4 files changed, 93 insertions, 243 deletions

diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
index 905d745c2f85..91a7e047a765 100644
--- a/crypto/asymmetric_keys/Kconfig
+++ b/crypto/asymmetric_keys/Kconfig
@@ -12,7 +12,6 @@ if ASYMMETRIC_KEY_TYPE
 config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 	tristate "Asymmetric public-key crypto algorithm subtype"
 	select MPILIB
-	select PUBLIC_KEY_ALGO_RSA
 	select CRYPTO_HASH_INFO
 	help
 	  This option provides support for asymmetric public key type handling.
@@ -20,12 +19,6 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 	  appropriate hash algorithms (such as SHA-1) must be available.
 	  ENOPKG will be reported if the requisite algorithm is unavailable.
 
-config PUBLIC_KEY_ALGO_RSA
-	tristate "RSA public-key algorithm"
-	select CRYPTO_RSA
-	help
-	  This option enables support for the RSA algorithm (PKCS#1, RFC3447).
-
 config X509_CERTIFICATE_PARSER
 	tristate "X.509 certificate parser"
 	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
index b78a194ea014..f90486256f01 100644
--- a/crypto/asymmetric_keys/Makefile
+++ b/crypto/asymmetric_keys/Makefile
@@ -7,7 +7,6 @@ obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += asymmetric_keys.o
 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
 
 #
 # X.509 Certificate handling
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index b383629b9e62..27ebc2f44394 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -17,8 +17,10 @@
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
+#include <linux/scatterlist.h>
 #include <keys/asymmetric-subtype.h>
 #include <crypto/public_key.h>
+#include <crypto/akcipher.h>
 
 MODULE_LICENSE("GPL");
 
@@ -35,12 +37,6 @@ 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.
  */
@@ -68,24 +64,110 @@ void public_key_destroy(void *payload)
 }
 EXPORT_SYMBOL_GPL(public_key_destroy);
 
+struct public_key_completion {
+	struct completion completion;
+	int err;
+};
+
+static void public_key_verify_done(struct crypto_async_request *req, int err)
+{
+	struct public_key_completion *compl = req->data;
+
+	if (err == -EINPROGRESS)
+		return;
+
+	compl->err = err;
+	complete(&compl->completion);
+}
+
 /*
  * Verify a signature using a public key.
  */
 int public_key_verify_signature(const struct public_key *pkey,
 				const struct public_key_signature *sig)
 {
+	struct public_key_completion compl;
+	struct crypto_akcipher *tfm;
+	struct akcipher_request *req;
+	struct scatterlist sig_sg, digest_sg;
+	const char *alg_name;
+	char alg_name_buf[CRYPTO_MAX_ALG_NAME];
+	void *output;
+	unsigned int outlen;
+	int ret = -ENOMEM;
+
+	pr_devel("==>%s()\n", __func__);
+
 	BUG_ON(!pkey);
 	BUG_ON(!sig);
 	BUG_ON(!sig->digest);
 	BUG_ON(!sig->s);
 
-	if (pkey->pkey_algo >= PKEY_ALGO__LAST)
-		return -ENOPKG;
+	alg_name = pkey_algo_name[sig->pkey_algo];
+	if (sig->pkey_algo == PKEY_ALGO_RSA) {
+		/* The data wangled by the RSA algorithm is typically padded
+		 * and encoded in some manner, such as EMSA-PKCS1-1_5 [RFC3447
+		 * sec 8.2].
+		 */
+		if (snprintf(alg_name_buf, CRYPTO_MAX_ALG_NAME,
+			     "pkcs1pad(rsa,%s)",
+			     hash_algo_name[sig->pkey_hash_algo]
+			     ) >= CRYPTO_MAX_ALG_NAME)
+			return -EINVAL;
+		alg_name = alg_name_buf;
+	}
+
+	tfm = crypto_alloc_akcipher(alg_name, 0, 0);
+	if (IS_ERR(tfm))
+		return PTR_ERR(tfm);
+
+	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;
+
+	outlen = crypto_akcipher_maxsize(tfm);
+	output = kmalloc(outlen, GFP_KERNEL);
+	if (!output)
+		goto error_free_req;
+
+	sg_init_one(&sig_sg, sig->s, sig->s_size);
+	sg_init_one(&digest_sg, output, outlen);
+	akcipher_request_set_crypt(req, &sig_sg, &digest_sg, 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);
+
+	/* Perform the verification calculation.  This doesn't actually do the
+	 * verification, but rather calculates the hash expected by the
+	 * signature and returns that to us.
+	 */
+	ret = crypto_akcipher_verify(req);
+	if (ret == -EINPROGRESS) {
+		wait_for_completion(&compl.completion);
+		ret = compl.err;
+	}
+	if (ret < 0)
+		goto out_free_output;
 
-	if (!alg_verify[pkey->pkey_algo])
-		return -ENOPKG;
+	/* Do the actual verification step. */
+	if (req->dst_len != sig->digest_size ||
+	    memcmp(sig->digest, output, sig->digest_size) != 0)
+		ret = -EKEYREJECTED;
 
-	return alg_verify[pkey->pkey_algo](pkey, sig);
+out_free_output:
+	kfree(output);
+error_free_req:
+	akcipher_request_free(req);
+error_free_tfm:
+	crypto_free_akcipher(tfm);
+	pr_devel("<==%s() = %d\n", __func__, ret);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(public_key_verify_signature);
 
diff --git a/crypto/asymmetric_keys/rsa.c b/crypto/asymmetric_keys/rsa.c
deleted file mode 100644
index 51502bca65e7..000000000000
--- a/crypto/asymmetric_keys/rsa.c
+++ /dev/null
@@ -1,224 +0,0 @@
-/* RSA asymmetric public-key algorithm [RFC3447]
- *
- * 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) "RSA: "fmt
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <crypto/akcipher.h>
-#include <crypto/public_key.h>
-#include <crypto/algapi.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].
- */
-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_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
-	 * note: leading zeros are stripped by the RSA implementation
-	 */
-	if (EM[0] != 0x01) {
-		kleave(" = -EBADMSG [EM[0] == %02u]", EM[0]);
-		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 = 1; 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);
-}
-
-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;
-
-	/* Initialize the output buffer */
-	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;
-	}
-
-	if (ret)
-		goto error_free_req;
-
-	/* Output from the operation is an encoded message (EM) of
-	 * length k octets.
-	 */
-	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_free_req:
-	akcipher_request_free(req);
-error_free_tfm:
-	crypto_free_akcipher(tfm);
-error_out:
-	kfree(outbuf);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(rsa_verify_signature);