DSA_SHA

enum gnutls_sign_algorithm_t

  typedef enum
  {
    GNUTLS_SIGN_UNKNOWN = 0,
    GNUTLS_SIGN_RSA_SHA1 = 1,
    GNUTLS_SIGN_DSA_SHA1,
    GNUTLS_SIGN_RSA_MD5,
    GNUTLS_SIGN_RSA_MD2,
    GNUTLS_SIGN_RSA_RMD160
  } gnutls_sign_algorithm_t;

gnutls_sign_algorithm_get_name ()

const char* gnutls_sign_algorithm_get_name  (gnutls_sign_algorithm_talgorithm );

gnutls_transport_ptr_t

struct gnutls_session_int

struct gnutls_session_int;

gnutls_session_t

struct gnutls_dh_params_int

struct gnutls_dh_params_int;

gnutls_dh_params_t

struct gnutls_x509_privkey_int

struct gnutls_x509_privkey_int;

gnutls_rsa_params_t

gnutls_init ()

int         gnutls_init                     (gnutls_session_t *session,
                                             gnutls_connection_end_t con_end);

This function initializes the current session to null. Every session must be initialized before use, so internal structures can be allocated. This function allocates structures which can only be free'd by calling gnutls_deinit(). Returns zero on success.

gnutls_deinit ()

void        gnutls_deinit                   (gnutls_session_t session);

This function clears all buffers associated with the session. This function will also remove session data from the session database if the session was terminated abnormally.

gnutls_bye ()

int         gnutls_bye                      (gnutls_session_t session,
                                             gnutls_close_request_t how);

Terminates the current TLS/SSL connection. The connection should have been initiated using gnutls_handshake(). how should be one of GNUTLS_SHUT_RDWR, GNUTLS_SHUT_WR.

In case of GNUTLS_SHUT_RDWR then the TLS connection gets terminated and further receives and sends will be disallowed. If the return value is zero you may continue using the connection. GNUTLS_SHUT_RDWR actually sends an alert containing a close request and waits for the peer to reply with the same message.

In case of GNUTLS_SHUT_WR then the TLS connection gets terminated and further sends will be disallowed. In order to reuse the connection you should wait for an EOF from the peer. GNUTLS_SHUT_WR sends an alert containing a close request.

Note that not all implementations will properly terminate a TLS connection. Some of them, usually for performance reasons, will terminate only the underlying transport layer, thus causing a transmission error to the peer. This error cannot be distinguished from a malicious party prematurely terminating the session, thus this behavior is not recommended.

This function may also return GNUTLS_E_AGAIN or GNUTLS_E_INTERRUPTED; cf. gnutls_record_get_direction().

gnutls_handshake ()

int         gnutls_handshake                (gnutls_session_t session);

This function does the handshake of the TLS/SSL protocol, and initializes the TLS connection.

This function will fail if any problem is encountered, and will return a negative error code. In case of a client, if the client has asked to resume a session, but the server couldn't, then a full handshake will be performed.

The non-fatal errors such as GNUTLS_E_AGAIN and GNUTLS_E_INTERRUPTED interrupt the handshake procedure, which should be later be resumed. Call this function again, until it returns 0; cf. gnutls_record_get_direction() and gnutls_error_is_fatal().

If this function is called by a server after a rehandshake request then GNUTLS_E_GOT_APPLICATION_DATA or GNUTLS_E_WARNING_ALERT_RECEIVED may be returned. Note that these are non fatal errors, only in the specific case of a rehandshake. Their meaning is that the client rejected the rehandshake request.

gnutls_rehandshake ()

int         gnutls_rehandshake              (gnutls_session_t session);

This function will renegotiate security parameters with the client. This should only be called in case of a server.

This message informs the peer that we want to renegotiate parameters (perform a handshake).

If this function succeeds (returns 0), you must call the gnutls_handshake() function in order to negotiate the new parameters.

If the client does not wish to renegotiate parameters he will should with an alert message, thus the return code will be GNUTLS_E_WARNING_ALERT_RECEIVED and the alert will be GNUTLS_A_NO_RENEGOTIATION. A client may also choose to ignore this message.

gnutls_alert_get ()

gnutls_alert_description_t gnutls_alert_get (gnutls_session_t session);

This function will return the last alert number received. This function should be called if GNUTLS_E_WARNING_ALERT_RECEIVED or GNUTLS_E_FATAL_ALERT_RECEIVED has been returned by a gnutls function. The peer may send alerts if he thinks some things were not right. Check gnutls.h for the available alert descriptions.

If no alert has been received the returned value is undefined.

gnutls_alert_send ()

int         gnutls_alert_send               (gnutls_session_t session,
                                             gnutls_alert_level_t level,
                                             gnutls_alert_description_t desc);

This function will send an alert to the peer in order to inform him of something important (eg. his Certificate could not be verified). If the alert level is Fatal then the peer is expected to close the connection, otherwise he may ignore the alert and continue.

The error code of the underlying record send function will be returned, so you may also receive GNUTLS_E_INTERRUPTED or GNUTLS_E_AGAIN as well.

gnutls_alert_send_appropriate ()

int         gnutls_alert_send_appropriate   (gnutls_session_t session,
                                             int err);

Sends an alert to the peer depending on the error code returned by a gnutls function. This function will call gnutls_error_to_alert() to determine the appropriate alert to send.

This function may also return GNUTLS_E_AGAIN, or GNUTLS_E_INTERRUPTED.

If the return value is GNUTLS_E_INVALID_REQUEST, then no alert has been sent to the peer.

gnutls_alert_get_name ()

const char* gnutls_alert_get_name           (gnutls_alert_description_t alert);

This function will return a string that describes the given alert number or NULL. See gnutls_alert_get().

gnutls_cipher_get ()

gnutls_cipher_algorithm_t gnutls_cipher_get (gnutls_session_t session);

gnutls_kx_get ()

gnutls_kx_algorithm_t gnutls_kx_get         (gnutls_session_t session);

gnutls_mac_get ()

gnutls_mac_algorithm_t gnutls_mac_get       (gnutls_session_t session);

gnutls_compression_get ()

gnutls_compression_method_t gnutls_compression_get
                                            (gnutls_session_tsession );

gnutls_certificate_type_get ()

gnutls_certificate_type_t gnutls_certificate_type_get
                                            (gnutls_session_tsession );

gnutls_cipher_get_key_size ()

size_t      gnutls_cipher_get_key_size      (gnutls_cipher_algorithm_t algorithm);

Returns the length (in bytes) of the given cipher's key size.

gnutls_cipher_get_name ()

const char* gnutls_cipher_get_name          (gnutls_cipher_algorithm_t algorithm);

gnutls_mac_get_name ()

const char* gnutls_mac_get_name             (gnutls_mac_algorithm_t algorithm);

gnutls_compression_get_name ()

const char* gnutls_compression_get_name     (gnutls_compression_method_talgorithm );

gnutls_kx_get_name ()

const char* gnutls_kx_get_name              (gnutls_kx_algorithm_t algorithm);

gnutls_certificate_type_get_name ()

const char* gnutls_certificate_type_get_name
                                            (gnutls_certificate_type_ttype );

gnutls_error_is_fatal ()

int         gnutls_error_is_fatal           (int error);

If a function returns a negative value you may feed that value to this function to see if it is fatal. Returns 1 for a fatal error 0 otherwise. However you may want to check the error code manually, since some non-fatal errors to the protocol may be fatal for you (your program).

This is only useful if you are dealing with errors from the record layer or the handshake layer.

gnutls_error_to_alert ()

int         gnutls_error_to_alert           (int err,
                                             int *level);

gnutls_perror ()

void        gnutls_perror                   (int error);

This function is like perror(). The only difference is that it accepts an error number returned by a gnutls function.

gnutls_strerror ()

const char* gnutls_strerror                 (int error);

This function is similar to strerror(). Differences: it accepts an error number returned by a gnutls function; In case of an unknown error a descriptive string is sent instead of NULL.

gnutls_handshake_set_private_extensions ()

void        gnutls_handshake_set_private_extensions
                                            (gnutls_session_t session,
                                             int allow);

This function will enable or disable the use of private cipher suites (the ones that start with 0xFF). By default or if allow is 0 then these cipher suites will not be advertized nor used.

Unless this function is called with the option to allow (1), then no compression algorithms, like LZO. That is because these algorithms are not yet defined in any RFC or even internet draft.

Enabling the private ciphersuites when talking to other than gnutls servers and clients may cause interoperability problems.

gnutls_handshake_get_last_out ()

gnutls_handshake_description_t gnutls_handshake_get_last_out
                                            (gnutls_session_t session);

gnutls_handshake_get_last_in ()

gnutls_handshake_description_t gnutls_handshake_get_last_in
                                            (gnutls_session_t session);

gnutls_record_send ()

ssize_t     gnutls_record_send              (gnutls_session_t session,
                                             const void *data,
                                             size_t sizeofdata);

This function has the similar semantics with send(). The only difference is that is accepts a GNUTLS session, and uses different error codes.

Note that if the send buffer is full, send() will block this function. See the send() documentation for full information. You can replace the default push function by using gnutls_transport_set_ptr2() with a call to send() with a MSG_DONTWAIT flag if blocking is a problem.

If the EINTR is returned by the internal push function (the default is send()} then GNUTLS_E_INTERRUPTED will be returned. If GNUTLS_E_INTERRUPTED or GNUTLS_E_AGAIN is returned, you must call this function again, with the same parameters; alternatively you could provide a NULL pointer for data, and 0 for size. cf. gnutls_record_get_direction().

gnutls_record_recv ()

ssize_t     gnutls_record_recv              (gnutls_session_t session,
                                             void *data,
                                             size_t sizeofdata);

This function has the similar semantics with recv(). The only difference is that is accepts a GNUTLS session, and uses different error codes.

In the special case that a server requests a renegotiation, the client may receive an error code of GNUTLS_E_REHANDSHAKE. This message may be simply ignored, replied with an alert containing NO_RENEGOTIATION, or replied with a new handshake, depending on the client's will.

If EINTR is returned by the internal push function (the default is code{recv()}) then GNUTLS_E_INTERRUPTED will be returned. If GNUTLS_E_INTERRUPTED or GNUTLS_E_AGAIN is returned, you must call this function again, with the same parameters; alternatively you could provide a NULL pointer for data, and 0 for size. cf. code{gnutls_record_get_direction()}.

A server may also receive GNUTLS_E_REHANDSHAKE when a client has initiated a handshake. In that case the server can only initiate a handshake or terminate the connection.

gnutls_read

#define     gnutls_read

gnutls_write

#define     gnutls_write

gnutls_record_get_direction ()

int         gnutls_record_get_direction     (gnutls_session_t session);

This function provides information about the internals of the record protocol and is only useful if a prior gnutls function call (e.g. gnutls_handshake()) was interrupted for some reason, that is, if a function returned GNUTLS_E_INTERRUPTED or GNUTLS_E_AGAIN. In such a case, you might want to call select() or poll() before calling the interrupted gnutls function again. To tell you whether a file descriptor should be selected for either reading or writing, gnutls_record_get_direction() returns 0 if the interrupted function was trying to read data, and 1 if it was trying to write data.

gnutls_record_get_max_size ()

size_t      gnutls_record_get_max_size      (gnutls_session_t session);

This function returns the maximum record packet size in this connection. The maximum record size is negotiated by the client after the first handshake message.

gnutls_record_set_max_size ()

ssize_t     gnutls_record_set_max_size      (gnutls_session_t session,
                                             size_t size);

This function sets the maximum record packet size in this connection. This property can only be set to clients. The server may choose not to accept the requested size.

Acceptable values are 512(=2^9), 1024(=2^10), 2048(=2^11) and 4096(=2^12).

gnutls_record_check_pending ()

size_t      gnutls_record_check_pending     (gnutls_session_t session);

This function checks if there are any data to receive in the gnutls buffers. Returns the size of that data or 0. Notice that you may also use select() to check for data in a TCP connection, instead of this function. (gnutls leaves some data in the tcp buffer in order for select to work).

gnutls_prf ()

int         gnutls_prf                      (gnutls_session_t session,
                                             size_t label_size,
                                             const char *label,
                                             int server_random_first,
                                             size_t extra_size,
                                             const char *extra,
                                             size_t outsize,
                                             char *out);

Apply the TLS Pseudo-Random-Function (PRF) using the master secret on some data, seeded with the client and server random fields.

The label variable usually contain a string denoting the purpose for the generated data. The server_random_first indicate whether the client random field or the server random field should be first in the seed. Non-0 indicate that the server random field is first, 0 that the client random field is first.

The extra variable can be used to add more data to the seed, after the random variables. It can be used to tie make sure the generated output is strongly connected to some additional data (e.g., a string used in user authentication).

The output is placed in *OUT, which must be pre-allocated.

gnutls_prf_raw ()

int         gnutls_prf_raw                  (gnutls_session_t session,
                                             size_t label_size,
                                             const char *label,
                                             size_t seed_size,
                                             const char *seed,
                                             size_t outsize,
                                             char *out);

Apply the TLS Pseudo-Random-Function (PRF) using the master secret on some data.

The label variable usually contain a string denoting the purpose for the generated data. The seed usually contain data such as the client and server random, perhaps together with some additional data that is added to guarantee uniqueness of the output for a particular purpose.

Because the output is not guaranteed to be unique for a particular session unless seed include the client random and server random fields (the PRF would output the same data on another connection resumed from the first one), it is not recommended to use this function directly. The gnutls_prf() function seed the PRF with the client and server random fields directly, and is recommended if you want to generate pseudo random data unique for each session.

enum gnutls_server_name_type_t

  typedef enum
  {
    GNUTLS_NAME_DNS = 1
  } gnutls_server_name_type_t;

gnutls_server_name_set ()

int         gnutls_server_name_set          (gnutls_session_t session,
                                             gnutls_server_name_type_t type,
                                             const void *name,
                                             size_t name_length);

This function is to be used by clients that want to inform (via a TLS extension mechanism) the server of the name they connected to. This should be used by clients that connect to servers that do virtual hosting.

The value of name depends on the ind type. In case of GNUTLS_NAME_DNS, an ASCII or UTF-8 null terminated string, without the trailing dot, is expected. IPv4 or IPv6 addresses are not permitted.

gnutls_server_name_get ()

int         gnutls_server_name_get          (gnutls_session_t session,
                                             void *data,
                                             size_t *data_length,
                                             unsigned int *type,
                                             unsigned int indx);

This function will allow you to get the name indication (if any), a client has sent. The name indication may be any of the enumeration gnutls_server_name_type_t.

If type is GNUTLS_NAME_DNS, then this function is to be used by servers that support virtual hosting, and the data will be a null terminated UTF-8 string.

If data has not enough size to hold the server name GNUTLS_E_SHORT_MEMORY_BUFFER is returned, and data_length will hold the required size.

index is used to retrieve more than one server names (if sent by the client). The first server name has an index of 0, the second 1 and so on. If no name with the given index exists GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE is returned.

gnutls_cipher_set_priority ()

int         gnutls_cipher_set_priority      (gnutls_session_t session,
                                             const int *list);

Sets the priority on the ciphers supported by gnutls. Priority is higher for ciphers specified before others. After specifying the ciphers you want, you must append a 0. Note that the priority is set on the client. The server does not use the algorithm's priority except for disabling algorithms that were not specified.

gnutls_mac_set_priority ()

int         gnutls_mac_set_priority         (gnutls_session_t session,
                                             const int *list);

Sets the priority on the mac algorithms supported by gnutls. Priority is higher for algorithms specified before others. After specifying the algorithms you want, you must append a 0. Note that the priority is set on the client. The server does not use the algorithm's priority except for disabling algorithms that were not specified.

gnutls_compression_set_priority ()

int         gnutls_compression_set_priority (gnutls_session_t session,
                                             const int *list);

Sets the priority on the compression algorithms supported by gnutls. Priority is higher for algorithms specified before others. After specifying the algorithms you want, you must append a 0. Note that the priority is set on the client. The server does not use the algorithm's priority except for disabling algorithms that were not specified.

TLS 1.0 does not define any compression algorithms except NULL. Other compression algorithms are to be considered as gnutls extensions.

gnutls_kx_set_priority ()

int         gnutls_kx_set_priority          (gnutls_session_t session,
                                             const int *list);

Sets the priority on the key exchange algorithms supported by gnutls. Priority is higher for algorithms specified before others. After specifying the algorithms you want, you must append a 0. Note that the priority is set on the client. The server does not use the algorithm's priority except for disabling algorithms that were not specified.

gnutls_protocol_set_priority ()

int         gnutls_protocol_set_priority    (gnutls_session_t session,
                                             const int *list);

Sets the priority on the protocol versions supported by gnutls. This function actually enables or disables protocols. Newer protocol versions always have highest priority.

gnutls_certificate_type_set_priority ()

int         gnutls_certificate_type_set_priority
                                            (gnutls_session_t session,
                                             const int *list);

Sets the priority on the certificate types supported by gnutls. Priority is higher for types specified before others. After specifying the types you want, you must append a 0. Note that the certificate type priority is set on the client. The server does not use the cert type priority except for disabling types that were not specified.

gnutls_set_default_priority ()

int         gnutls_set_default_priority     (gnutls_session_t session);

Sets some default priority on the ciphers, key exchange methods, macs and compression methods. This is to avoid using the gnutls_*_priority() functions, if these defaults are ok. You may override any of the following priorities by calling the appropriate functions.

The order is TLS1, SSL3 for protocols. RSA, DHE_DSS, DHE_RSA for key exchange algorithms. SHA, MD5 and RIPEMD160 for MAC algorithms. AES_128_CBC, 3DES_CBC, and ARCFOUR_128 for ciphers.

gnutls_set_default_export_priority ()

int         gnutls_set_default_export_priority
                                            (gnutls_session_t session);

Sets some default priority on the ciphers, key exchange methods, macs and compression methods. This is to avoid using the gnutls_*_priority() functions, if these defaults are ok. This function also includes weak algorithms. The order is TLS1, SSL3 for protocols, RSA, DHE_DSS, DHE_RSA, RSA_EXPORT for key exchange algorithms. SHA, MD5, RIPEMD160 for MAC algorithms, AES_256_CBC, AES_128_CBC, and 3DES_CBC, ARCFOUR_128, ARCFOUR_40 for ciphers.

gnutls_cipher_suite_get_name ()

const char* gnutls_cipher_suite_get_name    (gnutls_kx_algorithm_tkx_algorithm ,
                                             gnutls_cipher_algorithm_tcipher_algorithm ,
                                             gnutls_mac_algorithm_tmac_algorithm );

gnutls_protocol_get_version ()

gnutls_protocol_t gnutls_protocol_get_version
                                            (gnutls_session_t session);

gnutls_protocol_get_name ()

const char* gnutls_protocol_get_name        (gnutls_protocol_t version);

gnutls_session_set_data ()

int         gnutls_session_set_data         (gnutls_session_t session,
                                             const void *session_data,
                                             size_t session_data_size);

Sets all session parameters, in order to resume a previously established session. The session data given must be the one returned by gnutls_session_get_data(). This function should be called before gnutls_handshake().

Keep in mind that session resuming is advisory. The server may choose not to resume the session, thus a full handshake will be performed.

gnutls_session_get_data ()

int         gnutls_session_get_data         (gnutls_session_t session,
                                             void *session_data,
                                             size_t *session_data_size);

gnutls_session_get_data2 ()

int         gnutls_session_get_data2        (gnutls_session_t session,
                                             gnutls_datum *data);

GNUTLS_MAX_SESSION_ID

#define     GNUTLS_MAX_SESSION_ID

gnutls_session_get_id ()

int         gnutls_session_get_id           (gnutls_session_t session,
                                             void *session_id,
                                             size_t *session_id_size);

Returns the current session id. This can be used if you want to check if the next session you tried to resume was actually resumed. This is because resumed sessions have the same sessionID with the original session.

Session id is some data set by the server, that identify the current session. In TLS 1.0 and SSL 3.0 session id is always less than 32 bytes.

TLS_MASTER_SIZE

#define     TLS_MASTER_SIZE

TLS_RANDOM_SIZE

#define     TLS_RANDOM_SIZE

gnutls_session_get_server_random ()

const void* gnutls_session_get_server_random
                                            (gnutls_session_t session);

Return a pointer to the 32-byte server random field used in the session. The pointer must not be modified or deallocated.

If a server random value has not yet been established, the output will be garbage; in particular, a NULL return value should not be expected.

gnutls_session_get_client_random ()

const void* gnutls_session_get_client_random
                                            (gnutls_session_t session);

Return a pointer to the 32-byte client random field used in the session. The pointer must not be modified or deallocated.

If a client random value has not yet been established, the output will be garbage; in particular, a NULL return value should not be expected.

gnutls_session_get_master_secret ()

const void* gnutls_session_get_master_secret
                                            (gnutls_session_t session);

Return a pointer to the 48-byte master secret in the session. The pointer must not be modified or deallocated.

If a master secret value has not yet been established, the output will be garbage; in particular, a NULL return value should not be expected.

Consider using gnutls_prf() rather than extracting the master secret and use it to derive further data.

gnutls_session_is_resumed ()

int         gnutls_session_is_resumed       (gnutls_session_t session);

This function will return non zero if this session is a resumed one, or a zero if this is a new session.

gnutls_db_store_func ()

int         (*gnutls_db_store_func)         (void *,
                                             gnutls_datum_t key,
                                             gnutls_datum_t data);

gnutls_db_remove_func ()

int         (*gnutls_db_remove_func)        (void *,
                                             gnutls_datum_t key);

gnutls_db_retr_func ()

gnutls_datum_t (*gnutls_db_retr_func)       (void *,
                                             gnutls_datum_t key);

gnutls_db_set_cache_expiration ()

void        gnutls_db_set_cache_expiration  (gnutls_session_t session,
                                             int seconds);

Sets the expiration time for resumed sessions. The default is 3600 (one hour) at the time writing this.

gnutls_db_remove_session ()

void        gnutls_db_remove_session        (gnutls_session_t session);

This function will remove the current session data from the session database. This will prevent future handshakes reusing these session data. This function should be called if a session was terminated abnormally, and before gnutls_deinit() is called.

Normally gnutls_deinit() will remove abnormally terminated sessions.

gnutls_db_set_retrieve_function ()

void        gnutls_db_set_retrieve_function (gnutls_session_t session,
                                             gnutls_db_retr_func retr_func);

Sets the function that will be used to retrieve data from the resumed sessions database. This function must return a gnutls_datum_t containing the data on success, or a gnutls_datum_t containing null and 0 on failure.

The datum's data must be allocated using the function gnutls_malloc().

The first argument to retr_func() will be null unless gnutls_db_set_ptr() has been called.

gnutls_db_set_remove_function ()

void        gnutls_db_set_remove_function   (gnutls_session_t session,
                                             gnutls_db_remove_func rem_func);

Sets the function that will be used to remove data from the resumed sessions database. This function must return 0 on success.

The first argument to rem_func() will be null unless gnutls_db_set_ptr() has been called.

gnutls_db_set_store_function ()

void        gnutls_db_set_store_function    (gnutls_session_t session,
                                             gnutls_db_store_func store_func);

Sets the function that will be used to store data from the resumed sessions database. This function must remove 0 on success.

The first argument to store_func() will be null unless gnutls_db_set_ptr() has been called.

gnutls_db_set_ptr ()

void        gnutls_db_set_ptr               (gnutls_session_t session,
                                             void *ptr);

Sets the pointer that will be provided to db store, retrieve and delete functions, as the first argument.

gnutls_db_get_ptr ()

void*       gnutls_db_get_ptr               (gnutls_session_t session);

gnutls_db_check_entry ()

int         gnutls_db_check_entry           (gnutls_session_t session,
                                             gnutls_datum_t session_entry);

This function returns GNUTLS_E_EXPIRED, if the database entry has expired or 0 otherwise. This function is to be used when you want to clear unnesessary session which occupy space in your backend.

gnutls_handshake_set_max_packet_length ()

void        gnutls_handshake_set_max_packet_length
                                            (gnutls_session_t session,
                                             size_t max);

This function will set the maximum size of a handshake message. Handshake messages over this size are rejected. The default value is 16kb which is large enough. Set this to 0 if you do not want to set an upper limit.

gnutls_check_version ()

const char* gnutls_check_version            (const char *req_version);

Check that the version of the library is at minimum the requested one and return the version string; return NULL if the condition is not satisfied. If a NULL is passed to this function, no check is done, but the version string is simply returned.

gnutls_credentials_clear ()

void        gnutls_credentials_clear        (gnutls_session_t session);

Clears all the credentials previously set in this session.

gnutls_credentials_set ()

int         gnutls_credentials_set          (gnutls_session_t session,
                                             gnutls_credentials_type_t type,
                                             void *cred);

Sets the needed credentials for the specified type. Eg username, password - or public and private keys etc. The (void* cred) parameter is a structure that depends on the specified type and on the current session (client or server). [ In order to minimize memory usage, and share credentials between several threads gnutls keeps a pointer to cred, and not the whole cred structure. Thus you will have to keep the structure allocated until you call gnutls_deinit(). ]

For GNUTLS_CRD_ANON cred should be gnutls_anon_client_credentials_t in case of a client. In case of a server it should be gnutls_anon_server_credentials_t.

For GNUTLS_CRD_SRP cred should be gnutls_srp_client_credentials_t in case of a client, and gnutls_srp_server_credentials_t, in case of a server.

For GNUTLS_CRD_CERTIFICATE cred should be gnutls_certificate_credentials_t.

gnutls_cred_set

#define     gnutls_cred_set

struct gnutls_certificate_credentials_st

struct gnutls_certificate_credentials_st;

gnutls_anon_free_server_credentials ()

void        gnutls_anon_free_server_credentials
                                            (gnutls_anon_server_credentials_t sc);

This structure is complex enough to manipulate directly thus this helper function is provided in order to free (deallocate) it.

gnutls_anon_allocate_server_credentials ()

int         gnutls_anon_allocate_server_credentials
                                            (gnutls_anon_server_credentials_t *sc);

This structure is complex enough to manipulate directly thus this helper function is provided in order to allocate it.

gnutls_anon_set_server_dh_params ()

void        gnutls_anon_set_server_dh_params
                                            (gnutls_anon_server_credentials_t res,
                                             gnutls_dh_params_t dh_params);

This function will set the diffie hellman parameters for an anonymous server to use. These parameters will be used in Anonymous Diffie Hellman cipher suites.

gnutls_anon_set_server_params_function ()

void        gnutls_anon_set_server_params_function
                                            (gnutls_anon_server_credentials_tres ,
                                             gnutls_params_function *func);

This function will set a callback in order for the server to get the diffie hellman parameters for anonymous authentication. The callback should return zero on success.

gnutls_anon_free_client_credentials ()

void        gnutls_anon_free_client_credentials
                                            (gnutls_anon_client_credentials_tsc );

This structure is complex enough to manipulate directly thus this helper function is provided in order to free (deallocate) it.

gnutls_anon_allocate_client_credentials ()

int         gnutls_anon_allocate_client_credentials
                                            (gnutls_anon_client_credentials_t *sc);

This structure is complex enough to manipulate directly thus this helper function is provided in order to allocate it.

gnutls_certificate_free_credentials ()

void        gnutls_certificate_free_credentials
                                            (gnutls_certificate_credentials_tsc );

This structure is complex enough to manipulate directly thus this helper function is provided in order to free (deallocate) it.

This function does not free any temporary parameters associated with this structure (ie RSA and DH parameters are not freed by this function).

gnutls_certificate_allocate_credentials ()

int         gnutls_certificate_allocate_credentials
                                            (gnutls_certificate_credentials_t *res);

This structure is complex enough to manipulate directly thus this helper function is provided in order to allocate it.

gnutls_certificate_free_keys ()

void        gnutls_certificate_free_keys    (gnutls_certificate_credentials_t sc);

This function will delete all the keys and the certificates associated with the given credentials. This function must not be called when a TLS negotiation that uses the credentials is in progress.

gnutls_certificate_free_cas ()

void        gnutls_certificate_free_cas     (gnutls_certificate_credentials_t sc);

This function will delete all the CAs associated with the given credentials. Servers that do not use gnutls_certificate_verify_peers2() may call this to save some memory.

gnutls_certificate_free_ca_names ()

void        gnutls_certificate_free_ca_names
                                            (gnutls_certificate_credentials_t sc);

This function will delete all the CA name in the given credentials. Clients may call this to save some memory since in client side the CA names are not used.

CA names are used by servers to advertize the CAs they support to clients.

gnutls_certificate_free_crls ()

void        gnutls_certificate_free_crls    (gnutls_certificate_credentials_t sc);

This function will delete all the CRLs associated with the given credentials.

gnutls_certificate_set_dh_params ()

void        gnutls_certificate_set_dh_params
                                            (gnutls_certificate_credentials_t res,
                                             gnutls_dh_params_t dh_params);

This function will set the diffie hellman parameters for a certificate server to use. These parameters will be used in Ephemeral Diffie Hellman cipher suites. Note that only a pointer to the parameters are stored in the certificate handle, so if you deallocate the parameters before the certificate is deallocated, you must change the parameters stored in the certificate first.

gnutls_certificate_set_rsa_export_params ()

void        gnutls_certificate_set_rsa_export_params
                                            (gnutls_certificate_credentials_tres ,
                                             gnutls_rsa_params_t rsa_params);

This function will set the temporary RSA parameters for a certificate server to use. These parameters will be used in RSA-EXPORT cipher suites.

gnutls_certificate_set_verify_flags ()

void        gnutls_certificate_set_verify_flags
                                            (gnutls_certificate_credentials_tres ,
                                             unsigned int flags);

This function will set the flags to be used at verification of the certificates. Flags must be OR of the gnutls_certificate_verify_flags enumerations.

gnutls_certificate_set_verify_limits ()

void        gnutls_certificate_set_verify_limits
                                            (gnutls_certificate_credentials_tres ,
                                             unsigned int max_bits,
                                             unsigned int max_depth);

This function will set some upper limits for the default verification function, gnutls_certificate_verify_peers2(), to avoid denial of service attacks.

gnutls_certificate_set_x509_trust_file ()

int         gnutls_certificate_set_x509_trust_file
                                            (gnutls_certificate_credentials_tres ,
                                             const char *CAFILE,
                                             gnutls_x509_crt_fmt_t type);

This function adds the trusted CAs in order to verify client or server certificates. In case of a client this is not required to be called if the certificates are not verified using gnutls_certificate_verify_peers2(). This function may be called multiple times.

In case of a server the names of the CAs set here will be sent to the client if a certificate request is sent. This can be disabled using gnutls_certificate_send_x509_rdn_sequence().

gnutls_certificate_set_x509_trust_mem ()

int         gnutls_certificate_set_x509_trust_mem
                                            (gnutls_certificate_credentials_tres ,
                                             const gnutls_datum_t *CA,
                                             gnutls_x509_crt_fmt_t type);

This function adds the trusted CAs in order to verify client or server certificates. In case of a client this is not required to be called if the certificates are not verified using gnutls_certificate_verify_peers2(). This function may be called multiple times.

In case of a server the CAs set here will be sent to the client if a certificate request is sent. This can be disabled using gnutls_certificate_send_x509_rdn_sequence().

gnutls_certificate_set_x509_crl_file ()

int         gnutls_certificate_set_x509_crl_file
                                            (gnutls_certificate_credentials_tres ,
                                             const char *crlfile,
                                             gnutls_x509_crt_fmt_t type);

This function adds the trusted CRLs in order to verify client or server certificates. In case of a client this is not required to be called if the certificates are not verified using gnutls_certificate_verify_peers2(). This function may be called multiple times.

gnutls_certificate_set_x509_crl_mem ()

int         gnutls_certificate_set_x509_crl_mem
                                            (gnutls_certificate_credentials_tres ,
                                             const gnutls_datum_t *CRL,
                                             gnutls_x509_crt_fmt_t type);

This function adds the trusted CRLs in order to verify client or server certificates. In case of a client this is not required to be called if the certificates are not verified using gnutls_certificate_verify_peers2(). This function may be called multiple times.

gnutls_certificate_set_x509_key_file ()

int         gnutls_certificate_set_x509_key_file
                                            (gnutls_certificate_credentials_tres ,
                                             const char *CERTFILE,
                                             const char *KEYFILE,
                                             gnutls_x509_crt_fmt_t type);

This function sets a certificate/private key pair in the gnutls_certificate_credentials_t structure. This function may be called more than once (in case multiple keys/certificates exist for the server).

Currently only PKCS-1 encoded RSA and DSA private keys are accepted by this function.

gnutls_certificate_set_x509_key_mem ()

int         gnutls_certificate_set_x509_key_mem
                                            (gnutls_certificate_credentials_tres ,
                                             const gnutls_datum_t *CERT,
                                             const gnutls_datum_t *KEY,
                                             gnutls_x509_crt_fmt_t type);

This function sets a certificate/private key pair in the gnutls_certificate_credentials_t structure. This function may be called more than once (in case multiple keys/certificates exist for the server).

Currently are supported: RSA PKCS-1 encoded private keys, DSA private keys.

DSA private keys are encoded the OpenSSL way, which is an ASN.1 DER sequence of 6 INTEGERs - version, p, q, g, pub, priv.

Note that the keyUsage (2.5.29.15) PKIX extension in X.509 certificates is supported. This means that certificates intended for signing cannot be used for ciphersuites that require encryption.

If the certificate and the private key are given in PEM encoding then the strings that hold their values must be null terminated.

gnutls_certificate_set_x509_simple_pkcs12_file ()

int         gnutls_certificate_set_x509_simple_pkcs12_file
                                            (gnutls_certificate_credentials_t res,
                                             const char *pkcs12file,
                                             gnutls_x509_crt_fmt_t type,
                                             const char *password);

This function sets a certificate/private key pair and/or a CRL in the gnutls_certificate_credentials_t structure. This function may be called more than once (in case multiple keys/certificates exist for the server).

MAC:ed PKCS12 files are supported. Encrypted PKCS12 bags are supported. Encrypted PKCS8 private keys are supported. However, only password based security, and the same password for all operations, are supported.

The private keys may be RSA PKCS1 or DSA private keys encoded in the OpenSSL way.

PKCS12 file may contain many keys and/or certificates, and there is no way to identify which key/certificate pair you want. You should make sure the PKCS12 file only contain one key/certificate pair and/or one CRL.

It is believed that the limitations of this function is acceptable for most usage, and that any more flexibility would introduce complexity that would make it harder to use this functionality at all.

gnutls_x509_privkey_t

struct gnutls_x509_crl_int

struct gnutls_x509_crl_int;

gnutls_x509_crl_t

struct gnutls_x509_crt_int

struct gnutls_x509_crt_int;

gnutls_x509_crt_t

gnutls_certificate_set_x509_key ()

int         gnutls_certificate_set_x509_key (gnutls_certificate_credentials_t res,
                                             gnutls_x509_crt_t *cert_list,
                                             int cert_list_size,
                                             gnutls_x509_privkey_t key);

This function sets a certificate/private key pair in the gnutls_certificate_credentials_t structure. This function may be called more than once (in case multiple keys/certificates exist for the server).

gnutls_certificate_set_x509_trust ()

int         gnutls_certificate_set_x509_trust
                                            (gnutls_certificate_credentials_t res,
                                             gnutls_x509_crt_t *ca_list,
                                             int ca_list_size);

This function adds the trusted CAs in order to verify client or server certificates. In case of a client this is not required to be called if the certificates are not verified using gnutls_certificate_verify_peers2(). This function may be called multiple times.

In case of a server the CAs set here will be sent to the client if a certificate request is sent. This can be disabled using gnutls_certificate_send_x509_rdn_sequence().

gnutls_certificate_set_x509_crl ()

int         gnutls_certificate_set_x509_crl (gnutls_certificate_credentials_t res,
                                             gnutls_x509_crl_t *crl_list,
                                             int crl_list_size);

This function adds the trusted CRLs in order to verify client or server certificates. In case of a client this is not required to be called if the certificates are not verified using gnutls_certificate_verify_peers2(). This function may be called multiple times.

gnutls_global_init ()

int         gnutls_global_init              (void);

This function initializes the global data to defaults. Every gnutls application has a global data which holds common parameters shared by gnutls session structures. You must call gnutls_global_deinit() when gnutls usage is no longer needed

gnutls_global_deinit ()

void        gnutls_global_deinit            (void);

This function deinitializes the global data, that were initialized using gnutls_global_init().

Note! This function is not thread safe. See the discussion for gnutls_global_init() for more information.

gnutls_alloc_function ()

void*       (*gnutls_alloc_function)        (size_t );

gnutls_calloc_function ()

void*       (*gnutls_calloc_function)       (size_t ,
                                             size_t );

gnutls_is_secure_function ()

int         (*gnutls_is_secure_function)    (const void *);

gnutls_free_function ()

void        (*gnutls_free_function)         (void *);

gnutls_realloc_function ()

void*       (*gnutls_realloc_function)      (void *,
                                             size_t );

gnutls_global_set_mem_functions ()

void        gnutls_global_set_mem_functions (gnutls_alloc_function gt_alloc_func,
                                             gnutls_alloc_functiongt_secure_alloc_func ,
                                             gnutls_is_secure_functiongt_is_secure_func ,
                                             gnutls_realloc_function gt_realloc_func,
                                             gnutls_free_function gt_free_func);

This is the function were you set the memory allocation functions gnutls is going to use. By default the libc's allocation functions (malloc(), free()), are used by gnutls, to allocate both sensitive and not sensitive data. This function is provided to set the memory allocation functions to something other than the defaults (ie the gcrypt allocation functions).

This function must be called before gnutls_global_init() is called.

gnutls_malloc

  extern gnutls_alloc_function gnutls_malloc;

This function will allocate 's' bytes data, and return a pointer to memory. This function is supposed to be used by callbacks.

The allocation function used is the one set by gnutls_global_set_mem_functions().

gnutls_secure_malloc

  extern gnutls_alloc_function gnutls_secure_malloc;

gnutls_realloc

  extern gnutls_realloc_function gnutls_realloc;

gnutls_calloc

  extern gnutls_calloc_function gnutls_calloc;

gnutls_free

  extern gnutls_free_function gnutls_free;

This function will free data pointed by ptr.

The deallocation function used is the one set by gnutls_global_set_mem_functions().

gnutls_log_func ()

void        (*gnutls_log_func)              (...,
                                             const char *);

gnutls_global_set_log_function ()

void        gnutls_global_set_log_function  (gnutls_log_func log_func);

This is the function where you set the logging function gnutls is going to use. This function only accepts a character array. Normally you may not use this function since it is only used for debugging purposes.

gnutls_log_func is of the form, void (*gnutls_log_func)( int level, const char*);

gnutls_global_set_log_level ()

void        gnutls_global_set_log_level     (int level);

This is the function that allows you to set the log level. The level is an integer between 0 and 9. Higher values mean more verbosity. The default value is 0. Larger values should only be used with care, since they may reveal sensitive information.

Use a log level over 10 to enable all debugging options.

gnutls_dh_params_init ()

int         gnutls_dh_params_init           (gnutls_dh_params_t *dh_params);

This function will initialize the DH parameters structure.

gnutls_dh_params_deinit ()

void        gnutls_dh_params_deinit         (gnutls_dh_params_t dh_params);

This function will deinitialize the DH parameters structure.

gnutls_dh_params_import_raw ()

int         gnutls_dh_params_import_raw     (gnutls_dh_params_t dh_params,
                                             const gnutls_datum_t *prime,
                                             const gnutls_datum_t *generator);

This function will replace the pair of prime and generator for use in the Diffie-Hellman key exchange. The new parameters should be stored in the appropriate gnutls_datum.

gnutls_dh_params_import_pkcs3 ()

int         gnutls_dh_params_import_pkcs3   (gnutls_dh_params_t params,
                                             const gnutls_datum_t *pkcs3_params,
                                             gnutls_x509_crt_fmt_t format);

This function will extract the DHParams found in a PKCS3 formatted structure. This is the format generated by "openssl dhparam" tool.

If the structure is PEM encoded, it should have a header of "BEGIN DH PARAMETERS".

In case of failure a negative value will be returned, and 0 on success.

gnutls_dh_params_generate2 ()

int         gnutls_dh_params_generate2      (gnutls_dh_params_t params,
                                             unsigned int bits);

This function will generate a new pair of prime and generator for use in the Diffie-Hellman key exchange. The new parameters will be allocated using gnutls_malloc() and will be stored in the appropriate datum. This function is normally slow.

Note that the bits value should be one of 768, 1024, 2048, 3072 or 4096. Also note that the DH parameters are only useful to servers. Since clients use the parameters sent by the server, it's of no use to call this in client side.

gnutls_dh_params_export_pkcs3 ()

int         gnutls_dh_params_export_pkcs3   (gnutls_dh_params_t params,
                                             gnutls_x509_crt_fmt_t format,
                                             unsigned char *params_data,
                                             size_t *params_data_size);

This function will export the given dh parameters to a PKCS3 DHParams structure. This is the format generated by "openssl dhparam" tool. If the buffer provided is not long enough to hold the output, then GNUTLS_E_SHORT_MEMORY_BUFFER will be returned.

If the structure is PEM encoded, it will have a header of "BEGIN DH PARAMETERS".

In case of failure a negative value will be returned, and 0 on success.

gnutls_dh_params_export_raw ()

int         gnutls_dh_params_export_raw     (gnutls_dh_params_t params,
                                             gnutls_datum_t *prime,
                                             gnutls_datum_t *generator,
                                             unsigned int *bits);

This function will export the pair of prime and generator for use in the Diffie-Hellman key exchange. The new parameters will be allocated using gnutls_malloc() and will be stored in the appropriate datum.

gnutls_dh_params_cpy ()

int         gnutls_dh_params_cpy            (gnutls_dh_params_t dst,
                                             gnutls_dh_params_t src);

This function will copy the DH parameters structure from source to destination.

gnutls_rsa_params_init ()

int         gnutls_rsa_params_init          (gnutls_rsa_params_t *rsa_params);

This function will initialize the temporary RSA parameters structure.

gnutls_rsa_params_deinit ()

void        gnutls_rsa_params_deinit        (gnutls_rsa_params_t rsa_params);

This function will deinitialize the RSA parameters structure.

gnutls_rsa_params_cpy ()

int         gnutls_rsa_params_cpy           (gnutls_rsa_params_t dst,
                                             gnutls_rsa_params_t src);

This function will copy the RSA parameters structure from source to destination.

gnutls_rsa_params_import_raw ()

int         gnutls_rsa_params_import_raw    (gnutls_rsa_params_t rsa_params,
                                             const gnutls_datum_t *m,
                                             const gnutls_datum_t *e,
                                             const gnutls_datum_t *d,
                                             const gnutls_datum_t *p,
                                             const gnutls_datum_t *q,
                                             const gnutls_datum_t *u);

This function will replace the parameters in the given structure. The new parameters should be stored in the appropriate gnutls_datum.

gnutls_rsa_params_generate2 ()

int         gnutls_rsa_params_generate2     (gnutls_rsa_params_t params,
                                             unsigned int bits);

This function will generate new temporary RSA parameters for use in RSA-EXPORT ciphersuites. This function is normally slow.

Note that if the parameters are to be used in export cipher suites the bits value should be 512 or less. Also note that the generation of new RSA parameters is only useful to servers. Clients use the parameters sent by the server, thus it's no use calling this in client side.

gnutls_rsa_params_export_raw ()

int         gnutls_rsa_params_export_raw    (gnutls_rsa_params_t params,
                                             gnutls_datum_t *m,
                                             gnutls_datum_t *e,
                                             gnutls_datum_t *d,
                                             gnutls_datum_t *p,
                                             gnutls_datum_t *q,
                                             gnutls_datum_t *u,
                                             unsigned int *bits);

This function will export the RSA parameters found in the given structure. The new parameters will be allocated using gnutls_malloc() and will be stored in the appropriate datum.

gnutls_rsa_params_export_pkcs1 ()

int         gnutls_rsa_params_export_pkcs1  (gnutls_rsa_params_t params,
                                             gnutls_x509_crt_fmt_t format,
                                             unsigned char *params_data,
                                             size_t *params_data_size);

This function will export the given RSA parameters to a PKCS1 RSAPublicKey structure. If the buffer provided is not long enough to hold the output, then GNUTLS_E_SHORT_MEMORY_BUFFER will be returned.

If the structure is PEM encoded, it will have a header of "BEGIN RSA PRIVATE KEY".

In case of failure a negative value will be returned, and 0 on success.

gnutls_rsa_params_import_pkcs1 ()

int         gnutls_rsa_params_import_pkcs1  (gnutls_rsa_params_t params,
                                             const gnutls_datum_t *pkcs1_params,
                                             gnutls_x509_crt_fmt_t format);

This function will extract the RSAPublicKey found in a PKCS1 formatted structure.

If the structure is PEM encoded, it should have a header of "BEGIN RSA PRIVATE KEY".

In case of failure a negative value will be returned, and 0 on success.

gnutls_pull_func ()

ssize_t     (*gnutls_pull_func)             (gnutls_transport_ptr_t ,
                                             void *,
                                             size_t );

gnutls_push_func ()

ssize_t     (*gnutls_push_func)             (gnutls_transport_ptr_t ,
                                             const void *,
                                             size_t );

gnutls_transport_set_ptr ()

void        gnutls_transport_set_ptr        (gnutls_session_t session,
                                             gnutls_transport_ptr_t ptr);

Used to set the first argument of the transport function (like PUSH and PULL). In berkeley style sockets this function will set the connection handle.

gnutls_transport_set_ptr2 ()

void        gnutls_transport_set_ptr2       (gnutls_session_t session,
                                             gnutls_transport_ptr_t recv_ptr,
                                             gnutls_transport_ptr_t send_ptr);

Used to set the first argument of the transport function (like PUSH and PULL). In berkeley style sockets this function will set the connection handle. With this function you can use two different pointers for receiving and sending.

gnutls_transport_get_ptr ()

gnutls_transport_ptr_t gnutls_transport_get_ptr
                                            (gnutls_session_t session);

Used to get the first argument of the transport function (like PUSH and PULL). This must have been set using gnutls_transport_set_ptr().

gnutls_transport_get_ptr2 ()

void        gnutls_transport_get_ptr2       (gnutls_session_t session,
                                             gnutls_transport_ptr_t *recv_ptr,
                                             gnutls_transport_ptr_t *send_ptr);

Used to get the arguments of the transport functions (like PUSH and PULL). These should have been set using gnutls_transport_set_ptr2().

gnutls_transport_set_lowat ()

void        gnutls_transport_set_lowat      (gnutls_session_t session,
                                             int num);

Used to set the lowat value in order for select to check if there are pending data to socket buffer. Used only if you have changed the default low water value (default is 1). Normally you will not need that function. This function is only useful if using berkeley style sockets. Otherwise it must be called and set lowat to zero.

gnutls_transport_set_push_function ()

void        gnutls_transport_set_push_function
                                            (gnutls_session_t session,
                                             gnutls_push_func push_func);

This is the function where you set a push function for gnutls to use in order to send data. If you are going to use berkeley style sockets, you do not need to use this function since the default (send(2)) will probably be ok. Otherwise you should specify this function for gnutls to be able to send data. PUSH_FUNC is of the form, ssize_t (*gnutls_push_func)(gnutls_transport_ptr_t, const void*, size_t);

gnutls_transport_set_pull_function ()

void        gnutls_transport_set_pull_function
                                            (gnutls_session_t session,
                                             gnutls_pull_func pull_func);

This is the function where you set a function for gnutls to receive data. Normally, if you use berkeley style sockets, do not need to use this function since the default (recv(2)) will probably be ok.

PULL_FUNC is of the form, ssize_t (*gnutls_pull_func)(gnutls_transport_ptr_t, void*, size_t);

gnutls_session_set_ptr ()

void        gnutls_session_set_ptr          (gnutls_session_t session,
                                             void *ptr);

This function will set (associate) the user given pointer to the session structure. This is pointer can be accessed with gnutls_session_get_ptr().

gnutls_session_get_ptr ()

void*       gnutls_session_get_ptr          (gnutls_session_t session);

This function will return the user given pointer from the session structure. This is the pointer set with gnutls_session_set_ptr().

gnutls_openpgp_send_key ()

void        gnutls_openpgp_send_key         (gnutls_session_t session,
                                             gnutls_openpgp_key_status_t status);

This function will order gnutls to send the key fingerprint instead of the key in the initial handshake procedure. This should be used with care and only when there is indication or knowledge that the server can obtain the client's key.

gnutls_fingerprint ()

int         gnutls_fingerprint              (gnutls_digest_algorithm_t algo,
                                             const gnutls_datum_t *data,
                                             void *result,
                                             size_t *result_size);

This function will calculate a fingerprint (actually a hash), of the given data. The result is not printable data. You should convert it to hex, or to something else printable.

This is the usual way to calculate a fingerprint of an X.509 DER encoded certificate. Note however that the fingerprint of an OpenPGP is not just a hash and cannot be calculated with this function.

gnutls_srp_free_client_credentials ()

void        gnutls_srp_free_client_credentials
                                            (gnutls_srp_client_credentials_tsc );

This structure is complex enough to manipulate directly thus this helper function is provided in order to free (deallocate) it.

gnutls_srp_allocate_client_credentials ()

int         gnutls_srp_allocate_client_credentials
                                            (gnutls_srp_client_credentials_t *sc);

This structure is complex enough to manipulate directly thus this helper function is provided in order to allocate it.

gnutls_srp_set_client_credentials ()

int         gnutls_srp_set_client_credentials
                                            (gnutls_srp_client_credentials_t res,
                                             const char *username,
                                             const char *password);

This function sets the username and password, in a gnutls_srp_client_credentials_t structure. Those will be used in SRP authentication. username and password should be ASCII strings or UTF-8 strings prepared using the "SASLprep" profile of "stringprep".

gnutls_srp_free_server_credentials ()

void        gnutls_srp_free_server_credentials
                                            (gnutls_srp_server_credentials_tsc );

This structure is complex enough to manipulate directly thus this helper function is provided in order to free (deallocate) it.

gnutls_srp_allocate_server_credentials ()

int         gnutls_srp_allocate_server_credentials
                                            (gnutls_srp_server_credentials_t *sc);

This structure is complex enough to manipulate directly thus this helper function is provided in order to allocate it.

gnutls_srp_set_server_credentials_file ()

int         gnutls_srp_set_server_credentials_file
                                            (gnutls_srp_server_credentials_tres ,
                                             const char *password_file,
                                             const char *password_conf_file);

This function sets the password files, in a gnutls_srp_server_credentials_t structure. Those password files hold usernames and verifiers and will be used for SRP authentication.

gnutls_srp_server_get_username ()

const char* gnutls_srp_server_get_username  (gnutls_session_t session);

This function will return the username of the peer. This should only be called in case of SRP authentication and in case of a server.

gnutls_srp_verifier ()

int         gnutls_srp_verifier             (const char *username,
                                             const char *password,
                                             const gnutls_datum_t *salt,
                                             const gnutls_datum_t *generator,
                                             const gnutls_datum_t *prime,
                                             gnutls_datum_t *res);

This function will create an SRP verifier, as specified in RFC2945. The prime and generator should be one of the static parameters defined in gnutls/extra.h or may be generated using the GCRYPT functions gcry_prime_generate() and gcry_prime_group_generator(). The verifier will be allocated with malloc and will be stored in res using binary format.

gnutls_srp_2048_group_prime

  extern const gnutls_datum_t gnutls_srp_2048_group_prime;

gnutls_srp_2048_group_generator

  extern const gnutls_datum_t gnutls_srp_2048_group_generator;

gnutls_srp_1536_group_prime

  extern const gnutls_datum_t gnutls_srp_1536_group_prime;

gnutls_srp_1536_group_generator

  extern const gnutls_datum_t gnutls_srp_1536_group_generator;

gnutls_srp_1024_group_prime

  extern const gnutls_datum_t gnutls_srp_1024_group_prime;

gnutls_srp_1024_group_generator

  extern const gnutls_datum_t gnutls_srp_1024_group_generator;

gnutls_srp_set_server_credentials_function ()

void        gnutls_srp_set_server_credentials_function
                                            (gnutls_srp_server_credentials_t cred,
                                             gnutls_srp_server_credentials_function *func);

This function can be used to set a callback to retrieve the user's SRP credentials. The callback's function form is: int (*callback)(gnutls_session_t, const char* username, gnutls_datum_t* salt, gnutls_datum_t *verifier, gnutls_datum_t* g, gnutls_datum_t* n);

username contains the actual username. The salt, verifier, generator and prime must be filled in using the gnutls_malloc(). For convenience prime and generator may also be one of the static parameters defined in extra.h.

In case the callback returned a negative number then gnutls will assume that the username does not exist.

In order to prevent attackers from guessing valid usernames, if a user does not exist, g and n values should be filled in using a random user's parameters. In that case the callback must return the special value (1).

The callback function will only be called once per handshake. The callback function should return 0 on success, while -1 indicates an error.

gnutls_srp_set_client_credentials_function ()

void        gnutls_srp_set_client_credentials_function
                                            (gnutls_srp_client_credentials_t cred,
                                             gnutls_srp_client_credentials_function *func);

This function can be used to set a callback to retrieve the username and password for client SRP authentication. The callback's function form is: int (*callback)(gnutls_session_t, unsigned int times, char** username, char** password);

The username and password must be allocated using gnutls_malloc(). times will be 0 the first time called, and 1 the second. username and password should be ASCII strings or UTF-8 strings prepared using the "SASLprep" profile of "stringprep".

The callback function will be called once or twice per handshake. The first time called, is before the ciphersuite is negotiated. At that time if the callback returns a negative error code, the callback will be called again if SRP has been negotiated. This uses a special TLS-SRP idiom in order to avoid asking the user for SRP password and username if the server does not support SRP.

The callback should not return a negative error code the second time called, since the handshake procedure will be aborted.

The callback function should return 0 on success. -1 indicates an error.

gnutls_srp_base64_encode ()

int         gnutls_srp_base64_encode        (const gnutls_datum_t *data,
                                             char *result,
                                             size_t *result_size);

This function will convert the given data to printable data, using the base64 encoding, as used in the libsrp. This is the encoding used in SRP password files. If the provided buffer is not long enough GNUTLS_E_SHORT_MEMORY_BUFFER is returned.

gnutls_srp_base64_encode_alloc ()

int         gnutls_srp_base64_encode_alloc  (const gnutls_datum_t *data,
                                             gnutls_datum_t *result);

This function will convert the given data to printable data, using the base64 encoding. This is the encoding used in SRP password files. This function will allocate the required memory to hold the encoded data.

You should use gnutls_free() to free the returned data.

gnutls_srp_base64_decode ()

int         gnutls_srp_base64_decode        (const gnutls_datum_t *b64_data,
                                             char *result,
                                             size_t *result_size);

This function will decode the given encoded data, using the base64 encoding found in libsrp.

Note that b64_data should be null terminated.

gnutls_srp_base64_decode_alloc ()

int         gnutls_srp_base64_decode_alloc  (const gnutls_datum_t *b64_data,
                                             gnutls_datum_t *result);

This function will decode the given encoded data. The decoded data will be allocated, and stored into result. It will decode using the base64 algorithm found in libsrp.

You should use gnutls_free() to free the returned data.

gnutls_psk_free_client_credentials ()

void        gnutls_psk_free_client_credentials
                                            (gnutls_psk_client_credentials_tsc );

This structure is complex enough to manipulate directly thus this helper function is provided in order to free (deallocate) it.

gnutls_psk_allocate_client_credentials ()

int         gnutls_psk_allocate_client_credentials
                                            (gnutls_psk_client_credentials_t *sc);

This structure is complex enough to manipulate directly thus this helper function is provided in order to allocate it.

gnutls_psk_set_client_credentials ()

int         gnutls_psk_set_client_credentials
                                            (gnutls_psk_client_credentials_t res,
                                             const char *username,
                                             const gnutls_datum *key,
                                             unsigned int flags);

This function sets the username and password, in a gnutls_psk_client_credentials_t structure. Those will be used in PSK authentication. username should be an ASCII string or UTF-8 strings prepared using the "SASLprep" profile of "stringprep". The key can be either in raw byte format or in Hex (not with the '0x' prefix).

enum gnutls_psk_key_flags

  typedef enum gnutls_psk_key_flags
  {
    GNUTLS_PSK_KEY_RAW = 0,
    GNUTLS_PSK_KEY_HEX
  } gnutls_psk_key_flags;

gnutls_psk_free_server_credentials ()

void        gnutls_psk_free_server_credentials
                                            (gnutls_psk_server_credentials_tsc );

This structure is complex enough to manipulate directly thus this helper function is provided in order to free (deallocate) it.

gnutls_psk_allocate_server_credentials ()

int         gnutls_psk_allocate_server_credentials
                                            (gnutls_psk_server_credentials_t *sc);

This structure is complex enough to manipulate directly thus this helper function is provided in order to allocate it.

gnutls_psk_set_server_credentials_file ()

int         gnutls_psk_set_server_credentials_file
                                            (gnutls_psk_server_credentials_tres ,
                                             const char *password_file);

This function sets the password file, in a gnutls_psk_server_credentials_t structure. This password file holds usernames and keys and will be used for PSK authentication.

gnutls_psk_server_get_username ()

const char* gnutls_psk_server_get_username  (gnutls_session_t session);

This function will return the username of the peer. This should only be called in case of PSK authentication and in case of a server.

gnutls_psk_set_server_credentials_function ()

void        gnutls_psk_set_server_credentials_function
                                            (gnutls_psk_server_credentials_t cred,
                                             gnutls_psk_server_credentials_function *func);

This function can be used to set a callback to retrieve the user's PSK credentials. The callback's function form is: int (*callback)(gnutls_session_t, const char* username, gnutls_datum_t* key);

username contains the actual username. The key must be filled in using the gnutls_malloc().

In case the callback returned a negative number then gnutls will assume that the username does not exist.

The callback function will only be called once per handshake. The callback function should return 0 on success, while -1 indicates an error.

gnutls_psk_set_client_credentials_function ()

void        gnutls_psk_set_client_credentials_function
                                            (gnutls_psk_client_credentials_t cred,
                                             gnutls_psk_client_credentials_function *func);

This function can be used to set a callback to retrieve the username and password for client PSK authentication. The callback's function form is: int (*callback)(gnutls_session_t, char** username, gnutls_datum* key);

The username and key must be allocated using gnutls_malloc(). username should be ASCII strings or UTF-8 strings prepared using the "SASLprep" profile of "stringprep".

The callback function will be called once per handshake.

The callback function should return 0 on success. -1 indicates an error.

gnutls_hex_encode ()

int         gnutls_hex_encode               (const gnutls_datum_t *data,
                                             char *result,
                                             size_t *result_size);

This function will convert the given data to printable data, using the hex encoding, as used in the PSK password files.

gnutls_hex_decode ()

int         gnutls_hex_decode               (const gnutls_datum_t *hex_data,
                                             char *result,
                                             size_t *result_size);

This function will decode the given encoded data, using the hex encoding used by PSK password files.

Note that hex_data should be null terminated.

gnutls_psk_set_server_dh_params ()

void        gnutls_psk_set_server_dh_params (gnutls_psk_server_credentials_t res,
                                             gnutls_dh_params_t dh_params);

This function will set the diffie hellman parameters for an anonymous server to use. These parameters will be used in Diffie Hellman with PSK cipher suites.

gnutls_psk_set_server_params_function ()

void        gnutls_psk_set_server_params_function
                                            (gnutls_psk_server_credentials_tres ,
                                             gnutls_params_function *func);

This function will set a callback in order for the server to get the diffie hellman parameters for PSK authentication. The callback should return zero on success.

enum gnutls_x509_subject_alt_name_t

  typedef enum gnutls_x509_subject_alt_name_t
  {
    GNUTLS_SAN_DNSNAME = 1,
    GNUTLS_SAN_RFC822NAME,
    GNUTLS_SAN_URI,
    GNUTLS_SAN_IPADDRESS
  } gnutls_x509_subject_alt_name_t;

struct gnutls_openpgp_key_int

struct gnutls_openpgp_key_int;

gnutls_openpgp_key_t

struct gnutls_openpgp_privkey_int

struct gnutls_openpgp_privkey_int;

gnutls_openpgp_privkey_t

gnutls_auth_get_type ()

gnutls_credentials_type_t gnutls_auth_get_type
                                            (gnutls_session_t session);

gnutls_auth_server_get_type ()

gnutls_credentials_type_t gnutls_auth_server_get_type
                                            (gnutls_session_t session);

gnutls_auth_client_get_type ()

gnutls_credentials_type_t gnutls_auth_client_get_type
                                            (gnutls_session_t session);

gnutls_dh_set_prime_bits ()

void        gnutls_dh_set_prime_bits        (gnutls_session_t session,
                                             unsigned int bits);

This function sets the number of bits, for use in an Diffie Hellman key exchange. This is used both in DH ephemeral and DH anonymous cipher suites. This will set the minimum size of the prime that will be used for the handshake.

In the client side it sets the minimum accepted number of bits. If a server sends a prime with less bits than that GNUTLS_E_DH_PRIME_UNACCEPTABLE will be returned by the handshake.

gnutls_dh_get_secret_bits ()

int         gnutls_dh_get_secret_bits       (gnutls_session_t session);

This function will return the bits used in the last Diffie Hellman authentication with the peer. Should be used for both anonymous and ephemeral diffie Hellman.

gnutls_dh_get_peers_public_bits ()

int         gnutls_dh_get_peers_public_bits (gnutls_session_t session);

This function will return the bits used in the last Diffie Hellman authentication with the peer. Should be used for both anonymous and ephemeral diffie Hellman.

gnutls_dh_get_prime_bits ()

int         gnutls_dh_get_prime_bits        (gnutls_session_t session);

This function will return the bits of the prime used in the last Diffie Hellman authentication with the peer. Should be used for both anonymous and ephemeral diffie Hellman.

gnutls_dh_get_group ()

int         gnutls_dh_get_group             (gnutls_session_t session,
                                             gnutls_datum_t *raw_gen,
                                             gnutls_datum_t *raw_prime);

This function will return the group parameters used in the last Diffie Hellman authentication with the peer. These are the prime and the generator used. This function should be used for both anonymous and ephemeral diffie Hellman. The output parameters must be freed with gnutls_free().

gnutls_dh_get_pubkey ()

int         gnutls_dh_get_pubkey            (gnutls_session_t session,
                                             gnutls_datum_t *raw_key);

This function will return the peer's public key used in the last Diffie Hellman authentication. This function should be used for both anonymous and ephemeral diffie Hellman. The output parameters must be freed with gnutls_free().

gnutls_rsa_export_get_pubkey ()

int         gnutls_rsa_export_get_pubkey    (gnutls_session_t session,
                                             gnutls_datum_t *exponent,
                                             gnutls_datum_t *modulus);

This function will return the peer's public key exponent and modulus used in the last RSA-EXPORT authentication. The output parameters must be freed with gnutls_free().

gnutls_rsa_export_get_modulus_bits ()

int         gnutls_rsa_export_get_modulus_bits
                                            (gnutls_session_t session);

This function will return the bits used in the last RSA-EXPORT key exchange with the peer.

gnutls_certificate_client_set_retrieve_function ()

void        gnutls_certificate_client_set_retrieve_function
                                            (gnutls_certificate_credentials_t cred,
                                             gnutls_certificate_client_retrieve_function *func);

This function sets a callback to be called in order to retrieve the certificate to be used in the handshake. The callback's function prototype is: int (*callback)(gnutls_session_t, const gnutls_datum_t* req_ca_dn, int nreqs, gnutls_pk_algorithm_t* pk_algos, int pk_algos_length, gnutls_retr_st* st);

st should contain the certificates and private keys.

req_ca_cert, is only used in X.509 certificates. Contains a list with the CA names that the server considers trusted. Normally we should send a certificate that is signed by one of these CAs. These names are DER encoded. To get a more meaningful value use the function gnutls_x509_rdn_get().

pk_algos, contains a list with server's acceptable signature algorithms. The certificate returned should support the server's given algorithms.

If the callback function is provided then gnutls will call it, in the handshake, after the certificate request message has been received.

The callback function should set the certificate list to be sent, and return 0 on success. If no certificate was selected then the number of certificates should be set to zero. The value (-1) indicates error and the handshake will be terminated.

gnutls_certificate_server_set_retrieve_function ()

void        gnutls_certificate_server_set_retrieve_function
                                            (gnutls_certificate_credentials_t cred,
                                             gnutls_certificate_server_retrieve_function *func);

This function sets a callback to be called in order to retrieve the certificate to be used in the handshake. The callback's function prototype is: int (*callback)(gnutls_session_t, gnutls_retr_st* st);

st should contain the certificates and private keys.

If the callback function is provided then gnutls will call it, in the handshake, after the certificate request message has been received.

The callback function should set the certificate list to be sent, and return 0 on success. The value (-1) indicates error and the handshake will be terminated.

gnutls_certificate_server_set_request ()

void        gnutls_certificate_server_set_request
                                            (gnutls_session_t session,
                                             gnutls_certificate_request_treq );

This function specifies if we (in case of a server) are going to send a certificate request message to the client. If req is GNUTLS_CERT_REQUIRE then the server will return an error if the peer does not provide a certificate. If you do not call this function then the client will not be asked to send a certificate.

gnutls_certificate_get_peers ()

const gnutls_datum_t* gnutls_certificate_get_peers
                                            (gnutls_session_tsession ,
                                             unsigned int *list_size);

This function will return the peer's raw certificate (chain) as sent by the peer. These certificates are in raw format (DER encoded for X.509). In case of a X.509 then a certificate list may be present. The first certificate in the list is the peer's certificate, following the issuer's certificate, then the issuer's issuer etc.

In case of OpenPGP keys a single key will be returned in raw format.

gnutls_certificate_get_ours ()

const gnutls_datum_t* gnutls_certificate_get_ours
                                            (gnutls_session_tsession );

This function will return the certificate as sent to the peer, in the last handshake. These certificates are in raw format. In X.509 this is a certificate list. In OpenPGP this is a single certificate.

gnutls_certificate_activation_time_peers ()

time_t      gnutls_certificate_activation_time_peers
                                            (gnutls_session_t session);

This function will return the peer's certificate activation time. This is the creation time for openpgp keys.

gnutls_certificate_expiration_time_peers ()

time_t      gnutls_certificate_expiration_time_peers
                                            (gnutls_session_t session);

This function will return the peer's certificate expiration time.

gnutls_certificate_client_get_request_status ()

int         gnutls_certificate_client_get_request_status
                                            (gnutls_session_t session);

This function will return 0 if the peer (server) did not request client authentication or 1 otherwise.

gnutls_certificate_verify_peers2 ()

int         gnutls_certificate_verify_peers2
                                            (gnutls_session_t session,
                                             unsigned int *status);

This function will try to verify the peer's certificate and return its status (trusted, invalid etc.). The value of status should be one or more of the gnutls_certificate_status_t enumerated elements bitwise or'd. To avoid denial of service attacks some default upper limits regarding the certificate key size and chain size are set. To override them use gnutls_certificate_set_verify_limits().

Note that you must also check the peer's name in order to check if the verified certificate belongs to the actual peer.

gnutls_certificate_verify_peers ()

int         gnutls_certificate_verify_peers (gnutls_session_t session);

This function will try to verify the peer's certificate and return its status (trusted, invalid etc.). However you must also check the peer's name in order to check if the verified certificate belongs to the actual peer.

The return value should be one or more of the gnutls_certificate_status_t enumerated elements bitwise or'd, or a negative value on error.

This is the same as gnutls_x509_verify_certificate().

gnutls_pem_base64_encode ()

int         gnutls_pem_base64_encode        (const char *msg,
                                             const gnutls_datum_t *data,
                                             char *result,
                                             size_t *result_size);

This function will convert the given data to printable data, using the base64 encoding. This is the encoding used in PEM messages. If the provided buffer is not long enough GNUTLS_E_SHORT_MEMORY_BUFFER is returned.

The output string will be null terminated, although the size will not include the terminating null.

gnutls_pem_base64_decode ()

int         gnutls_pem_base64_decode        (const char *header,
                                             const gnutls_datum_t *b64_data,
                                             unsigned char *result,
                                             size_t *result_size);

This function will decode the given encoded data. If the header given is non null this function will search for "-----BEGIN header" and decode only this part. Otherwise it will decode the first PEM packet found.

gnutls_pem_base64_encode_alloc ()

int         gnutls_pem_base64_encode_alloc  (const char *msg,
                                             const gnutls_datum_t *data,
                                             gnutls_datum_t *result);

This function will convert the given data to printable data, using the base64 encoding. This is the encoding used in PEM messages. This function will allocate the required memory to hold the encoded data.

You should use gnutls_free() to free the returned data.

gnutls_pem_base64_decode_alloc ()

int         gnutls_pem_base64_decode_alloc  (const char *header,
                                             const gnutls_datum_t *b64_data,
                                             gnutls_datum_t *result);

This function will decode the given encoded data. The decoded data will be allocated, and stored into result. If the header given is non null this function will search for "-----BEGIN header" and decode only this part. Otherwise it will decode the first PEM packet found.

You should use gnutls_free() to free the returned data.

GNUTLS_KEY_DIGITAL_SIGNATURE

#define     GNUTLS_KEY_DIGITAL_SIGNATURE

GNUTLS_KEY_NON_REPUDIATION

#define     GNUTLS_KEY_NON_REPUDIATION

GNUTLS_KEY_KEY_ENCIPHERMENT

#define     GNUTLS_KEY_KEY_ENCIPHERMENT

GNUTLS_KEY_DATA_ENCIPHERMENT

#define     GNUTLS_KEY_DATA_ENCIPHERMENT

GNUTLS_KEY_KEY_AGREEMENT

#define     GNUTLS_KEY_KEY_AGREEMENT

GNUTLS_KEY_KEY_CERT_SIGN

#define     GNUTLS_KEY_KEY_CERT_SIGN

GNUTLS_KEY_CRL_SIGN

#define     GNUTLS_KEY_CRL_SIGN

GNUTLS_KEY_ENCIPHER_ONLY

#define     GNUTLS_KEY_ENCIPHER_ONLY

GNUTLS_KEY_DECIPHER_ONLY

#define     GNUTLS_KEY_DECIPHER_ONLY

gnutls_certificate_set_params_function ()

void        gnutls_certificate_set_params_function
                                            (gnutls_certificate_credentials_t res,
                                             gnutls_params_function *func);

This function will set a callback in order for the server to get the diffie hellman or RSA parameters for certificate authentication. The callback should return zero on success.

gnutls_anon_set_params_function ()

void        gnutls_anon_set_params_function (gnutls_anon_server_credentials_t res,
                                             gnutls_params_function *func);

This function will set a callback in order for the server to get the diffie hellman or RSA parameters for anonymous authentication. The callback should return zero on success.

gnutls_psk_set_params_function ()

void        gnutls_psk_set_params_function  (gnutls_psk_server_credentials_t res,
                                             gnutls_params_function *func);

This function will set a callback in order for the server to get the diffie hellman or RSA parameters for psk authentication. The callback should return zero on success.

GNUTLS_E_SUCCESS

#define     GNUTLS_E_SUCCESS

GNUTLS_E_UNKNOWN_COMPRESSION_ALGORITHM

#define     GNUTLS_E_UNKNOWN_COMPRESSION_ALGORITHM

GNUTLS_E_UNKNOWN_CIPHER_TYPE

#define     GNUTLS_E_UNKNOWN_CIPHER_TYPE

GNUTLS_E_LARGE_PACKET

#define     GNUTLS_E_LARGE_PACKET

GNUTLS_E_UNSUPPORTED_VERSION_PACKET

#define     GNUTLS_E_UNSUPPORTED_VERSION_PACKET

GNUTLS_E_UNEXPECTED_PACKET_LENGTH

#define     GNUTLS_E_UNEXPECTED_PACKET_LENGTH

GNUTLS_E_INVALID_SESSION

#define     GNUTLS_E_INVALID_SESSION

GNUTLS_E_FATAL_ALERT_RECEIVED

#define     GNUTLS_E_FATAL_ALERT_RECEIVED

GNUTLS_E_UNEXPECTED_PACKET

#define     GNUTLS_E_UNEXPECTED_PACKET

GNUTLS_E_WARNING_ALERT_RECEIVED

#define     GNUTLS_E_WARNING_ALERT_RECEIVED

GNUTLS_E_ERROR_IN_FINISHED_PACKET

#define     GNUTLS_E_ERROR_IN_FINISHED_PACKET

GNUTLS_E_UNEXPECTED_HANDSHAKE_PACKET

#define     GNUTLS_E_UNEXPECTED_HANDSHAKE_PACKET

GNUTLS_E_UNKNOWN_CIPHER_SUITE

#define     GNUTLS_E_UNKNOWN_CIPHER_SUITE

GNUTLS_E_UNWANTED_ALGORITHM

#define     GNUTLS_E_UNWANTED_ALGORITHM

GNUTLS_E_MPI_SCAN_FAILED

#define     GNUTLS_E_MPI_SCAN_FAILED

GNUTLS_E_DECRYPTION_FAILED

#define     GNUTLS_E_DECRYPTION_FAILED

GNUTLS_E_MEMORY_ERROR

#define     GNUTLS_E_MEMORY_ERROR

GNUTLS_E_DECOMPRESSION_FAILED

#define     GNUTLS_E_DECOMPRESSION_FAILED

GNUTLS_E_COMPRESSION_FAILED

#define     GNUTLS_E_COMPRESSION_FAILED

GNUTLS_E_AGAIN

#define     GNUTLS_E_AGAIN

GNUTLS_E_EXPIRED

#define     GNUTLS_E_EXPIRED

GNUTLS_E_DB_ERROR

#define     GNUTLS_E_DB_ERROR

GNUTLS_E_SRP_PWD_ERROR