diff options
Diffstat (limited to 'g10/mainproc.c')
| -rw-r--r-- | g10/mainproc.c | 59 |
1 files changed, 32 insertions, 27 deletions
diff --git a/g10/mainproc.c b/g10/mainproc.c index 969c65066..3689525ef 100644 --- a/g10/mainproc.c +++ b/g10/mainproc.c @@ -239,37 +239,42 @@ add_signature( CTX c, PACKET *pkt ) } static void -symkey_decrypt_sesskey( DEK *dek, byte *sesskey, size_t slen ) +symkey_decrypt_sesskey (DEK * dek, byte *sesskey, size_t slen) { - CIPHER_HANDLE hd; - int n; + CIPHER_HANDLE hd; + int n; - if ( slen < 17 || slen > 33 ) { - log_error ( _("weird size for an encrypted session key (%d)\n"), - (int)slen); - return; + if (slen < 17 || slen > 33) + { + log_error ( _("weird size for an encrypted session key (%d)\n"), + (int)slen); + return; } - gcry_cipher_open ( &hd, dek->algo, GCRY_CIPHER_MODE_CFB, 1 ); - gcry_cipher_setkey( hd, dek->key, dek->keylen ); - gcry_cipher_setiv( hd, NULL, 0 ); - gcry_cipher_decrypt( hd, sesskey, slen, NULL, 0); - gcry_cipher_close( hd ); - /* check first byte (the cipher algo) */ - if ( sesskey[0] > 10 ) { - log_error ( _("invalid symkey algorithm detected (%d)\n"), - sesskey[0] ); - return; + /* we checked the DEK values before, so consider all errors as fatal */ + if (gcry_cipher_open (&hd, dek->algo, GCRY_CIPHER_MODE_CFB, 1)) + BUG(); + if (gcry_cipher_setkey (hd, dek->key, dek->keylen)) + BUG(); + gcry_cipher_setiv (hd, NULL, 0); + gcry_cipher_decrypt (hd, sesskey, slen, NULL, 0); + gcry_cipher_close (hd); + /* check first byte (the cipher algo) */ + if (openpgp_cipher_test_algo (sesskey[0])) + { + log_error (_("invalid symkey algorithm detected (%d)\n"), + sesskey[0]); + return; } - n = gcry_cipher_get_algo_keylen (sesskey[0]); - if (n > DIM(dek->key)) - BUG (); - /* now we replace the dek components with the real session key - to decrypt the contents of the sequencing packet. */ - dek->keylen = gcry_cipher_get_algo_keylen (sesskey[0]); - dek->algo = sesskey[0]; - memcpy (dek->key, sesskey + 1, dek->keylen); - /*log_hexdump( "thekey", dek->key, dek->keylen );*/ -} + n = gcry_cipher_get_algo_keylen (sesskey[0]); + if (n > DIM(dek->key)) + BUG (); + /* now we replace the dek components with the real session key + to decrypt the contents of the sequencing packet. */ + dek->keylen = n; + dek->algo = sesskey[0]; + memcpy (dek->key, sesskey + 1, dek->keylen); + /*log_hexdump ("thekey", dek->key, dek->keylen);*/ +} static void proc_symkey_enc( CTX c, PACKET *pkt ) |