diff options
Diffstat (limited to 'g10/encrypt.c')
| -rw-r--r-- | g10/encrypt.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/g10/encrypt.c b/g10/encrypt.c index a021c0e07..388c3db74 100644 --- a/g10/encrypt.c +++ b/g10/encrypt.c @@ -538,6 +538,17 @@ setup_symkey (STRING2KEY **symkey_s2k, DEK **symkey_dek) int s2kdigest; defcipher = default_cipher_algo (); + if (openpgp_cipher_blocklen (defcipher) < 16 + && !opt.flags.allow_old_cipher_algos) + { + log_error (_("cipher algorithm '%s' may not be used for encryption\n"), + openpgp_cipher_algo_name (defcipher)); + if (!opt.quiet) + log_info (_("(use option \"%s\" to override)\n"), + "--allow-old-cipher-algos"); + return gpg_error (GPG_ERR_CIPHER_ALGO); + } + if (!gnupg_cipher_is_allowed (opt.compliance, 1, defcipher, GCRY_CIPHER_MODE_CFB)) { @@ -741,10 +752,18 @@ encrypt_crypt (ctrl_t ctrl, int filefd, const char *filename, entry for 3DES, and the pk_list cannot be empty. In this case, use 3DES anyway as it's the safest choice - perhaps the v3 key is being used in an OpenPGP implementation and we know - that the implementation behind any v4 key can handle 3DES. */ + that the implementation behind any v4 key can handle 3DES. + Note that we do not support v3 keys since version 2.2 so the + above description gives only historical background. */ if (cfx.dek->algo == -1) { - cfx.dek->algo = CIPHER_ALGO_3DES; + /* If does not make sense to fallback to the rfc4880 + * required 3DES if we will reject that algo later. Thus we + * fallback to AES anticipating RFC4880bis rules. */ + if (opt.flags.allow_old_cipher_algos) + cfx.dek->algo = CIPHER_ALGO_3DES; + else + cfx.dek->algo = CIPHER_ALGO_AES; } /* In case 3DES has been selected, print a warning if any key @@ -770,6 +789,18 @@ encrypt_crypt (ctrl_t ctrl, int filefd, const char *filename, cfx.dek->algo = opt.def_cipher_algo; } + if (openpgp_cipher_blocklen (cfx.dek->algo) < 16 + && !opt.flags.allow_old_cipher_algos) + { + log_error (_("cipher algorithm '%s' may not be used for encryption\n"), + openpgp_cipher_algo_name (cfx.dek->algo)); + if (!opt.quiet) + log_info (_("(use option \"%s\" to override)\n"), + "--allow-old-cipher-algos"); + rc = gpg_error (GPG_ERR_CIPHER_ALGO); + goto leave; + } + /* Check compliance. */ if (! gnupg_cipher_is_allowed (opt.compliance, 1, cfx.dek->algo, GCRY_CIPHER_MODE_CFB)) |