Wed Dec 4 21:08:52 CET 2002 Jochen Eisinger <c0ffee@penguin-breeder.org>

	* Verify signature payload for signed messages. Affected files
	  irssi/src/silc/core/client_ops.h, irssi/src/silc/core/silc-servers.c,
	  irssi/src/silc/core/silc-core.h

diff --git a/apps/irssi/src/silc/core/client_ops.c b/apps/irssi/src/silc/core/client_ops.c
index 41418bc5a1377d3d971dc503ecab4253c90ea8d1..b05e23bbe4f18bda3ffd0444319ce411bc2e7984 100644 (file)
--- a/apps/irssi/src/silc/core/client_ops.c
+++ b/apps/irssi/src/silc/core/client_ops.c
@@ -153,6 +153,92 @@ void silc_say_error(char *msg, ...)
   va_end(va);
 }
 
+/* try to verify a message using locally stored public key data */
+int verify_message_signature(SilcClientEntry sender,
+                            SilcMessageSignedPayload sig,
+                            SilcMessagePayload message)
+{
+  SilcPublicKey pk;
+  char file[256], filename[256];
+  char *fingerprint, *fingerprint2;
+  unsigned char *pk_data;
+  SilcUInt32 pk_datalen;
+  struct stat st;
+  int ret = SILC_MSG_SIGNED_VERIFIED, i;
+
+  if (sig == NULL)
+    return SILC_MSG_SIGNED_UNKNOWN;
+
+  /* get public key from the signature payload and compare it with the
+     one stored in the client entry */
+  pk = silc_message_signed_get_public_key(sig, &pk_data, &pk_datalen);
+
+  if (pk != NULL) {
+    fingerprint = silc_hash_fingerprint(NULL, pk_data, pk_datalen);
+
+    if (sender->fingerprint) {
+      fingerprint2 = silc_fingerprint(sender->fingerprint,
+                                     sender->fingerprint_len);
+      if (strcmp(fingerprint, fingerprint2)) {
+        /* since the public key differs from the senders public key, the
+           verification _failed_ */
+        silc_pkcs_public_key_free(pk);
+        silc_free(fingerprint);
+        ret = SILC_MSG_SIGNED_UNKNOWN;
+      }
+      silc_free(fingerprint2);
+    }
+  } else if (sender->fingerprint)
+    fingerprint = silc_fingerprint(sender->fingerprint,
+                                  sender->fingerprint_len);
+  else
+    /* no idea, who or what signed that message ... */
+    return SILC_MSG_SIGNED_UNKNOWN;
+  
+  /* search our local client key cache */
+  for (i = 0; i < strlen(fingerprint); i++)
+    if (fingerprint[i] == ' ')
+      fingerprint[i] = '_';
+    
+  snprintf(file, sizeof(file) - 1, "clientkey_%s.pub", fingerprint);
+  snprintf(filename, sizeof(filename) - 1, "%s/clientkeys/%s", 
+          get_irssi_dir(), file);
+  silc_free(fingerprint);
+  
+  if (stat(filename, &st) < 0)
+    /* we don't have the public key cached ... use the one from the sig */
+    ret = SILC_MSG_SIGNED_UNKNOWN;
+  else {
+    SilcPublicKey cached_pk;
+
+    /* try to load the file */
+    if (!silc_pkcs_load_public_key(filename, &cached_pk, SILC_PKCS_FILE_PEM) &&
+       !silc_pkcs_load_public_key(filename, &cached_pk, 
+                                  SILC_PKCS_FILE_BIN)) {
+      printformat_module("fe-common/silc", NULL, NULL, MSGLEVEL_CRAP, 
+                        SILCTXT_PUBKEY_COULD_NOT_LOAD, "client");
+      if (pk == NULL)
+       return SILC_MSG_SIGNED_UNKNOWN;
+      else
+       ret = SILC_MSG_SIGNED_UNKNOWN;
+    }
+
+    if (pk)
+      silc_pkcs_public_key_free(pk);
+    pk = cached_pk; 
+  }
+
+  /* the public key is now in pk, our "level of trust" in ret */
+  if (silc_message_signed_verify(sig, message, pk, silc_client->sha1hash) 
+      != SILC_AUTH_OK)
+    ret = SILC_MSG_SIGNED_FAILED;
+
+  if (pk)
+    silc_pkcs_public_key_free(pk);
+
+  return ret;
+}
+
 /* Message for a channel. The `sender' is the nickname of the sender 
    received in the packet. The `channel_name' is the name of the channel. */
 
@@ -165,6 +251,7 @@ void silc_channel_message(SilcClient client, SilcClientConnection conn,
   SILC_SERVER_REC *server;
   SILC_NICK_REC *nick;
   SILC_CHANNEL_REC *chanrec;
+  int verified = 0;
   
   SILC_LOG_DEBUG(("Start"));
 
@@ -187,13 +274,8 @@ void silc_channel_message(SilcClient client, SilcClientConnection conn,
   /* If the messages is digitally signed, verify it, if possible. */
   if (flags & SILC_MESSAGE_FLAG_SIGNED) {
     SilcMessageSignedPayload sig = silc_message_get_signature(payload);
-/*
-    if (sig) {
-      if (silc_message_signed_verify(sig, payload, client->public_key,
-                                    client->sha1hash) != SILC_AUTH_OK)
-       silc_say_error(("Could not verify signature in message"));
-    }
-*/
+
+    verified = verify_message_signature(sender, sig, payload);
   }
   
   if (flags & SILC_MESSAGE_FLAG_DATA) {
@@ -224,6 +306,8 @@ void silc_channel_message(SilcClient client, SilcClientConnection conn,
   if (!message)
     return;
 
+  /* FIXME: replace those printformat calls with signals and add signature
+            information to them (if present) */
   if (flags & SILC_MESSAGE_FLAG_ACTION)
     printformat_module("fe-common/silc", server, channel->channel_name,
                       MSGLEVEL_ACTIONS, SILCTXT_CHANNEL_ACTION, 
@@ -245,18 +329,30 @@ void silc_channel_message(SilcClient client, SilcClientConnection conn,
 
       silc_utf8_decode(message, message_len, SILC_STRING_LANGUAGE,
                       cp, message_len);
-      signal_emit("message public", 6, server, cp,
-                 nick == NULL ? "[<unknown>]" : nick->nick,
-                 nick == NULL ? "" : nick->host == NULL ? "" : nick->host,
-                 chanrec->name, nick);
+      if (flags & SILC_MESSAGE_FLAG_SIGNED)
+        signal_emit("message signed_public", 6, server, cp,
+                   nick == NULL ? "[<unknown>]" : nick->nick,
+                   nick == NULL ? "" : nick->host == NULL ? "" : nick->host,
+                   chanrec->name, verified);
+      else
+        signal_emit("message public", 6, server, cp,
+                   nick == NULL ? "[<unknown>]" : nick->nick,
+                   nick == NULL ? "" : nick->host == NULL ? "" : nick->host,
+                   chanrec->name, nick);
       silc_free(dm);
       return;
     }
 
-    signal_emit("message public", 6, server, message,
-               nick == NULL ? "[<unknown>]" : nick->nick,
-               nick == NULL ? "" : nick->host == NULL ? "" : nick->host,
-               chanrec->name, nick);
+    if (flags & SILC_MESSAGE_FLAG_SIGNED)
+      signal_emit("message signed_public", 6, server, message,
+                 nick == NULL ? "[<unknown>]" : nick->nick,
+                 nick == NULL ? "" : nick->host == NULL ? "" : nick->host,
+                 chanrec->name, verified);
+    else
+      signal_emit("message public", 6, server, message,
+                 nick == NULL ? "[<unknown>]" : nick->nick,
+                 nick == NULL ? "" : nick->host == NULL ? "" : nick->host,
+                 chanrec->name, nick);
   }
 }
 
@@ -271,6 +367,7 @@ void silc_private_message(SilcClient client, SilcClientConnection conn,
 {
   SILC_SERVER_REC *server;
   char userhost[256];
+  int verified = 0;
   
   SILC_LOG_DEBUG(("Start"));
 
@@ -283,9 +380,8 @@ void silc_private_message(SilcClient client, SilcClientConnection conn,
   /* If the messages is digitally signed, verify it, if possible. */
   if (flags & SILC_MESSAGE_FLAG_SIGNED) {
     SilcMessageSignedPayload sig = silc_message_get_signature(payload);
-    if (sig) {
 
-    }
+    verified = verify_message_signature(sender, sig, payload);
   }
   
   if (flags & SILC_MESSAGE_FLAG_DATA) {
@@ -329,16 +425,26 @@ void silc_private_message(SilcClient client, SilcClientConnection conn,
 
     silc_utf8_decode(message, message_len, SILC_STRING_LANGUAGE,
                     cp, message_len);
-    signal_emit("message private", 4, server, cp,
-               sender->nickname ? sender->nickname : "[<unknown>]",
-               sender->username ? userhost : NULL);
+    if (flags & SILC_MESSAGE_FLAG_SIGNED)
+      signal_emit("message signed_private", 5, server, cp,
+                 sender->nickname ? sender->nickname : "[<unknown>]",
+                 sender->username ? userhost : NULL, verified);
+    else
+      signal_emit("message private", 4, server, cp,
+                 sender->nickname ? sender->nickname : "[<unknown>]",
+                 sender->username ? userhost : NULL);
     silc_free(dm);
     return;
   }
 
-  signal_emit("message private", 4, server, message,
-             sender->nickname ? sender->nickname : "[<unknown>]",
-             sender->username ? userhost : NULL);
+  if (flags & SILC_MESSAGE_FLAG_SIGNED)
+    signal_emit("message signed_private", 5, server, message,
+               sender->nickname ? sender->nickname : "[<unknown>]",
+               sender->username ? userhost : NULL, verified);
+  else
+    signal_emit("message private", 4, server, message,
+               sender->nickname ? sender->nickname : "[<unknown>]",
+               sender->username ? userhost : NULL);
 }
 
 /* Notify message to the client. The notify arguments are sent in the

diff --git a/apps/irssi/src/silc/core/silc-core.h b/apps/irssi/src/silc/core/silc-core.h
index 0ae04ab2e9bbcba20d5f2904a08365a1bc5597b2..594c3ffe91cdeef96e7aad034ac2b5715b9b2c0d 100644 (file)
--- a/apps/irssi/src/silc/core/silc-core.h
+++ b/apps/irssi/src/silc/core/silc-core.h
@@ -29,4 +29,8 @@ extern SilcClient silc_client;
 
 #define IS_SILC_ITEM(rec) (IS_SILC_CHANNEL(rec) || IS_SILC_QUERY(rec))
 
+#define SILC_MSG_SIGNED_VERIFIED 0
+#define SILC_MSG_SIGNED_UNKNOWN 1
+#define SILC_MSG_SIGNED_FAILED 2
+
 #endif

diff --git a/apps/irssi/src/silc/core/silc-servers.c b/apps/irssi/src/silc/core/silc-servers.c
index ec9addf4d63855481927169da2684a24a5d70eb4..bb77b016f0bc00870ecf582a810821599785938d 100644 (file)
--- a/apps/irssi/src/silc/core/silc-servers.c
+++ b/apps/irssi/src/silc/core/silc-servers.c
@@ -559,7 +559,7 @@ static void command_smsg(const char *data, SILC_SERVER_REC *server,
   }
 
   signal_emit(target != NULL && target_type == SEND_TARGET_CHANNEL ?
-             "message own_public" : "message own_private", 4,
+             "message signed_own_public" : "message signed_own_private", 4,
              server, msg, target, origtarget);
 
   if (free_ret && target != NULL) g_free(target);