diff mbox

[v4] crypto: KEYS: convert public key and digsig asym to the akcipher api

Message ID 20151223143352.5035.85876.stgit@tstruk-mobl1 (mailing list archive)
State Superseded
Delegated to: Herbert Xu
Headers show

Commit Message

Tadeusz Struk Dec. 23, 2015, 2:33 p.m. UTC
This patch converts the module verification and digital signature
code to the new akcipher API.
RSA implementation has been removed from crypto/asymmetric_keys and the
new API is used for cryptographic primitives.
There is no need for MPI above the akcipher API anymore.
Modules can be verified with software as well as HW RSA implementations.

Patches generated against cryptodev-2.6

Changes in v4:
- Flatten both patches into one to avoid bisect compilation problems.

Changes in v3:
- Don't include keys/asymmetric-type.h in crypto/public_key.h

Changes in v2:
- Fix the whey public_key_signature is setup. The pointer s needs to
  point to the signature instread of the signature_v2_hdr.
- Select CRYPTO_RSA when INTEGRITY_ASYMMETRIC_KEYS is selected.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
---
 crypto/asymmetric_keys/Kconfig            |    2 
 crypto/asymmetric_keys/Makefile           |    7 -
 crypto/asymmetric_keys/pkcs7_parser.c     |   12 +-
 crypto/asymmetric_keys/pkcs7_trust.c      |    2 
 crypto/asymmetric_keys/pkcs7_verify.c     |    2 
 crypto/asymmetric_keys/public_key.c       |   64 +++------
 crypto/asymmetric_keys/public_key.h       |   36 -----
 crypto/asymmetric_keys/rsa.c              |  213 +++++++++++------------------
 crypto/asymmetric_keys/x509_cert_parser.c |   37 +----
 crypto/asymmetric_keys/x509_public_key.c  |   17 +-
 crypto/asymmetric_keys/x509_rsakey.asn1   |    4 -
 include/crypto/public_key.h               |   48 +------
 security/integrity/Kconfig                |    1 
 security/integrity/digsig_asymmetric.c    |   10 -
 14 files changed, 139 insertions(+), 316 deletions(-)
 delete mode 100644 crypto/asymmetric_keys/public_key.h
 delete mode 100644 crypto/asymmetric_keys/x509_rsakey.asn1


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Comments

Herbert Xu Dec. 23, 2015, 2:51 p.m. UTC | #1
On Wed, Dec 23, 2015 at 06:33:53AM -0800, Tadeusz Struk wrote:
>
> Changes in v4:
> - Flatten both patches into one to avoid bisect compilation problems.

Why is this necessary?

Cheers,
Tadeusz Struk Dec. 23, 2015, 2:58 p.m. UTC | #2
On 12/23/2015 06:51 AM, Herbert Xu wrote:
>> > Changes in v4:
>> > - Flatten both patches into one to avoid bisect compilation problems.
> Why is this necessary?

Because the first patch modifies the struct public_key and removes the MPIs from it,
which the code modified in the second patch still uses. If bisect only takes the first
then the build will fail on the security/integrity/digsig_asymmetric.c as reported by
kbuild test robot:

>> security/integrity/digsig_asymmetric.c:95:5: error: 'struct public_key_signature' has no member named 'nr_mpi'
     pks.nr_mpi = 1;

Thanks,
Herbert Xu Dec. 23, 2015, 8:21 p.m. UTC | #3
On Wed, Dec 23, 2015 at 06:58:55AM -0800, Tadeusz Struk wrote:
> 
> Because the first patch modifies the struct public_key and removes the MPIs from it,
> which the code modified in the second patch still uses. If bisect only takes the first
> then the build will fail on the security/integrity/digsig_asymmetric.c as reported by
> kbuild test robot:

Why not just leave the MPIs in the structure and only remove them
by adding a third patch?

Cheers,
Tadeusz Struk Dec. 24, 2015, 3 a.m. UTC | #4
On 12/23/2015 12:21 PM, Herbert Xu wrote:
> Why not just leave the MPIs in the structure and only remove them
> by adding a third patch?

Right, I think that's a better way of resolving this. v5 on it's way.
Thanks,
diff mbox

Patch

diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
index 4870f28..905d745 100644
--- a/crypto/asymmetric_keys/Kconfig
+++ b/crypto/asymmetric_keys/Kconfig
@@ -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).
 
diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
index cd1406f..b78a194 100644
--- a/crypto/asymmetric_keys/Makefile
+++ b/crypto/asymmetric_keys/Makefile
@@ -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
diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
index 758acab..12912c1 100644
--- a/crypto/asymmetric_keys/pkcs7_parser.c
+++ b/crypto/asymmetric_keys/pkcs7_parser.c
@@ -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);
@@ -616,16 +616,14 @@  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;
 }
 
diff --git a/crypto/asymmetric_keys/pkcs7_trust.c b/crypto/asymmetric_keys/pkcs7_trust.c
index 90d6d47..3bbdcc7 100644
--- a/crypto/asymmetric_keys/pkcs7_trust.c
+++ b/crypto/asymmetric_keys/pkcs7_trust.c
@@ -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"
 
 /**
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index 325575c..f5db137 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -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"
 
 /*
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index 6db4c01..b383629 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -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);
 
diff --git a/crypto/asymmetric_keys/public_key.h b/crypto/asymmetric_keys/public_key.h
deleted file mode 100644
index 5c37a22..0000000
--- a/crypto/asymmetric_keys/public_key.h
+++ /dev/null
@@ -1,36 +0,0 @@ 
-/* 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);
diff --git a/crypto/asymmetric_keys/rsa.c b/crypto/asymmetric_keys/rsa.c
index 508b57b..8b08ffc 100644
--- a/crypto/asymmetric_keys/rsa.c
+++ b/crypto/asymmetric_keys/rsa.c
@@ -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);
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 021d39c..7502029 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -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)
 
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 2a44b37..2e18dfc 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -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 */
diff --git a/crypto/asymmetric_keys/x509_rsakey.asn1 b/crypto/asymmetric_keys/x509_rsakey.asn1
deleted file mode 100644
index 4ec7cc6..0000000
--- a/crypto/asymmetric_keys/x509_rsakey.asn1
+++ /dev/null
@@ -1,4 +0,0 @@ 
-RSAPublicKey ::= SEQUENCE {
-	modulus			INTEGER ({ rsa_extract_mpi }),	-- n
-	publicExponent		INTEGER ({ rsa_extract_mpi })	-- e
-	}
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index cc2516d..a1693ed 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -14,7 +14,6 @@ 
 #ifndef _LINUX_PUBLIC_KEY_H
 #define _LINUX_PUBLIC_KEY_H
 
-#include <linux/mpi.h>
 #include <crypto/hash_info.h>
 
 enum pkey_algo {
@@ -24,7 +23,6 @@  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 +57,10 @@  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);
@@ -92,23 +69,15 @@  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[] */
+	u8 digest_size;		/* Number of bytes in digest */
 	enum pkey_algo pkey_algo : 8;
 	enum hash_algo pkey_hash_algo : 8;
-	union {
-		MPI mpi[2];
-		struct {
-			MPI s;		/* m^d mod n */
-		} rsa;
-		struct {
-			MPI r;
-			MPI s;
-		} dsa;
-	};
 };
 
+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 +88,9 @@  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 */
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index 73c457b..f0b2463 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -36,6 +36,7 @@  config INTEGRITY_ASYMMETRIC_KEYS
         select ASYMMETRIC_KEY_TYPE
         select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
         select PUBLIC_KEY_ALGO_RSA
+        select CRYPTO_RSA
         select X509_CERTIFICATE_PARSER
 	help
 	  This option enables digital signature verification using
diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
index 4fec181..5629372 100644
--- a/security/integrity/digsig_asymmetric.c
+++ b/security/integrity/digsig_asymmetric.c
@@ -92,13 +92,9 @@  int asymmetric_verify(struct key *keyring, const char *sig,
 	pks.pkey_hash_algo = hdr->hash_algo;
 	pks.digest = (u8 *)data;
 	pks.digest_size = datalen;
-	pks.nr_mpi = 1;
-	pks.rsa.s = mpi_read_raw_data(hdr->sig, siglen);
-
-	if (pks.rsa.s)
-		ret = verify_signature(key, &pks);
-
-	mpi_free(pks.rsa.s);
+	pks.s = hdr->sig;
+	pks.s_size = siglen;
+	ret = verify_signature(key, &pks);
 	key_put(key);
 	pr_debug("%s() = %d\n", __func__, ret);
 	return ret;