diff mbox

[RFC,v3,2/3] crypto: RSA: KEYS: convert rsa and public key to new PKE API

Message ID 20150603224414.22310.17260.stgit@tstruk-mobl1 (mailing list archive)
State RFC
Delegated to: Herbert Xu
Headers show

Commit Message

Tadeusz Struk June 3, 2015, 10:44 p.m. UTC
Change the existing rsa and public key code to integrate it
with the new Public Key Encryption API.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
---
 crypto/asymmetric_keys/Kconfig            |    1 
 crypto/asymmetric_keys/Makefile           |    1 
 crypto/asymmetric_keys/pkcs7_parser.c     |    2 
 crypto/asymmetric_keys/pkcs7_trust.c      |    2 
 crypto/asymmetric_keys/pkcs7_verify.c     |    2 
 crypto/asymmetric_keys/public_key.c       |   53 +--
 crypto/asymmetric_keys/public_key.h       |   36 --
 crypto/asymmetric_keys/rsa.c              |  467 ++++++++++++++++-------------
 crypto/asymmetric_keys/rsa_pkcs1_v1_5.c   |  259 ++++++++++++++++
 crypto/asymmetric_keys/x509_cert_parser.c |    2 
 crypto/asymmetric_keys/x509_public_key.c  |    4 
 include/crypto/public_key.h               |   11 -
 12 files changed, 540 insertions(+), 300 deletions(-)
 delete mode 100644 crypto/asymmetric_keys/public_key.h
 create mode 100644 crypto/asymmetric_keys/rsa_pkcs1_v1_5.c


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Comments

Herbert Xu June 4, 2015, 6:53 a.m. UTC | #1
On Wed, Jun 03, 2015 at 03:44:14PM -0700, Tadeusz Struk wrote:
> Change the existing rsa and public key code to integrate it
> with the new Public Key Encryption API.
> 
> Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>

I'd like to see this split into multiple patches.  First of all
the new crypto_akcipher implementation should coexist with the
existing code.  That way the exiting users can be converted over
one-by-one.

Also you should implement the crypto_akcipher completely before
converting anybody over, that means doing encoding/wrapping in
addition to the crypto.

That way we don't have to have craziness like converting in and
out of MPI multiple times.

Lastly you should consider adding an MPI helper that writes to
an existing buffer instead of allocating a new one and copying
it over.

Thanks,
Tadeusz Struk June 4, 2015, 5:23 p.m. UTC | #2
On 06/03/2015 11:53 PM, Herbert Xu wrote:
> I'd like to see this split into multiple patches.  First of all
> the new crypto_akcipher implementation should coexist with the
> existing code.  That way the exiting users can be converted over
> one-by-one.
> 
> Also you should implement the crypto_akcipher completely before
> converting anybody over, that means doing encoding/wrapping in
> addition to the crypto.
> 
> That way we don't have to have craziness like converting in and
> out of MPI multiple times.

That's cool. It will make it easier for me. I wanted to convert
one to show that the interface is working.

> 
> Lastly you should consider adding an MPI helper that writes to
> an existing buffer instead of allocating a new one and copying
> it over.

I'll think about something.

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Paul Bolle June 5, 2015, 8:50 a.m. UTC | #3
A few remarks, perhaps not of the kind you'd like for an RFC, that I
hope are still relevant after Herbert's comment.

On Wed, 2015-06-03 at 15:44 -0700, Tadeusz Struk wrote:
> --- a/crypto/asymmetric_keys/Makefile
> +++ b/crypto/asymmetric_keys/Makefile
> @@ -8,6 +8,7 @@ asymmetric_keys-y := asymmetric_type.o signature.o
>  
>  obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
>  obj-$(CONFIG_PUBLIC_KEY_ALGO_RSA) += rsa.o
> +obj-$(CONFIG_PUBLIC_KEY_ALGO_RSA) += rsa_pkcs1_v1_5.o

This builds two modules if PUBLIC_KEY_ALGO_RSA = 'm': rsa.ko and
rsa_pkcs1_v1_5.ko. Is that what you want?
 
> --- a/crypto/asymmetric_keys/public_key.c
> +++ b/crypto/asymmetric_keys/public_key.c

> +int rsa_pkcs1_v1_5_verify_signature(const struct public_key *pkey,
> +				    const struct public_key_signature *sig);
> +

> -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)
>  {
> [...]
> -	return algo->verify_signature(pk, sig);
> +	return rsa_pkcs1_v1_5_verify_signature(pkey, sig);
>  }


> --- a/crypto/asymmetric_keys/rsa.c
> +++ b/crypto/asymmetric_keys/rsa.c
 
>  MODULE_LICENSE("GPL");
>  MODULE_DESCRIPTION("RSA Public Key Algorithm");

> +static int rsa_init(void)
> +{
> +	return crypto_register_akcipher(&rsa);
> +}

Is there a reason not to mark this __init? (This is not a rhetorical
question, perhaps there really is.)

> +static void rsa_exit(void)
> +{
> +	crypto_unregister_akcipher(&rsa);
> +}

Ditto for __exit.

> +module_init(rsa_init);
> +module_exit(rsa_exit);
> +MODULE_ALIAS_CRYPTO("rsa");

Could the MODULE_* macros be grouped in one place please?

> --- /dev/null
> +++ b/crypto/asymmetric_keys/rsa_pkcs1_v1_5.c

> +/*
> + * Perform the verification step [RFC3447 sec 8.2.2].
> + */
> +int rsa_pkcs1_v1_5_verify_signature(const struct public_key *pkey,
> +				    const struct public_key_signature *sig)
> +{
> [...]
> +}

public_key.c uses this, so it can end up in public_key.ko. But it's not
exported. So a _quick and dirty_ build test generated:
    WARNING: "rsa_pkcs1_v1_5_verify_signature" [[...]/crypto/asymmetric_keys/public_key.ko] undefined!

Also no MODULE_LICENSE() macro, so loading rsa_pkcs1_v1_5.ko should
trigger a warning and taint the kernel.

Thanks,


Paul Bolle

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Tadeusz Struk June 5, 2015, 4:42 p.m. UTC | #4
On 06/05/2015 01:50 AM, Paul Bolle wrote:
> This builds two modules if PUBLIC_KEY_ALGO_RSA = 'm': rsa.ko and
> rsa_pkcs1_v1_5.ko. Is that what you want?

No, this not what I wanted.

> 
> public_key.c uses this, so it can end up in public_key.ko. But it's not
> exported. So a _quick and dirty_ build test generated:
>     WARNING: "rsa_pkcs1_v1_5_verify_signature" [[...]/crypto/asymmetric_keys/public_key.ko] undefined!
> 
> Also no MODULE_LICENSE() macro, so loading rsa_pkcs1_v1_5.ko should
> trigger a warning and taint the kernel.

Thank you Paul for taking the time to review the patches and for your feedback.
I'll have to change this again based on Herbert's feedback so this rsa_pkcs1_v1_5.c file
will go away anyway.
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diff mbox

Patch

diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
index 4870f28..4d27116 100644
--- a/crypto/asymmetric_keys/Kconfig
+++ b/crypto/asymmetric_keys/Kconfig
@@ -23,6 +23,7 @@  config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 config PUBLIC_KEY_ALGO_RSA
 	tristate "RSA public-key algorithm"
 	select MPILIB
+	select CRYPTO_AKCIPHER
 	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 e47fcd9..a9cb1b8 100644
--- a/crypto/asymmetric_keys/Makefile
+++ b/crypto/asymmetric_keys/Makefile
@@ -8,6 +8,7 @@  asymmetric_keys-y := asymmetric_type.o signature.o
 
 obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
 obj-$(CONFIG_PUBLIC_KEY_ALGO_RSA) += rsa.o
+obj-$(CONFIG_PUBLIC_KEY_ALGO_RSA) += rsa_pkcs1_v1_5.o
 
 #
 # X.509 Certificate handling
diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
index 3bd5a1e..054f110 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"
 
diff --git a/crypto/asymmetric_keys/pkcs7_trust.c b/crypto/asymmetric_keys/pkcs7_trust.c
index 1d29376..68ebae2 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 cd45545..c32a337 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 2f6e4fb..4685aed 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -18,30 +18,26 @@ 
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 #include <keys/asymmetric-subtype.h>
-#include "public_key.h"
+#include <crypto/public_key.h>
+#include <crypto/akcipher.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",
 };
 EXPORT_SYMBOL_GPL(pkey_id_type_name);
 
+int rsa_pkcs1_v1_5_verify_signature(const struct public_key *pkey,
+				    const struct public_key_signature *sig);
+
 /*
  * Provide a part of a description of the key for /proc/keys.
  */
@@ -52,7 +48,8 @@  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]);
 }
 
 /*
@@ -74,37 +71,20 @@  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(!pkey->mpi[0]);
+	BUG_ON(!pkey->mpi[1]);
 	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;
-	}
+	if (pkey->pkey_algo != PKEY_ALGO_RSA)
+		return -ENOPKG;
 
-	if (!algo->verify_signature)
-		return -ENOTSUPP;
-
-	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;
-	}
-
-	return algo->verify_signature(pk, sig);
+	return rsa_pkcs1_v1_5_verify_signature(pkey, sig);
 }
 EXPORT_SYMBOL_GPL(public_key_verify_signature);
 
@@ -112,6 +92,7 @@  static int public_key_verify_signature_2(const struct key *key,
 					 const struct public_key_signature *sig)
 {
 	const struct public_key *pk = key->payload.data;
+
 	return public_key_verify_signature(pk, sig);
 }
 
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 459cf97..9e805ae 100644
--- a/crypto/asymmetric_keys/rsa.c
+++ b/crypto/asymmetric_keys/rsa.c
@@ -3,276 +3,317 @@ 
  * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
+ * Split to RSA cryptographic primitives and RSA encryption schemes
+ * added support for encrypt, decrypt and sign
+ * Tadeusz Struk <tadeusz.struk@intel.com>
+ * Copyright (c) 2015, Intel Corporation
+ *
  * 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) "RSA: "fmt
 #include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <crypto/algapi.h>
-#include "public_key.h"
+#include <linux/scatterlist.h>
+#include <crypto/public_key.h>
+#include <crypto/akcipher.h>
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("RSA Public Key Algorithm");
 
-#define kenter(FMT, ...) \
-	pr_devel("==> %s("FMT")\n", __func__, ##__VA_ARGS__)
-#define kleave(FMT, ...) \
-	pr_devel("<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
-
 /*
- * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
+ * RSAEP function [RFC3447 sec 5.1.1]
+ * c = m^e mod n;
  */
-static const u8 RSA_digest_info_MD5[] = {
-	0x30, 0x20, 0x30, 0x0C, 0x06, 0x08,
-	0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x02, 0x05, /* OID */
-	0x05, 0x00, 0x04, 0x10
-};
-
-static const u8 RSA_digest_info_SHA1[] = {
-	0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
-	0x2B, 0x0E, 0x03, 0x02, 0x1A,
-	0x05, 0x00, 0x04, 0x14
-};
-
-static const u8 RSA_digest_info_RIPE_MD_160[] = {
-	0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
-	0x2B, 0x24, 0x03, 0x02, 0x01,
-	0x05, 0x00, 0x04, 0x14
-};
+static int _rsa_enc(const struct public_key *key, MPI c, MPI m)
+{
+	/* (1) Validate 0 <= m < n */
+	if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->rsa.n) >= 0)
+		return -EBADMSG;
 
-static const u8 RSA_digest_info_SHA224[] = {
-	0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
-	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
-	0x05, 0x00, 0x04, 0x1C
-};
+	/* (2) c = m^e mod n */
+	return mpi_powm(c, m, key->rsa.e, key->rsa.n);
+}
 
-static const u8 RSA_digest_info_SHA256[] = {
-	0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
-	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
-	0x05, 0x00, 0x04, 0x20
-};
+/*
+ * RSADP function [RFC3447 sec 5.1.2]
+ * m = c^d mod n;
+ */
+static int _rsa_dec(const struct public_key *key, MPI m, MPI c)
+{
+	/* (1) Validate 0 <= c < n */
+	if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->rsa.n) >= 0)
+		return -EBADMSG;
 
-static const u8 RSA_digest_info_SHA384[] = {
-	0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
-	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
-	0x05, 0x00, 0x04, 0x30
-};
+	/* (2) m = c^d mod n */
+	return mpi_powm(m, c, key->rsa.d, key->rsa.n);
+}
 
-static const u8 RSA_digest_info_SHA512[] = {
-	0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
-	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
-	0x05, 0x00, 0x04, 0x40
-};
+/*
+ * RSASP1 function [RFC3447 sec 5.2.1]
+ * s = m^d mod n
+ */
+static int _rsa_sign(const struct public_key *key, MPI s, MPI m)
+{
+	/* (1) Validate 0 <= m < n */
+	if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->rsa.n) >= 0)
+		return -EBADMSG;
 
-static const struct {
-	const u8 *data;
-	size_t size;
-} RSA_ASN1_templates[PKEY_HASH__LAST] = {
-#define _(X) { RSA_digest_info_##X, sizeof(RSA_digest_info_##X) }
-	[HASH_ALGO_MD5]		= _(MD5),
-	[HASH_ALGO_SHA1]	= _(SHA1),
-	[HASH_ALGO_RIPE_MD_160]	= _(RIPE_MD_160),
-	[HASH_ALGO_SHA256]	= _(SHA256),
-	[HASH_ALGO_SHA384]	= _(SHA384),
-	[HASH_ALGO_SHA512]	= _(SHA512),
-	[HASH_ALGO_SHA224]	= _(SHA224),
-#undef _
-};
+	/* (2) s = m^d mod n */
+	return mpi_powm(s, m, key->rsa.d, key->rsa.n);
+}
 
 /*
- * RSAVP1() function [RFC3447 sec 5.2.2]
+ * RSAVP1 function [RFC3447 sec 5.2.2]
+ * m = s^e mod n;
  */
-static int RSAVP1(const struct public_key *key, MPI s, MPI *_m)
+static int _rsa_verify(const struct public_key *key, MPI m, MPI s)
 {
-	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]");
+	if (mpi_cmp_ui(s, 0) < 0 || mpi_cmp(s, key->rsa.n) >= 0)
 		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;
+	return mpi_powm(m, s, key->rsa.e, key->rsa.n);
 }
 
-/*
- * Integer to Octet String conversion [RFC3447 sec 4.1]
- */
-static int RSA_I2OSP(MPI x, size_t xLen, u8 **_X)
+static int rsa_enc(struct akcipher_request *req)
 {
-	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)
+	struct crypto_akcipher *tfm = akcipher_request_get_tfm(req);
+	const struct public_key *pkey = tfm->pkey;
+	MPI m, c = mpi_alloc(0);
+	char *buf;
+	unsigned int len;
+	int ret = 0;
+	int sign;
+
+	if (!c)
 		return -ENOMEM;
-	if (X_sign < 0) {
-		kfree(X);
-		return -EBADMSG;
+
+	m = mpi_read_raw_data(req->src, req->src_len);
+	if (!m) {
+		ret = -ENOMEM;
+		goto err_free_c;
 	}
-	if (X_size != xLen - 1) {
-		kfree(X);
-		return -EBADMSG;
+
+	ret = _rsa_enc(pkey, c, m);
+	if (ret)
+		goto err_free_m;
+
+	buf = mpi_get_buffer(c, &len, &sign);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto err_free_m;
+	}
+
+	if (sign < 0) {
+		ret = -EBADMSG;
+		goto err_free_buf;
 	}
 
-	*_X = X;
-	return 0;
+	if (req->dst_len < len) {
+		ret = -EINVAL;
+		goto err_free_buf;
+	}
+
+	if (req->result_len)
+		*req->result_len = len;
+
+	memcpy(req->dst, buf, len);
+
+err_free_buf:
+	kfree(buf);
+err_free_m:
+	mpi_free(m);
+err_free_c:
+	mpi_free(c);
+	return ret;
 }
 
-/*
- * Perform the RSA signature verification.
- * @H: Value of hash of data and metadata
- * @EM: The computed signature value
- * @k: The size of EM (EM[0] is an invalid location but should hold 0x00)
- * @hash_size: The size of H
- * @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,
-		      const u8 *asn1_template, size_t asn1_size)
+static int rsa_dec(struct akcipher_request *req)
 {
-	unsigned PS_end, T_offset, i;
+	struct crypto_akcipher *tfm = akcipher_request_get_tfm(req);
+	const struct public_key *pkey = tfm->pkey;
+	MPI c, m = mpi_alloc(0);
+	char *buf;
+	unsigned int len;
+	int ret = 0;
+	int sign;
 
-	kenter(",,%zu,%zu,%zu", k, hash_size, asn1_size);
+	if (!m)
+		return -ENOMEM;
 
-	if (k < 2 + 1 + asn1_size + hash_size)
-		return -EBADMSG;
+	c = mpi_read_raw_data(req->src, req->src_len);
+	if (!c) {
+		ret = -ENOMEM;
+		goto err_free_m;
+	}
 
-	/* Decode the EMSA-PKCS1-v1_5 */
-	if (EM[1] != 0x01) {
-		kleave(" = -EBADMSG [EM[1] == %02u]", EM[1]);
-		return -EBADMSG;
+	ret = _rsa_dec(pkey, m, c);
+	if (ret)
+		goto err_free_c;
+
+	buf = mpi_get_buffer(m, &len, &sign);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto err_free_c;
 	}
 
-	T_offset = k - (asn1_size + hash_size);
-	PS_end = T_offset - 1;
-	if (EM[PS_end] != 0x00) {
-		kleave(" = -EBADMSG [EM[T-1] == %02u]", EM[PS_end]);
-		return -EBADMSG;
+	if (sign < 0) {
+		ret = -EBADMSG;
+		goto err_free_buf;
 	}
 
-	for (i = 2; i < PS_end; i++) {
-		if (EM[i] != 0xff) {
-			kleave(" = -EBADMSG [EM[PS%x] == %02u]", i - 2, EM[i]);
-			return -EBADMSG;
-		}
+	if (req->dst_len < len) {
+		ret = -EINVAL;
+		goto err_free_buf;
 	}
 
-	if (crypto_memneq(asn1_template, EM + T_offset, asn1_size) != 0) {
-		kleave(" = -EBADMSG [EM[T] ASN.1 mismatch]");
-		return -EBADMSG;
+	if (req->result_len)
+		*req->result_len = len;
+
+	memcpy(req->dst, buf, len);
+
+err_free_buf:
+	kfree(buf);
+err_free_c:
+	mpi_free(c);
+err_free_m:
+	mpi_free(m);
+	return ret;
+}
+
+static int rsa_sign(struct akcipher_request *req)
+{
+	struct crypto_akcipher *tfm = akcipher_request_get_tfm(req);
+	const struct public_key *pkey = tfm->pkey;
+	MPI m, s = mpi_alloc(0);
+	char *buf;
+	unsigned int len;
+	int ret = 0;
+	int sign;
+
+	if (!s)
+		return -ENOMEM;
+
+	m = mpi_read_raw_data(req->src, req->src_len);
+	if (!m) {
+		ret = -ENOMEM;
+		goto err_free_s;
+	}
+	ret = _rsa_sign(pkey, s, m);
+	if (ret)
+		goto err_free_m;
+
+	buf = mpi_get_buffer(s, &len, &sign);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto err_free_m;
+	}
+
+	if (sign < 0) {
+		ret = -EBADMSG;
+		goto err_free_buf;
 	}
 
-	if (crypto_memneq(H, EM + T_offset + asn1_size, hash_size) != 0) {
-		kleave(" = -EKEYREJECTED [EM[T] hash mismatch]");
-		return -EKEYREJECTED;
+	if (req->dst_len < len) {
+		ret = -EINVAL;
+		goto err_free_buf;
 	}
 
-	kleave(" = 0");
-	return 0;
+	if (req->result_len)
+		*req->result_len = len;
+
+	memcpy(req->dst, buf, len);
+
+err_free_buf:
+	kfree(buf);
+err_free_m:
+	mpi_free(m);
+err_free_s:
+	mpi_free(s);
+	return ret;
 }
 
-/*
- * 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 int rsa_verify(struct akcipher_request *req)
 {
-	size_t tsize;
-	int ret;
-
-	/* Variables as per RFC3447 sec 8.2.2 */
-	const u8 *H = sig->digest;
-	u8 *EM = NULL;
-	MPI m = NULL;
-	size_t k;
-
-	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);
-
-	/* 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) {
+	struct crypto_akcipher *tfm = akcipher_request_get_tfm(req);
+	const struct public_key *pkey = tfm->pkey;
+	MPI s, m = mpi_alloc(0);
+	char *buf;
+	unsigned int len;
+	int ret = 0;
+	int sign;
+
+	if (!m)
+		return -ENOMEM;
+
+	s = mpi_read_raw_data(req->src, req->src_len);
+	if (!s) {
+		ret = -ENOMEM;
+		goto err_free_m;
+	}
+
+	ret = _rsa_verify(pkey, m, s);
+	if (ret)
+		goto err_free_s;
+
+	buf = mpi_get_buffer(m, &len, &sign);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto err_free_s;
+	}
+
+	if (sign < 0) {
 		ret = -EBADMSG;
-		goto error;
+		goto err_free_buf;
+	}
+
+	if (req->dst_len < len) {
+		ret = -EINVAL;
+		goto err_free_buf;
 	}
 
-	/* Round up and convert to octets */
-	k = (k + 7) / 8;
-
-	/* (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()!
-	 */
-	ret = RSA_I2OSP(m, k, &EM);
-	if (ret < 0)
-		goto error;
-
-	ret = RSA_verify(H, EM - 1, k, sig->digest_size,
-			 RSA_ASN1_templates[sig->pkey_hash_algo].data,
-			 RSA_ASN1_templates[sig->pkey_hash_algo].size);
-
-error:
-	kfree(EM);
+	if (req->result_len)
+		*req->result_len = len;
+
+	memcpy(req->dst, buf, len);
+
+err_free_buf:
+	kfree(buf);
+err_free_s:
+	mpi_free(s);
+err_free_m:
 	mpi_free(m);
-	kleave(" = %d", ret);
 	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,
+static struct akcipher_alg rsa = {
+	.encrypt = rsa_enc,
+	.decrypt = rsa_dec,
+	.sign = rsa_sign,
+	.verify = rsa_verify,
+	.base = {
+		.cra_name = "rsa",
+		.cra_driver_name = "rsa-generic",
+		.cra_priority = 100,
+		.cra_ctxsize = 0,
+		.cra_alignmask = 0,
+		.cra_module = THIS_MODULE,
+	},
 };
-EXPORT_SYMBOL_GPL(RSA_public_key_algorithm);
+
+static int rsa_init(void)
+{
+	return crypto_register_akcipher(&rsa);
+}
+
+static void rsa_exit(void)
+{
+	crypto_unregister_akcipher(&rsa);
+}
+
+module_init(rsa_init);
+module_exit(rsa_exit);
+MODULE_ALIAS_CRYPTO("rsa");
diff --git a/crypto/asymmetric_keys/rsa_pkcs1_v1_5.c b/crypto/asymmetric_keys/rsa_pkcs1_v1_5.c
new file mode 100644
index 0000000..8feb28e
--- /dev/null
+++ b/crypto/asymmetric_keys/rsa_pkcs1_v1_5.c
@@ -0,0 +1,259 @@ 
+/* RSA asymmetric public-key algorithm [RFC3447]
+ * RSA encryption schemes part
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * Split to RSA cryptographic primitives and RSA encryption schemes
+ * Tadeusz Struk <tadeusz.struk@intel.com>
+ * Copyright (c) 2015, Intel Corporation
+ *
+ * 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/slab.h>
+#include <crypto/public_key.h>
+#include <crypto/akcipher.h>
+#include <crypto/algapi.h>
+
+#define kenter(FMT, ...) \
+	pr_devel("==> %s("FMT")\n", __func__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+	pr_devel("<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
+
+/*
+ * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
+ */
+static const u8 RSA_digest_info_MD5[] = {
+	0x30, 0x20, 0x30, 0x0C, 0x06, 0x08,
+	0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x02, 0x05, /* OID */
+	0x05, 0x00, 0x04, 0x10
+};
+
+static const u8 RSA_digest_info_SHA1[] = {
+	0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
+	0x2B, 0x0E, 0x03, 0x02, 0x1A,
+	0x05, 0x00, 0x04, 0x14
+};
+
+static const u8 RSA_digest_info_RIPE_MD_160[] = {
+	0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
+	0x2B, 0x24, 0x03, 0x02, 0x01,
+	0x05, 0x00, 0x04, 0x14
+};
+
+static const u8 RSA_digest_info_SHA224[] = {
+	0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
+	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
+	0x05, 0x00, 0x04, 0x1C
+};
+
+static const u8 RSA_digest_info_SHA256[] = {
+	0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
+	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
+	0x05, 0x00, 0x04, 0x20
+};
+
+static const u8 RSA_digest_info_SHA384[] = {
+	0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
+	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
+	0x05, 0x00, 0x04, 0x30
+};
+
+static const u8 RSA_digest_info_SHA512[] = {
+	0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
+	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
+	0x05, 0x00, 0x04, 0x40
+};
+
+static const struct {
+	const u8 *data;
+	size_t size;
+} RSA_ASN1_templates[PKEY_HASH__LAST] = {
+#define _(X) { RSA_digest_info_##X, sizeof(RSA_digest_info_##X) }
+	[HASH_ALGO_MD5]		= _(MD5),
+	[HASH_ALGO_SHA1]	= _(SHA1),
+	[HASH_ALGO_RIPE_MD_160]	= _(RIPE_MD_160),
+	[HASH_ALGO_SHA256]	= _(SHA256),
+	[HASH_ALGO_SHA384]	= _(SHA384),
+	[HASH_ALGO_SHA512]	= _(SHA512),
+	[HASH_ALGO_SHA224]	= _(SHA224),
+#undef _
+};
+
+struct rsa_completion {
+	struct completion completion;
+	int err;
+};
+
+/*
+ * Perform the RSA signature verification.
+ * @H: Value of hash of data and metadata
+ * @EM: The computed signature value
+ * @k: The size of EM (EM[0] is an invalid location but should hold 0x00)
+ * @hash_size: The size of H
+ * @asn1_template: The DigestInfo ASN.1 template
+ * @asn1_size: Size of asm1_template[]
+ */
+static int rsa_signture_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;
+
+	kenter(",,%zu,%zu,%zu", k, hash_size, asn1_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]);
+		return -EBADMSG;
+	}
+
+	T_offset = k - (asn1_size + hash_size);
+	PS_end = T_offset - 1;
+	if (EM[PS_end] != 0x00) {
+		kleave(" = -EBADMSG [EM[T-1] == %02u]", EM[PS_end]);
+		return -EBADMSG;
+	}
+
+	for (i = 2; i < PS_end; i++) {
+		if (EM[i] != 0xff) {
+			kleave(" = -EBADMSG [EM[PS%x] == %02u]", i - 2, EM[i]);
+			return -EBADMSG;
+		}
+	}
+
+	if (crypto_memneq(asn1_template, EM + T_offset, asn1_size) != 0) {
+		kleave(" = -EBADMSG [EM[T] ASN.1 mismatch]");
+		return -EBADMSG;
+	}
+
+	if (crypto_memneq(H, EM + T_offset + asn1_size, hash_size) != 0) {
+		kleave(" = -EKEYREJECTED [EM[T] hash mismatch]");
+		return -EKEYREJECTED;
+	}
+
+	kleave(" = 0");
+	return 0;
+}
+
+static void public_key_verify_done(struct crypto_async_request *req, int err)
+{
+	struct rsa_completion *compl = req->data;
+
+	if (err == -EINPROGRESS)
+		return;
+
+	compl->err = err;
+	complete(&compl->completion);
+}
+
+/*
+ * Perform the verification step [RFC3447 sec 8.2.2].
+ */
+int rsa_pkcs1_v1_5_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;
+	void *outbuf = NULL;
+	void *inbuf = NULL;
+	size_t tsize;
+	unsigned int len, len_out;
+	int ret;
+	/* Variables as per RFC3447 sec 8.2.2 */
+	const u8 *H = sig->digest;
+	size_t k;
+
+	kenter("");
+	tfm = crypto_alloc_akcipher("rsa", 0, 0);
+	if (IS_ERR(tfm)) {
+		ret = -ENOMEM;
+		goto error_out;
+	}
+
+	req = akcipher_request_alloc(tfm, GFP_KERNEL);
+	if (!req) {
+		ret = -ENOMEM;
+		goto error_free_tfm;
+	}
+	/* (1) Check the signature size against the public key modulus size */
+	k = mpi_get_nbits(pkey->rsa.n);
+	tsize = mpi_get_nbits(sig->rsa.s);
+
+	/* 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.
+	 */
+	if (k < tsize) {
+		ret = -EBADMSG;
+		goto error_free_req;
+	}
+
+	/* initialize input with signature */
+	inbuf = mpi_get_buffer(sig->rsa.s, &len, NULL);
+	if (!inbuf) {
+		ret = -ENOMEM;
+		goto error_free_req;
+	}
+
+	/* Expect the same result size as the size of the signature */
+	len_out = len;
+
+	/* initlialzie out buf */
+	outbuf = kmalloc(len_out, GFP_KERNEL);
+	if (!outbuf) {
+		ret = -ENOMEM;
+		goto error_free_req;
+	}
+
+	/* Perform RSA verification primitive */
+	crypto_akcipher_setkey(tfm, pkey);
+	akcipher_request_set_crypt(req, inbuf, outbuf, len, len_out, &len_out);
+	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;
+	}
+
+	if (ret)
+		goto error_free_req;
+
+	/* Round up and convert to octets */
+	k = (k + 7) / 8;
+
+	/*
+	 * Output from the operation is 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()!
+	 */
+	ret = rsa_signture_verify(H, outbuf - 1, k, sig->digest_size,
+				  RSA_ASN1_templates[sig->pkey_hash_algo].data,
+				  RSA_ASN1_templates[sig->pkey_hash_algo].size);
+error_free_req:
+	akcipher_request_free(req);
+error_free_tfm:
+	crypto_free_akcipher(tfm);
+error_out:
+	kfree(inbuf);
+	kfree(outbuf);
+	kleave(" = %d", ret);
+	return ret;
+}
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index a668d90..bab3fdd 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_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 "x509_parser.h"
 #include "x509-asn1.h"
 #include "x509_rsakey-asn1.h"
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index a6c4203..8f35975 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -21,7 +21,6 @@ 
 #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;
@@ -250,8 +249,6 @@  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;
@@ -270,7 +267,6 @@  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/include/crypto/public_key.h b/include/crypto/public_key.h
index 54add20..34b6fb8 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -25,7 +25,6 @@  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)
@@ -45,12 +44,6 @@  extern const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST];
  * 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_algo pkey_algo : 8;
 	enum pkey_id_type id_type : 8;
 	union {
@@ -95,6 +88,7 @@  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);
@@ -104,4 +98,7 @@  extern struct key *x509_request_asymmetric_key(struct key *keyring,
 					       const struct asymmetric_key_id *kid,
 					       bool partial);
 
+int public_key_verify_signature(const struct public_key *pkey,
+				const struct public_key_signature *sig);
+
 #endif /* _LINUX_PUBLIC_KEY_H */