diff options
Diffstat (limited to 'g10/pkclist.c')
| -rw-r--r-- | g10/pkclist.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/g10/pkclist.c b/g10/pkclist.c index 9847e0f8f..5678c99f1 100644 --- a/g10/pkclist.c +++ b/g10/pkclist.c @@ -926,17 +926,40 @@ build_pk_list( STRLIST remusr, PK_LIST *ret_pk_list, unsigned use ) } +/* In pgp6 mode, disallow all ciphers except IDEA (1), 3DES (2), and + CAST5 (3), all hashes except MD5 (1), SHA1 (2), and RIPEMD160 (3), + and all compressions except none (0) and ZIP (1). For a true PGP6 + key all of this is unneeded as they are the only items present in + the preferences subpacket, but checking here covers the weird case + of encrypting to a key that had preferences from a different + implementation which was then used with PGP6. I am not completely + comfortable with this as the right thing to do, as it slightly + alters the list of what the user is supposedly requesting. It is + not against the RFC however, as the preference chosen will never be + one that the user didn't specify somewhere ("The implementation may + use any mechanism to pick an algorithm in the intersection"), and + PGP6 has no mechanism to fix such a broken preference list, so I'm + including it. -dms */ static int algo_available( int preftype, int algo ) { if( preftype == PREFTYPE_SYM ) { + if( opt.pgp6 && ( algo != 1 && algo != 2 && algo != 3) ) + return 0; + return algo && !check_cipher_algo( algo ); } else if( preftype == PREFTYPE_HASH ) { + if( opt.pgp6 && ( algo != 1 && algo != 2 && algo != 3) ) + return 0; + return algo && !check_digest_algo( algo ); } else if( preftype == PREFTYPE_ZIP ) { + if ( opt.pgp6 && ( algo !=0 && algo != 1) ) + return 0; + return !algo || algo == 1 || algo == 2; } else @@ -1080,5 +1103,3 @@ select_mdc_from_pklist (PK_LIST pk_list) } return 1; /* can be used */ } - - |