[PATCH] fips: Skip PCT if RSA keygen test-parms specified

[Clemens Lang]

* cipher/rsa.c (rsa_generate): Skip PCT is test-parms were specified.
* tests/t-rsa-testparm.c: Add test for this functionality
* tests/Makefile.am: Add test to build system

--

ACVP testing uses the test-parms option to specify p and q to be checked
for primality. When test-parms is specified, generate_fips() always
returns keys with p=q=0. These keys then fail the pairwise consistency
test, because they cannot be used to successfully sign a message and
verify the signature.

Skip the PCT when test-parms is specified.

Add a regression test to check that this functionality continues to work
in the future.

Signed-off-by: Clemens Lang <cllang at redhat.com>
---
 cipher/rsa.c           |   5 +-
 tests/Makefile.am      |   2 +-
 tests/t-rsa-testparm.c | 130 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 135 insertions(+), 2 deletions(-)
 create mode 100644 tests/t-rsa-testparm.c

diff --git a/cipher/rsa.c b/cipher/rsa.c
index 87f57b55..1a935d80 100644
--- a/cipher/rsa.c
+++ b/cipher/rsa.c
@@ -1218,6 +1218,7 @@ rsa_generate (const gcry_sexp_t genparms, gcry_sexp_t *r_skey)
   int flags = 0;
   gcry_sexp_t l1;
   gcry_sexp_t swap_info = NULL;
+  int testparms = 0;
 
   memset (&sk, 0, sizeof sk);
 
@@ -1274,6 +1275,8 @@ rsa_generate (const gcry_sexp_t genparms, gcry_sexp_t *r_skey)
         }
       deriveparms = (genparms? sexp_find_token (genparms, "test-parms", 0)
                      /**/    : NULL);
+      if (deriveparms)
+        testparms = 1;
 
       /* Generate.  */
       if (deriveparms || fips_mode ())
@@ -1311,7 +1314,7 @@ rsa_generate (const gcry_sexp_t genparms, gcry_sexp_t *r_skey)
   mpi_free (sk.u);
   sexp_release (swap_info);
 
-  if (!ec && fips_mode () && test_keys_fips (*r_skey))
+  if (!ec && !testparms && fips_mode () && test_keys_fips (*r_skey))
     {
       sexp_release (*r_skey); *r_skey = NULL;
       fips_signal_error ("self-test after key generation failed");
diff --git a/tests/Makefile.am b/tests/Makefile.am
index f65725bc..302d923b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -28,7 +28,7 @@ tests_bin = \
 	aeswrap random
 
 if USE_RSA
-tests_bin += pkcs1v2 t-rsa-pss t-rsa-15
+tests_bin += pkcs1v2 t-rsa-pss t-rsa-15 t-rsa-testparm
 endif
 
 if USE_DSA
diff --git a/tests/t-rsa-testparm.c b/tests/t-rsa-testparm.c
new file mode 100644
index 00000000..65617855
--- /dev/null
+++ b/tests/t-rsa-testparm.c
@@ -0,0 +1,130 @@
+/* t-rsa-testparm.c - Check the RSA Key Generation test-parm parameter
+ * Copyright (C) 2022 g10 Code GmbH
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Libgcrypt is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * Libgcrypt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <gcrypt.h>
+
+#include "stopwatch.h"
+
+#define PGM "t-rsa-testparm"
+#include "t-common.h"
+
+
+static void
+check_rsa_testparm ()
+{
+  gpg_error_t err;
+  gcry_sexp_t keyspec = NULL;
+  gcry_sexp_t key = NULL;
+  const char *sexp = "(genkey (rsa (nbits \"2048\") (test-parms "
+    "(e \"65537\")"
+    "(p #00bbccabcee15d343944a47e492d4b1f4de79633e20cbb46f7d2d6813392a807ad048"
+        "cf77528edd19f77e7453f25173b9dcb70423afa2037aae147b81a33d541fc58f875ef"
+        "f1e852ab55e2e09a3debfbc151b3b0d17fef6f74d81fca14fbae531418e211ef81859"
+        "2af70de5cec3b92795cc3578572bf456099cd8727150e523261#)"
+    "(q #00ca87ecf2883f4ed00a9ec65abdeba81d28edbfcc34ecc563d587f166b52d42bfbe2"
+        "2bbc095b0b8426a2f8bbc55baaa8859b42cbc376ed3067db3ef7b135b63481322911e"
+        "bbd7014db83aa051e0ca2dbf302b75cd37f2ae8df90e134226e92f6353a284b28bb30"
+        "af0bbf925b345b955328379866ebac11d55bc80fe84f105d415#)"
+    ")))";
+
+  info ("Checking RSA KeyGen test-parm parameter.\n");
+
+  err = gcry_sexp_build (&keyspec, NULL, sexp);
+  if (err)
+    {
+      fail ("error building SEXP for test: %s", gpg_strerror (err));
+      goto leave;
+    }
+
+  err = gcry_pk_genkey (&key, keyspec);
+  if (err)
+    {
+      fail ("gcry_pk_genkey failed for test: %s", gpg_strerror (err));
+      goto leave;
+    }
+
+leave:
+  if (key)
+    gcry_sexp_release (key);
+  if (keyspec)
+    gcry_sexp_release (keyspec);
+}
+
+
+int
+main (int argc, char **argv)
+{
+  int last_argc = -1;
+
+  if (argc)
+    { argc--; argv++; }
+
+  while (argc && last_argc != argc )
+    {
+      last_argc = argc;
+      if (!strcmp (*argv, "--"))
+        {
+          argc--; argv++;
+          break;
+        }
+      else if (!strcmp (*argv, "--help"))
+        {
+          fputs ("usage: " PGM " [options]\n"
+                 "Options:\n"
+                 "  --verbose       print timings etc.\n"
+                 "  --debug         flyswatter\n",
+                 stdout);
+          exit (0);
+        }
+      else if (!strcmp (*argv, "--verbose"))
+        {
+          verbose++;
+          argc--; argv++;
+        }
+      else if (!strcmp (*argv, "--debug"))
+        {
+          verbose += 2;
+          debug++;
+          argc--; argv++;
+        }
+      else if (!strncmp (*argv, "--", 2))
+        die ("unknown option '%s'", *argv);
+
+    }
+
+  xgcry_control ((GCRYCTL_DISABLE_SECMEM, 0));
+  if (!gcry_check_version (GCRYPT_VERSION))
+    die ("version mismatch\n");
+  if (debug)
+    xgcry_control ((GCRYCTL_SET_DEBUG_FLAGS, 0xffffffff, 0));
+
+  start_timer ();
+  check_rsa_testparm ();
+  stop_timer ();
+
+  info ("All tests completed in %s.  Errors: %d\n",
+        elapsed_time (1), error_count);
+  return !!error_count;
+}
-- 
2.37.3