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 #include "mbedtls/bignum.h"
00034 
00035 #include <string.h>
00036 
00037 #if defined(MBEDTLS_ECP_C)
00038 #include "mbedtls/ecp.h"
00039 #endif
00040 
00041 #if defined(MBEDTLS_ECDSA_C)
00042 #include "mbedtls/ecdsa.h"
00043 #endif
00044 
00045 #if defined(MBEDTLS_PLATFORM_C)
00046 #include "mbedtls/platform.h"
00047 #else
00048 #include <stdlib.h>
00049 #define mbedtls_calloc    calloc
00050 #define mbedtls_free       free
00051 #endif
00052 
00053 #include <limits.h>
00054 
00055 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
00056 /* Implementation that should never be optimized out by the compiler */
00057 static void mbedtls_zeroize( void *v, size_t n ) {
00058     volatile unsigned char *p = v; while( n-- ) *p++ = 0;
00059 }
00060 #endif
00061 
00062 #if defined(MBEDTLS_RSA_C)
00063 static int rsa_can_do( mbedtls_pk_type_t type )
00064 {
00065     return( type == MBEDTLS_PK_RSA ||
00066             type == MBEDTLS_PK_RSASSA_PSS );
00067 }
00068 
00069 static size_t rsa_get_bitlen( const void *ctx )
00070 {
00071     return( 8 * ((const mbedtls_rsa_context *) ctx)->len );
00072 }
00073 
00074 static int rsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00075                    const unsigned char *hash, size_t hash_len,
00076                    const unsigned char *sig, size_t sig_len )
00077 {
00078     int ret;
00079 
00080 #if defined(MBEDTLS_HAVE_INT64)
00081     if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
00082         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
00083 #endif /* MBEDTLS_HAVE_INT64 */
00084 
00085     if( sig_len < ((mbedtls_rsa_context *) ctx)->len )
00086         return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
00087 
00088     if( ( ret = mbedtls_rsa_pkcs1_verify( (mbedtls_rsa_context *) ctx, NULL, NULL,
00089                                   MBEDTLS_RSA_PUBLIC, md_alg,
00090                                   (unsigned int) hash_len, hash, sig ) ) != 0 )
00091         return( ret );
00092 
00093     if( sig_len > ((mbedtls_rsa_context *) ctx)->len )
00094         return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
00095 
00096     return( 0 );
00097 }
00098 
00099 static int rsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00100                    const unsigned char *hash, size_t hash_len,
00101                    unsigned char *sig, size_t *sig_len,
00102                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00103 {
00104 #if defined(MBEDTLS_HAVE_INT64)
00105     if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
00106         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
00107 #endif /* MBEDTLS_HAVE_INT64 */
00108 
00109     *sig_len = ((mbedtls_rsa_context *) ctx)->len;
00110 
00111     return( mbedtls_rsa_pkcs1_sign( (mbedtls_rsa_context *) ctx, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
00112                 md_alg, (unsigned int) hash_len, hash, sig ) );
00113 }
00114 
00115 static int rsa_decrypt_wrap( void *ctx,
00116                     const unsigned char *input, size_t ilen,
00117                     unsigned char *output, size_t *olen, size_t osize,
00118                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00119 {
00120     if( ilen != ((mbedtls_rsa_context *) ctx)->len )
00121         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
00122 
00123     return( mbedtls_rsa_pkcs1_decrypt( (mbedtls_rsa_context *) ctx, f_rng, p_rng,
00124                 MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
00125 }
00126 
00127 static int rsa_encrypt_wrap( void *ctx,
00128                     const unsigned char *input, size_t ilen,
00129                     unsigned char *output, size_t *olen, size_t osize,
00130                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00131 {
00132     *olen = ((mbedtls_rsa_context *) ctx)->len;
00133 
00134     if( *olen > osize )
00135         return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE );
00136 
00137     return( mbedtls_rsa_pkcs1_encrypt( (mbedtls_rsa_context *) ctx,
00138                 f_rng, p_rng, MBEDTLS_RSA_PUBLIC, ilen, input, output ) );
00139 }
00140 
00141 static int rsa_check_pair_wrap( const void *pub, const void *prv )
00142 {
00143     return( mbedtls_rsa_check_pub_priv( (const mbedtls_rsa_context *) pub,
00144                                 (const mbedtls_rsa_context *) prv ) );
00145 }
00146 
00147 static void *rsa_alloc_wrap( void )
00148 {
00149     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_context ) );
00150 
00151     if( ctx != NULL )
00152         mbedtls_rsa_init( (mbedtls_rsa_context *) ctx, 0, 0 );
00153 
00154     return( ctx );
00155 }
00156 
00157 static void rsa_free_wrap( void *ctx )
00158 {
00159     mbedtls_rsa_free( (mbedtls_rsa_context *) ctx );
00160     mbedtls_free( ctx );
00161 }
00162 
00163 static void rsa_debug( const void *ctx, mbedtls_pk_debug_item *items )
00164 {
00165     items->type = MBEDTLS_PK_DEBUG_MPI;
00166     items->name = "rsa.N";
00167     items->value = &( ((mbedtls_rsa_context *) ctx)->N );
00168 
00169     items++;
00170 
00171     items->type = MBEDTLS_PK_DEBUG_MPI;
00172     items->name = "rsa.E";
00173     items->value = &( ((mbedtls_rsa_context *) ctx)->E );
00174 }
00175 
00176 const mbedtls_pk_info_t mbedtls_rsa_info = {
00177     MBEDTLS_PK_RSA,
00178     "RSA",
00179     rsa_get_bitlen,
00180     rsa_can_do,
00181     rsa_verify_wrap,
00182     rsa_sign_wrap,
00183     rsa_decrypt_wrap,
00184     rsa_encrypt_wrap,
00185     rsa_check_pair_wrap,
00186     rsa_alloc_wrap,
00187     rsa_free_wrap,
00188     rsa_debug,
00189 };
00190 #endif /* MBEDTLS_RSA_C */
00191 
00192 #if defined(MBEDTLS_ECP_C)
00193 /*
00194  * Generic EC key
00195  */
00196 static int eckey_can_do( mbedtls_pk_type_t type )
00197 {
00198     return( type == MBEDTLS_PK_ECKEY ||
00199             type == MBEDTLS_PK_ECKEY_DH ||
00200             type == MBEDTLS_PK_ECDSA );
00201 }
00202 
00203 static size_t eckey_get_bitlen( const void *ctx )
00204 {
00205     return( ((mbedtls_ecp_keypair *) ctx)->grp.pbits );
00206 }
00207 
00208 #if defined(MBEDTLS_ECDSA_C)
00209 /* Forward declarations */
00210 static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00211                        const unsigned char *hash, size_t hash_len,
00212                        const unsigned char *sig, size_t sig_len );
00213 
00214 static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00215                    const unsigned char *hash, size_t hash_len,
00216                    unsigned char *sig, size_t *sig_len,
00217                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
00218 
00219 static int eckey_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00220                        const unsigned char *hash, size_t hash_len,
00221                        const unsigned char *sig, size_t sig_len )
00222 {
00223     int ret;
00224     mbedtls_ecdsa_context ecdsa;
00225 
00226     mbedtls_ecdsa_init( &ecdsa );
00227 
00228     if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
00229         ret = ecdsa_verify_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len );
00230 
00231     mbedtls_ecdsa_free( &ecdsa );
00232 
00233     return( ret );
00234 }
00235 
00236 static int eckey_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00237                    const unsigned char *hash, size_t hash_len,
00238                    unsigned char *sig, size_t *sig_len,
00239                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00240 {
00241     int ret;
00242     mbedtls_ecdsa_context ecdsa;
00243 
00244     mbedtls_ecdsa_init( &ecdsa );
00245 
00246     if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
00247         ret = ecdsa_sign_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len,
00248                                f_rng, p_rng );
00249 
00250     mbedtls_ecdsa_free( &ecdsa );
00251 
00252     return( ret );
00253 }
00254 
00255 #endif /* MBEDTLS_ECDSA_C */
00256 
00257 static int eckey_check_pair( const void *pub, const void *prv )
00258 {
00259     return( mbedtls_ecp_check_pub_priv( (const mbedtls_ecp_keypair *) pub,
00260                                 (const mbedtls_ecp_keypair *) prv ) );
00261 }
00262 
00263 static void *eckey_alloc_wrap( void )
00264 {
00265     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );
00266 
00267     if( ctx != NULL )
00268         mbedtls_ecp_keypair_init( ctx );
00269 
00270     return( ctx );
00271 }
00272 
00273 static void eckey_free_wrap( void *ctx )
00274 {
00275     mbedtls_ecp_keypair_free( (mbedtls_ecp_keypair *) ctx );
00276     mbedtls_free( ctx );
00277 }
00278 
00279 static void eckey_debug( const void *ctx, mbedtls_pk_debug_item *items )
00280 {
00281     items->type = MBEDTLS_PK_DEBUG_ECP;
00282     items->name = "eckey.Q";
00283     items->value = &( ((mbedtls_ecp_keypair *) ctx)->Q );
00284 }
00285 
00286 const mbedtls_pk_info_t mbedtls_eckey_info = {
00287     MBEDTLS_PK_ECKEY,
00288     "EC",
00289     eckey_get_bitlen,
00290     eckey_can_do,
00291 #if defined(MBEDTLS_ECDSA_C)
00292     eckey_verify_wrap,
00293     eckey_sign_wrap,
00294 #else
00295     NULL,
00296     NULL,
00297 #endif
00298     NULL,
00299     NULL,
00300     eckey_check_pair,
00301     eckey_alloc_wrap,
00302     eckey_free_wrap,
00303     eckey_debug,
00304 };
00305 
00306 /*
00307  * EC key restricted to ECDH
00308  */
00309 static int eckeydh_can_do( mbedtls_pk_type_t type )
00310 {
00311     return( type == MBEDTLS_PK_ECKEY ||
00312             type == MBEDTLS_PK_ECKEY_DH );
00313 }
00314 
00315 const mbedtls_pk_info_t mbedtls_eckeydh_info = {
00316     MBEDTLS_PK_ECKEY_DH,
00317     "EC_DH",
00318     eckey_get_bitlen,         /* Same underlying key structure */
00319     eckeydh_can_do,
00320     NULL,
00321     NULL,
00322     NULL,
00323     NULL,
00324     eckey_check_pair,
00325     eckey_alloc_wrap,       /* Same underlying key structure */
00326     eckey_free_wrap,        /* Same underlying key structure */
00327     eckey_debug,            /* Same underlying key structure */
00328 };
00329 #endif /* MBEDTLS_ECP_C */
00330 
00331 #if defined(MBEDTLS_ECDSA_C)
00332 static int ecdsa_can_do( mbedtls_pk_type_t type )
00333 {
00334     return( type == MBEDTLS_PK_ECDSA );
00335 }
00336 
00337 static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00338                        const unsigned char *hash, size_t hash_len,
00339                        const unsigned char *sig, size_t sig_len )
00340 {
00341     int ret;
00342     ((void) md_alg);
00343 
00344     ret = mbedtls_ecdsa_read_signature( (mbedtls_ecdsa_context *) ctx,
00345                                 hash, hash_len, sig, sig_len );
00346 
00347     if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
00348         return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
00349 
00350     return( ret );
00351 }
00352 
00353 static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00354                    const unsigned char *hash, size_t hash_len,
00355                    unsigned char *sig, size_t *sig_len,
00356                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00357 {
00358     return( mbedtls_ecdsa_write_signature( (mbedtls_ecdsa_context *) ctx,
00359                 md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng ) );
00360 }
00361 
00362 static void *ecdsa_alloc_wrap( void )
00363 {
00364     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_context ) );
00365 
00366     if( ctx != NULL )
00367         mbedtls_ecdsa_init( (mbedtls_ecdsa_context *) ctx );
00368 
00369     return( ctx );
00370 }
00371 
00372 static void ecdsa_free_wrap( void *ctx )
00373 {
00374     mbedtls_ecdsa_free( (mbedtls_ecdsa_context *) ctx );
00375     mbedtls_free( ctx );
00376 }
00377 
00378 const mbedtls_pk_info_t mbedtls_ecdsa_info = {
00379     MBEDTLS_PK_ECDSA,
00380     "ECDSA",
00381     eckey_get_bitlen,     /* Compatible key structures */
00382     ecdsa_can_do,
00383     ecdsa_verify_wrap,
00384     ecdsa_sign_wrap,
00385     NULL,
00386     NULL,
00387     eckey_check_pair,   /* Compatible key structures */
00388     ecdsa_alloc_wrap,
00389     ecdsa_free_wrap,
00390     eckey_debug,        /* Compatible key structures */
00391 };
00392 #endif /* MBEDTLS_ECDSA_C */
00393 
00394 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
00395 /*
00396  * Support for alternative RSA-private implementations
00397  */
00398 
00399 static int rsa_alt_can_do( mbedtls_pk_type_t type )
00400 {
00401     return( type == MBEDTLS_PK_RSA );
00402 }
00403 
00404 static size_t rsa_alt_get_bitlen( const void *ctx )
00405 {
00406     const mbedtls_rsa_alt_context *rsa_alt = (const mbedtls_rsa_alt_context *) ctx;
00407 
00408     return( 8 * rsa_alt->key_len_func( rsa_alt->key ) );
00409 }
00410 
00411 static int rsa_alt_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00412                    const unsigned char *hash, size_t hash_len,
00413                    unsigned char *sig, size_t *sig_len,
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 #if defined(MBEDTLS_HAVE_INT64)
00419     if( UINT_MAX < hash_len )
00420         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
00421 #endif /* MBEDTLS_HAVE_INT64 */
00422 
00423     *sig_len = rsa_alt->key_len_func( rsa_alt->key );
00424 
00425     return( rsa_alt->sign_func( rsa_alt->key, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
00426                 md_alg, (unsigned int) hash_len, hash, sig ) );
00427 }
00428 
00429 static int rsa_alt_decrypt_wrap( void *ctx,
00430                     const unsigned char *input, size_t ilen,
00431                     unsigned char *output, size_t *olen, size_t osize,
00432                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00433 {
00434     mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
00435 
00436     ((void) f_rng);
00437     ((void) p_rng);
00438 
00439     if( ilen != rsa_alt->key_len_func( rsa_alt->key ) )
00440         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
00441 
00442     return( rsa_alt->decrypt_func( rsa_alt->key,
00443                 MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
00444 }
00445 
00446 #if defined(MBEDTLS_RSA_C)
00447 static int rsa_alt_check_pair( const void *pub, const void *prv )
00448 {
00449     unsigned char sig[MBEDTLS_MPI_MAX_SIZE];
00450     unsigned char hash[32];
00451     size_t sig_len = 0;
00452     int ret;
00453 
00454     if( rsa_alt_get_bitlen( prv ) != rsa_get_bitlen( pub ) )
00455         return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
00456 
00457     memset( hash, 0x2a, sizeof( hash ) );
00458 
00459     if( ( ret = rsa_alt_sign_wrap( (void *) prv, MBEDTLS_MD_NONE,
00460                                    hash, sizeof( hash ),
00461                                    sig, &sig_len, NULL, NULL ) ) != 0 )
00462     {
00463         return( ret );
00464     }
00465 
00466     if( rsa_verify_wrap( (void *) pub, MBEDTLS_MD_NONE,
00467                          hash, sizeof( hash ), sig, sig_len ) != 0 )
00468     {
00469         return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
00470     }
00471 
00472     return( 0 );
00473 }
00474 #endif /* MBEDTLS_RSA_C */
00475 
00476 static void *rsa_alt_alloc_wrap( void )
00477 {
00478     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_alt_context ) );
00479 
00480     if( ctx != NULL )
00481         memset( ctx, 0, sizeof( mbedtls_rsa_alt_context ) );
00482 
00483     return( ctx );
00484 }
00485 
00486 static void rsa_alt_free_wrap( void *ctx )
00487 {
00488     mbedtls_zeroize( ctx, sizeof( mbedtls_rsa_alt_context ) );
00489     mbedtls_free( ctx );
00490 }
00491 
00492 const mbedtls_pk_info_t mbedtls_rsa_alt_info = {
00493     MBEDTLS_PK_RSA_ALT,
00494     "RSA-alt",
00495     rsa_alt_get_bitlen,
00496     rsa_alt_can_do,
00497     NULL,
00498     rsa_alt_sign_wrap,
00499     rsa_alt_decrypt_wrap,
00500     NULL,
00501 #if defined(MBEDTLS_RSA_C)
00502     rsa_alt_check_pair,
00503 #else
00504     NULL,
00505 #endif
00506     rsa_alt_alloc_wrap,
00507     rsa_alt_free_wrap,
00508     NULL,
00509 };
00510 
00511 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
00512 
00513 #endif /* MBEDTLS_PK_C */