- Added reset functionality for HMAC context. Speed-up for some use-cases.

library/md2.c

@@ -260,6 +260,15 @@ void md2_hmac_finish( md2_context *ctx, unsigned char output[16] )
     memset( tmpbuf, 0, sizeof( tmpbuf ) );
 }
 
+/*
+ * MD2 HMAC context reset
+ */
+void md2_hmac_reset( md2_context *ctx )
+{
+    md2_starts( ctx );
+    md2_update( ctx, ctx->ipad, 64 );
+}
+
 /*
  * output = HMAC-MD2( hmac key, input buffer )
  */

library/md4.c

@@ -356,6 +356,15 @@ void md4_hmac_finish( md4_context *ctx, unsigned char output[16] )
     memset( tmpbuf, 0, sizeof( tmpbuf ) );
 }
 
+/*
+ * MD4 HMAC context reset
+ */
+void md4_hmac_reset( md4_context *ctx )
+{
+    md4_starts( ctx );
+    md4_update( ctx, ctx->ipad, 64 );
+}
+
 /*
  * output = HMAC-MD4( hmac key, input buffer )
  */

library/md5.c

@@ -375,6 +375,15 @@ void md5_hmac_finish( md5_context *ctx, unsigned char output[16] )
     memset( tmpbuf, 0, sizeof( tmpbuf ) );
 }
 
+/*
+ * MD5 HMAC context reset
+ */
+void md5_hmac_reset( md5_context *ctx )
+{
+    md5_starts( ctx );
+    md5_update( ctx, ctx->ipad, 64 );
+}
+
 /*
  * output = HMAC-MD5( hmac key, input buffer )
  */

library/sha1.c

@@ -410,6 +410,15 @@ void sha1_hmac_finish( sha1_context *ctx, unsigned char output[20] )
     memset( tmpbuf, 0, sizeof( tmpbuf ) );
 }
 
+/*
+ * SHA1 HMAC context reset
+ */
+void sha1_hmac_reset( sha1_context *ctx )
+{
+    sha1_starts( ctx );
+    sha1_update( ctx, ctx->ipad, 64 );
+}
+
 /*
  * output = HMAC-SHA-1( hmac key, input buffer )
  */

library/sha2.c

@@ -417,6 +417,15 @@ void sha2_hmac_finish( sha2_context *ctx, unsigned char output[32] )
     memset( tmpbuf, 0, sizeof( tmpbuf ) );
 }
 
+/*
+ * SHA-256 HMAC context reset
+ */
+void sha2_hmac_reset( sha2_context *ctx )
+{
+    sha2_starts( ctx, ctx->is224 );
+    sha2_update( ctx, ctx->ipad, 64 );
+}
+
 /*
  * output = HMAC-SHA-256( hmac key, input buffer )
  */

library/sha4.c

@@ -416,6 +416,15 @@ void sha4_hmac_finish( sha4_context *ctx, unsigned char output[64] )
     memset( tmpbuf, 0, sizeof( tmpbuf ) );
 }
 
+/*
+ * SHA-512 HMAC context reset
+ */
+void sha4_hmac_reset( sha4_context *ctx )
+{
+    sha4_starts( ctx, ctx->is384 );
+    sha4_update( ctx, ctx->ipad, 128 );
+}
+
 /*
  * output = HMAC-SHA-512( hmac key, input buffer )
  */