# HG changeset patch
# User Mikael Berthe <mikael@lilotux.net>
# Date 1165061504 -3600
# Node ID a5dc85fdebdedaa53f4d5672132abb394b9efb95
# Parent  6de60e142372e1f7bd76dc6aa92c194958373d2e
Add key comparison for signatures & use user-provided PGP keys for encryption
When we receive a signed presence/message, we check that the key used matches
the one which has been set with "/pgp setkey".
If provided, we use this key for encryption too.

diff -r 6de60e142372 -r a5dc85fdebde mcabber/src/jabglue.c
--- a/mcabber/src/jabglue.c	Sat Dec 02 12:45:17 2006 +0100
+++ b/mcabber/src/jabglue.c	Sat Dec 02 13:11:44 2006 +0100
@@ -544,21 +544,29 @@
   // which hopefully will give us the most likely resource.
   if (rname)
     rname++;
-#endif
 
 #ifdef HAVE_GPGME
   if (type == ROSTER_TYPE_USER && sl_buddy && gpg_enabled()) {
     if (!settings_pgp_getdisabled(barejid)) { // disabled for this contact?
       struct pgp_data *res_pgpdata;
       res_pgpdata = buddy_resource_pgp(sl_buddy->data, rname);
-      if (res_pgpdata && res_pgpdata->sign_keyid)
-        enc = gpg_encrypt(text, res_pgpdata->sign_keyid);
+      if (res_pgpdata && res_pgpdata->sign_keyid) {
+        /* Remote client has PGP support (we have a signature).
+         * If the contact has a specific KeyId, we'll use it;
+         * if not, we'll use the key used for the signature.
+         * Both keys should match, in theory (cf. XEP-0027). */
+        const char *key;
+        key = settings_pgp_getkeyid(barejid);
+        if (!key)
+          key = res_pgpdata->sign_keyid;
+        enc = gpg_encrypt(text, key);
+      }
     }
   }
-#endif
-#if defined HAVE_GPGME || defined JEP0022 || defined JEP0085
+#endif // HAVE_GPGME
+
   g_free(barejid);
-#endif
+#endif // HAVE_GPGME || defined JEP0022 || defined JEP0085
 
   x = jutil_msgnew(strtype, (char*)fjid, NULL,
                    (enc ? "This message is PGP-encrypted." : (char*)text));
@@ -1479,11 +1487,22 @@
 
   key = gpg_verify(p, text, &sigsum);
   if (key) {
+    const char *expectedkey;
+    char *buf;
     g_free(res_pgpdata->sign_keyid);
     res_pgpdata->sign_keyid = key;
     res_pgpdata->last_sigsum = sigsum;
     if (sigsum & GPGME_SIGSUM_RED) {
-      char *buf = g_strdup_printf("Bad signature from <%s/%s>", barejid, rname);
+      buf = g_strdup_printf("Bad signature from <%s/%s>", barejid, rname);
+      scr_WriteIncomingMessage(barejid, buf, 0, HBB_PREFIX_INFO);
+      scr_LogPrint(LPRINT_LOGNORM, "%s", buf);
+      g_free(buf);
+    }
+    // Verify that the key id is the one we expect.
+    expectedkey = settings_pgp_getkeyid(barejid);
+    if (expectedkey && strcasecmp(key, expectedkey)) {
+      buf = g_strdup_printf("Warning: The KeyId from <%s/%s> doesn't match "
+                            "the key you set up", barejid, rname);
       scr_WriteIncomingMessage(barejid, buf, 0, HBB_PREFIX_INFO);
       scr_LogPrint(LPRINT_LOGNORM, "%s", buf);
       g_free(buf);