pk_wrap.c

00001 /*
00002  *  Public Key abstraction layer: wrapper functions
00003  *
00004  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
00005  *  SPDX-License-Identifier: Apache-2.0
00006  *
00007  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00008  *  not use this file except in compliance with the License.
00009  *  You may obtain a copy of the License at
00010  *
00011  *  http://www.apache.org/licenses/LICENSE-2.0
00012  *
00013  *  Unless required by applicable law or agreed to in writing, software
00014  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00015  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00016  *  See the License for the specific language governing permissions and
00017  *  limitations under the License.
00018  *
00019  *  This file is part of mbed TLS (https://tls.mbed.org)
00020  */
00021 
00022 #if !defined(MBEDTLS_CONFIG_FILE)
00023 #include "mbedtls/config.h"
00024 #else
00025 #include MBEDTLS_CONFIG_FILE
00026 #endif
00027 
00028 #if defined(MBEDTLS_PK_C)
00029 #include "mbedtls/pk_internal.h"
00030 
00031 /* Even if RSA not activated, for the sake of RSA-alt */
00032 #include "mbedtls/rsa.h"
00033 
00034 #include <string.h>
00035 
00036 #if defined(MBEDTLS_ECP_C)
00037 #include "mbedtls/ecp.h"
00038 #endif
00039 
00040 #if defined(MBEDTLS_ECDSA_C)
00041 #include "mbedtls/ecdsa.h"
00042 #endif
00043 
00044 #if defined(MBEDTLS_PLATFORM_C)
00045 #include "mbedtls/platform.h"
00046 #else
00047 #include <stdlib.h>
00048 #define mbedtls_calloc    calloc
00049 #define mbedtls_free       free
00050 #endif
00051 
00052 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
00053 /* Implementation that should never be optimized out by the compiler */
00054 static void mbedtls_zeroize( void *v, size_t n ) {
00055     volatile unsigned char *p = v; while( n-- ) *p++ = 0;
00056 }
00057 #endif
00058 
00059 #if defined(MBEDTLS_RSA_C)
00060 static int rsa_can_do( mbedtls_pk_type_t type )
00061 {
00062     return( type == MBEDTLS_PK_RSA ||
00063             type == MBEDTLS_PK_RSASSA_PSS );
00064 }
00065 
00066 static size_t rsa_get_bitlen( const void *ctx )
00067 {
00068     return( 8 * ((const mbedtls_rsa_context *) ctx)->len );
00069 }
00070 
00071 static int rsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00072                    const unsigned char *hash, size_t hash_len,
00073                    const unsigned char *sig, size_t sig_len )
00074 {
00075     int ret;
00076 
00077     if( sig_len < ((mbedtls_rsa_context *) ctx)->len )
00078         return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
00079 
00080     if( ( ret = mbedtls_rsa_pkcs1_verify( (mbedtls_rsa_context *) ctx, NULL, NULL,
00081                                   MBEDTLS_RSA_PUBLIC, md_alg,
00082                                   (unsigned int) hash_len, hash, sig ) ) != 0 )
00083         return( ret );
00084 
00085     if( sig_len > ((mbedtls_rsa_context *) ctx)->len )
00086         return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
00087 
00088     return( 0 );
00089 }
00090 
00091 static int rsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00092                    const unsigned char *hash, size_t hash_len,
00093                    unsigned char *sig, size_t *sig_len,
00094                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00095 {
00096     *sig_len = ((mbedtls_rsa_context *) ctx)->len;
00097 
00098     return( mbedtls_rsa_pkcs1_sign( (mbedtls_rsa_context *) ctx, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
00099                 md_alg, (unsigned int) hash_len, hash, sig ) );
00100 }
00101 
00102 static int rsa_decrypt_wrap( void *ctx,
00103                     const unsigned char *input, size_t ilen,
00104                     unsigned char *output, size_t *olen, size_t osize,
00105                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00106 {
00107     if( ilen != ((mbedtls_rsa_context *) ctx)->len )
00108         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
00109 
00110     return( mbedtls_rsa_pkcs1_decrypt( (mbedtls_rsa_context *) ctx, f_rng, p_rng,
00111                 MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
00112 }
00113 
00114 static int rsa_encrypt_wrap( void *ctx,
00115                     const unsigned char *input, size_t ilen,
00116                     unsigned char *output, size_t *olen, size_t osize,
00117                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00118 {
00119     *olen = ((mbedtls_rsa_context *) ctx)->len;
00120 
00121     if( *olen > osize )
00122         return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE );
00123 
00124     return( mbedtls_rsa_pkcs1_encrypt( (mbedtls_rsa_context *) ctx,
00125                 f_rng, p_rng, MBEDTLS_RSA_PUBLIC, ilen, input, output ) );
00126 }
00127 
00128 static int rsa_check_pair_wrap( const void *pub, const void *prv )
00129 {
00130     return( mbedtls_rsa_check_pub_priv( (const mbedtls_rsa_context *) pub,
00131                                 (const mbedtls_rsa_context *) prv ) );
00132 }
00133 
00134 static void *rsa_alloc_wrap( void )
00135 {
00136     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_context ) );
00137 
00138     if( ctx != NULL )
00139         mbedtls_rsa_init( (mbedtls_rsa_context *) ctx, 0, 0 );
00140 
00141     return( ctx );
00142 }
00143 
00144 static void rsa_free_wrap( void *ctx )
00145 {
00146     mbedtls_rsa_free( (mbedtls_rsa_context *) ctx );
00147     mbedtls_free( ctx );
00148 }
00149 
00150 static void rsa_debug( const void *ctx, mbedtls_pk_debug_item *items )
00151 {
00152     items->type = MBEDTLS_PK_DEBUG_MPI;
00153     items->name = "rsa.N";
00154     items->value = &( ((mbedtls_rsa_context *) ctx)->N );
00155 
00156     items++;
00157 
00158     items->type = MBEDTLS_PK_DEBUG_MPI;
00159     items->name = "rsa.E";
00160     items->value = &( ((mbedtls_rsa_context *) ctx)->E );
00161 }
00162 
00163 const mbedtls_pk_info_t mbedtls_rsa_info = {
00164     MBEDTLS_PK_RSA,
00165     "RSA",
00166     rsa_get_bitlen,
00167     rsa_can_do,
00168     rsa_verify_wrap,
00169     rsa_sign_wrap,
00170     rsa_decrypt_wrap,
00171     rsa_encrypt_wrap,
00172     rsa_check_pair_wrap,
00173     rsa_alloc_wrap,
00174     rsa_free_wrap,
00175     rsa_debug,
00176 };
00177 #endif /* MBEDTLS_RSA_C */
00178 
00179 #if defined(MBEDTLS_ECP_C)
00180 /*
00181  * Generic EC key
00182  */
00183 static int eckey_can_do( mbedtls_pk_type_t type )
00184 {
00185     return( type == MBEDTLS_PK_ECKEY ||
00186             type == MBEDTLS_PK_ECKEY_DH ||
00187             type == MBEDTLS_PK_ECDSA );
00188 }
00189 
00190 static size_t eckey_get_bitlen( const void *ctx )
00191 {
00192     return( ((mbedtls_ecp_keypair *) ctx)->grp.pbits );
00193 }
00194 
00195 #if defined(MBEDTLS_ECDSA_C)
00196 /* Forward declarations */
00197 static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00198                        const unsigned char *hash, size_t hash_len,
00199                        const unsigned char *sig, size_t sig_len );
00200 
00201 static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00202                    const unsigned char *hash, size_t hash_len,
00203                    unsigned char *sig, size_t *sig_len,
00204                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
00205 
00206 static int eckey_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00207                        const unsigned char *hash, size_t hash_len,
00208                        const unsigned char *sig, size_t sig_len )
00209 {
00210     int ret;
00211     mbedtls_ecdsa_context ecdsa;
00212 
00213     mbedtls_ecdsa_init( &ecdsa );
00214 
00215     if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
00216         ret = ecdsa_verify_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len );
00217 
00218     mbedtls_ecdsa_free( &ecdsa );
00219 
00220     return( ret );
00221 }
00222 
00223 static int eckey_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00224                    const unsigned char *hash, size_t hash_len,
00225                    unsigned char *sig, size_t *sig_len,
00226                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00227 {
00228     int ret;
00229     mbedtls_ecdsa_context ecdsa;
00230 
00231     mbedtls_ecdsa_init( &ecdsa );
00232 
00233     if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
00234         ret = ecdsa_sign_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len,
00235                                f_rng, p_rng );
00236 
00237     mbedtls_ecdsa_free( &ecdsa );
00238 
00239     return( ret );
00240 }
00241 
00242 #endif /* MBEDTLS_ECDSA_C */
00243 
00244 static int eckey_check_pair( const void *pub, const void *prv )
00245 {
00246     return( mbedtls_ecp_check_pub_priv( (const mbedtls_ecp_keypair *) pub,
00247                                 (const mbedtls_ecp_keypair *) prv ) );
00248 }
00249 
00250 static void *eckey_alloc_wrap( void )
00251 {
00252     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );
00253 
00254     if( ctx != NULL )
00255         mbedtls_ecp_keypair_init( ctx );
00256 
00257     return( ctx );
00258 }
00259 
00260 static void eckey_free_wrap( void *ctx )
00261 {
00262     mbedtls_ecp_keypair_free( (mbedtls_ecp_keypair *) ctx );
00263     mbedtls_free( ctx );
00264 }
00265 
00266 static void eckey_debug( const void *ctx, mbedtls_pk_debug_item *items )
00267 {
00268     items->type = MBEDTLS_PK_DEBUG_ECP;
00269     items->name = "eckey.Q";
00270     items->value = &( ((mbedtls_ecp_keypair *) ctx)->Q );
00271 }
00272 
00273 const mbedtls_pk_info_t mbedtls_eckey_info = {
00274     MBEDTLS_PK_ECKEY,
00275     "EC",
00276     eckey_get_bitlen,
00277     eckey_can_do,
00278 #if defined(MBEDTLS_ECDSA_C)
00279     eckey_verify_wrap,
00280     eckey_sign_wrap,
00281 #else
00282     NULL,
00283     NULL,
00284 #endif
00285     NULL,
00286     NULL,
00287     eckey_check_pair,
00288     eckey_alloc_wrap,
00289     eckey_free_wrap,
00290     eckey_debug,
00291 };
00292 
00293 /*
00294  * EC key restricted to ECDH
00295  */
00296 static int eckeydh_can_do( mbedtls_pk_type_t type )
00297 {
00298     return( type == MBEDTLS_PK_ECKEY ||
00299             type == MBEDTLS_PK_ECKEY_DH );
00300 }
00301 
00302 const mbedtls_pk_info_t mbedtls_eckeydh_info = {
00303     MBEDTLS_PK_ECKEY_DH,
00304     "EC_DH",
00305     eckey_get_bitlen,         /* Same underlying key structure */
00306     eckeydh_can_do,
00307     NULL,
00308     NULL,
00309     NULL,
00310     NULL,
00311     eckey_check_pair,
00312     eckey_alloc_wrap,       /* Same underlying key structure */
00313     eckey_free_wrap,        /* Same underlying key structure */
00314     eckey_debug,            /* Same underlying key structure */
00315 };
00316 #endif /* MBEDTLS_ECP_C */
00317 
00318 #if defined(MBEDTLS_ECDSA_C)
00319 static int ecdsa_can_do( mbedtls_pk_type_t type )
00320 {
00321     return( type == MBEDTLS_PK_ECDSA );
00322 }
00323 
00324 static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00325                        const unsigned char *hash, size_t hash_len,
00326                        const unsigned char *sig, size_t sig_len )
00327 {
00328     int ret;
00329     ((void) md_alg);
00330 
00331     ret = mbedtls_ecdsa_read_signature( (mbedtls_ecdsa_context *) ctx,
00332                                 hash, hash_len, sig, sig_len );
00333 
00334     if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
00335         return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
00336 
00337     return( ret );
00338 }
00339 
00340 static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00341                    const unsigned char *hash, size_t hash_len,
00342                    unsigned char *sig, size_t *sig_len,
00343                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00344 {
00345     return( mbedtls_ecdsa_write_signature( (mbedtls_ecdsa_context *) ctx,
00346                 md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng ) );
00347 }
00348 
00349 static void *ecdsa_alloc_wrap( void )
00350 {
00351     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_context ) );
00352 
00353     if( ctx != NULL )
00354         mbedtls_ecdsa_init( (mbedtls_ecdsa_context *) ctx );
00355 
00356     return( ctx );
00357 }
00358 
00359 static void ecdsa_free_wrap( void *ctx )
00360 {
00361     mbedtls_ecdsa_free( (mbedtls_ecdsa_context *) ctx );
00362     mbedtls_free( ctx );
00363 }
00364 
00365 const mbedtls_pk_info_t mbedtls_ecdsa_info = {
00366     MBEDTLS_PK_ECDSA,
00367     "ECDSA",
00368     eckey_get_bitlen,     /* Compatible key structures */
00369     ecdsa_can_do,
00370     ecdsa_verify_wrap,
00371     ecdsa_sign_wrap,
00372     NULL,
00373     NULL,
00374     eckey_check_pair,   /* Compatible key structures */
00375     ecdsa_alloc_wrap,
00376     ecdsa_free_wrap,
00377     eckey_debug,        /* Compatible key structures */
00378 };
00379 #endif /* MBEDTLS_ECDSA_C */
00380 
00381 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
00382 /*
00383  * Support for alternative RSA-private implementations
00384  */
00385 
00386 static int rsa_alt_can_do( mbedtls_pk_type_t type )
00387 {
00388     return( type == MBEDTLS_PK_RSA );
00389 }
00390 
00391 static size_t rsa_alt_get_bitlen( const void *ctx )
00392 {
00393     const mbedtls_rsa_alt_context *rsa_alt = (const mbedtls_rsa_alt_context *) ctx;
00394 
00395     return( 8 * rsa_alt->key_len_func( rsa_alt->key ) );
00396 }
00397 
00398 static int rsa_alt_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00399                    const unsigned char *hash, size_t hash_len,
00400                    unsigned char *sig, size_t *sig_len,
00401                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00402 {
00403     mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
00404 
00405     *sig_len = rsa_alt->key_len_func( rsa_alt->key );
00406 
00407     return( rsa_alt->sign_func( rsa_alt->key, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
00408                 md_alg, (unsigned int) hash_len, hash, sig ) );
00409 }
00410 
00411 static int rsa_alt_decrypt_wrap( void *ctx,
00412                     const unsigned char *input, size_t ilen,
00413                     unsigned char *output, size_t *olen, size_t osize,
00414                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00415 {
00416     mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
00417 
00418     ((void) f_rng);
00419     ((void) p_rng);
00420 
00421     if( ilen != rsa_alt->key_len_func( rsa_alt->key ) )
00422         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
00423 
00424     return( rsa_alt->decrypt_func( rsa_alt->key,
00425                 MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
00426 }
00427 
00428 #if defined(MBEDTLS_RSA_C)
00429 static int rsa_alt_check_pair( const void *pub, const void *prv )
00430 {
00431     unsigned char sig[MBEDTLS_MPI_MAX_SIZE];
00432     unsigned char hash[32];
00433     size_t sig_len = 0;
00434     int ret;
00435 
00436     if( rsa_alt_get_bitlen( prv ) != rsa_get_bitlen( pub ) )
00437         return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
00438 
00439     memset( hash, 0x2a, sizeof( hash ) );
00440 
00441     if( ( ret = rsa_alt_sign_wrap( (void *) prv, MBEDTLS_MD_NONE,
00442                                    hash, sizeof( hash ),
00443                                    sig, &sig_len, NULL, NULL ) ) != 0 )
00444     {
00445         return( ret );
00446     }
00447 
00448     if( rsa_verify_wrap( (void *) pub, MBEDTLS_MD_NONE,
00449                          hash, sizeof( hash ), sig, sig_len ) != 0 )
00450     {
00451         return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
00452     }
00453 
00454     return( 0 );
00455 }
00456 #endif /* MBEDTLS_RSA_C */
00457 
00458 static void *rsa_alt_alloc_wrap( void )
00459 {
00460     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_alt_context ) );
00461 
00462     if( ctx != NULL )
00463         memset( ctx, 0, sizeof( mbedtls_rsa_alt_context ) );
00464 
00465     return( ctx );
00466 }
00467 
00468 static void rsa_alt_free_wrap( void *ctx )
00469 {
00470     mbedtls_zeroize( ctx, sizeof( mbedtls_rsa_alt_context ) );
00471     mbedtls_free( ctx );
00472 }
00473 
00474 const mbedtls_pk_info_t mbedtls_rsa_alt_info = {
00475     MBEDTLS_PK_RSA_ALT,
00476     "RSA-alt",
00477     rsa_alt_get_bitlen,
00478     rsa_alt_can_do,
00479     NULL,
00480     rsa_alt_sign_wrap,
00481     rsa_alt_decrypt_wrap,
00482     NULL,
00483 #if defined(MBEDTLS_RSA_C)
00484     rsa_alt_check_pair,
00485 #else
00486     NULL,
00487 #endif
00488     rsa_alt_alloc_wrap,
00489     rsa_alt_free_wrap,
00490     NULL,
00491 };
00492 
00493 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
00494 
00495 #endif /* MBEDTLS_PK_C */