X.509: parse public key parameters from x509 for akcipher

Some public key algorithms (like EC-DSA) keep in parameters field
important data such as digest and curve OIDs (possibly more for
different EC-DSA variants). Thus, just setting a public key (as
for RSA) is not enough.

Append parameters into the key stream for akcipher_set_{pub,priv}_key.
Appended data is: (u32) algo OID, (u32) parameters length, parameters
data.

This does not affect current akcipher API nor RSA ciphers (they could
ignore it). Idea of appending parameters to the key stream is by Herbert
Xu.

Cc: David Howells <dhowells@redhat.com>
Cc: Denis Kenzior <denkenz@gmail.com>
Cc: keyrings@vger.kernel.org
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 14 insertions, 8 deletions

diff --git a/include/crypto/akcipher.h b/include/crypto/akcipher.h
index 2d26939fff51..8884046659a0 100644
--- a/include/crypto/akcipher.h
+++ b/include/crypto/akcipher.h
@@ -74,10 +74,10 @@ struct crypto_akcipher {
  *		operation
  * @set_pub_key: Function invokes the algorithm specific set public key
  *		function, which knows how to decode and interpret
- *		the BER encoded public key
+ *		the BER encoded public key and parameters
  * @set_priv_key: Function invokes the algorithm specific set private key
  *		function, which knows how to decode and interpret
- *		the BER encoded private key
+ *		the BER encoded private key and parameters
  * @max_size:	Function returns dest buffer size required for a given key.
  * @init:	Initialize the cryptographic transformation object.
  *		This function is used to initialize the cryptographic
@@ -379,11 +379,12 @@ static inline int crypto_akcipher_verify(struct akcipher_request *req)
  * crypto_akcipher_set_pub_key() - Invoke set public key operation
  *
  * Function invokes the algorithm specific set key function, which knows
- * how to decode and interpret the encoded key
+ * how to decode and interpret the encoded key and parameters
  *
  * @tfm:	tfm handle
- * @key:	BER encoded public key
- * @keylen:	length of the key
+ * @key:	BER encoded public key, algo OID, paramlen, BER encoded
+ *		parameters
+ * @keylen:	length of the key (not including other data)
  *
  * Return: zero on success; error code in case of error
  */
@@ -400,11 +401,12 @@ static inline int crypto_akcipher_set_pub_key(struct crypto_akcipher *tfm,
  * crypto_akcipher_set_priv_key() - Invoke set private key operation
  *
  * Function invokes the algorithm specific set key function, which knows
- * how to decode and interpret the encoded key
+ * how to decode and interpret the encoded key and parameters
  *
  * @tfm:	tfm handle
- * @key:	BER encoded private key
- * @keylen:	length of the key
+ * @key:	BER encoded private key, algo OID, paramlen, BER encoded
+ *		parameters
+ * @keylen:	length of the key (not including other data)
  *
  * Return: zero on success; error code in case of error
  */
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index be626eac9113..712fe1214b5f 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -15,6 +15,7 @@
 #define _LINUX_PUBLIC_KEY_H
 
 #include <linux/keyctl.h>
+#include <linux/oid_registry.h>
 
 /*
  * Cryptographic data for the public-key subtype of the asymmetric key type.
@@ -25,6 +26,9 @@
 struct public_key {
 	void *key;
 	u32 keylen;
+	enum OID algo;
+	void *params;
+	u32 paramlen;
 	bool key_is_private;
 	const char *id_type;
 	const char *pkey_algo;