[gnutls-devel] [PATCH 2/2] pkcs11: implement correct DSA key pair generating

[Jan Vcelak]

Signed-off-by: Jan Vcelak <jan.vcelak at nic.cz>
---
 lib/pkcs11_privkey.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 59 insertions(+), 4 deletions(-)

diff --git a/lib/pkcs11_privkey.c b/lib/pkcs11_privkey.c
index fa4acb4..531f646 100644
--- a/lib/pkcs11_privkey.c
+++ b/lib/pkcs11_privkey.c
@@ -657,6 +657,58 @@ gnutls_pkcs11_privkey_generate2(const char *url, gnutls_pk_algorithm_t pk,
 
 static const char def_rsa_pub_exp[3] = { 1,0,1 }; // 65537 = 0x10001
 
+struct dsa_params {
+	/* FIPS 186-3 maximal size for L and N length pair is (3072,256). */
+	uint8_t prime[384];
+	uint8_t subprime[32];
+	uint8_t generator[384];
+};
+
+static int
+_dsa_params_generate(struct ck_function_list *module, ck_session_handle_t session,
+		     unsigned long bits, struct dsa_params *params,
+		     struct ck_attribute *a, int *a_val)
+{
+	struct ck_mechanism mech = { CKM_DSA_PARAMETER_GEN };
+	struct ck_attribute attr = { CKA_PRIME_BITS, &bits, sizeof(bits) };
+	ck_object_handle_t key;
+	ck_rv_t rv;
+
+	/* Generate DSA parameters from prime length. */
+
+	rv = pkcs11_generate_key(module, session, &mech, &attr, 1, &key);
+	if (rv != CKR_OK) {
+		gnutls_assert();
+		_gnutls_debug_log("p11: %s\n", pkcs11_strerror(rv));
+		return pkcs11_rv_to_err(rv);
+	}
+
+	/* Retrieve generated parameters to be used with the new key pair. */
+
+	a[*a_val + 0].type = CKA_PRIME;
+	a[*a_val + 0].value = params->prime;
+	a[*a_val + 0].value_len = sizeof(params->prime);
+
+	a[*a_val + 1].type = CKA_SUBPRIME;
+	a[*a_val + 1].value = params->subprime;
+	a[*a_val + 1].value_len = sizeof(params->subprime);
+
+	a[*a_val + 2].type = CKA_BASE;
+	a[*a_val + 2].value = params->generator;
+	a[*a_val + 2].value_len = sizeof(params->generator);
+
+	rv = pkcs11_get_attribute_value(module, session, key, &a[*a_val], 3);
+	if (rv != CKR_OK) {
+		gnutls_assert();
+		_gnutls_debug_log("p11: %s\n", pkcs11_strerror(rv));
+		return pkcs11_rv_to_err(rv);
+	}
+
+	*a_val += 3;
+
+	return 0;
+}
+
 /**
  * gnutls_pkcs11_privkey_generate3:
  * @url: a token URL
@@ -709,6 +761,7 @@ gnutls_pkcs11_privkey_generate3(const char *url, gnutls_pk_algorithm_t pk,
 	gnutls_datum_t der = {NULL, 0};
 	ck_key_type_t key_type;
 	uint8_t id[20];
+	struct dsa_params dsa_params;
 
 	PKCS11_CHECK_INIT;
 	FIX_KEY_USAGE(pk, key_usage);
@@ -831,10 +884,12 @@ gnutls_pkcs11_privkey_generate3(const char *url, gnutls_pk_algorithm_t pk,
 		a[a_val].value_len = sizeof(tval);
 		a_val++;
 
-		a[a_val].type = CKA_MODULUS_BITS;
-		a[a_val].value = &_bits;
-		a[a_val].value_len = sizeof(_bits);
-		a_val++;
+		ret = _dsa_params_generate(sinfo.module, sinfo.pks, _bits,
+					   &dsa_params, a, &a_val);
+		if (ret < 0) {
+			goto cleanup;
+		}
+
 		break;
 	case GNUTLS_PK_EC:
 		p[p_val].type = CKA_SIGN;
-- 
2.5.0