Add support for RFC 2617 Digest Access Authentication

src/ChangeLog

@@ -1,3 +1,8 @@
+2012-07-07  Tim Ruehsen <tim.ruehsen@gmx.de>
+
+	(digest_authentication_encode): Add support for RFC 2617 Digest
+	Access Authentication.
+
 2012-07-07  Giuseppe Scrivano  <gscrivano@gnu.org>
 
 	* http.c (http_loop): Fix log message.

src/http.c

@@ -3655,19 +3655,23 @@ digest_authentication_encode (const char *au, const char *user,
                               const char *passwd, const char *method,
                               const char *path)
 {
-  static char *realm, *opaque, *nonce;
+  static char *realm, *opaque, *nonce, *qop;
   static struct {
     const char *name;
     char **variable;
   } options[] = {
     { "realm", &realm },
     { "opaque", &opaque },
-    { "nonce", &nonce }
+    { "nonce", &nonce },
+    { "qop", &qop }
   };
+  char cnonce[16] = "";
   char *res;
+  size_t res_size;
   param_token name, value;
 
-  realm = opaque = nonce = NULL;
+
+  realm = opaque = nonce = qop = NULL;
 
   au += 6;                      /* skip over `Digest' */
   while (extract_param (&au, &name, &value, ','))
@@ -3683,11 +3687,19 @@ digest_authentication_encode (const char *au, const char *user,
             break;
           }
     }
+
+  if (qop != NULL && strcmp(qop,"auth"))
+    {
+      logprintf (LOG_NOTQUIET, _("Unsupported quality of protection '%s'.\n"), qop);
+      user = NULL; /* force freeing mem and return */
+    }
+
   if (!realm || !nonce || !user || !passwd || !path || !method)
     {
       xfree_null (realm);
       xfree_null (opaque);
       xfree_null (nonce);
+      xfree_null (qop);
       return NULL;
     }
 
@@ -3716,6 +3728,30 @@ digest_authentication_encode (const char *au, const char *user,
     md5_finish_ctx (&ctx, hash);
     dump_hash (a2buf, hash);
 
+    if (!strcmp(qop,"auth"))
+      {
+        /* RFC 2617 Digest Access Authentication */
+        /* generate random hex string */
+        snprintf(cnonce, sizeof(cnonce), "%08x", random_number(INT_MAX));
+
+        /* RESPONSE_DIGEST = H(A1BUF ":" nonce ":" noncecount ":" clientnonce ":" qop ": " A2BUF) */
+        md5_init_ctx (&ctx);
+        md5_process_bytes ((unsigned char *)a1buf, MD5_DIGEST_SIZE * 2, &ctx);
+        md5_process_bytes ((unsigned char *)":", 1, &ctx);
+        md5_process_bytes ((unsigned char *)nonce, strlen (nonce), &ctx);
+        md5_process_bytes ((unsigned char *)":", 1, &ctx);
+        md5_process_bytes ((unsigned char *)"00000001", 8, &ctx); /* TODO: keep track of server nonce values */
+        md5_process_bytes ((unsigned char *)":", 1, &ctx);
+        md5_process_bytes ((unsigned char *)cnonce, strlen(cnonce), &ctx);
+        md5_process_bytes ((unsigned char *)":", 1, &ctx);
+        md5_process_bytes ((unsigned char *)qop, strlen(qop), &ctx);
+        md5_process_bytes ((unsigned char *)":", 1, &ctx);
+        md5_process_bytes ((unsigned char *)a2buf, MD5_DIGEST_SIZE * 2, &ctx);
+        md5_finish_ctx (&ctx, hash);
+      }
+    else
+      {
+        /* RFC 2069 Digest Access Authentication */
         /* RESPONSE_DIGEST = H(A1BUF ":" nonce ":" A2BUF) */
         md5_init_ctx (&ctx);
         md5_process_bytes ((unsigned char *)a1buf, MD5_DIGEST_SIZE * 2, &ctx);
@@ -3724,19 +3760,37 @@ digest_authentication_encode (const char *au, const char *user,
         md5_process_bytes ((unsigned char *)":", 1, &ctx);
         md5_process_bytes ((unsigned char *)a2buf, MD5_DIGEST_SIZE * 2, &ctx);
         md5_finish_ctx (&ctx, hash);
+      }
+
     dump_hash (response_digest, hash);
 
-    res = xmalloc (strlen (user)
+    res_size = strlen (user)
              + strlen (user)
              + strlen (realm)
              + strlen (nonce)
              + strlen (path)
              + 2 * MD5_DIGEST_SIZE /*strlen (response_digest)*/
              + (opaque ? strlen (opaque) : 0)
-                   + 128);
+             + (qop ? 128: 0)
-    sprintf (res, "Digest \
+             + 128;
-username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", response=\"%s\"",
+
+    res = xmalloc (res_size);
+
+    if (!strcmp(qop,"auth"))
+      {
+        snprintf (res, res_size, "Digest "\
+                "username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", response=\"%s\""\
+                ", qop=auth, nc=00000001, cnonce=\"%s\"",
+                  user, realm, nonce, path, response_digest, cnonce);
+
+      }
+    else
+      {
+        snprintf (res, res_size, "Digest "\
+                "username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", response=\"%s\"",
                   user, realm, nonce, path, response_digest);
+      }
+
     if (opaque)
       {
         char *p = res + strlen (res);