library/pk_wrap.c - mirror/mbed-tls - TrustedFirmware Git Browser

 /*
  *  Public Key abstraction layer: wrapper functions
  *
  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
  *  not use this file except in compliance with the License.
  *  You may obtain a copy of the License at
  *
  *  http://www.apache.org/licenses/LICENSE-2.0
  *
  *  Unless required by applicable law or agreed to in writing, software
  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  *
  *  This file is part of mbed TLS (https://tls.mbed.org)
  */

 #if !defined(MBEDTLS_CONFIG_FILE)
 #include "mbedtls/config.h"
 #else
 #include MBEDTLS_CONFIG_FILE
 #endif

 #if defined(MBEDTLS_PK_C)
 #include "mbedtls/pk_internal.h"

 /* Even if RSA not activated, for the sake of RSA-alt */
 #include "mbedtls/rsa.h"

 #include <string.h>

 #if defined(MBEDTLS_ECP_C)
 #include "mbedtls/ecp.h"
 #endif

 #if defined(MBEDTLS_ECDSA_C)
 #include "mbedtls/ecdsa.h"
 #endif

 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
 #include "mbedtls/platform_util.h"
 #endif

 #if defined(MBEDTLS_PLATFORM_C)
 #include "mbedtls/platform.h"
 #else
 #include <stdlib.h>
 #define mbedtls_calloc    calloc
 #define mbedtls_free       free
 #endif

 #include <limits.h>
 #include <stdint.h>

 #if defined(MBEDTLS_RSA_C)
 static int rsa_can_do( mbedtls_pk_type_t type )
 {
     return( type == MBEDTLS_PK_RSA ||
             type == MBEDTLS_PK_RSASSA_PSS );
 }

 static size_t rsa_get_bitlen( const void *ctx )
 {
     const mbedtls_rsa_context * rsa = (const mbedtls_rsa_context *) ctx;
     return( 8 * mbedtls_rsa_get_len( rsa ) );
 }

 static int rsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,
                    const unsigned char *sig, size_t sig_len )
 {
     int ret;
     mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
     size_t rsa_len = mbedtls_rsa_get_len( rsa );

 #if SIZE_MAX > UINT_MAX
     if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 #endif /* SIZE_MAX > UINT_MAX */

     if( sig_len < rsa_len )
         return( MBEDTLS_ERR_RSA_VERIFY_FAILED );

     if( ( ret = mbedtls_rsa_pkcs1_verify( rsa, NULL, NULL,
                                   MBEDTLS_RSA_PUBLIC, md_alg,
                                   (unsigned int) hash_len, hash, sig ) ) != 0 )
         return( ret );

     /* The buffer contains a valid signature followed by extra data.
      * We have a special error code for that so that so that callers can
      * use mbedtls_pk_verify() to check "Does the buffer start with a
      * valid signature?" and not just "Does the buffer contain a valid
      * signature?". */
     if( sig_len > rsa_len )
         return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );

     return( 0 );
 }

 static int rsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,
                    unsigned char *sig, size_t *sig_len,
                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
     mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;

 #if SIZE_MAX > UINT_MAX
     if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 #endif /* SIZE_MAX > UINT_MAX */

     *sig_len = mbedtls_rsa_get_len( rsa );

     return( mbedtls_rsa_pkcs1_sign( rsa, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
                 md_alg, (unsigned int) hash_len, hash, sig ) );
 }

 static int rsa_decrypt_wrap( void *ctx,
                     const unsigned char *input, size_t ilen,
                     unsigned char *output, size_t *olen, size_t osize,
                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
     mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;

     if( ilen != mbedtls_rsa_get_len( rsa ) )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );

     return( mbedtls_rsa_pkcs1_decrypt( rsa, f_rng, p_rng,
                 MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
 }

 static int rsa_encrypt_wrap( void *ctx,
                     const unsigned char *input, size_t ilen,
                     unsigned char *output, size_t *olen, size_t osize,
                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
     mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
     *olen = mbedtls_rsa_get_len( rsa );

     if( *olen > osize )
         return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE );

     return( mbedtls_rsa_pkcs1_encrypt( rsa, f_rng, p_rng, MBEDTLS_RSA_PUBLIC,
                                        ilen, input, output ) );
 }

 static int rsa_check_pair_wrap( const void *pub, const void *prv )
 {
     return( mbedtls_rsa_check_pub_priv( (const mbedtls_rsa_context *) pub,
                                 (const mbedtls_rsa_context *) prv ) );
 }

 static void *rsa_alloc_wrap( void )
 {
     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_context ) );

     if( ctx != NULL )
         mbedtls_rsa_init( (mbedtls_rsa_context *) ctx, 0, 0 );

     return( ctx );
 }

 static void rsa_free_wrap( void *ctx )
 {
     mbedtls_rsa_free( (mbedtls_rsa_context *) ctx );
     mbedtls_free( ctx );
 }

 static void rsa_debug( const void *ctx, mbedtls_pk_debug_item *items )
 {
     items->type = MBEDTLS_PK_DEBUG_MPI;
     items->name = "rsa.N";
     items->value = &( ((mbedtls_rsa_context *) ctx)->N );

     items++;

     items->type = MBEDTLS_PK_DEBUG_MPI;
     items->name = "rsa.E";
     items->value = &( ((mbedtls_rsa_context *) ctx)->E );
 }

 const mbedtls_pk_info_t mbedtls_rsa_info = {
     MBEDTLS_PK_RSA,
     "RSA",
     rsa_get_bitlen,
     rsa_can_do,
     rsa_verify_wrap,
     rsa_sign_wrap,
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     NULL,
     NULL,
 #endif
     rsa_decrypt_wrap,
     rsa_encrypt_wrap,
     rsa_check_pair_wrap,
     rsa_alloc_wrap,
     rsa_free_wrap,
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     NULL,
     NULL,
 #endif
     rsa_debug,
 };
 #endif /* MBEDTLS_RSA_C */

 #if defined(MBEDTLS_ECP_C)
 /*
  * Generic EC key
  */
 static int eckey_can_do( mbedtls_pk_type_t type )
 {
     return( type == MBEDTLS_PK_ECKEY ||
             type == MBEDTLS_PK_ECKEY_DH ||
             type == MBEDTLS_PK_ECDSA );
 }

 static size_t eckey_get_bitlen( const void *ctx )
 {
     return( ((mbedtls_ecp_keypair *) ctx)->grp.pbits );
 }

 #if defined(MBEDTLS_ECDSA_C)
 /* Forward declarations */
 static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
                        const unsigned char *hash, size_t hash_len,
                        const unsigned char *sig, size_t sig_len );

 static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,
                    unsigned char *sig, size_t *sig_len,
                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );

 static int eckey_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
                        const unsigned char *hash, size_t hash_len,
                        const unsigned char *sig, size_t sig_len )
 {
     int ret;
     mbedtls_ecdsa_context ecdsa;

     mbedtls_ecdsa_init( &ecdsa );

     if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
         ret = ecdsa_verify_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len );

     mbedtls_ecdsa_free( &ecdsa );

     return( ret );
 }

 static int eckey_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,
                    unsigned char *sig, size_t *sig_len,
                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
     int ret;
     mbedtls_ecdsa_context ecdsa;

     mbedtls_ecdsa_init( &ecdsa );

     if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
         ret = ecdsa_sign_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len,
                                f_rng, p_rng );

     mbedtls_ecdsa_free( &ecdsa );

     return( ret );
 }

 #if defined(MBEDTLS_ECP_RESTARTABLE)
 /* Forward declarations */
 static int ecdsa_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
                        const unsigned char *hash, size_t hash_len,
                        const unsigned char *sig, size_t sig_len,
                        void *rs_ctx );

 static int ecdsa_sign_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,
                    unsigned char *sig, size_t *sig_len,
                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
                    void *rs_ctx );

 /*
  * Restart context for ECDSA operations with ECKEY context
  *
  * We need to store an actual ECDSA context, as we need to pass the same to
  * the underlying ecdsa function, so we can't create it on the fly every time.
  */
 typedef struct
 {
     mbedtls_ecdsa_restart_ctx ecdsa_rs;
     mbedtls_ecdsa_context ecdsa_ctx;
 } eckey_restart_ctx;

 static void *eckey_rs_alloc( void )
 {
     eckey_restart_ctx *rs_ctx;

     void *ctx = mbedtls_calloc( 1, sizeof( eckey_restart_ctx ) );

     if( ctx != NULL )
     {
         rs_ctx = ctx;
         mbedtls_ecdsa_restart_init( &rs_ctx->ecdsa_rs );
         mbedtls_ecdsa_init( &rs_ctx->ecdsa_ctx );
     }

     return( ctx );
 }

 static void eckey_rs_free( void *ctx )
 {
     eckey_restart_ctx *rs_ctx;

     if( ctx == NULL)
         return;

     rs_ctx = ctx;
     mbedtls_ecdsa_restart_free( &rs_ctx->ecdsa_rs );
     mbedtls_ecdsa_free( &rs_ctx->ecdsa_ctx );

     mbedtls_free( ctx );
 }

 static int eckey_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
                        const unsigned char *hash, size_t hash_len,
                        const unsigned char *sig, size_t sig_len,
                        void *rs_ctx )
 {
     int ret;
     eckey_restart_ctx *rs = rs_ctx;

     /* Should never happen */
     if( rs == NULL )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );

     /* set up our own sub-context if needed (that is, on first run) */
     if( rs->ecdsa_ctx.grp.pbits == 0 )
         MBEDTLS_MPI_CHK( mbedtls_ecdsa_from_keypair( &rs->ecdsa_ctx, ctx ) );

     MBEDTLS_MPI_CHK( ecdsa_verify_rs_wrap( &rs->ecdsa_ctx,
                                            md_alg, hash, hash_len,
                                            sig, sig_len, &rs->ecdsa_rs ) );

 cleanup:
     return( ret );
 }

 static int eckey_sign_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,
                    unsigned char *sig, size_t *sig_len,
                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
                        void *rs_ctx )
 {
     int ret;
     eckey_restart_ctx *rs = rs_ctx;

     /* Should never happen */
     if( rs == NULL )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );

     /* set up our own sub-context if needed (that is, on first run) */
     if( rs->ecdsa_ctx.grp.pbits == 0 )
         MBEDTLS_MPI_CHK( mbedtls_ecdsa_from_keypair( &rs->ecdsa_ctx, ctx ) );

     MBEDTLS_MPI_CHK( ecdsa_sign_rs_wrap( &rs->ecdsa_ctx, md_alg,
                                          hash, hash_len, sig, sig_len,
                                          f_rng, p_rng, &rs->ecdsa_rs ) );

 cleanup:
     return( ret );
 }
 #endif /* MBEDTLS_ECP_RESTARTABLE */
 #endif /* MBEDTLS_ECDSA_C */

 static int eckey_check_pair( const void *pub, const void *prv )
 {
     return( mbedtls_ecp_check_pub_priv( (const mbedtls_ecp_keypair *) pub,
                                 (const mbedtls_ecp_keypair *) prv ) );
 }

 static void *eckey_alloc_wrap( void )
 {
     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );

     if( ctx != NULL )
         mbedtls_ecp_keypair_init( ctx );

     return( ctx );
 }

 static void eckey_free_wrap( void *ctx )
 {
     mbedtls_ecp_keypair_free( (mbedtls_ecp_keypair *) ctx );
     mbedtls_free( ctx );
 }

 static void eckey_debug( const void *ctx, mbedtls_pk_debug_item *items )
 {
     items->type = MBEDTLS_PK_DEBUG_ECP;
     items->name = "eckey.Q";
     items->value = &( ((mbedtls_ecp_keypair *) ctx)->Q );
 }

 const mbedtls_pk_info_t mbedtls_eckey_info = {
     MBEDTLS_PK_ECKEY,
     "EC",
     eckey_get_bitlen,
     eckey_can_do,
 #if defined(MBEDTLS_ECDSA_C)
     eckey_verify_wrap,
     eckey_sign_wrap,
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     eckey_verify_rs_wrap,
     eckey_sign_rs_wrap,
 #endif
 #else /* MBEDTLS_ECDSA_C */
     NULL,
     NULL,
 #endif /* MBEDTLS_ECDSA_C */
     NULL,
     NULL,
     eckey_check_pair,
     eckey_alloc_wrap,
     eckey_free_wrap,
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     eckey_rs_alloc,
     eckey_rs_free,
 #endif
     eckey_debug,
 };

 /*
  * EC key restricted to ECDH
  */
 static int eckeydh_can_do( mbedtls_pk_type_t type )
 {
     return( type == MBEDTLS_PK_ECKEY ||
             type == MBEDTLS_PK_ECKEY_DH );
 }

 const mbedtls_pk_info_t mbedtls_eckeydh_info = {
     MBEDTLS_PK_ECKEY_DH,
     "EC_DH",
     eckey_get_bitlen,         /* Same underlying key structure */
     eckeydh_can_do,
     NULL,
     NULL,
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     NULL,
     NULL,
 #endif
     NULL,
     NULL,
     eckey_check_pair,
     eckey_alloc_wrap,       /* Same underlying key structure */
     eckey_free_wrap,        /* Same underlying key structure */
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     NULL,
     NULL,
 #endif
     eckey_debug,            /* Same underlying key structure */
 };
 #endif /* MBEDTLS_ECP_C */

 #if defined(MBEDTLS_ECDSA_C)
 static int ecdsa_can_do( mbedtls_pk_type_t type )
 {
     return( type == MBEDTLS_PK_ECDSA );
 }

 static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
                        const unsigned char *hash, size_t hash_len,
                        const unsigned char *sig, size_t sig_len )
 {
     int ret;
     ((void) md_alg);

     ret = mbedtls_ecdsa_read_signature( (mbedtls_ecdsa_context *) ctx,
                                 hash, hash_len, sig, sig_len );

     if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
         return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );

     return( ret );
 }

 static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,
                    unsigned char *sig, size_t *sig_len,
                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
     return( mbedtls_ecdsa_write_signature( (mbedtls_ecdsa_context *) ctx,
                 md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng ) );
 }

 #if defined(MBEDTLS_ECP_RESTARTABLE)
 static int ecdsa_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
                        const unsigned char *hash, size_t hash_len,
                        const unsigned char *sig, size_t sig_len,
                        void *rs_ctx )
 {
     int ret;
     ((void) md_alg);

     ret = mbedtls_ecdsa_read_signature_restartable(
             (mbedtls_ecdsa_context *) ctx,
             hash, hash_len, sig, sig_len,
             (mbedtls_ecdsa_restart_ctx *) rs_ctx );

     if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
         return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );

     return( ret );
 }

 static int ecdsa_sign_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,
                    unsigned char *sig, size_t *sig_len,
                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
                    void *rs_ctx )
 {
     return( mbedtls_ecdsa_write_signature_restartable(
                 (mbedtls_ecdsa_context *) ctx,
                 md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng,
                 (mbedtls_ecdsa_restart_ctx *) rs_ctx ) );

 }
 #endif /* MBEDTLS_ECP_RESTARTABLE */

 static void *ecdsa_alloc_wrap( void )
 {
     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_context ) );

     if( ctx != NULL )
         mbedtls_ecdsa_init( (mbedtls_ecdsa_context *) ctx );

     return( ctx );
 }

 static void ecdsa_free_wrap( void *ctx )
 {
     mbedtls_ecdsa_free( (mbedtls_ecdsa_context *) ctx );
     mbedtls_free( ctx );
 }

 #if defined(MBEDTLS_ECP_RESTARTABLE)
 static void *ecdsa_rs_alloc( void )
 {
     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_restart_ctx ) );

     if( ctx != NULL )
         mbedtls_ecdsa_restart_init( ctx );

     return( ctx );
 }

 static void ecdsa_rs_free( void *ctx )
 {
     mbedtls_ecdsa_restart_free( ctx );
     mbedtls_free( ctx );
 }
 #endif /* MBEDTLS_ECP_RESTARTABLE */

 const mbedtls_pk_info_t mbedtls_ecdsa_info = {
     MBEDTLS_PK_ECDSA,
     "ECDSA",
     eckey_get_bitlen,     /* Compatible key structures */
     ecdsa_can_do,
     ecdsa_verify_wrap,
     ecdsa_sign_wrap,
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     ecdsa_verify_rs_wrap,
     ecdsa_sign_rs_wrap,
 #endif
     NULL,
     NULL,
     eckey_check_pair,   /* Compatible key structures */
     ecdsa_alloc_wrap,
     ecdsa_free_wrap,
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     ecdsa_rs_alloc,
     ecdsa_rs_free,
 #endif
     eckey_debug,        /* Compatible key structures */
 };
 #endif /* MBEDTLS_ECDSA_C */

 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
 /*
  * Support for alternative RSA-private implementations
  */

 static int rsa_alt_can_do( mbedtls_pk_type_t type )
 {
     return( type == MBEDTLS_PK_RSA );
 }

 static size_t rsa_alt_get_bitlen( const void *ctx )
 {
     const mbedtls_rsa_alt_context *rsa_alt = (const mbedtls_rsa_alt_context *) ctx;

     return( 8 * rsa_alt->key_len_func( rsa_alt->key ) );
 }

 static int rsa_alt_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,
                    unsigned char *sig, size_t *sig_len,
                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
     mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;

 #if SIZE_MAX > UINT_MAX
     if( UINT_MAX < hash_len )
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 #endif /* SIZE_MAX > UINT_MAX */

     *sig_len = rsa_alt->key_len_func( rsa_alt->key );

     return( rsa_alt->sign_func( rsa_alt->key, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
                 md_alg, (unsigned int) hash_len, hash, sig ) );
 }

 static int rsa_alt_decrypt_wrap( void *ctx,
                     const unsigned char *input, size_t ilen,
                     unsigned char *output, size_t *olen, size_t osize,
                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
     mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;

     ((void) f_rng);
     ((void) p_rng);

     if( ilen != rsa_alt->key_len_func( rsa_alt->key ) )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );

     return( rsa_alt->decrypt_func( rsa_alt->key,
                 MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
 }

 #if defined(MBEDTLS_RSA_C)
 static int rsa_alt_check_pair( const void *pub, const void *prv )
 {
     unsigned char sig[MBEDTLS_MPI_MAX_SIZE];
     unsigned char hash[32];
     size_t sig_len = 0;
     int ret;

     if( rsa_alt_get_bitlen( prv ) != rsa_get_bitlen( pub ) )
         return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );

     memset( hash, 0x2a, sizeof( hash ) );

     if( ( ret = rsa_alt_sign_wrap( (void *) prv, MBEDTLS_MD_NONE,
                                    hash, sizeof( hash ),
                                    sig, &sig_len, NULL, NULL ) ) != 0 )
     {
         return( ret );
     }

     if( rsa_verify_wrap( (void *) pub, MBEDTLS_MD_NONE,
                          hash, sizeof( hash ), sig, sig_len ) != 0 )
     {
         return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
     }

     return( 0 );
 }
 #endif /* MBEDTLS_RSA_C */

 static void *rsa_alt_alloc_wrap( void )
 {
     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_alt_context ) );

     if( ctx != NULL )
         memset( ctx, 0, sizeof( mbedtls_rsa_alt_context ) );

     return( ctx );
 }

 static void rsa_alt_free_wrap( void *ctx )
 {
     mbedtls_platform_zeroize( ctx, sizeof( mbedtls_rsa_alt_context ) );
     mbedtls_free( ctx );
 }

 const mbedtls_pk_info_t mbedtls_rsa_alt_info = {
     MBEDTLS_PK_RSA_ALT,
     "RSA-alt",
     rsa_alt_get_bitlen,
     rsa_alt_can_do,
     NULL,
     rsa_alt_sign_wrap,
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     NULL,
     NULL,
 #endif
     rsa_alt_decrypt_wrap,
     NULL,
 #if defined(MBEDTLS_RSA_C)
     rsa_alt_check_pair,
 #else
     NULL,
 #endif
     rsa_alt_alloc_wrap,
     rsa_alt_free_wrap,
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     NULL,
     NULL,
 #endif
     NULL,
 };

 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */

 #endif /* MBEDTLS_PK_C */
	/*
	* Public Key abstraction layer: wrapper functions
	*
	* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
	* SPDX-License-Identifier: Apache-2.0
	*
	* Licensed under the Apache License, Version 2.0 (the "License"); you may
	* not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*
	* This file is part of mbed TLS (https://tls.mbed.org)
	*/

	#if !defined(MBEDTLS_CONFIG_FILE)
	#include "mbedtls/config.h"
	#else
	#include MBEDTLS_CONFIG_FILE
	#endif

	#if defined(MBEDTLS_PK_C)
	#include "mbedtls/pk_internal.h"

	/* Even if RSA not activated, for the sake of RSA-alt */
	#include "mbedtls/rsa.h"

	#include <string.h>

	#if defined(MBEDTLS_ECP_C)
	#include "mbedtls/ecp.h"
	#endif

	#if defined(MBEDTLS_ECDSA_C)
	#include "mbedtls/ecdsa.h"
	#endif

	#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
	#include "mbedtls/platform_util.h"
	#endif

	#if defined(MBEDTLS_PLATFORM_C)
	#include "mbedtls/platform.h"
	#else
	#include <stdlib.h>
	#define mbedtls_calloc calloc
	#define mbedtls_free free
	#endif

	#include <limits.h>
	#include <stdint.h>

	#if defined(MBEDTLS_RSA_C)
	static int rsa_can_do( mbedtls_pk_type_t type )
	{
	return( type == MBEDTLS_PK_RSA \|\|
	type == MBEDTLS_PK_RSASSA_PSS );
	}

	static size_t rsa_get_bitlen( const void *ctx )
	{
	const mbedtls_rsa_context * rsa = (const mbedtls_rsa_context *) ctx;
	return( 8 * mbedtls_rsa_get_len( rsa ) );
	}

	static int rsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	const unsigned char *sig, size_t sig_len )
	{
	int ret;
	mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
	size_t rsa_len = mbedtls_rsa_get_len( rsa );

	#if SIZE_MAX > UINT_MAX
	if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
	return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
	#endif /* SIZE_MAX > UINT_MAX */

	if( sig_len < rsa_len )
	return( MBEDTLS_ERR_RSA_VERIFY_FAILED );

	if( ( ret = mbedtls_rsa_pkcs1_verify( rsa, NULL, NULL,
	MBEDTLS_RSA_PUBLIC, md_alg,
	(unsigned int) hash_len, hash, sig ) ) != 0 )
	return( ret );

	/* The buffer contains a valid signature followed by extra data.
	* We have a special error code for that so that so that callers can
	* use mbedtls_pk_verify() to check "Does the buffer start with a
	* valid signature?" and not just "Does the buffer contain a valid
	* signature?". */
	if( sig_len > rsa_len )
	return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );

	return( 0 );
	}

	static int rsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	unsigned char sig, size_t sig_len,
	int (f_rng)(void , unsigned char , size_t), void p_rng )
	{
	mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;

	#if SIZE_MAX > UINT_MAX
	if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
	return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
	#endif /* SIZE_MAX > UINT_MAX */

	*sig_len = mbedtls_rsa_get_len( rsa );

	return( mbedtls_rsa_pkcs1_sign( rsa, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
	md_alg, (unsigned int) hash_len, hash, sig ) );
	}

	static int rsa_decrypt_wrap( void *ctx,
	const unsigned char *input, size_t ilen,
	unsigned char output, size_t olen, size_t osize,
	int (f_rng)(void , unsigned char , size_t), void p_rng )
	{
	mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;

	if( ilen != mbedtls_rsa_get_len( rsa ) )
	return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );

	return( mbedtls_rsa_pkcs1_decrypt( rsa, f_rng, p_rng,
	MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
	}

	static int rsa_encrypt_wrap( void *ctx,
	const unsigned char *input, size_t ilen,
	unsigned char output, size_t olen, size_t osize,
	int (f_rng)(void , unsigned char , size_t), void p_rng )
	{
	mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
	*olen = mbedtls_rsa_get_len( rsa );

	if( *olen > osize )
	return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE );

	return( mbedtls_rsa_pkcs1_encrypt( rsa, f_rng, p_rng, MBEDTLS_RSA_PUBLIC,
	ilen, input, output ) );
	}

	static int rsa_check_pair_wrap( const void pub, const void prv )
	{
	return( mbedtls_rsa_check_pub_priv( (const mbedtls_rsa_context *) pub,
	(const mbedtls_rsa_context *) prv ) );
	}

	static void *rsa_alloc_wrap( void )
	{
	void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_context ) );

	if( ctx != NULL )
	mbedtls_rsa_init( (mbedtls_rsa_context *) ctx, 0, 0 );

	return( ctx );
	}

	static void rsa_free_wrap( void *ctx )
	{
	mbedtls_rsa_free( (mbedtls_rsa_context *) ctx );
	mbedtls_free( ctx );
	}

	static void rsa_debug( const void ctx, mbedtls_pk_debug_item items )
	{
	items->type = MBEDTLS_PK_DEBUG_MPI;
	items->name = "rsa.N";
	items->value = &( ((mbedtls_rsa_context *) ctx)->N );

	items++;

	items->type = MBEDTLS_PK_DEBUG_MPI;
	items->name = "rsa.E";
	items->value = &( ((mbedtls_rsa_context *) ctx)->E );
	}

	const mbedtls_pk_info_t mbedtls_rsa_info = {
	MBEDTLS_PK_RSA,
	"RSA",
	rsa_get_bitlen,
	rsa_can_do,
	rsa_verify_wrap,
	rsa_sign_wrap,
	#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
	NULL,
	NULL,
	#endif
	rsa_decrypt_wrap,
	rsa_encrypt_wrap,
	rsa_check_pair_wrap,
	rsa_alloc_wrap,
	rsa_free_wrap,
	#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
	NULL,
	NULL,
	#endif
	rsa_debug,
	};
	#endif /* MBEDTLS_RSA_C */

	#if defined(MBEDTLS_ECP_C)
	/*
	* Generic EC key
	*/
	static int eckey_can_do( mbedtls_pk_type_t type )
	{
	return( type == MBEDTLS_PK_ECKEY \|\|
	type == MBEDTLS_PK_ECKEY_DH \|\|
	type == MBEDTLS_PK_ECDSA );
	}

	static size_t eckey_get_bitlen( const void *ctx )
	{
	return( ((mbedtls_ecp_keypair *) ctx)->grp.pbits );
	}

	#if defined(MBEDTLS_ECDSA_C)
	/* Forward declarations */
	static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	const unsigned char *sig, size_t sig_len );

	static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	unsigned char sig, size_t sig_len,
	int (f_rng)(void , unsigned char , size_t), void p_rng );

	static int eckey_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	const unsigned char *sig, size_t sig_len )
	{
	int ret;
	mbedtls_ecdsa_context ecdsa;

	mbedtls_ecdsa_init( &ecdsa );

	if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
	ret = ecdsa_verify_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len );

	mbedtls_ecdsa_free( &ecdsa );

	return( ret );
	}

	static int eckey_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	unsigned char sig, size_t sig_len,
	int (f_rng)(void , unsigned char , size_t), void p_rng )
	{
	int ret;
	mbedtls_ecdsa_context ecdsa;

	mbedtls_ecdsa_init( &ecdsa );

	if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
	ret = ecdsa_sign_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len,
	f_rng, p_rng );

	mbedtls_ecdsa_free( &ecdsa );

	return( ret );
	}

	#if defined(MBEDTLS_ECP_RESTARTABLE)
	/* Forward declarations */
	static int ecdsa_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	const unsigned char *sig, size_t sig_len,
	void *rs_ctx );

	static int ecdsa_sign_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	unsigned char sig, size_t sig_len,
	int (f_rng)(void , unsigned char , size_t), void p_rng,
	void *rs_ctx );

	/*
	* Restart context for ECDSA operations with ECKEY context
	*
	* We need to store an actual ECDSA context, as we need to pass the same to
	* the underlying ecdsa function, so we can't create it on the fly every time.
	*/
	typedef struct
	{
	mbedtls_ecdsa_restart_ctx ecdsa_rs;
	mbedtls_ecdsa_context ecdsa_ctx;
	} eckey_restart_ctx;

	static void *eckey_rs_alloc( void )
	{
	eckey_restart_ctx *rs_ctx;

	void *ctx = mbedtls_calloc( 1, sizeof( eckey_restart_ctx ) );

	if( ctx != NULL )
	{
	rs_ctx = ctx;
	mbedtls_ecdsa_restart_init( &rs_ctx->ecdsa_rs );
	mbedtls_ecdsa_init( &rs_ctx->ecdsa_ctx );
	}

	return( ctx );
	}

	static void eckey_rs_free( void *ctx )
	{
	eckey_restart_ctx *rs_ctx;

	if( ctx == NULL)
	return;

	rs_ctx = ctx;
	mbedtls_ecdsa_restart_free( &rs_ctx->ecdsa_rs );
	mbedtls_ecdsa_free( &rs_ctx->ecdsa_ctx );

	mbedtls_free( ctx );
	}

	static int eckey_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	const unsigned char *sig, size_t sig_len,
	void *rs_ctx )
	{
	int ret;
	eckey_restart_ctx *rs = rs_ctx;

	/* Should never happen */
	if( rs == NULL )
	return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );

	/* set up our own sub-context if needed (that is, on first run) */
	if( rs->ecdsa_ctx.grp.pbits == 0 )
	MBEDTLS_MPI_CHK( mbedtls_ecdsa_from_keypair( &rs->ecdsa_ctx, ctx ) );

	MBEDTLS_MPI_CHK( ecdsa_verify_rs_wrap( &rs->ecdsa_ctx,
	md_alg, hash, hash_len,
	sig, sig_len, &rs->ecdsa_rs ) );

	cleanup:
	return( ret );
	}

	static int eckey_sign_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	unsigned char sig, size_t sig_len,
	int (f_rng)(void , unsigned char , size_t), void p_rng,
	void *rs_ctx )
	{
	int ret;
	eckey_restart_ctx *rs = rs_ctx;

	/* Should never happen */
	if( rs == NULL )
	return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );

	/* set up our own sub-context if needed (that is, on first run) */
	if( rs->ecdsa_ctx.grp.pbits == 0 )
	MBEDTLS_MPI_CHK( mbedtls_ecdsa_from_keypair( &rs->ecdsa_ctx, ctx ) );

	MBEDTLS_MPI_CHK( ecdsa_sign_rs_wrap( &rs->ecdsa_ctx, md_alg,
	hash, hash_len, sig, sig_len,
	f_rng, p_rng, &rs->ecdsa_rs ) );

	cleanup:
	return( ret );
	}
	#endif /* MBEDTLS_ECP_RESTARTABLE */
	#endif /* MBEDTLS_ECDSA_C */

	static int eckey_check_pair( const void pub, const void prv )
	{
	return( mbedtls_ecp_check_pub_priv( (const mbedtls_ecp_keypair *) pub,
	(const mbedtls_ecp_keypair *) prv ) );
	}

	static void *eckey_alloc_wrap( void )
	{
	void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );

	if( ctx != NULL )
	mbedtls_ecp_keypair_init( ctx );

	return( ctx );
	}

	static void eckey_free_wrap( void *ctx )
	{
	mbedtls_ecp_keypair_free( (mbedtls_ecp_keypair *) ctx );
	mbedtls_free( ctx );
	}

	static void eckey_debug( const void ctx, mbedtls_pk_debug_item items )
	{
	items->type = MBEDTLS_PK_DEBUG_ECP;
	items->name = "eckey.Q";
	items->value = &( ((mbedtls_ecp_keypair *) ctx)->Q );
	}

	const mbedtls_pk_info_t mbedtls_eckey_info = {
	MBEDTLS_PK_ECKEY,
	"EC",
	eckey_get_bitlen,
	eckey_can_do,
	#if defined(MBEDTLS_ECDSA_C)
	eckey_verify_wrap,
	eckey_sign_wrap,
	#if defined(MBEDTLS_ECP_RESTARTABLE)
	eckey_verify_rs_wrap,
	eckey_sign_rs_wrap,
	#endif
	#else /* MBEDTLS_ECDSA_C */
	NULL,
	NULL,
	#endif /* MBEDTLS_ECDSA_C */
	NULL,
	NULL,
	eckey_check_pair,
	eckey_alloc_wrap,
	eckey_free_wrap,
	#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
	eckey_rs_alloc,
	eckey_rs_free,
	#endif
	eckey_debug,
	};

	/*
	* EC key restricted to ECDH
	*/
	static int eckeydh_can_do( mbedtls_pk_type_t type )
	{
	return( type == MBEDTLS_PK_ECKEY \|\|
	type == MBEDTLS_PK_ECKEY_DH );
	}

	const mbedtls_pk_info_t mbedtls_eckeydh_info = {
	MBEDTLS_PK_ECKEY_DH,
	"EC_DH",
	eckey_get_bitlen, /* Same underlying key structure */
	eckeydh_can_do,
	NULL,
	NULL,
	#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
	NULL,
	NULL,
	#endif
	NULL,
	NULL,
	eckey_check_pair,
	eckey_alloc_wrap, /* Same underlying key structure */
	eckey_free_wrap, /* Same underlying key structure */
	#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
	NULL,
	NULL,
	#endif
	eckey_debug, /* Same underlying key structure */
	};
	#endif /* MBEDTLS_ECP_C */

	#if defined(MBEDTLS_ECDSA_C)
	static int ecdsa_can_do( mbedtls_pk_type_t type )
	{
	return( type == MBEDTLS_PK_ECDSA );
	}

	static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	const unsigned char *sig, size_t sig_len )
	{
	int ret;
	((void) md_alg);

	ret = mbedtls_ecdsa_read_signature( (mbedtls_ecdsa_context *) ctx,
	hash, hash_len, sig, sig_len );

	if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
	return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );

	return( ret );
	}

	static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	unsigned char sig, size_t sig_len,
	int (f_rng)(void , unsigned char , size_t), void p_rng )
	{
	return( mbedtls_ecdsa_write_signature( (mbedtls_ecdsa_context *) ctx,
	md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng ) );
	}

	#if defined(MBEDTLS_ECP_RESTARTABLE)
	static int ecdsa_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	const unsigned char *sig, size_t sig_len,
	void *rs_ctx )
	{
	int ret;
	((void) md_alg);

	ret = mbedtls_ecdsa_read_signature_restartable(
	(mbedtls_ecdsa_context *) ctx,
	hash, hash_len, sig, sig_len,
	(mbedtls_ecdsa_restart_ctx *) rs_ctx );

	if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
	return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );

	return( ret );
	}

	static int ecdsa_sign_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	unsigned char sig, size_t sig_len,
	int (f_rng)(void , unsigned char , size_t), void p_rng,
	void *rs_ctx )
	{
	return( mbedtls_ecdsa_write_signature_restartable(
	(mbedtls_ecdsa_context *) ctx,
	md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng,
	(mbedtls_ecdsa_restart_ctx *) rs_ctx ) );

	}
	#endif /* MBEDTLS_ECP_RESTARTABLE */

	static void *ecdsa_alloc_wrap( void )
	{
	void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_context ) );

	if( ctx != NULL )
	mbedtls_ecdsa_init( (mbedtls_ecdsa_context *) ctx );

	return( ctx );
	}

	static void ecdsa_free_wrap( void *ctx )
	{
	mbedtls_ecdsa_free( (mbedtls_ecdsa_context *) ctx );
	mbedtls_free( ctx );
	}

	#if defined(MBEDTLS_ECP_RESTARTABLE)
	static void *ecdsa_rs_alloc( void )
	{
	void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_restart_ctx ) );

	if( ctx != NULL )
	mbedtls_ecdsa_restart_init( ctx );

	return( ctx );
	}

	static void ecdsa_rs_free( void *ctx )
	{
	mbedtls_ecdsa_restart_free( ctx );
	mbedtls_free( ctx );
	}
	#endif /* MBEDTLS_ECP_RESTARTABLE */

	const mbedtls_pk_info_t mbedtls_ecdsa_info = {
	MBEDTLS_PK_ECDSA,
	"ECDSA",
	eckey_get_bitlen, /* Compatible key structures */
	ecdsa_can_do,
	ecdsa_verify_wrap,
	ecdsa_sign_wrap,
	#if defined(MBEDTLS_ECP_RESTARTABLE)
	ecdsa_verify_rs_wrap,
	ecdsa_sign_rs_wrap,
	#endif
	NULL,
	NULL,
	eckey_check_pair, /* Compatible key structures */
	ecdsa_alloc_wrap,
	ecdsa_free_wrap,
	#if defined(MBEDTLS_ECP_RESTARTABLE)
	ecdsa_rs_alloc,
	ecdsa_rs_free,
	#endif
	eckey_debug, /* Compatible key structures */
	};
	#endif /* MBEDTLS_ECDSA_C */

	#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
	/*
	* Support for alternative RSA-private implementations
	*/

	static int rsa_alt_can_do( mbedtls_pk_type_t type )
	{
	return( type == MBEDTLS_PK_RSA );
	}

	static size_t rsa_alt_get_bitlen( const void *ctx )
	{
	const mbedtls_rsa_alt_context rsa_alt = (const mbedtls_rsa_alt_context ) ctx;

	return( 8 * rsa_alt->key_len_func( rsa_alt->key ) );
	}

	static int rsa_alt_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
	const unsigned char *hash, size_t hash_len,
	unsigned char sig, size_t sig_len,
	int (f_rng)(void , unsigned char , size_t), void p_rng )
	{
	mbedtls_rsa_alt_context rsa_alt = (mbedtls_rsa_alt_context ) ctx;

	#if SIZE_MAX > UINT_MAX
	if( UINT_MAX < hash_len )
	return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
	#endif /* SIZE_MAX > UINT_MAX */

	*sig_len = rsa_alt->key_len_func( rsa_alt->key );

	return( rsa_alt->sign_func( rsa_alt->key, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
	md_alg, (unsigned int) hash_len, hash, sig ) );
	}

	static int rsa_alt_decrypt_wrap( void *ctx,
	const unsigned char *input, size_t ilen,
	unsigned char output, size_t olen, size_t osize,
	int (f_rng)(void , unsigned char , size_t), void p_rng )
	{
	mbedtls_rsa_alt_context rsa_alt = (mbedtls_rsa_alt_context ) ctx;

	((void) f_rng);
	((void) p_rng);

	if( ilen != rsa_alt->key_len_func( rsa_alt->key ) )
	return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );

	return( rsa_alt->decrypt_func( rsa_alt->key,
	MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
	}

	#if defined(MBEDTLS_RSA_C)
	static int rsa_alt_check_pair( const void pub, const void prv )
	{
	unsigned char sig[MBEDTLS_MPI_MAX_SIZE];
	unsigned char hash[32];
	size_t sig_len = 0;
	int ret;

	if( rsa_alt_get_bitlen( prv ) != rsa_get_bitlen( pub ) )
	return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );

	memset( hash, 0x2a, sizeof( hash ) );

	if( ( ret = rsa_alt_sign_wrap( (void *) prv, MBEDTLS_MD_NONE,
	hash, sizeof( hash ),
	sig, &sig_len, NULL, NULL ) ) != 0 )
	{
	return( ret );
	}

	if( rsa_verify_wrap( (void *) pub, MBEDTLS_MD_NONE,
	hash, sizeof( hash ), sig, sig_len ) != 0 )
	{
	return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
	}

	return( 0 );
	}
	#endif /* MBEDTLS_RSA_C */

	static void *rsa_alt_alloc_wrap( void )
	{
	void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_alt_context ) );

	if( ctx != NULL )
	memset( ctx, 0, sizeof( mbedtls_rsa_alt_context ) );

	return( ctx );
	}

	static void rsa_alt_free_wrap( void *ctx )
	{
	mbedtls_platform_zeroize( ctx, sizeof( mbedtls_rsa_alt_context ) );
	mbedtls_free( ctx );
	}

	const mbedtls_pk_info_t mbedtls_rsa_alt_info = {
	MBEDTLS_PK_RSA_ALT,
	"RSA-alt",
	rsa_alt_get_bitlen,
	rsa_alt_can_do,
	NULL,
	rsa_alt_sign_wrap,
	#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
	NULL,
	NULL,
	#endif
	rsa_alt_decrypt_wrap,
	NULL,
	#if defined(MBEDTLS_RSA_C)
	rsa_alt_check_pair,
	#else
	NULL,
	#endif
	rsa_alt_alloc_wrap,
	rsa_alt_free_wrap,
	#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
	NULL,
	NULL,
	#endif
	NULL,
	};

	#endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */

	#endif /* MBEDTLS_PK_C */