Changeset e0a0a42

Timestamp:

2012-02-10T13:37:08Z (12 years ago)

Author:

Wilmer van der Gaast <wilmer@…>

Branches:

master

Children:

bb2d198

Parents:

7d27962

Message:

Added sha1_random_uuid function, which I will use later to generate random
Jabber roomnames.

Location:

lib

Files:

• sha1.c (modified) (2 diffs)
• sha1.h (modified) (1 diff)

lib/sha1.c

@@ -37 +37 @@
 
 #include <string.h>
+#include <stdio.h>
 #include "sha1.h"
 
@@ -421 +422 @@
         sha1_finish( &sha1, Message_Digest );
 }
+
+/* I think this follows the scheme described on:
+   http://en.wikipedia.org/wiki/Universally_unique_identifier#Version_4_.28random.29
+   My random data comes from a SHA1 generator but hey, it's random enough for
+   me, and RFC 4122 looks way more complicated than I need this to be.
+   
+   Returns a value that must be free()d. */
+char *sha1_random_uuid( sha1_state_t * context )
+{
+        uint8_t dig[sha1_hash_size];
+        char *ret = g_new0( char, 40 ); /* 36 chars + \0 */
+        int i, p;
+        
+        sha1_finish(context, dig);
+        for( p = i = 0; i < 16; i ++ )
+        {
+                if( i == 4 || i == 6 || i == 8 || i == 10 )
+                        ret[p++] = '-';
+                if( i == 6 )
+                        dig[i] = ( dig[i] & 0x0f ) | 0x40;
+                if( i == 8 )
+                        dig[i] = ( dig[i] & 0x30 ) | 0x80;
+                
+                sprintf( ret + p, "%02x", dig[i] );
+                p += 2;
+        }
+        ret[p] = '\0';
+        
+        return ret;
+}

lib/sha1.h

@@ -68 +68 @@
 G_MODULE_EXPORT int sha1_finish(sha1_state_t *, uint8_t Message_Digest[sha1_hash_size]);
 G_MODULE_EXPORT void sha1_hmac(const char *key_, size_t key_len, const char *payload, size_t payload_len, uint8_t Message_Digest[sha1_hash_size]);
+G_MODULE_EXPORT char *sha1_random_uuid( sha1_state_t * context );
 
 #endif