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gnupg
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2003-08-18 Timo Schulz <twoaday@freakmail.de> 

* encode.c (encode_sesskey): Checked the code and removed
        the warning since all compatibility checks with PGP succeeded.
        * mainproc.c (symkey_decrypt_sesskey): Better check for the
        algorithm and check the return values of some functions.
This commit is contained in:
Timo Schulz 2003-08-18 21:25:03 +00:00
parent 4eb5165019
commit 73b5da4c7d
3 changed files with 64 additions and 49 deletions
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7
g10/ChangeLog
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@ -1,3 +1,10 @@
2003-08-18 Timo Schulz <twoaday@freakmail.de>
* encode.c (encode_sesskey): Checked the code and removed
the warning since all compatibility checks with PGP succeeded.
* mainproc.c (symkey_decrypt_sesskey): Better check for the
algorithm and check the return values of some functions.
2003-08-07 Werner Koch <wk@gnupg.org> 2003-08-07 Werner Koch <wk@gnupg.org>
* pkglue.c (pk_sign): Fix last change. * pkglue.c (pk_sign): Fix last change.

47
g10/encode.c
View File

@ -78,34 +78,37 @@ encode_store( const char *filename )
} }
static void static void
encode_sesskey( DEK *dek, DEK **ret_dek, byte *enckey ) encode_sesskey (DEK * dek, DEK ** ret_dek, byte * enckey)
{ {
#warning This functions needs a review. CIPHER_HANDLE hd;
CIPHER_HANDLE hd; DEK * c;
DEK *c; byte buf[33];
byte buf[33];
assert ( dek->keylen < 32 ); assert (dek->keylen < 32);
c = xcalloc (1, sizeof *c ); c = xcalloc (1, sizeof *c);
c->keylen = dek->keylen; c->keylen = dek->keylen;
c->algo = dek->algo; c->algo = dek->algo;
make_session_key( c ); make_session_key (c);
/*log_hexdump( "thekey", c->key, c->keylen );*/ /*log_hexdump ("thekey", c->key, c->keylen);*/
buf[0] = c->algo; /* the encrypted session key is prefixed with a one-octet algorithm id */
memcpy( buf + 1, c->key, c->keylen ); buf[0] = c->algo;
memcpy (buf + 1, c->key, c->keylen);
/* due to the fact that we use only checked values, consider each
failure 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_encrypt (hd, buf, c->keylen + 1, NULL, 0);
gcry_cipher_close (hd);
gcry_cipher_open (&hd, dek->algo, GCRY_CIPHER_MODE_CFB, 1 ); memcpy (enckey, buf, c->keylen + 1);
gcry_cipher_setkey( hd, dek->key, dek->keylen ); wipememory (buf, sizeof buf); /* burn key */
gcry_cipher_setiv( hd, NULL, 0 ); *ret_dek = c;
gcry_cipher_encrypt( hd, buf, c->keylen + 1, NULL, 0 );
gcry_cipher_close( hd );
memcpy( enckey, buf, c->keylen + 1 );
wipememory( buf, sizeof buf ); /* burn key */
*ret_dek = c;
} }
/* We try very hard to use a MDC */ /* We try very hard to use a MDC */

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