From 74e3c5ac7dfb70a96f5e38502865b70f79cc8282 Mon Sep 17 00:00:00 2001 From: David Shaw Date: Sat, 29 Nov 2003 22:44:05 +0000 Subject: [PATCH] * revoke.c (gen_desig_revoke): Specify in the comment when a designated revocation is generated. * getkey.c (merge_selfsigs_main, merge_selfsigs_subkey, get_seckey_byname2): Disallow use of sign+encrypt Elgamal keys for anything except revocations. * sign.c (do_sign): Catchall for any Elgamal signatures except revocations. --- g10/ChangeLog | 12 +++++++++++- g10/getkey.c | 18 +++++++++++++++++- g10/revoke.c | 2 +- g10/sign.c | 6 ++++++ 4 files changed, 35 insertions(+), 3 deletions(-) diff --git a/g10/ChangeLog b/g10/ChangeLog index f542eb2ec..e3b1ecf8f 100644 --- a/g10/ChangeLog +++ b/g10/ChangeLog @@ -1,9 +1,19 @@ 2003-11-29 David Shaw + * revoke.c (gen_desig_revoke): Specify in the comment when a + designated revocation is generated. + + * getkey.c (merge_selfsigs_main, merge_selfsigs_subkey, + get_seckey_byname2): Disallow use of sign+encrypt Elgamal keys for + anything except revocations. + + * sign.c (do_sign): Catchall for any Elgamal signatures except + revocations. + * trustdb.c (validate_keys): Reset the trustdb before checking if we have any ultimately trusted keys. This ensures that if we lose all our ultimately trusted keys, we don't leave behind the - old validity calculations. + old validity calculations. Noted by Peter Palfrader. 2003-11-20 David Shaw diff --git a/g10/getkey.c b/g10/getkey.c index d8516c689..ecd3b2d02 100644 --- a/g10/getkey.c +++ b/g10/getkey.c @@ -1049,7 +1049,11 @@ get_seckey_byname2( GETKEY_CTX *retctx, ctx.items[0].mode = KEYDB_SEARCH_MODE_FIRST; rc = lookup( &ctx, &kb, 1 ); if (!rc && sk ) - sk_from_block ( &ctx, sk, kb ); + { + sk_from_block ( &ctx, sk, kb ); + if(sk->pubkey_algo==PUBKEY_ALGO_ELGAMAL) + rc=G10ERR_UNU_SECKEY; + } release_kbnode ( kb ); get_seckey_end( &ctx ); } @@ -1655,6 +1659,11 @@ 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 ) { @@ -1869,6 +1878,13 @@ 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/revoke.c b/g10/revoke.c index db73938e2..703342a97 100644 --- a/g10/revoke.c +++ b/g10/revoke.c @@ -313,7 +313,7 @@ gen_desig_revoke( const char *uname ) goto leave; afx.what = 1; - afx.hdrlines = "Comment: A revocation certificate should follow\n"; + afx.hdrlines = "Comment: A designated revocation certificate should follow\n"; iobuf_push_filter( out, armor_filter, &afx ); /* create it */ diff --git a/g10/sign.c b/g10/sign.c index 017d6800c..9c9b92440 100644 --- a/g10/sign.c +++ b/g10/sign.c @@ -266,6 +266,12 @@ do_sign( PKT_secret_key *sk, PKT_signature *sig, return G10ERR_TIME_CONFLICT; } + /* For safety, only allow revocation sigs from Elgamal + sign+encrypt keys. Note that this allows for Elgamal + designated revocations as well, but that's arguably a good + thing. */ + if(sk->pubkey_algo==PUBKEY_ALGO_ELGAMAL && sig->sig_class!=0x20) + return G10ERR_UNU_SECKEY; print_pubkey_algo_note(sk->pubkey_algo);