gnutls_x509_privkey_generate*: allow specifying the SPKI parameters for key generation

This in turn removes the need for reading the flag GNUTLS_PRIVKEY_FLAG_REPRODUCIBLE
on the key generation process. The flag is now only used during key signing
which is also its documented purpose.

Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>

3 files changed, 26 insertions, 16 deletions

diff --git a/lib/includes/gnutls/x509.h b/lib/includes/gnutls/x509.h
index d0a0da14cb..3175dcff8f 100644
--- a/lib/includes/gnutls/x509.h
+++ b/lib/includes/gnutls/x509.h
@@ -1209,12 +1209,14 @@ void gnutls_x509_privkey_set_flags(gnutls_x509_privkey_t key, unsigned int flags
  * gnutls_keygen_types_t:
  * @GNUTLS_KEYGEN_SEED: Specifies the seed to be used in key generation.
  * @GNUTLS_KEYGEN_DIGEST: The size field specifies the hash algorithm to be used in key generation.
+ * @GNUTLS_KEYGEN_SPKI: data points to a %gnutls_x509_spki_t structure; it is not used after the key generation call.
  *
  * Enumeration of different key exchange algorithms.
  */
 typedef enum {
 	GNUTLS_KEYGEN_SEED = 1,
 	GNUTLS_KEYGEN_DIGEST = 2,
+	GNUTLS_KEYGEN_SPKI = 3
 } gnutls_keygen_types_t;
 
 typedef struct {
diff --git a/lib/privkey.c b/lib/privkey.c
index 543886eef0..2011ca8a45 100644
--- a/lib/privkey.c
+++ b/lib/privkey.c
@@ -345,10 +345,10 @@ _gnutls_privkey_update_spki_params(gnutls_privkey_t key,
 			salt_size = params->salt_size;
 		}
 
-		if (!(flags & GNUTLS_PRIVKEY_FLAG_REPRODUCIBLE))
-			salt_size = _gnutls_find_rsa_pss_salt_size(bits, me, salt_size);
-
-		params->salt_size = salt_size;
+		if (flags & GNUTLS_PRIVKEY_FLAG_REPRODUCIBLE)
+			params->salt_size = 0;
+		else
+			params->salt_size = _gnutls_find_rsa_pss_salt_size(bits, me, salt_size);
 		params->rsa_pss_dig = dig;
 	}
 
diff --git a/lib/x509/privkey.c b/lib/x509/privkey.c
index c5236223df..cc3c72d7a8 100644
--- a/lib/x509/privkey.c
+++ b/lib/x509/privkey.c
@@ -1619,6 +1619,9 @@ gnutls_x509_privkey_generate(gnutls_x509_privkey_t key,
  * For DSA keys, if the subgroup size needs to be specified check
  * the GNUTLS_SUBGROUP_TO_BITS() macro.
  *
+ * When generating RSA-PSS keys which should require specific parameters, you should
+ * use @data of type %GNUTLS_KEYGEN_SPKI to specify the SubjectPublicKeyInfo parameters.
+ *
  * Do not set the number of bits directly, use gnutls_sec_param_to_pk_bits().
  *
  * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
@@ -1631,6 +1634,7 @@ gnutls_x509_privkey_generate2(gnutls_x509_privkey_t key,
 {
 	int ret;
 	unsigned i;
+	gnutls_x509_spki_t tpki = NULL;
 
 	if (key == NULL) {
 		gnutls_assert();
@@ -1645,6 +1649,8 @@ gnutls_x509_privkey_generate2(gnutls_x509_privkey_t key,
 			memcpy(key->params.seed, data[i].data, data[i].size);
 		} else if (data[i].type == GNUTLS_KEYGEN_DIGEST) {
 			key->params.palgo = data[i].size;
+		} else if (data[i].type == GNUTLS_KEYGEN_SPKI) {
+			tpki = (void*)data[i].data;
 		}
 	}
 
@@ -1672,14 +1678,12 @@ gnutls_x509_privkey_generate2(gnutls_x509_privkey_t key,
 		return ret;
 	}
 
-	if (algo == GNUTLS_PK_RSA_PSS && (flags & GNUTLS_PRIVKEY_FLAG_CA)) {
+	if (algo == GNUTLS_PK_RSA_PSS && (flags & GNUTLS_PRIVKEY_FLAG_CA) &&
+	    !key->params.spki.pk) {
 		const mac_entry_st *me;
-
 		key->params.spki.pk = GNUTLS_PK_RSA_PSS;
-		if (key->params.palgo != GNUTLS_DIG_UNKNOWN)
-			key->params.spki.rsa_pss_dig = key->params.palgo;
-		else
-			key->params.spki.rsa_pss_dig = _gnutls_pk_bits_to_sha_hash(bits);
+
+		key->params.spki.rsa_pss_dig = _gnutls_pk_bits_to_sha_hash(bits);
 
 		me = hash_to_entry(key->params.spki.rsa_pss_dig);
 		if (unlikely(me == NULL)) {
@@ -1688,12 +1692,8 @@ gnutls_x509_privkey_generate2(gnutls_x509_privkey_t key,
 			goto cleanup;
 		}
 
-		if (flags & GNUTLS_PRIVKEY_FLAG_REPRODUCIBLE)
-			key->params.spki.salt_size = 0;
-		else {
-			key->params.spki.salt_size =
-			    _gnutls_find_rsa_pss_salt_size(bits, me, 0);
-		}
+		key->params.spki.salt_size =
+		    _gnutls_find_rsa_pss_salt_size(bits, me, 0);
 	}
 
 	ret = _gnutls_pk_generate_keys(algo, bits, &key->params, 0);
@@ -1708,6 +1708,14 @@ gnutls_x509_privkey_generate2(gnutls_x509_privkey_t key,
 		goto cleanup;
 	}
 
+	if (tpki) {
+		ret = gnutls_x509_privkey_set_spki(key, tpki, 0);
+		if (ret < 0) {
+			gnutls_assert();
+			goto cleanup;
+		}
+	}
+
 	ret = _gnutls_asn1_encode_privkey(&key->key, &key->params, key->flags&GNUTLS_PRIVKEY_FLAG_EXPORT_COMPAT);
 	if (ret < 0) {
 		gnutls_assert();