Copyright (C) 2000-2012 |
Manpages hmacSection: OpenSSL (3ssl)Updated: 0.9.6c Index Return to Main Contents NAMEHMAC, HMAC_Init, HMAC_Update, HMAC_Final, HMAC_cleanup - HMAC message authentication codeSYNOPSIS
#include <openssl/hmac.h> unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len, const unsigned char *d, int n, unsigned char *md, unsigned int *md_len); void HMAC_Init(HMAC_CTX *ctx, const void *key, int key_len, const EVP_MD *md); void HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, int len); void HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len); void HMAC_cleanup(HMAC_CTX *ctx); DESCRIPTIONHMAC is a MAC (message authentication code), i.e. a keyed hash function used for message authentication, which is based on a hash function.HMAC() computes the message authentication code of the n bytes at d using the hash function evp_md and the key key which is key_len bytes long. It places the result in md (which must have space for the output of the hash function, which is no more than EVP_MAX_MD_SIZE bytes). If md is NULL, the digest is placed in a static array. The size of the output is placed in md_len, unless it is NULL. evp_md can be EVP_sha1(), EVP_ripemd160() etc. key and evp_md may be NULL if a key and hash function have been set in a previous call to HMAC_Init() for that HMAC_CTX. HMAC_cleanup() erases the key and other data from the HMAC_CTX. The following functions may be used if the message is not completely stored in memory: HMAC_Init() initializes a HMAC_CTX structure to use the hash function evp_md and the key key which is key_len bytes long. HMAC_Update() can be called repeatedly with chunks of the message to be authenticated (len bytes at data). HMAC_Final() places the message authentication code in md, which must have space for the hash function output. RETURN VALUESHMAC() returns a pointer to the message authentication code.HMAC_Init(), HMAC_Update(), HMAC_Final() and HMAC_cleanup() do not return values. CONFORMING TORFC 2104SEE ALSOsha(3), evp(3)HISTORYHMAC(), HMAC_Init(), HMAC_Update(), HMAC_Final() and HMAC_cleanup() are available since SSLeay 0.9.0.
IndexThis document was created by man2html, using the manual pages. Time: 23:56:46 GMT, April 26, 2024 |