E.13 Compatibility API

The following functions are carried over from old GnuTLS released. They might be removed at a later version. Their prototypes lie in gnutls/compat.h.

gnutls_compression_get

Function: gnutls_compression_method_t gnutls_compression_get (gnutls_session_t session)

session: is a gnutls_session_t type.

Get the currently used compression algorithm.

Returns: the currently used compression method, a gnutls_compression_method_t value.

gnutls_compression_get_id

Function: gnutls_compression_method_t gnutls_compression_get_id (const char * name)

name: is a compression method name

The names are compared in a case insensitive way.

Returns: an id of the specified in a string compression method, or GNUTLS_COMP_UNKNOWN on error.

gnutls_compression_get_name

Function: const char * gnutls_compression_get_name (gnutls_compression_method_t algorithm)

algorithm: is a Compression algorithm

Convert a gnutls_compression_method_t value to a string.

Returns: a pointer to a string that contains the name of the specified compression algorithm, or NULL .

gnutls_compression_list

Function: const gnutls_compression_method_t * gnutls_compression_list ( void)

Get a list of compression methods.

Returns: a zero-terminated list of gnutls_compression_method_t integers indicating the available compression methods.

gnutls_global_set_mem_functions

Function: void gnutls_global_set_mem_functions (gnutls_alloc_function alloc_func, gnutls_alloc_function secure_alloc_func, gnutls_is_secure_function is_secure_func, gnutls_realloc_function realloc_func, gnutls_free_function free_func)

alloc_func: it’s the default memory allocation function. Like malloc() .

secure_alloc_func: This is the memory allocation function that will be used for sensitive data.

is_secure_func: a function that returns 0 if the memory given is not secure. May be NULL.

realloc_func: A realloc function

free_func: The function that frees allocated data. Must accept a NULL pointer.

Deprecated: since 3.3.0 it is no longer possible to replace the internally used memory allocation functions

This is the function where 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

This function must be called before gnutls_global_init() is called. This function is not thread safe.

gnutls_openpgp_privkey_sign_hash

Function: int gnutls_openpgp_privkey_sign_hash (gnutls_openpgp_privkey_t key, const gnutls_datum_t * hash, gnutls_datum_t * signature)

key: Holds the key

hash: holds the data to be signed

signature: will contain newly allocated signature

This function is no-op.

Returns: GNUTLS_E_UNIMPLEMENTED_FEATURE .

gnutls_priority_compression_list

Function: int gnutls_priority_compression_list (gnutls_priority_t pcache, const unsigned int ** list)

pcache: is a gnutls_priority_t type.

list: will point to an integer list

Get a list of available compression method in the priority structure.

Returns: the number of methods, or an error code.

Since: 3.0

gnutls_x509_crt_get_preferred_hash_algorithm

Function: int gnutls_x509_crt_get_preferred_hash_algorithm (gnutls_x509_crt_t crt, gnutls_digest_algorithm_t * hash, unsigned int * mand)

crt: Holds the certificate

hash: The result of the call with the hash algorithm used for signature

mand: If non-zero it means that the algorithm MUST use this hash. May be NULL .

This function will read the certificate and return the appropriate digest algorithm to use for signing with this certificate. Some certificates (i.e. DSA might not be able to sign without the preferred algorithm).

Deprecated: Please use gnutls_pubkey_get_preferred_hash_algorithm() .

Returns: the 0 if the hash algorithm is found. A negative error code is returned on error.

Since: 2.12.0

gnutls_x509_privkey_sign_hash

Function: int gnutls_x509_privkey_sign_hash (gnutls_x509_privkey_t key, const gnutls_datum_t * hash, gnutls_datum_t * signature)

key: a key

hash: holds the data to be signed

signature: will contain newly allocated signature

This function will sign the given hash using the private key. Do not use this function directly unless you know what it is. Typical signing requires the data to be hashed and stored in special formats (e.g. BER Digest-Info for RSA).

This API is provided only for backwards compatibility, and thus restricted to RSA, DSA and ECDSA key types. For other key types please use gnutls_privkey_sign_hash() and gnutls_privkey_sign_data() .

Returns: On success, GNUTLS_E_SUCCESS (0) is returned, otherwise a negative error value.

Deprecated in: 2.12.0