Commit 57f96bba authored by Tadeusz Struk's avatar Tadeusz Struk Committed by Herbert Xu

crypto: asymmetric_keys - convert public key and digsig asym to the akcipher api

This patch converts the module verification code to the new akcipher API.
Signed-off-by: default avatarTadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent b31dde2a
......@@ -22,7 +22,7 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
config PUBLIC_KEY_ALGO_RSA
tristate "RSA public-key algorithm"
select MPILIB
select CRYPTO_RSA
help
This option enables support for the RSA algorithm (PKCS#1, RFC3447).
......
......@@ -16,21 +16,18 @@ obj-$(CONFIG_X509_CERTIFICATE_PARSER) += x509_key_parser.o
x509_key_parser-y := \
x509-asn1.o \
x509_akid-asn1.o \
x509_rsakey-asn1.o \
x509_cert_parser.o \
x509_public_key.o
$(obj)/x509_cert_parser.o: \
$(obj)/x509-asn1.h \
$(obj)/x509_akid-asn1.h \
$(obj)/x509_rsakey-asn1.h
$(obj)/x509_akid-asn1.h
$(obj)/x509-asn1.o: $(obj)/x509-asn1.c $(obj)/x509-asn1.h
$(obj)/x509_akid-asn1.o: $(obj)/x509_akid-asn1.c $(obj)/x509_akid-asn1.h
$(obj)/x509_rsakey-asn1.o: $(obj)/x509_rsakey-asn1.c $(obj)/x509_rsakey-asn1.h
clean-files += x509-asn1.c x509-asn1.h
clean-files += x509_akid-asn1.c x509_akid-asn1.h
clean-files += x509_rsakey-asn1.c x509_rsakey-asn1.h
#
# PKCS#7 message handling
......
......@@ -15,7 +15,7 @@
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/oid_registry.h>
#include "public_key.h"
#include <crypto/public_key.h>
#include "pkcs7_parser.h"
#include "pkcs7-asn1.h"
......@@ -44,7 +44,7 @@ struct pkcs7_parse_context {
static void pkcs7_free_signed_info(struct pkcs7_signed_info *sinfo)
{
if (sinfo) {
mpi_free(sinfo->sig.mpi[0]);
kfree(sinfo->sig.s);
kfree(sinfo->sig.digest);
kfree(sinfo->signing_cert_id);
kfree(sinfo);
......@@ -614,16 +614,14 @@ int pkcs7_sig_note_signature(void *context, size_t hdrlen,
const void *value, size_t vlen)
{
struct pkcs7_parse_context *ctx = context;
MPI mpi;
BUG_ON(ctx->sinfo->sig.pkey_algo != PKEY_ALGO_RSA);
mpi = mpi_read_raw_data(value, vlen);
if (!mpi)
ctx->sinfo->sig.s = kmemdup(value, vlen, GFP_KERNEL);
if (!ctx->sinfo->sig.s)
return -ENOMEM;
ctx->sinfo->sig.mpi[0] = mpi;
ctx->sinfo->sig.nr_mpi = 1;
ctx->sinfo->sig.s_size = vlen;
return 0;
}
......
......@@ -17,7 +17,7 @@
#include <linux/asn1.h>
#include <linux/key.h>
#include <keys/asymmetric-type.h>
#include "public_key.h"
#include <crypto/public_key.h>
#include "pkcs7_parser.h"
/**
......
......@@ -16,7 +16,7 @@
#include <linux/err.h>
#include <linux/asn1.h>
#include <crypto/hash.h>
#include "public_key.h"
#include <crypto/public_key.h>
#include "pkcs7_parser.h"
/*
......
......@@ -18,24 +18,16 @@
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <keys/asymmetric-subtype.h>
#include "public_key.h"
#include <crypto/public_key.h>
MODULE_LICENSE("GPL");
const char *const pkey_algo_name[PKEY_ALGO__LAST] = {
[PKEY_ALGO_DSA] = "DSA",
[PKEY_ALGO_RSA] = "RSA",
[PKEY_ALGO_DSA] = "dsa",
[PKEY_ALGO_RSA] = "rsa",
};
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_id_type_name[PKEY_ID_TYPE__LAST] = {
[PKEY_ID_PGP] = "PGP",
[PKEY_ID_X509] = "X509",
......@@ -43,6 +35,12 @@ const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = {
};
EXPORT_SYMBOL_GPL(pkey_id_type_name);
static int (*alg_verify[PKEY_ALGO__LAST])(const struct public_key *pkey,
const struct public_key_signature *sig) = {
NULL,
rsa_verify_signature
};
/*
* Provide a part of a description of the key for /proc/keys.
*/
......@@ -53,7 +51,8 @@ static void public_key_describe(const struct key *asymmetric_key,
if (key)
seq_printf(m, "%s.%s",
pkey_id_type_name[key->id_type], key->algo->name);
pkey_id_type_name[key->id_type],
pkey_algo_name[key->pkey_algo]);
}
/*
......@@ -62,50 +61,31 @@ static void public_key_describe(const struct key *asymmetric_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);
}
if (key)
kfree(key->key);
kfree(key);
}
EXPORT_SYMBOL_GPL(public_key_destroy);
/*
* Verify a signature using a public key.
*/
int public_key_verify_signature(const struct public_key *pk,
int public_key_verify_signature(const struct public_key *pkey,
const struct public_key_signature *sig)
{
const struct public_key_algorithm *algo;
BUG_ON(!pk);
BUG_ON(!pk->mpi[0]);
BUG_ON(!pk->mpi[1]);
BUG_ON(!pkey);
BUG_ON(!sig);
BUG_ON(!sig->digest);
BUG_ON(!sig->mpi[0]);
algo = pk->algo;
if (!algo) {
if (pk->pkey_algo >= PKEY_ALGO__LAST)
return -ENOPKG;
algo = pkey_algo[pk->pkey_algo];
if (!algo)
return -ENOPKG;
}
BUG_ON(!sig->s);
if (!algo->verify_signature)
return -ENOTSUPP;
if (pkey->pkey_algo >= PKEY_ALGO__LAST)
return -ENOPKG;
if (sig->nr_mpi != algo->n_sig_mpi) {
pr_debug("Signature has %u MPI not %u\n",
sig->nr_mpi, algo->n_sig_mpi);
return -EINVAL;
}
if (!alg_verify[pkey->pkey_algo])
return -ENOPKG;
return algo->verify_signature(pk, sig);
return alg_verify[pkey->pkey_algo](pkey, sig);
}
EXPORT_SYMBOL_GPL(public_key_verify_signature);
......
/* 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);
};
extern const struct public_key_algorithm RSA_public_key_algorithm;
/*
* public_key.c
*/
extern int public_key_verify_signature(const struct public_key *pk,
const struct public_key_signature *sig);
......@@ -11,10 +11,10 @@
#define pr_fmt(fmt) "RSA: "fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <crypto/akcipher.h>
#include <crypto/public_key.h>
#include <crypto/algapi.h>
#include "public_key.h"
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RSA Public Key Algorithm");
......@@ -84,72 +84,10 @@ static const struct {
#undef _
};
/*
* RSAVP1() function [RFC3447 sec 5.2.2]
*/
static int RSAVP1(const struct public_key *key, MPI s, MPI *_m)
{
MPI m;
int ret;
/* (1) Validate 0 <= s < n */
if (mpi_cmp_ui(s, 0) < 0) {
kleave(" = -EBADMSG [s < 0]");
return -EBADMSG;
}
if (mpi_cmp(s, key->rsa.n) >= 0) {
kleave(" = -EBADMSG [s >= n]");
return -EBADMSG;
}
m = mpi_alloc(0);
if (!m)
return -ENOMEM;
/* (2) m = s^e mod n */
ret = mpi_powm(m, s, key->rsa.e, key->rsa.n);
if (ret < 0) {
mpi_free(m);
return ret;
}
*_m = m;
return 0;
}
/*
* Integer to Octet String conversion [RFC3447 sec 4.1]
*/
static int RSA_I2OSP(MPI x, size_t xLen, u8 **pX)
{
unsigned X_size, x_size;
int X_sign;
u8 *X;
/* Make sure the string is the right length. The number should begin
* with { 0x00, 0x01, ... } so we have to account for 15 leading zero
* bits not being reported by MPI.
*/
x_size = mpi_get_nbits(x);
pr_devel("size(x)=%u xLen*8=%zu\n", x_size, xLen * 8);
if (x_size != xLen * 8 - 15)
return -ERANGE;
X = mpi_get_buffer(x, &X_size, &X_sign);
if (!X)
return -ENOMEM;
if (X_sign < 0) {
kfree(X);
return -EBADMSG;
}
if (X_size != xLen - 1) {
kfree(X);
return -EBADMSG;
}
*pX = X;
return 0;
}
struct rsa_completion {
struct completion completion;
int err;
};
/*
* Perform the RSA signature verification.
......@@ -160,7 +98,7 @@ static int RSA_I2OSP(MPI x, size_t xLen, u8 **pX)
* @asn1_template: The DigestInfo ASN.1 template
* @asn1_size: Size of asm1_template[]
*/
static int RSA_verify(const u8 *H, const u8 *EM, size_t k, size_t hash_size,
static int rsa_verify(const u8 *H, const u8 *EM, size_t k, size_t hash_size,
const u8 *asn1_template, size_t asn1_size)
{
unsigned PS_end, T_offset, i;
......@@ -169,10 +107,10 @@ static int RSA_verify(const u8 *H, const u8 *EM, size_t k, size_t hash_size,
if (k < 2 + 1 + asn1_size + hash_size)
return -EBADMSG;
/* Decode the EMSA-PKCS1-v1_5 */
if (EM[1] != 0x01) {
kleave(" = -EBADMSG [EM[1] == %02u]", EM[1]);
/* Decode the EMSA-PKCS1-v1_5
* note: leading zeros are stirpped by the RSA implementation */
if (EM[0] != 0x01) {
kleave(" = -EBADMSG [EM[0] == %02u]", EM[0]);
return -EBADMSG;
}
......@@ -183,7 +121,7 @@ static int RSA_verify(const u8 *H, const u8 *EM, size_t k, size_t hash_size,
return -EBADMSG;
}
for (i = 2; i < PS_end; i++) {
for (i = 1; i < PS_end; i++) {
if (EM[i] != 0xff) {
kleave(" = -EBADMSG [EM[PS%x] == %02u]", i - 2, EM[i]);
return -EBADMSG;
......@@ -204,75 +142,82 @@ static int RSA_verify(const u8 *H, const u8 *EM, size_t k, size_t hash_size,
return 0;
}
/*
* Perform the verification step [RFC3447 sec 8.2.2].
*/
static int RSA_verify_signature(const struct public_key *key,
const struct public_key_signature *sig)
static void public_key_verify_done(struct crypto_async_request *req, int err)
{
size_t tsize;
int ret;
struct rsa_completion *compl = req->data;
/* Variables as per RFC3447 sec 8.2.2 */
const u8 *H = sig->digest;
u8 *EM = NULL;
MPI m = NULL;
size_t k;
if (err == -EINPROGRESS)
return;
kenter("");
if (!RSA_ASN1_templates[sig->pkey_hash_algo].data)
return -ENOTSUPP;
/* (1) Check the signature size against the public key modulus size */
k = mpi_get_nbits(key->rsa.n);
tsize = mpi_get_nbits(sig->rsa.s);
compl->err = err;
complete(&compl->completion);
}
/* According to RFC 4880 sec 3.2, length of MPI is computed starting
* from most significant bit. So the RFC 3447 sec 8.2.2 size check
* must be relaxed to conform with shorter signatures - so we fail here
* only if signature length is longer than modulus size.
*/
pr_devel("step 1: k=%zu size(S)=%zu\n", k, tsize);
if (k < tsize) {
ret = -EBADMSG;
goto error;
int rsa_verify_signature(const struct public_key *pkey,
const struct public_key_signature *sig)
{
struct crypto_akcipher *tfm;
struct akcipher_request *req;
struct rsa_completion compl;
struct scatterlist sig_sg, sg_out;
void *outbuf = NULL;
unsigned int outlen = 0;
int ret = -ENOMEM;
tfm = crypto_alloc_akcipher("rsa", 0, 0);
if (IS_ERR(tfm))
goto error_out;
req = akcipher_request_alloc(tfm, GFP_KERNEL);
if (!req)
goto error_free_tfm;
ret = crypto_akcipher_set_pub_key(tfm, pkey->key, pkey->keylen);
if (ret)
goto error_free_req;
ret = -EINVAL;
outlen = crypto_akcipher_maxsize(tfm);
if (!outlen)
goto error_free_req;
/* initlialzie out buf */
ret = -ENOMEM;
outbuf = kmalloc(outlen, GFP_KERNEL);
if (!outbuf)
goto error_free_req;
sg_init_one(&sig_sg, sig->s, sig->s_size);
sg_init_one(&sg_out, outbuf, outlen);
akcipher_request_set_crypt(req, &sig_sg, &sg_out, sig->s_size, outlen);
init_completion(&compl.completion);
akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
CRYPTO_TFM_REQ_MAY_SLEEP,
public_key_verify_done, &compl);
ret = crypto_akcipher_verify(req);
if (ret == -EINPROGRESS) {
wait_for_completion(&compl.completion);
ret = compl.err;
}
/* Round up and convert to octets */
k = (k + 7) / 8;
if (ret)
goto error_free_req;
/* (2b) Apply the RSAVP1 verification primitive to the public key */
ret = RSAVP1(key, sig->rsa.s, &m);
if (ret < 0)
goto error;
/* (2c) Convert the message representative (m) to an encoded message
* (EM) of length k octets.
*
* NOTE! The leading zero byte is suppressed by MPI, so we pass a
* pointer to the _preceding_ byte to RSA_verify()!
/*
* Output from the operation is an encoded message (EM) of
* length k octets.
*/
ret = RSA_I2OSP(m, k, &EM);
if (ret < 0)
goto error;
ret = RSA_verify(H, EM - 1, k, sig->digest_size,
outlen = req->dst_len;
ret = rsa_verify(sig->digest, outbuf, outlen, sig->digest_size,
RSA_ASN1_templates[sig->pkey_hash_algo].data,
RSA_ASN1_templates[sig->pkey_hash_algo].size);
error:
kfree(EM);
mpi_free(m);
kleave(" = %d", ret);
error_free_req:
akcipher_request_free(req);
error_free_tfm:
crypto_free_akcipher(tfm);
error_out:
kfree(outbuf);
return ret;
}
const struct public_key_algorithm RSA_public_key_algorithm = {
.name = "RSA",
.n_pub_mpi = 2,
.n_sec_mpi = 3,
.n_sig_mpi = 1,
.verify_signature = RSA_verify_signature,
};
EXPORT_SYMBOL_GPL(RSA_public_key_algorithm);
EXPORT_SYMBOL_GPL(rsa_verify_signature);
......@@ -15,11 +15,10 @@
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/oid_registry.h>
#include "public_key.h"
#include <crypto/public_key.h>
#include "x509_parser.h"
#include "x509-asn1.h"
#include "x509_akid-asn1.h"
#include "x509_rsakey-asn1.h"
struct x509_parse_context {
struct x509_certificate *cert; /* Certificate being constructed */
......@@ -56,7 +55,7 @@ void x509_free_certificate(struct x509_certificate *cert)
kfree(cert->akid_id);
kfree(cert->akid_skid);
kfree(cert->sig.digest);
mpi_free(cert->sig.rsa.s);
kfree(cert->sig.s);
kfree(cert);
}
}
......@@ -103,12 +102,12 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
}
}
/* Decode the public key */
ret = asn1_ber_decoder(&x509_rsakey_decoder, ctx,
ctx->key, ctx->key_size);
if (ret < 0)
cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
if (!cert->pub->key)
goto error_decode;
cert->pub->keylen = ctx->key_size;
/* Generate cert issuer + serial number key ID */
kid = asymmetric_key_generate_id(cert->raw_serial,
cert->raw_serial_size,
......@@ -124,6 +123,7 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
return cert;
error_decode:
kfree(cert->pub->key);
kfree(ctx);
error_no_ctx:
x509_free_certificate(cert);
......@@ -404,29 +404,6 @@ int x509_extract_key_data(void *context, size_t hdrlen,
return 0;
}
/*
* Extract a RSA public key value
*/
int rsa_extract_mpi(void *context, size_t hdrlen,
unsigned char tag,
const void *value, size_t vlen)
{
struct x509_parse_context *ctx = context;
MPI mpi;
if (ctx->nr_mpi >= ARRAY_SIZE(ctx->cert->pub->mpi)) {
pr_err("Too many public key MPIs in certificate\n");
return -EBADMSG;
}
mpi = mpi_read_raw_data(value, vlen);
if (!mpi)
return -ENOMEM;
ctx->cert->pub->mpi[ctx->nr_mpi++] = mpi;
return 0;
}
/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
#define SEQ_TAG_KEYID (ASN1_CONT << 6)
......
......@@ -13,15 +13,11 @@
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/mpi.h>
#include <linux/asn1_decoder.h>
#include <keys/asymmetric-subtype.h>
#include <keys/asymmetric-parser.h>
#include <keys/system_keyring.h>
#include <crypto/hash.h>
#include "asymmetric_keys.h"
#include "public_key.h"
#include "x509_parser.h"
static bool use_builtin_keys;
......@@ -167,13 +163,15 @@ int x509_get_sig_params(struct x509_certificate *cert)
if (cert->unsupported_crypto)
return -ENOPKG;
if (cert->sig.rsa.s)
if (cert->sig.s)
return 0;
cert->sig.rsa.s = mpi_read_raw_data(cert->raw_sig, cert->raw_sig_size);
if (!cert->sig.rsa.s)
cert->sig.s = kmemdup(cert->raw_sig, cert->raw_sig_size,
GFP_KERNEL);
if (!cert->sig.s)
return -ENOMEM;
cert->sig.nr_mpi = 1;
cert->sig.s_size = cert->raw_sig_size;
/* Allocate the hashing algorithm we're going to need and find out how
* big the hash operational data will be.
......@@ -296,8 +294,6 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
if (cert->pub->pkey_algo >= PKEY_ALGO__LAST ||
cert->sig.pkey_algo >= PKEY_ALGO__LAST ||
cert->sig.pkey_hash_algo >= PKEY_HASH__LAST ||
!pkey_algo[cert->pub->pkey_algo] ||
!pkey_algo[cert->sig.pkey_algo] ||
!hash_algo_name[cert->sig.pkey_hash_algo]) {
ret = -ENOPKG;
goto error_free_cert;
......@@ -309,7 +305,6 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
pkey_algo_name[cert->sig.pkey_algo],
hash_algo_name[cert->sig.pkey_hash_algo]);
cert->pub->algo = pkey_algo[cert->pub->pkey_algo];
cert->pub->id_type = PKEY_ID_X509;
/* Check the signature on the key if it appears to be self-signed */
......
RSAPublicKey ::= SEQUENCE {
modulus INTEGER ({ rsa_extract_mpi }), -- n
publicExponent INTEGER ({ rsa_extract_mpi }) -- e
}
......@@ -24,7 +24,6 @@ enum pkey_algo {
};
extern const char *const pkey_algo_name[PKEY_ALGO__LAST];
extern const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST];
/* asymmetric key implementation supports only up to SHA224 */
#define PKEY_HASH__LAST (HASH_ALGO_SHA224 + 1)
......@@ -59,31 +58,10 @@ extern const char *const key_being_used_for[NR__KEY_BEING_USED_FOR];
* 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
void *key;
u32 keylen;
enum pkey_algo pkey_algo : 8;
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);
......@@ -92,6 +70,8 @@ extern void public_key_destroy(void *payload);
* Public key cryptography signature data
*/
struct public_key_signature {
u8 *s; /* Signature */
u32 s_size; /* Number of bytes in signature */
u8 *digest;
u8 digest_size; /* Number of bytes in digest */
u8 nr_mpi; /* Occupancy of mpi[] */
......@@ -109,6 +89,7 @@ struct public_key_signature {
};
};
extern struct asymmetric_key_subtype public_key_subtype;
struct key;
extern int verify_signature(const struct key *key,
const struct public_key_signature *sig);
......@@ -119,4 +100,9 @@ extern struct key *x509_request_asymmetric_key(struct key *keyring,
const struct asymmetric_key_id *skid,
bool partial);
int public_key_verify_signature(const struct public_key *pkey,
const struct public_key_signature *sig);
int rsa_verify_signature(const struct public_key *pkey,
const struct public_key_signature *sig);
#endif /* _LINUX_PUBLIC_KEY_H */
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