X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=ucw%2Fsha1.h;h=4b17da548c97c6eaf98b158dddd2a28f7e6a43b4;hb=342e0c3edeacf4eecd03da36c879ca817c64a0f3;hp=d9ca009e2bfea6c5e7ca8deb0bed443b7a4ba672;hpb=1ac0074ba074457f7910c3ed97f5bd73bd547582;p=libucw.git

diff --git a/ucw/sha1.h b/ucw/sha1.h
index d9ca009e..4b17da54 100644
--- a/ucw/sha1.h
+++ b/ucw/sha1.h
@@ -1,7 +1,7 @@
 /*
  *	SHA-1 Hash Function (FIPS 180-1, RFC 3174)
  *
- *	(c) 2008 Martin Mares <mj@ucw.cz>
+ *	(c) 2008--2009 Martin Mares <mj@ucw.cz>
  *
  *	Based on the code from libgcrypt-1.2.3, which was:
  *
@@ -16,8 +16,7 @@
 
 /**
  * Internal SHA1 state.
- * You can consider it an opaque handle, if you want just hash
- * functions.
+ * You should use it just as an opaque handle only.
  */
 typedef struct {
   u32 h0,h1,h2,h3,h4;
@@ -31,27 +30,30 @@ void sha1_init(sha1_context *hd); /** Initialize new algorithm run in the @hd co
  * Push another @inlen bytes of data pointed to by @inbuf onto the
  * SHA1 hash currently in @hd. You can call this any times you want on
  * the same hash (and you do not need to reinitialize it by
- * sha1_init()). It has the same effect as concatenating all the data
+ * @sha1_init()). It has the same effect as concatenating all the data
  * together and passing them at once.
  */
 void sha1_update(sha1_context *hd, const byte *inbuf, uns inlen);
 /**
- * No more sha1_update() calls will be done. This terminates the hash
- * and returns pointer to it.
+ * No more @sha1_update() calls will be done. This terminates the hash
+ * and returns a pointer to it.
  *
- * Note the pointer points into data in the @hd context. If it ceases
+ * Note that the pointer points into data in the @hd context. If it ceases
  * to exist, the pointer becomes invalid.
+ *
+ * To convert the hash to its usual hexadecimal representation, see
+ * <<string:mem_to_hex()>>.
  */
 byte *sha1_final(sha1_context *hd);
 
 /**
- * Convenience one-shot function for SHA1 hash.
+ * A convenience one-shot function for SHA1 hash.
  * It is equivalent to this snippet of code:
  *
  *  sha1_context hd;
  *  sha1_init(&hd);
  *  sha1_update(&hd, buffer, length);
- *  memcpy(outbuf, sha1_final(&hd), 20);
+ *  memcpy(outbuf, sha1_final(&hd), SHA1_SIZE);
  */
 void sha1_hash_buffer(byte *outbuf, const byte *buffer, uns length);
 
@@ -61,6 +63,19 @@ void sha1_hash_buffer(byte *outbuf, const byte *buffer, uns length);
  */
 void sha1_hmac(byte *outbuf, const byte *key, uns keylen, const byte *data, uns datalen);
 
+/**
+ * The HMAC also exists in a stream version in a way analogous to the
+ * plain SHA1. Pass this as a context.
+ */
+typedef struct {
+  sha1_context ictx;
+  sha1_context octx;
+} sha1_hmac_context;
+
+void sha1_hmac_init(sha1_hmac_context *hd, const byte *key, uns keylen);	/** Initialize HMAC with context @hd and the given key. See sha1_init(). */
+void sha1_hmac_update(sha1_hmac_context *hd, const byte *data, uns datalen);	/** Hash another @datalen bytes of data. See sha1_update(). */
+byte *sha1_hmac_final(sha1_hmac_context *hd);					/** Terminate the HMAC and return a pointer to the allocated hash. See sha1_final(). */
+
 #define SHA1_SIZE 20 /** Size of the SHA1 hash in its binary representation **/
 #define SHA1_HEX_SIZE 41 /** Buffer length for a string containing SHA1 in hexadecimal format. **/
 #define SHA1_BLOCK_SIZE 64 /** SHA1 splits input to blocks of this size. **/