+++ /dev/null
-=pod
-
-=head1 NAME
-
-HMAC, HMAC_Init, HMAC_Update, HMAC_Final, HMAC_cleanup - HMAC message
-authentication code
-
-=head1 SYNOPSIS
-
- #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_CTX_init(HMAC_CTX *ctx);
-
- int HMAC_Init(HMAC_CTX *ctx, const void *key, int key_len,
- const EVP_MD *md);
- int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int key_len,
- const EVP_MD *md, ENGINE *impl);
- int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, int len);
- int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len);
-
- void HMAC_CTX_cleanup(HMAC_CTX *ctx);
- void HMAC_cleanup(HMAC_CTX *ctx);
-
-=head1 DESCRIPTION
-
-HMAC 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 B<n> bytes at
-B<d> using the hash function B<evp_md> and the key B<key> which is
-B<key_len> bytes long.
-
-It places the result in B<md> (which must have space for the output of
-the hash function, which is no more than B<EVP_MAX_MD_SIZE> bytes).
-If B<md> is NULL, the digest is placed in a static array. The size of
-the output is placed in B<md_len>, unless it is B<NULL>.
-
-B<evp_md> can be EVP_sha1(), EVP_ripemd160() etc.
-
-HMAC_CTX_init() initialises a B<HMAC_CTX> before first use. It must be
-called.
-
-HMAC_CTX_cleanup() erases the key and other data from the B<HMAC_CTX>
-and releases any associated resources. It must be called when an
-B<HMAC_CTX> is no longer required.
-
-HMAC_cleanup() is an alias for HMAC_CTX_cleanup() included for back
-compatibility with 0.9.6b, it is deprecated.
-
-The following functions may be used if the message is not completely
-stored in memory:
-
-HMAC_Init() initializes a B<HMAC_CTX> structure to use the hash
-function B<evp_md> and the key B<key> which is B<key_len> bytes
-long. It is deprecated and only included for backward compatibility
-with OpenSSL 0.9.6b.
-
-HMAC_Init_ex() initializes or reuses a B<HMAC_CTX> structure to use
-the function B<evp_md> and key B<key>. Either can be NULL, in which
-case the existing one will be reused. HMAC_CTX_init() must have been
-called before the first use of an B<HMAC_CTX> in this
-function. B<N.B. HMAC_Init() had this undocumented behaviour in
-previous versions of OpenSSL - failure to switch to HMAC_Init_ex() in
-programs that expect it will cause them to stop working>.
-
-HMAC_Update() can be called repeatedly with chunks of the message to
-be authenticated (B<len> bytes at B<data>).
-
-HMAC_Final() places the message authentication code in B<md>, which
-must have space for the hash function output.
-
-=head1 RETURN VALUES
-
-HMAC() returns a pointer to the message authentication code or NULL if
-an error occurred.
-
-HMAC_Init_ex(), HMAC_Update() and HMAC_Final() return 1 for success or 0 if
-an error occurred.
-
-HMAC_CTX_init() and HMAC_CTX_cleanup() do not return values.
-
-=head1 CONFORMING TO
-
-RFC 2104
-
-=head1 SEE ALSO
-
-L<sha(3)|sha(3)>, L<evp(3)|evp(3)>
-
-=head1 HISTORY
-
-HMAC(), HMAC_Init(), HMAC_Update(), HMAC_Final() and HMAC_cleanup()
-are available since SSLeay 0.9.0.
-
-HMAC_CTX_init(), HMAC_Init_ex() and HMAC_CTX_cleanup() are available
-since OpenSSL 0.9.7.
-
-HMAC_Init_ex(), HMAC_Update() and HMAC_Final() did not return values in
-versions of OpenSSL before 1.0.0.
-
-=cut
projects / cassiopeia.git / blobdiff