Commit a9681bf3 authored by David Howells's avatar David Howells Committed by Rusty Russell

KEYS: Asymmetric public-key algorithm crypto key subtype

Add a subtype for supporting asymmetric public-key encryption algorithms such
as DSA (FIPS-186) and RSA (PKCS#1 / RFC1337).
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 46c6f177
......@@ -9,5 +9,13 @@ menuconfig ASYMMETRIC_KEY_TYPE
if ASYMMETRIC_KEY_TYPE
config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
tristate "Asymmetric public-key crypto algorithm subtype"
select MPILIB
help
This option provides support for asymmetric public key type handling.
If signature generation and/or verification are to be used,
appropriate hash algorithms (such as SHA-1) must be available.
ENOPKG will be reported if the requisite algorithm is unavailable.
endif # ASYMMETRIC_KEY_TYPE
......@@ -5,3 +5,5 @@
obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += asymmetric_keys.o
asymmetric_keys-y := asymmetric_type.o
obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
/* In-software asymmetric public-key crypto subtype
*
* See Documentation/crypto/asymmetric-keys.txt
*
* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* 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.
*/
#define pr_fmt(fmt) "PKEY: "fmt
#include <linux/module.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <keys/asymmetric-subtype.h>
#include "public_key.h"
MODULE_LICENSE("GPL");
const char *const pkey_algo[PKEY_ALGO__LAST] = {
[PKEY_ALGO_DSA] = "DSA",
[PKEY_ALGO_RSA] = "RSA",
};
EXPORT_SYMBOL_GPL(pkey_algo);
const char *const pkey_hash_algo[PKEY_HASH__LAST] = {
[PKEY_HASH_MD4] = "md4",
[PKEY_HASH_MD5] = "md5",
[PKEY_HASH_SHA1] = "sha1",
[PKEY_HASH_RIPE_MD_160] = "rmd160",
[PKEY_HASH_SHA256] = "sha256",
[PKEY_HASH_SHA384] = "sha384",
[PKEY_HASH_SHA512] = "sha512",
[PKEY_HASH_SHA224] = "sha224",
};
EXPORT_SYMBOL_GPL(pkey_hash_algo);
const char *const pkey_id_type[PKEY_ID_TYPE__LAST] = {
[PKEY_ID_PGP] = "PGP",
[PKEY_ID_X509] = "X509",
};
EXPORT_SYMBOL_GPL(pkey_id_type);
/*
* Provide a part of a description of the key for /proc/keys.
*/
static void public_key_describe(const struct key *asymmetric_key,
struct seq_file *m)
{
struct public_key *key = asymmetric_key->payload.data;
if (key)
seq_printf(m, "%s.%s",
pkey_id_type[key->id_type], key->algo->name);
}
/*
* Destroy a public key algorithm key.
*/
void public_key_destroy(void *payload)
{
struct public_key *key = payload;
int i;
if (key) {
for (i = 0; i < ARRAY_SIZE(key->mpi); i++)
mpi_free(key->mpi[i]);
kfree(key);
}
}
EXPORT_SYMBOL_GPL(public_key_destroy);
/*
* Verify a signature using a public key.
*/
static int public_key_verify_signature(const struct key *key,
const struct public_key_signature *sig)
{
const struct public_key *pk = key->payload.data;
if (!pk->algo->verify_signature)
return -ENOTSUPP;
if (sig->nr_mpi != pk->algo->n_sig_mpi) {
pr_debug("Signature has %u MPI not %u\n",
sig->nr_mpi, pk->algo->n_sig_mpi);
return -EINVAL;
}
return pk->algo->verify_signature(pk, sig);
}
/*
* Public key algorithm asymmetric key subtype
*/
struct asymmetric_key_subtype public_key_subtype = {
.owner = THIS_MODULE,
.name = "public_key",
.describe = public_key_describe,
.destroy = public_key_destroy,
.verify_signature = public_key_verify_signature,
};
EXPORT_SYMBOL_GPL(public_key_subtype);
/* Public key algorithm internals
*
* See Documentation/crypto/asymmetric-keys.txt
*
* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* 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 public_key_subtype;
/*
* Public key algorithm definition.
*/
struct public_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 */
int (*verify_signature)(const struct public_key *key,
const struct public_key_signature *sig);
};
/* Asymmetric public-key algorithm definitions
*
* See Documentation/crypto/asymmetric-keys.txt
*
* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* 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.
*/
#ifndef _LINUX_PUBLIC_KEY_H
#define _LINUX_PUBLIC_KEY_H
#include <linux/mpi.h>
enum pkey_algo {
PKEY_ALGO_DSA,
PKEY_ALGO_RSA,
PKEY_ALGO__LAST
};
extern const char *const pkey_algo[PKEY_ALGO__LAST];
enum pkey_hash_algo {
PKEY_HASH_MD4,
PKEY_HASH_MD5,
PKEY_HASH_SHA1,
PKEY_HASH_RIPE_MD_160,
PKEY_HASH_SHA256,
PKEY_HASH_SHA384,
PKEY_HASH_SHA512,
PKEY_HASH_SHA224,
PKEY_HASH__LAST
};
extern const char *const pkey_hash_algo[PKEY_HASH__LAST];
enum pkey_id_type {
PKEY_ID_PGP, /* OpenPGP generated key ID */
PKEY_ID_X509, /* X.509 arbitrary subjectKeyIdentifier */
PKEY_ID_TYPE__LAST
};
extern const char *const pkey_id_type[PKEY_ID_TYPE__LAST];
/*
* Cryptographic data for the public-key subtype of the asymmetric key type.
*
* Note that this may include private part of the key as well as the public
* part.
*/
struct public_key {
const struct public_key_algorithm *algo;
u8 capabilities;
#define PKEY_CAN_ENCRYPT 0x01
#define PKEY_CAN_DECRYPT 0x02
#define PKEY_CAN_SIGN 0x04
#define PKEY_CAN_VERIFY 0x08
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);
/*
* Public key cryptography signature data
*/
struct public_key_signature {
u8 *digest;
u8 digest_size; /* Number of bytes in digest */
u8 nr_mpi; /* Occupancy of mpi[] */
enum pkey_hash_algo pkey_hash_algo : 8;
union {
MPI mpi[2];
struct {
MPI s; /* m^d mod n */
} rsa;
struct {
MPI r;
MPI s;
} dsa;
};
};
#endif /* _LINUX_PUBLIC_KEY_H */
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment