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authorYang Zhang <yang.z.zhang@intel.com>2015-08-28 09:58:54 +0800
committerYang Zhang <yang.z.zhang@intel.com>2015-09-01 12:44:00 +0800
commite44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch)
tree66b09f592c55df2878107a468a91d21506104d3f /qemu/roms/ipxe/src/crypto/rsa.c
parent9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff)
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5 Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/roms/ipxe/src/crypto/rsa.c')
-rw-r--r--qemu/roms/ipxe/src/crypto/rsa.c705
1 files changed, 705 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/crypto/rsa.c b/qemu/roms/ipxe/src/crypto/rsa.c
new file mode 100644
index 000000000..0ab7b2ad3
--- /dev/null
+++ b/qemu/roms/ipxe/src/crypto/rsa.c
@@ -0,0 +1,705 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <errno.h>
+#include <ipxe/asn1.h>
+#include <ipxe/crypto.h>
+#include <ipxe/bigint.h>
+#include <ipxe/random_nz.h>
+#include <ipxe/md5.h>
+#include <ipxe/sha1.h>
+#include <ipxe/sha256.h>
+#include <ipxe/rsa.h>
+
+/** @file
+ *
+ * RSA public-key cryptography
+ *
+ * RSA is documented in RFC 3447.
+ */
+
+/* Disambiguate the various error causes */
+#define EACCES_VERIFY \
+ __einfo_error ( EINFO_EACCES_VERIFY )
+#define EINFO_EACCES_VERIFY \
+ __einfo_uniqify ( EINFO_EACCES, 0x01, "RSA signature incorrect" )
+
+/** "rsaEncryption" object identifier */
+static uint8_t oid_rsa_encryption[] = { ASN1_OID_RSAENCRYPTION };
+
+/** "md5WithRSAEncryption" object identifier */
+static uint8_t oid_md5_with_rsa_encryption[] =
+ { ASN1_OID_MD5WITHRSAENCRYPTION };
+
+/** "sha1WithRSAEncryption" object identifier */
+static uint8_t oid_sha1_with_rsa_encryption[] =
+ { ASN1_OID_SHA1WITHRSAENCRYPTION };
+
+/** "sha256WithRSAEncryption" object identifier */
+static uint8_t oid_sha256_with_rsa_encryption[] =
+ { ASN1_OID_SHA256WITHRSAENCRYPTION };
+
+/** "rsaEncryption" OID-identified algorithm */
+struct asn1_algorithm rsa_encryption_algorithm __asn1_algorithm = {
+ .name = "rsaEncryption",
+ .pubkey = &rsa_algorithm,
+ .digest = NULL,
+ .oid = ASN1_OID_CURSOR ( oid_rsa_encryption ),
+};
+
+/** "md5WithRSAEncryption" OID-identified algorithm */
+struct asn1_algorithm md5_with_rsa_encryption_algorithm __asn1_algorithm = {
+ .name = "md5WithRSAEncryption",
+ .pubkey = &rsa_algorithm,
+ .digest = &md5_algorithm,
+ .oid = ASN1_OID_CURSOR ( oid_md5_with_rsa_encryption ),
+};
+
+/** "sha1WithRSAEncryption" OID-identified algorithm */
+struct asn1_algorithm sha1_with_rsa_encryption_algorithm __asn1_algorithm = {
+ .name = "sha1WithRSAEncryption",
+ .pubkey = &rsa_algorithm,
+ .digest = &sha1_algorithm,
+ .oid = ASN1_OID_CURSOR ( oid_sha1_with_rsa_encryption ),
+};
+
+/** "sha256WithRSAEncryption" OID-identified algorithm */
+struct asn1_algorithm sha256_with_rsa_encryption_algorithm __asn1_algorithm = {
+ .name = "sha256WithRSAEncryption",
+ .pubkey = &rsa_algorithm,
+ .digest = &sha256_algorithm,
+ .oid = ASN1_OID_CURSOR ( oid_sha256_with_rsa_encryption ),
+};
+
+/** MD5 digestInfo prefix */
+static const uint8_t rsa_md5_prefix_data[] =
+ { RSA_DIGESTINFO_PREFIX ( MD5_DIGEST_SIZE, ASN1_OID_MD5 ) };
+
+/** SHA-1 digestInfo prefix */
+static const uint8_t rsa_sha1_prefix_data[] =
+ { RSA_DIGESTINFO_PREFIX ( SHA1_DIGEST_SIZE, ASN1_OID_SHA1 ) };
+
+/** SHA-256 digestInfo prefix */
+static const uint8_t rsa_sha256_prefix_data[] =
+ { RSA_DIGESTINFO_PREFIX ( SHA256_DIGEST_SIZE, ASN1_OID_SHA256 ) };
+
+/** MD5 digestInfo prefix */
+struct rsa_digestinfo_prefix rsa_md5_prefix __rsa_digestinfo_prefix = {
+ .digest = &md5_algorithm,
+ .data = rsa_md5_prefix_data,
+ .len = sizeof ( rsa_md5_prefix_data ),
+};
+
+/** SHA-1 digestInfo prefix */
+struct rsa_digestinfo_prefix rsa_sha1_prefix __rsa_digestinfo_prefix = {
+ .digest = &sha1_algorithm,
+ .data = rsa_sha1_prefix_data,
+ .len = sizeof ( rsa_sha1_prefix_data ),
+};
+
+/** SHA-256 digestInfo prefix */
+struct rsa_digestinfo_prefix rsa_sha256_prefix __rsa_digestinfo_prefix = {
+ .digest = &sha256_algorithm,
+ .data = rsa_sha256_prefix_data,
+ .len = sizeof ( rsa_sha256_prefix_data ),
+};
+
+/**
+ * Identify RSA prefix
+ *
+ * @v digest Digest algorithm
+ * @ret prefix RSA prefix, or NULL
+ */
+static struct rsa_digestinfo_prefix *
+rsa_find_prefix ( struct digest_algorithm *digest ) {
+ struct rsa_digestinfo_prefix *prefix;
+
+ for_each_table_entry ( prefix, RSA_DIGESTINFO_PREFIXES ) {
+ if ( prefix->digest == digest )
+ return prefix;
+ }
+ return NULL;
+}
+
+/**
+ * Free RSA dynamic storage
+ *
+ * @v context RSA context
+ */
+static void rsa_free ( struct rsa_context *context ) {
+
+ free ( context->dynamic );
+ context->dynamic = NULL;
+}
+
+/**
+ * Allocate RSA dynamic storage
+ *
+ * @v context RSA context
+ * @v modulus_len Modulus length
+ * @v exponent_len Exponent length
+ * @ret rc Return status code
+ */
+static int rsa_alloc ( struct rsa_context *context, size_t modulus_len,
+ size_t exponent_len ) {
+ unsigned int size = bigint_required_size ( modulus_len );
+ unsigned int exponent_size = bigint_required_size ( exponent_len );
+ bigint_t ( size ) *modulus;
+ bigint_t ( exponent_size ) *exponent;
+ size_t tmp_len = bigint_mod_exp_tmp_len ( modulus, exponent );
+ struct {
+ bigint_t ( size ) modulus;
+ bigint_t ( exponent_size ) exponent;
+ bigint_t ( size ) input;
+ bigint_t ( size ) output;
+ uint8_t tmp[tmp_len];
+ } __attribute__ (( packed )) *dynamic;
+
+ /* Free any existing dynamic storage */
+ rsa_free ( context );
+
+ /* Allocate dynamic storage */
+ dynamic = malloc ( sizeof ( *dynamic ) );
+ if ( ! dynamic )
+ return -ENOMEM;
+
+ /* Assign dynamic storage */
+ context->dynamic = dynamic;
+ context->modulus0 = &dynamic->modulus.element[0];
+ context->size = size;
+ context->max_len = modulus_len;
+ context->exponent0 = &dynamic->exponent.element[0];
+ context->exponent_size = exponent_size;
+ context->input0 = &dynamic->input.element[0];
+ context->output0 = &dynamic->output.element[0];
+ context->tmp = &dynamic->tmp;
+
+ return 0;
+}
+
+/**
+ * Parse RSA integer
+ *
+ * @v integer Integer to fill in
+ * @v raw ASN.1 cursor
+ * @ret rc Return status code
+ */
+static int rsa_parse_integer ( struct asn1_cursor *integer,
+ const struct asn1_cursor *raw ) {
+
+ /* Enter integer */
+ memcpy ( integer, raw, sizeof ( *integer ) );
+ asn1_enter ( integer, ASN1_INTEGER );
+
+ /* Skip initial sign byte if applicable */
+ if ( ( integer->len > 1 ) &&
+ ( *( ( uint8_t * ) integer->data ) == 0x00 ) ) {
+ integer->data++;
+ integer->len--;
+ }
+
+ /* Fail if cursor or integer are invalid */
+ if ( ! integer->len )
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * Parse RSA modulus and exponent
+ *
+ * @v modulus Modulus to fill in
+ * @v exponent Exponent to fill in
+ * @v raw ASN.1 cursor
+ * @ret rc Return status code
+ */
+static int rsa_parse_mod_exp ( struct asn1_cursor *modulus,
+ struct asn1_cursor *exponent,
+ const struct asn1_cursor *raw ) {
+ struct asn1_bit_string bits;
+ struct asn1_cursor cursor;
+ int is_private;
+ int rc;
+
+ /* Enter subjectPublicKeyInfo/RSAPrivateKey */
+ memcpy ( &cursor, raw, sizeof ( cursor ) );
+ asn1_enter ( &cursor, ASN1_SEQUENCE );
+
+ /* Determine key format */
+ if ( asn1_type ( &cursor ) == ASN1_INTEGER ) {
+
+ /* Private key */
+ is_private = 1;
+
+ /* Skip version */
+ asn1_skip_any ( &cursor );
+
+ } else {
+
+ /* Public key */
+ is_private = 0;
+
+ /* Skip algorithm */
+ asn1_skip ( &cursor, ASN1_SEQUENCE );
+
+ /* Enter subjectPublicKey */
+ if ( ( rc = asn1_integral_bit_string ( &cursor, &bits ) ) != 0 )
+ return rc;
+ cursor.data = bits.data;
+ cursor.len = bits.len;
+
+ /* Enter RSAPublicKey */
+ asn1_enter ( &cursor, ASN1_SEQUENCE );
+ }
+
+ /* Extract modulus */
+ if ( ( rc = rsa_parse_integer ( modulus, &cursor ) ) != 0 )
+ return rc;
+ asn1_skip_any ( &cursor );
+
+ /* Skip public exponent, if applicable */
+ if ( is_private )
+ asn1_skip ( &cursor, ASN1_INTEGER );
+
+ /* Extract publicExponent/privateExponent */
+ if ( ( rc = rsa_parse_integer ( exponent, &cursor ) ) != 0 )
+ return rc;
+
+ return 0;
+}
+
+/**
+ * Initialise RSA cipher
+ *
+ * @v ctx RSA context
+ * @v key Key
+ * @v key_len Length of key
+ * @ret rc Return status code
+ */
+static int rsa_init ( void *ctx, const void *key, size_t key_len ) {
+ struct rsa_context *context = ctx;
+ struct asn1_cursor modulus;
+ struct asn1_cursor exponent;
+ struct asn1_cursor cursor;
+ int rc;
+
+ /* Initialise context */
+ memset ( context, 0, sizeof ( *context ) );
+
+ /* Initialise cursor */
+ cursor.data = key;
+ cursor.len = key_len;
+
+ /* Parse modulus and exponent */
+ if ( ( rc = rsa_parse_mod_exp ( &modulus, &exponent, &cursor ) ) != 0 ){
+ DBGC ( context, "RSA %p invalid modulus/exponent:\n", context );
+ DBGC_HDA ( context, 0, cursor.data, cursor.len );
+ goto err_parse;
+ }
+
+ DBGC ( context, "RSA %p modulus:\n", context );
+ DBGC_HDA ( context, 0, modulus.data, modulus.len );
+ DBGC ( context, "RSA %p exponent:\n", context );
+ DBGC_HDA ( context, 0, exponent.data, exponent.len );
+
+ /* Allocate dynamic storage */
+ if ( ( rc = rsa_alloc ( context, modulus.len, exponent.len ) ) != 0 )
+ goto err_alloc;
+
+ /* Construct big integers */
+ bigint_init ( ( ( bigint_t ( context->size ) * ) context->modulus0 ),
+ modulus.data, modulus.len );
+ bigint_init ( ( ( bigint_t ( context->exponent_size ) * )
+ context->exponent0 ), exponent.data, exponent.len );
+
+ return 0;
+
+ rsa_free ( context );
+ err_alloc:
+ err_parse:
+ return rc;
+}
+
+/**
+ * Calculate RSA maximum output length
+ *
+ * @v ctx RSA context
+ * @ret max_len Maximum output length
+ */
+static size_t rsa_max_len ( void *ctx ) {
+ struct rsa_context *context = ctx;
+
+ return context->max_len;
+}
+
+/**
+ * Perform RSA cipher operation
+ *
+ * @v context RSA context
+ * @v in Input buffer
+ * @v out Output buffer
+ */
+static void rsa_cipher ( struct rsa_context *context,
+ const void *in, void *out ) {
+ bigint_t ( context->size ) *input = ( ( void * ) context->input0 );
+ bigint_t ( context->size ) *output = ( ( void * ) context->output0 );
+ bigint_t ( context->size ) *modulus = ( ( void * ) context->modulus0 );
+ bigint_t ( context->exponent_size ) *exponent =
+ ( ( void * ) context->exponent0 );
+
+ /* Initialise big integer */
+ bigint_init ( input, in, context->max_len );
+
+ /* Perform modular exponentiation */
+ bigint_mod_exp ( input, modulus, exponent, output, context->tmp );
+
+ /* Copy out result */
+ bigint_done ( output, out, context->max_len );
+}
+
+/**
+ * Encrypt using RSA
+ *
+ * @v ctx RSA context
+ * @v plaintext Plaintext
+ * @v plaintext_len Length of plaintext
+ * @v ciphertext Ciphertext
+ * @ret ciphertext_len Length of ciphertext, or negative error
+ */
+static int rsa_encrypt ( void *ctx, const void *plaintext,
+ size_t plaintext_len, void *ciphertext ) {
+ struct rsa_context *context = ctx;
+ void *temp;
+ uint8_t *encoded;
+ size_t max_len = ( context->max_len - 11 );
+ size_t random_nz_len = ( max_len - plaintext_len + 8 );
+ int rc;
+
+ /* Sanity check */
+ if ( plaintext_len > max_len ) {
+ DBGC ( context, "RSA %p plaintext too long (%zd bytes, max "
+ "%zd)\n", context, plaintext_len, max_len );
+ return -ERANGE;
+ }
+ DBGC ( context, "RSA %p encrypting:\n", context );
+ DBGC_HDA ( context, 0, plaintext, plaintext_len );
+
+ /* Construct encoded message (using the big integer output
+ * buffer as temporary storage)
+ */
+ temp = context->output0;
+ encoded = temp;
+ encoded[0] = 0x00;
+ encoded[1] = 0x02;
+ if ( ( rc = get_random_nz ( &encoded[2], random_nz_len ) ) != 0 ) {
+ DBGC ( context, "RSA %p could not generate random data: %s\n",
+ context, strerror ( rc ) );
+ return rc;
+ }
+ encoded[ 2 + random_nz_len ] = 0x00;
+ memcpy ( &encoded[ context->max_len - plaintext_len ],
+ plaintext, plaintext_len );
+
+ /* Encipher the encoded message */
+ rsa_cipher ( context, encoded, ciphertext );
+ DBGC ( context, "RSA %p encrypted:\n", context );
+ DBGC_HDA ( context, 0, ciphertext, context->max_len );
+
+ return context->max_len;
+}
+
+/**
+ * Decrypt using RSA
+ *
+ * @v ctx RSA context
+ * @v ciphertext Ciphertext
+ * @v ciphertext_len Ciphertext length
+ * @v plaintext Plaintext
+ * @ret plaintext_len Plaintext length, or negative error
+ */
+static int rsa_decrypt ( void *ctx, const void *ciphertext,
+ size_t ciphertext_len, void *plaintext ) {
+ struct rsa_context *context = ctx;
+ void *temp;
+ uint8_t *encoded;
+ uint8_t *end;
+ uint8_t *zero;
+ uint8_t *start;
+ size_t plaintext_len;
+
+ /* Sanity check */
+ if ( ciphertext_len != context->max_len ) {
+ DBGC ( context, "RSA %p ciphertext incorrect length (%zd "
+ "bytes, should be %zd)\n",
+ context, ciphertext_len, context->max_len );
+ return -ERANGE;
+ }
+ DBGC ( context, "RSA %p decrypting:\n", context );
+ DBGC_HDA ( context, 0, ciphertext, ciphertext_len );
+
+ /* Decipher the message (using the big integer input buffer as
+ * temporary storage)
+ */
+ temp = context->input0;
+ encoded = temp;
+ rsa_cipher ( context, ciphertext, encoded );
+
+ /* Parse the message */
+ end = ( encoded + context->max_len );
+ if ( ( encoded[0] != 0x00 ) || ( encoded[1] != 0x02 ) )
+ goto invalid;
+ zero = memchr ( &encoded[2], 0, ( end - &encoded[2] ) );
+ if ( ! zero )
+ goto invalid;
+ start = ( zero + 1 );
+ plaintext_len = ( end - start );
+
+ /* Copy out message */
+ memcpy ( plaintext, start, plaintext_len );
+ DBGC ( context, "RSA %p decrypted:\n", context );
+ DBGC_HDA ( context, 0, plaintext, plaintext_len );
+
+ return plaintext_len;
+
+ invalid:
+ DBGC ( context, "RSA %p invalid decrypted message:\n", context );
+ DBGC_HDA ( context, 0, encoded, context->max_len );
+ return -EINVAL;
+}
+
+/**
+ * Encode RSA digest
+ *
+ * @v context RSA context
+ * @v digest Digest algorithm
+ * @v value Digest value
+ * @v encoded Encoded digest
+ * @ret rc Return status code
+ */
+static int rsa_encode_digest ( struct rsa_context *context,
+ struct digest_algorithm *digest,
+ const void *value, void *encoded ) {
+ struct rsa_digestinfo_prefix *prefix;
+ size_t digest_len = digest->digestsize;
+ uint8_t *temp = encoded;
+ size_t digestinfo_len;
+ size_t max_len;
+ size_t pad_len;
+
+ /* Identify prefix */
+ prefix = rsa_find_prefix ( digest );
+ if ( ! prefix ) {
+ DBGC ( context, "RSA %p has no prefix for %s\n",
+ context, digest->name );
+ return -ENOTSUP;
+ }
+ digestinfo_len = ( prefix->len + digest_len );
+
+ /* Sanity check */
+ max_len = ( context->max_len - 11 );
+ if ( digestinfo_len > max_len ) {
+ DBGC ( context, "RSA %p %s digestInfo too long (%zd bytes, max"
+ "%zd)\n",
+ context, digest->name, digestinfo_len, max_len );
+ return -ERANGE;
+ }
+ DBGC ( context, "RSA %p encoding %s digest:\n",
+ context, digest->name );
+ DBGC_HDA ( context, 0, value, digest_len );
+
+ /* Construct encoded message */
+ *(temp++) = 0x00;
+ *(temp++) = 0x01;
+ pad_len = ( max_len - digestinfo_len + 8 );
+ memset ( temp, 0xff, pad_len );
+ temp += pad_len;
+ *(temp++) = 0x00;
+ memcpy ( temp, prefix->data, prefix->len );
+ temp += prefix->len;
+ memcpy ( temp, value, digest_len );
+ temp += digest_len;
+ assert ( temp == ( encoded + context->max_len ) );
+ DBGC ( context, "RSA %p encoded %s digest:\n", context, digest->name );
+ DBGC_HDA ( context, 0, encoded, context->max_len );
+
+ return 0;
+}
+
+/**
+ * Sign digest value using RSA
+ *
+ * @v ctx RSA context
+ * @v digest Digest algorithm
+ * @v value Digest value
+ * @v signature Signature
+ * @ret signature_len Signature length, or negative error
+ */
+static int rsa_sign ( void *ctx, struct digest_algorithm *digest,
+ const void *value, void *signature ) {
+ struct rsa_context *context = ctx;
+ void *temp;
+ int rc;
+
+ DBGC ( context, "RSA %p signing %s digest:\n", context, digest->name );
+ DBGC_HDA ( context, 0, value, digest->digestsize );
+
+ /* Encode digest (using the big integer output buffer as
+ * temporary storage)
+ */
+ temp = context->output0;
+ if ( ( rc = rsa_encode_digest ( context, digest, value, temp ) ) != 0 )
+ return rc;
+
+ /* Encipher the encoded digest */
+ rsa_cipher ( context, temp, signature );
+ DBGC ( context, "RSA %p signed %s digest:\n", context, digest->name );
+ DBGC_HDA ( context, 0, signature, context->max_len );
+
+ return context->max_len;
+}
+
+/**
+ * Verify signed digest value using RSA
+ *
+ * @v ctx RSA context
+ * @v digest Digest algorithm
+ * @v value Digest value
+ * @v signature Signature
+ * @v signature_len Signature length
+ * @ret rc Return status code
+ */
+static int rsa_verify ( void *ctx, struct digest_algorithm *digest,
+ const void *value, const void *signature,
+ size_t signature_len ) {
+ struct rsa_context *context = ctx;
+ void *temp;
+ void *expected;
+ void *actual;
+ int rc;
+
+ /* Sanity check */
+ if ( signature_len != context->max_len ) {
+ DBGC ( context, "RSA %p signature incorrect length (%zd "
+ "bytes, should be %zd)\n",
+ context, signature_len, context->max_len );
+ return -ERANGE;
+ }
+ DBGC ( context, "RSA %p verifying %s digest:\n",
+ context, digest->name );
+ DBGC_HDA ( context, 0, value, digest->digestsize );
+ DBGC_HDA ( context, 0, signature, signature_len );
+
+ /* Decipher the signature (using the big integer input buffer
+ * as temporary storage)
+ */
+ temp = context->input0;
+ expected = temp;
+ rsa_cipher ( context, signature, expected );
+ DBGC ( context, "RSA %p deciphered signature:\n", context );
+ DBGC_HDA ( context, 0, expected, context->max_len );
+
+ /* Encode digest (using the big integer output buffer as
+ * temporary storage)
+ */
+ temp = context->output0;
+ actual = temp;
+ if ( ( rc = rsa_encode_digest ( context, digest, value, actual ) ) !=0 )
+ return rc;
+
+ /* Verify the signature */
+ if ( memcmp ( actual, expected, context->max_len ) != 0 ) {
+ DBGC ( context, "RSA %p signature verification failed\n",
+ context );
+ return -EACCES_VERIFY;
+ }
+
+ DBGC ( context, "RSA %p signature verified successfully\n", context );
+ return 0;
+}
+
+/**
+ * Finalise RSA cipher
+ *
+ * @v ctx RSA context
+ */
+static void rsa_final ( void *ctx ) {
+ struct rsa_context *context = ctx;
+
+ rsa_free ( context );
+}
+
+/**
+ * Check for matching RSA public/private key pair
+ *
+ * @v private_key Private key
+ * @v private_key_len Private key length
+ * @v public_key Public key
+ * @v public_key_len Public key length
+ * @ret rc Return status code
+ */
+static int rsa_match ( const void *private_key, size_t private_key_len,
+ const void *public_key, size_t public_key_len ) {
+ struct asn1_cursor private_modulus;
+ struct asn1_cursor private_exponent;
+ struct asn1_cursor private_cursor;
+ struct asn1_cursor public_modulus;
+ struct asn1_cursor public_exponent;
+ struct asn1_cursor public_cursor;
+ int rc;
+
+ /* Initialise cursors */
+ private_cursor.data = private_key;
+ private_cursor.len = private_key_len;
+ public_cursor.data = public_key;
+ public_cursor.len = public_key_len;
+
+ /* Parse moduli and exponents */
+ if ( ( rc = rsa_parse_mod_exp ( &private_modulus, &private_exponent,
+ &private_cursor ) ) != 0 )
+ return rc;
+ if ( ( rc = rsa_parse_mod_exp ( &public_modulus, &public_exponent,
+ &public_cursor ) ) != 0 )
+ return rc;
+
+ /* Compare moduli */
+ if ( asn1_compare ( &private_modulus, &public_modulus ) != 0 )
+ return -ENOTTY;
+
+ return 0;
+}
+
+/** RSA public-key algorithm */
+struct pubkey_algorithm rsa_algorithm = {
+ .name = "rsa",
+ .ctxsize = sizeof ( struct rsa_context ),
+ .init = rsa_init,
+ .max_len = rsa_max_len,
+ .encrypt = rsa_encrypt,
+ .decrypt = rsa_decrypt,
+ .sign = rsa_sign,
+ .verify = rsa_verify,
+ .final = rsa_final,
+ .match = rsa_match,
+};