common,gpg,sm: Restrict the use of algorithms according to CO_DE_VS.

* common/compliance.c (gnupg_pk_is_allowed): New function.
(gnupg_cipher_is_allowed): Likewise.
(gnupg_digest_is_allowed): Likewise.
* common/compliance.h (enum pk_use_case): New definition.
(gnupg_pk_is_allowed): New prototype.
(gnupg_cipher_is_allowed): Likewise.
(gnupg_digest_is_allowed): Likewise.
* g10/decrypt-data.c (decrypt_data): Restrict use of algorithms using
the new predicates.
* g10/encrypt.c (encrypt_crypt): Likewise.
* g10/gpg.c (main): Likewise.
* g10/pubkey-enc.c (get_session_key): Likewise.
* g10/sig-check.c (check_signature2): Likewise.
* g10/sign.c (do_sign): Likewise.
* sm/decrypt.c (gpgsm_decrypt): Likewise.
* sm/encrypt.c (gpgsm_encrypt): Likewise.
* sm/gpgsm.c (main): Likewise.
* sm/sign.c (gpgsm_sign): Likewise.
* sm/verify.c (gpgsm_verify): Likewise.
--

With this change, policies can effectively restrict what algorithms
are used for different purposes.  The algorithm policy for CO_DE_VS is
implemented.

GnuPG-bug-id: 3191
Signed-off-by: Justus Winter <[email protected]>

1 files changed, 27 insertions, 0 deletions

diff --git a/sm/sign.c b/sm/sign.c
index e65562d54..2fbee7516 100644
--- a/sm/sign.c
+++ b/sm/sign.c
@@ -460,6 +460,33 @@ gpgsm_sign (ctrl_t ctrl, certlist_t signerlist,
           break;
         }
       cl->hash_algo_oid = oid;
+
+      /* Check compliance.  */
+      if (! gnupg_digest_is_allowed (opt.compliance, 1, cl->hash_algo))
+        {
+          log_error (_ ("you may not use digest algorithm '%s'"
+                        " while in %s mode\n"),
+                     gcry_md_algo_name (cl->hash_algo),
+                     gnupg_compliance_option_string (opt.compliance));
+          err = gpg_error (GPG_ERR_DIGEST_ALGO);
+          goto leave;
+        }
+
+      {
+        unsigned int nbits;
+        int pk_algo = gpgsm_get_key_algo_info (cl->cert, &nbits);
+
+        if (! gnupg_pk_is_allowed (opt.compliance, PK_USE_SIGNING, pk_algo,
+                                   NULL, nbits, NULL))
+          {
+            log_error ("certificate ID 0x%08lX not suitable for "
+                       "signing while in %s mode\n",
+                       gpgsm_get_short_fingerprint (cl->cert, NULL),
+                       gnupg_compliance_option_string (opt.compliance));
+            err = gpg_error (GPG_ERR_PUBKEY_ALGO);
+            goto leave;
+          }
+      }
     }
 
   if (opt.verbose)