Rename OSSL_SERIALIZER / OSSL_DESERIALIZER to OSSL_ENCODE / OSSL_DECODE

[openssl.git] / doc / man3 / HMAC.pod

diff --git a/doc/man3/HMAC.pod b/doc/man3/HMAC.pod
index 493b9338210f4476907df6e58671981703f7cddb..816d6e325d839d23f044a56d3ded8b7bfb623a24 100644 (file)
--- a/doc/man3/HMAC.pod
+++ b/doc/man3/HMAC.pod
@@ -20,8 +20,12 @@ HMAC_size
 
  #include <openssl/hmac.h>
 
+Deprecated since OpenSSL 3.0, can be hidden entirely by defining
+B<OPENSSL_API_COMPAT> with a suitable version value, see
+L<openssl_user_macros(7)>:
+
  unsigned char *HMAC(const EVP_MD *evp_md, const void *key,
-                     int key_len, const unsigned char *d, int n,
+                     int key_len, const unsigned char *d, size_t n,
                      unsigned char *md, unsigned int *md_len);
 
  HMAC_CTX *HMAC_CTX_new(void);
@@ -29,7 +33,7 @@ HMAC_size
 
  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_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len);
  int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len);
 
  void HMAC_CTX_free(HMAC_CTX *ctx);
@@ -40,15 +44,19 @@ HMAC_size
 
  size_t HMAC_size(const HMAC_CTX *e);
 
-Deprecated:
+Deprecated since OpenSSL 1.1.0, can be hidden entirely by defining
+B<OPENSSL_API_COMPAT> with a suitable version value, see
+L<openssl_user_macros(7)>:
 
- #if OPENSSL_API_COMPAT < 0x10100000L
  int HMAC_Init(HMAC_CTX *ctx, const void *key, int key_len,
                const EVP_MD *md);
- #endif
 
 =head1 DESCRIPTION
 
+All of the functions described on this page are deprecated. Applications should
+instead use L<EVP_MAC_CTX_new(3)>, L<EVP_MAC_CTX_free(3)>, L<EVP_MAC_init(3)>,
+L<EVP_MAC_update(3)> and L<EVP_MAC_final(3)>.
+
 HMAC is a MAC (message authentication code), i.e. a keyed hash
 function used for message authentication, which is based on a hash
 function.
@@ -63,11 +71,13 @@ 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>. Note: passing a NULL
 value for B<md>  to use the static array is not thread safe.
 
-B<evp_md> can be EVP_sha1(), EVP_ripemd160() etc.
+B<evp_md> is a message digest such as EVP_sha1(), EVP_ripemd160() etc. HMAC does
+not support variable output length digests such as EVP_shake128() and
+EVP_shake256().
 
 HMAC_CTX_new() creates a new HMAC_CTX in heap memory.
 
-HMAC_CTX_reset() zeroes an existing B<HMAC_CTX> and associated
+HMAC_CTX_reset() clears an existing B<HMAC_CTX> and associated
 resources, making it suitable for new computations as if it was newly
 created with HMAC_CTX_new().
 
@@ -78,23 +88,21 @@ itself.
 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 hash
-function B<evp_md> and key B<key>. If both are NULL (or B<evp_md> is the same
-as the previous digest used by B<ctx> and B<key> is NULL) the existing key is
+function B<evp_md> and key B<key>. If both are NULL, or if B<key> is NULL
+and B<evp_md> is the same as the previous call, then the
+existing key is
 reused. B<ctx> must have been created with HMAC_CTX_new() 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>.
+of an B<HMAC_CTX> in this function.
 
-B<NOTE:> If HMAC_Init_ex() is called with B<key> NULL and B<evp_md> is not the
+If HMAC_Init_ex() is called with B<key> NULL and B<evp_md> is not the
 same as the previous digest used by B<ctx> then an error is returned
 because reuse of an existing key with a different digest is not supported.
 
+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.
+
 HMAC_Update() can be called repeatedly with chunks of the message to
 be authenticated (B<len> bytes at B<data>).
 
@@ -138,6 +146,8 @@ L<SHA1(3)>, L<evp(7)>
 
 =head1 HISTORY
 
+All of these functions were deprecated in OpenSSL 3.0.
+
 HMAC_CTX_init() was replaced with HMAC_CTX_reset() in OpenSSL 1.1.0.
 
 HMAC_CTX_cleanup() existed in OpenSSL before version 1.1.0.
@@ -149,9 +159,9 @@ OpenSSL before version 1.0.0.
 
 =head1 COPYRIGHT
 
-Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
 
-Licensed under the OpenSSL license (the "License").  You may not use
+Licensed under the Apache License 2.0 (the "License").  You may not use
 this file except in compliance with the License.  You can obtain a copy
 in the file LICENSE in the source distribution or at
 L<https://www.openssl.org/source/license.html>.