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, 30 insertions, 0 deletions

diff --git a/g10/encrypt.c b/g10/encrypt.c
index 66f49f4a0..ee2f07851 100644
--- a/g10/encrypt.c
+++ b/g10/encrypt.c
@@ -38,6 +38,7 @@
 #include "../common/i18n.h"
 #include "../common/status.h"
 #include "pkglue.h"
+#include "../common/compliance.h"
 
 
 static int encrypt_simple( const char *filename, int mode, int use_seskey );
@@ -612,6 +613,35 @@ encrypt_crypt (ctrl_t ctrl, int filefd, const char *filename,
       cfx.dek->algo = opt.def_cipher_algo;
     }
 
+  /* Check compliance.  */
+  if (! gnupg_cipher_is_allowed (opt.compliance, 1, cfx.dek->algo,
+                                 GCRY_CIPHER_MODE_CFB))
+    {
+      log_error (_ ("you may not use cipher algorithm '%s'"
+		    " while in %s mode\n"),
+		 openpgp_cipher_algo_name (cfx.dek->algo),
+		 gnupg_compliance_option_string (opt.compliance));
+      rc = gpg_error (GPG_ERR_CIPHER_ALGO);
+      goto leave;
+    }
+
+  {
+    pk_list_t pkr;
+    for (pkr = pk_list; pkr; pkr = pkr->next)
+      {
+        PKT_public_key *pk = pkr->pk;
+        if (! gnupg_pk_is_allowed (opt.compliance, PK_USE_ENCRYPTION, pk->pubkey_algo,
+                                   pk->pkey, nbits_from_pk (pk), NULL))
+          {
+            log_error ("key %s not suitable for encryption while in %s mode\n",
+                       keystr_from_pk (pk),
+                       gnupg_compliance_option_string (opt.compliance));
+            rc = gpg_error (GPG_ERR_PUBKEY_ALGO);
+            goto leave;
+          }
+      }
+  }
+
   cfx.dek->use_mdc = use_mdc (pk_list,cfx.dek->algo);
 
   /* Only do the is-file-already-compressed check if we are using a