KEYS: Move the algorithm pointer array from x509 to public_key.c

Move the public-key algorithm pointer array from x509_public_key.c to
public_key.c as it isn't X.509 specific.

Note that to make this configure correctly, the public key part must be
dependent on the RSA module rather than the other way round.  This needs a
further patch to make use of the crypto module loading stuff rather than using
a fixed table.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>

crypto/asymmetric_keys/Kconfig

@@ -12,6 +12,7 @@ if ASYMMETRIC_KEY_TYPE
 config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 	tristate "Asymmetric public-key crypto algorithm subtype"
 	select MPILIB
+	select PUBLIC_KEY_ALGO_RSA
 	help
 	  This option provides support for asymmetric public key type handling.
 	  If signature generation and/or verification are to be used,
@@ -20,7 +21,6 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 
 config PUBLIC_KEY_ALGO_RSA
 	tristate "RSA public-key algorithm"
-	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 	select MPILIB_EXTRA
 	help
 	  This option enables support for the RSA algorithm (PKCS#1, RFC3447).

crypto/asymmetric_keys/public_key.c

@@ -28,6 +28,14 @@ const char *const pkey_algo_name[PKEY_ALGO__LAST] = {
 };
 EXPORT_SYMBOL_GPL(pkey_algo_name);
 
+const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST] = {
+#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \
+	defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE)
+	[PKEY_ALGO_RSA]		= &RSA_public_key_algorithm,
+#endif
+};
+EXPORT_SYMBOL_GPL(pkey_algo);
+
 const char *const pkey_hash_algo_name[PKEY_HASH__LAST] = {
 	[PKEY_HASH_MD4]		= "md4",
 	[PKEY_HASH_MD5]		= "md5",

crypto/asymmetric_keys/x509_public_key.c

@@ -23,15 +23,6 @@
 #include "public_key.h"
 #include "x509_parser.h"
 
-static const
-struct public_key_algorithm *x509_public_key_algorithms[PKEY_ALGO__LAST] = {
-	[PKEY_ALGO_DSA]		= NULL,
-#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \
-	defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE)
-	[PKEY_ALGO_RSA]		= &RSA_public_key_algorithm,
-#endif
-};
-
 /*
  * Check the signature on a certificate using the provided public key
  */
@@ -174,7 +165,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 		goto error_free_cert;
 	}
 
-	cert->pub->algo = x509_public_key_algorithms[cert->pkey_algo];
+	cert->pub->algo = pkey_algo[cert->pkey_algo];
 	cert->pub->id_type = PKEY_ID_X509;
 
 	/* Check the signature on the key */

include/crypto/public_key.h

@@ -23,6 +23,7 @@ enum pkey_algo {
 };
 
 extern const char *const pkey_algo_name[PKEY_ALGO__LAST];
+extern const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST];
 
 enum pkey_hash_algo {
 	PKEY_HASH_MD4,