[PATCH V4 01/15] asymmetric keys: add interface and skeleton for implement signature generation

From: Lee, Chun-Yi
Date: Sat Sep 14 2013 - 21:01:10 EST


Add generate_signature interface on signature.c, asymmetric-subtype and
rsa.c for prepare to implement signature generation.

Reviewed-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Lee, Chun-Yi <jlee@xxxxxxxx>
---
crypto/asymmetric_keys/private_key.h | 29 +++++++++++++++++++++++++++++
crypto/asymmetric_keys/public_key.c | 31 +++++++++++++++++++++++++++++++
crypto/asymmetric_keys/rsa.c | 22 ++++++++++++++++++++++
crypto/asymmetric_keys/signature.c | 28 ++++++++++++++++++++++++++++
include/crypto/public_key.h | 25 +++++++++++++++++++++++++
include/keys/asymmetric-subtype.h | 6 ++++++
6 files changed, 141 insertions(+), 0 deletions(-)
create mode 100644 crypto/asymmetric_keys/private_key.h

diff --git a/crypto/asymmetric_keys/private_key.h b/crypto/asymmetric_keys/private_key.h
new file mode 100644
index 0000000..c022eee
--- /dev/null
+++ b/crypto/asymmetric_keys/private_key.h
@@ -0,0 +1,29 @@
+/* Private key algorithm internals
+ *
+ * Copyright (C) 2013 SUSE Linux Products GmbH. All rights reserved.
+ * Written by Chun-Yi Lee (jlee@xxxxxxxx)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <crypto/public_key.h>
+
+extern struct asymmetric_key_subtype private_key_subtype;
+
+/*
+ * Private key algorithm definition.
+ */
+struct private_key_algorithm {
+ const char *name;
+ u8 n_pub_mpi; /* Number of MPIs in public key */
+ u8 n_sec_mpi; /* Number of MPIs in secret key */
+ u8 n_sig_mpi; /* Number of MPIs in a signature */
+ struct public_key_signature* (*generate_signature)(
+ const struct private_key *key, u8 *M,
+ enum pkey_hash_algo hash_algo, const bool hash);
+};
+
+extern const struct private_key_algorithm RSA_private_key_algorithm;
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index cb2e291..80c19cd 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -19,6 +19,7 @@
#include <linux/seq_file.h>
#include <keys/asymmetric-subtype.h>
#include "public_key.h"
+#include "private_key.h"

MODULE_LICENSE("GPL");

@@ -96,6 +97,24 @@ static int public_key_verify_signature(const struct key *key,
}

/*
+ * Generate a signature using a private key.
+ */
+static struct public_key_signature *private_key_generate_signature(
+ const struct key *key, u8 *M, enum pkey_hash_algo hash_algo,
+ const bool hash)
+{
+ const struct private_key *pk = key->payload.data;
+
+ pr_info("private_key_generate_signature start\n");
+
+ if (!pk->algo->generate_signature)
+ return ERR_PTR(-ENOTSUPP);
+
+ return pk->algo->generate_signature(pk, M, hash_algo, hash);
+
+}
+
+/*
* Public key algorithm asymmetric key subtype
*/
struct asymmetric_key_subtype public_key_subtype = {
@@ -106,3 +125,15 @@ struct asymmetric_key_subtype public_key_subtype = {
.verify_signature = public_key_verify_signature,
};
EXPORT_SYMBOL_GPL(public_key_subtype);
+
+/*
+ * Private key algorithm asymmetric key subtype
+ */
+struct asymmetric_key_subtype private_key_subtype = {
+ .owner = THIS_MODULE,
+ .name = "private_key",
+ .describe = public_key_describe,
+ .destroy = public_key_destroy,
+ .generate_signature = private_key_generate_signature,
+};
+EXPORT_SYMBOL_GPL(private_key_subtype);
diff --git a/crypto/asymmetric_keys/rsa.c b/crypto/asymmetric_keys/rsa.c
index 4a6a069..47f3be4 100644
--- a/crypto/asymmetric_keys/rsa.c
+++ b/crypto/asymmetric_keys/rsa.c
@@ -14,6 +14,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include "public_key.h"
+#include "private_key.h"

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RSA Public Key Algorithm");
@@ -267,6 +268,18 @@ error:
return ret;
}

+/*
+ * Perform the generation step [RFC3447 sec 8.2.1].
+ */
+static struct public_key_signature *RSA_generate_signature(
+ const struct private_key *key, u8 *M,
+ enum pkey_hash_algo hash_algo, const bool hash)
+{
+ pr_info("RSA_generate_signature start\n");
+
+ return 0;
+}
+
const struct public_key_algorithm RSA_public_key_algorithm = {
.name = "RSA",
.n_pub_mpi = 2,
@@ -275,3 +288,12 @@ const struct public_key_algorithm RSA_public_key_algorithm = {
.verify_signature = RSA_verify_signature,
};
EXPORT_SYMBOL_GPL(RSA_public_key_algorithm);
+
+const struct private_key_algorithm RSA_private_key_algorithm = {
+ .name = "RSA",
+ .n_pub_mpi = 2,
+ .n_sec_mpi = 3,
+ .n_sig_mpi = 1,
+ .generate_signature = RSA_generate_signature,
+};
+EXPORT_SYMBOL_GPL(RSA_private_key_algorithm);
diff --git a/crypto/asymmetric_keys/signature.c b/crypto/asymmetric_keys/signature.c
index 50b3f88..a1bf6be 100644
--- a/crypto/asymmetric_keys/signature.c
+++ b/crypto/asymmetric_keys/signature.c
@@ -47,3 +47,31 @@ int verify_signature(const struct key *key,
return ret;
}
EXPORT_SYMBOL_GPL(verify_signature);
+
+/**
+ * generate_signature - Initiate the use of an asymmetric key to generate a signature
+ * @key: The asymmetric key to generate against
+ * @M: The message to be signed, or a hash result. Dependent on the hash parameter
+ * @hash_algo: The hash algorithm to generate digest
+ * @hash: true means M is a original mesagse, false means M is a hash result
+ *
+ * Returns public_key-signature if successful or else an error.
+ */
+struct public_key_signature *generate_signature(const struct key *key, u8 *M,
+ enum pkey_hash_algo hash_algo, const bool hash)
+{
+ const struct asymmetric_key_subtype *subtype;
+
+ pr_info("==>%s()\n", __func__);
+
+ if (key->type != &key_type_asymmetric)
+ return ERR_PTR(-EINVAL);
+ subtype = asymmetric_key_subtype(key);
+ if (!subtype || !key->payload.data)
+ return ERR_PTR(-EINVAL);
+ if (!subtype->generate_signature)
+ return ERR_PTR(-ENOTSUPP);
+
+ return subtype->generate_signature(key, M, hash_algo, hash);
+}
+EXPORT_SYMBOL_GPL(generate_signature);
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index f5b0224..d44b29f 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -79,6 +79,29 @@ struct public_key {
};
};

+struct private_key {
+ const struct private_key_algorithm *algo;
+ u8 capabilities;
+ enum pkey_id_type id_type:8;
+ union {
+ MPI mpi[5];
+ struct {
+ MPI p; /* DSA prime */
+ MPI q; /* DSA group order */
+ MPI g; /* DSA group generator */
+ MPI y; /* DSA public-key value = g^x mod p */
+ MPI x; /* DSA secret exponent (if present) */
+ } dsa;
+ struct {
+ MPI n; /* RSA public modulus */
+ MPI e; /* RSA public encryption exponent */
+ MPI d; /* RSA secret encryption exponent (if present) */
+ MPI p; /* RSA secret prime (if present) */
+ MPI q; /* RSA secret prime (if present) */
+ } rsa;
+ };
+};
+
extern void public_key_destroy(void *payload);

/*
@@ -104,5 +127,7 @@ struct public_key_signature {
struct key;
extern int verify_signature(const struct key *key,
const struct public_key_signature *sig);
+extern struct public_key_signature *generate_signature(const struct key *key,
+ u8 *M, enum pkey_hash_algo hash_algo, const bool hash);

#endif /* _LINUX_PUBLIC_KEY_H */
diff --git a/include/keys/asymmetric-subtype.h b/include/keys/asymmetric-subtype.h
index 4b840e8..af79939 100644
--- a/include/keys/asymmetric-subtype.h
+++ b/include/keys/asymmetric-subtype.h
@@ -18,6 +18,7 @@
#include <keys/asymmetric-type.h>

struct public_key_signature;
+enum pkey_hash_algo;

/*
* Keys of this type declare a subtype that indicates the handlers and
@@ -37,6 +38,11 @@ struct asymmetric_key_subtype {
/* Verify the signature on a key of this subtype (optional) */
int (*verify_signature)(const struct key *key,
const struct public_key_signature *sig);
+
+ /* Generate the signature by key of this subtype (optional) */
+ struct public_key_signature* (*generate_signature)
+ (const struct key *key, u8 *M, enum pkey_hash_algo hash_algo,
+ const bool hash);
};

/**
--
1.6.0.2

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