From 973c868961233686b4072c56f641ec70ba27f783 Mon Sep 17 00:00:00 2001
From: David Shaw <dshaw@jabberwocky.com>
Date: Thu, 27 Nov 2003 13:53:34 +0000
Subject: [PATCH] * keygen.c (ask_algo): Remove ability to generate Elgamal
 sign+encrypt keys.

* getkey.c (merge_selfsigs_main, merge_selfsigs_subkey): Disallow use of
sign+encrypt Elgamal keys.
---
 g10/ChangeLog |  8 ++++++++
 g10/getkey.c  | 12 ++++++++++++
 g10/keygen.c  | 29 ++++++-----------------------
 3 files changed, 26 insertions(+), 23 deletions(-)

diff --git a/g10/ChangeLog b/g10/ChangeLog
index 1fb7bfbb0..8e74aaa8f 100644
--- a/g10/ChangeLog
+++ b/g10/ChangeLog
@@ -1,3 +1,11 @@
+2003-11-27  David Shaw  <dshaw@jabberwocky.com>
+
+	* keygen.c (ask_algo): Remove ability to generate Elgamal
+	sign+encrypt keys.
+
+	* getkey.c (merge_selfsigs_main, merge_selfsigs_subkey): Disallow
+	use of sign+encrypt Elgamal keys.
+
 2003-11-20  David Shaw  <dshaw@jabberwocky.com>
 
 	* seskey.c (do_encode_md): Comment about earlier (pre-PGP 2.3)
diff --git a/g10/getkey.c b/g10/getkey.c
index 72b80ba76..d1be8e51e 100644
--- a/g10/getkey.c
+++ b/g10/getkey.c
@@ -1677,6 +1677,11 @@ merge_selfsigs_main( KBNODE keyblock, int *r_revoked )
         if ( x ) /* mask it down to the actual allowed usage */
             key_usage &= x; 
     }
+
+    /* Type 20 Elgamal keys are not usable. */
+    if(pk->pubkey_algo==PUBKEY_ALGO_ELGAMAL)
+      key_usage=0;
+
     pk->pubkey_usage = key_usage;
 
     if ( !key_expire_seen ) {
@@ -1893,6 +1898,13 @@ merge_selfsigs_subkey( KBNODE keyblock, KBNODE subnode )
         if ( x ) /* mask it down to the actual allowed usage */
             key_usage &= x; 
     }
+
+    /* Type 20 Elgamal subkeys or any subkey on a type 20 primary are
+       not usable. */
+    if(mainpk->pubkey_algo==PUBKEY_ALGO_ELGAMAL
+       || subpk->pubkey_algo==PUBKEY_ALGO_ELGAMAL)
+      key_usage=0;
+
     subpk->pubkey_usage = key_usage;
     
     p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_KEY_EXPIRE, NULL);
diff --git a/g10/keygen.c b/g10/keygen.c
index 51354af4c..6b8cf0ecd 100644
--- a/g10/keygen.c
+++ b/g10/keygen.c
@@ -1052,13 +1052,11 @@ ask_algo (int addmode, unsigned int *r_usage)
     tty_printf(    _("   (%d) DSA (sign only)\n"), 2 );
     if( addmode )
 	tty_printf(    _("   (%d) ElGamal (encrypt only)\n"), 3 );
-    if (opt.expert)
-        tty_printf(    _("   (%d) ElGamal (sign and encrypt)\n"), 4 );
-    tty_printf(    _("   (%d) RSA (sign only)\n"), 5 );
+    tty_printf(    _("   (%d) RSA (sign only)\n"), 4 );
     if (addmode)
-        tty_printf(    _("   (%d) RSA (encrypt only)\n"), 6 );
+        tty_printf(    _("   (%d) RSA (encrypt only)\n"), 5 );
     if (opt.expert)
-      tty_printf(    _("   (%d) RSA (sign and encrypt)\n"), 7 );
+      tty_printf(    _("   (%d) RSA (sign and encrypt)\n"), 6 );
 
     for(;;) {
 	answer = cpr_get("keygen.algo",_("Your selection? "));
@@ -1069,36 +1067,21 @@ ask_algo (int addmode, unsigned int *r_usage)
 	    algo = 0;	/* create both keys */
 	    break;
 	}
-	else if( algo == 7 && opt.expert ) {
+	else if( algo == 6 && opt.expert ) {
 	    algo = PUBKEY_ALGO_RSA;
 	    *r_usage = PUBKEY_USAGE_ENC | PUBKEY_USAGE_SIG;
 	    break;
 	}
-	else if( algo == 6 && addmode ) {
+	else if( algo == 5 && addmode ) {
 	    algo = PUBKEY_ALGO_RSA;
             *r_usage = PUBKEY_USAGE_ENC;
 	    break;
 	}
-	else if( algo == 5 ) {
+	else if( algo == 4 ) {
 	    algo = PUBKEY_ALGO_RSA;
             *r_usage = PUBKEY_USAGE_SIG;
 	    break;
 	}
-	else if( algo == 4 && opt.expert)
-	  {
-	    tty_printf(_(
-"The use of this algorithm is only supported by GnuPG.  You will not be\n"
-"able to use this key to communicate with PGP users.  This algorithm is also\n"
-"very slow, and may not be as secure as the other choices.\n"));
-
-	    if( cpr_get_answer_is_yes("keygen.algo.elg_se",
-				      _("Create anyway? ")))
-	      {
-		algo = PUBKEY_ALGO_ELGAMAL;
-		*r_usage = PUBKEY_USAGE_ENC | PUBKEY_USAGE_SIG;
-		break;
-	      }
-	}
 	else if( algo == 3 && addmode ) {
 	    algo = PUBKEY_ALGO_ELGAMAL_E;
             *r_usage = PUBKEY_USAGE_ENC;