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gpg: Fix flaw in symmetric algorithm selection in mixed mode. 

* g10/encrypt.c (setup_symkey): Use default_cipher_algo function
instead of the fallback s2k_cipher_algo.  Fix error code.
(encrypt_simple): Use setup_symkey.
--

Aside of removing code duplication this patch fixes the flaw that the
S2K cipher algorithm was used when mixing public key and symmetric
encryption or signatures with symmetric encrypion.  The
default_algorithm function should be used here so that the command
line option --cipher-algo and --personal-cipher-preferences have an
effect.

Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2020-07-07 12:58:29 +02:00
parent 969abcf40c
commit 6864bba78e
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
3 changed files with 10 additions and 18 deletions
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24
g10/encrypt.c
View File

@ -319,19 +319,11 @@ encrypt_simple (const char *filename, int mode, int use_seskey)
cfx.dek = NULL;
if ( mode )
{
int canceled;
aead_algo_t aead_algo;
s2k = xmalloc_clear( sizeof *s2k );
s2k->mode = opt.s2k_mode;
s2k->hash_algo = S2K_DIGEST_ALGO;
cfx.dek = passphrase_to_dek (default_cipher_algo (), s2k, 1, 0,
NULL, &canceled);
if ( !cfx.dek || !cfx.dek->keylen )
rc = setup_symkey (&s2k, &cfx.dek);
if (rc)
{
rc = gpg_error (canceled? GPG_ERR_CANCELED:GPG_ERR_INV_PASSPHRASE);
xfree (cfx.dek);
xfree (s2k);
iobuf_close (inp);
log_error (_("error creating passphrase: %s\n"), gpg_strerror (rc));
release_progress_context (pfx);
@ -534,22 +526,22 @@ encrypt_simple (const char *filename, int mode, int use_seskey)
}
int
setup_symkey (STRING2KEY **symkey_s2k,DEK **symkey_dek)
gpg_error_t
setup_symkey (STRING2KEY **symkey_s2k, DEK **symkey_dek)
{
int canceled;
*symkey_s2k=xmalloc_clear(sizeof(STRING2KEY));
*symkey_s2k = xmalloc_clear (sizeof **symkey_s2k);
(*symkey_s2k)->mode = opt.s2k_mode;
(*symkey_s2k)->hash_algo = S2K_DIGEST_ALGO;
*symkey_dek = passphrase_to_dek (opt.s2k_cipher_algo,
*symkey_dek = passphrase_to_dek (default_cipher_algo (),
*symkey_s2k, 1, 0, NULL, &canceled);
if(!*symkey_dek || !(*symkey_dek)->keylen)
if (!*symkey_dek || !(*symkey_dek)->keylen)
{
xfree(*symkey_dek);
xfree(*symkey_s2k);
return gpg_error (canceled?GPG_ERR_CANCELED:GPG_ERR_BAD_PASSPHRASE);
return gpg_error (canceled?GPG_ERR_CANCELED:GPG_ERR_INV_PASSPHRASE);
}
return 0;

2
g10/main.h
View File

@ -234,7 +234,7 @@ int cpr_get_answer_okay_cancel (const char *keyword,
void display_online_help( const char *keyword );
/*-- encode.c --*/
int setup_symkey (STRING2KEY **symkey_s2k,DEK **symkey_dek);
gpg_error_t setup_symkey (STRING2KEY **symkey_s2k,DEK **symkey_dek);
gpg_error_t encrypt_seskey (DEK *dek, aead_algo_t aead_algo, DEK **r_seskey,
void **r_enckey, size_t *r_enckeylen);
aead_algo_t use_aead (pk_list_t pk_list, int algo);

2
g10/passphrase.c
View File

@ -268,7 +268,7 @@ passphrase_to_dek (int cipher_algo, STRING2KEY *s2k,
*canceled = 0;
if (opt.no_symkey_cache)
nocache = 1; /* Force no symmtric key caching. */
nocache = 1; /* Force no symmetric key caching. */
if ( !s2k )
{