gpg: Stop early when trying to create a primary Elgamal key.

* g10/misc.c (openpgp_pk_test_algo2): Add extra check.
--

The problem is that --key-gen --batch with a parameter file didn't
detect that Elgamal is not capable of signing and so an error was only
triggered at the time the self-signature was created.  See the code
comment for details.

GnuPG-bug-id: 4329
Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2019-01-22 10:06:15 +01:00
parent e6d613711a
commit f97dc55ff1
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
1 changed files with 7 additions and 0 deletions

View File

@ -723,6 +723,13 @@ openpgp_pk_test_algo2 (pubkey_algo_t algo, unsigned int use)
if (!ga)
return gpg_error (GPG_ERR_PUBKEY_ALGO);
/* Elgamal in OpenPGP used to support signing and Libgcrypt still
* does. However, we removed the signing capability from gpg ages
* ago. This function should reflect this so that errors are thrown
* early and not only when we try to sign using Elgamal. */
if (ga == GCRY_PK_ELG && (use & (PUBKEY_USAGE_CERT | PUBKEY_USAGE_SIG)))
return gpg_error (GPG_ERR_WRONG_PUBKEY_ALGO);
/* Now check whether Libgcrypt has support for the algorithm. */
return gcry_pk_algo_info (ga, GCRYCTL_TEST_ALGO, NULL, &use_buf);
}