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 #include <limits.h>
00053 #include <stdint.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     const mbedtls_rsa_context * rsa = (const mbedtls_rsa_context *) ctx;
00072     return( 8 * mbedtls_rsa_get_len( rsa ) );
00073 }
00074 
00075 static int rsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00076                    const unsigned char *hash, size_t hash_len,
00077                    const unsigned char *sig, size_t sig_len )
00078 {
00079     int ret;
00080     mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
00081     size_t rsa_len = mbedtls_rsa_get_len( rsa );
00082 
00083 #if SIZE_MAX > UINT_MAX
00084     if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
00085         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
00086 #endif /* SIZE_MAX > UINT_MAX */
00087 
00088     if( sig_len < rsa_len )
00089         return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
00090 
00091     if( ( ret = mbedtls_rsa_pkcs1_verify( rsa, NULL, NULL,
00092                                   MBEDTLS_RSA_PUBLIC, md_alg,
00093                                   (unsigned int) hash_len, hash, sig ) ) != 0 )
00094         return( ret );
00095 
00096     if( sig_len > rsa_len )
00097         return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
00098 
00099     return( 0 );
00100 }
00101 
00102 static int rsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00103                    const unsigned char *hash, size_t hash_len,
00104                    unsigned char *sig, size_t *sig_len,
00105                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00106 {
00107     mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
00108 
00109 #if SIZE_MAX > UINT_MAX
00110     if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
00111         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
00112 #endif /* SIZE_MAX > UINT_MAX */
00113 
00114     *sig_len = mbedtls_rsa_get_len( rsa );
00115 
00116     return( mbedtls_rsa_pkcs1_sign( rsa, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
00117                 md_alg, (unsigned int) hash_len, hash, sig ) );
00118 }
00119 
00120 static int rsa_decrypt_wrap( void *ctx,
00121                     const unsigned char *input, size_t ilen,
00122                     unsigned char *output, size_t *olen, size_t osize,
00123                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00124 {
00125     mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
00126 
00127     if( ilen != mbedtls_rsa_get_len( rsa ) )
00128         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
00129 
00130     return( mbedtls_rsa_pkcs1_decrypt( rsa, f_rng, p_rng,
00131                 MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
00132 }
00133 
00134 static int rsa_encrypt_wrap( void *ctx,
00135                     const unsigned char *input, size_t ilen,
00136                     unsigned char *output, size_t *olen, size_t osize,
00137                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00138 {
00139     mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
00140     *olen = mbedtls_rsa_get_len( rsa );
00141 
00142     if( *olen > osize )
00143         return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE );
00144 
00145     return( mbedtls_rsa_pkcs1_encrypt( rsa, f_rng, p_rng, MBEDTLS_RSA_PUBLIC,
00146                                        ilen, input, output ) );
00147 }
00148 
00149 static int rsa_check_pair_wrap( const void *pub, const void *prv )
00150 {
00151     return( mbedtls_rsa_check_pub_priv( (const mbedtls_rsa_context *) pub,
00152                                 (const mbedtls_rsa_context *) prv ) );
00153 }
00154 
00155 static void *rsa_alloc_wrap( void )
00156 {
00157     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_context ) );
00158 
00159     if( ctx != NULL )
00160         mbedtls_rsa_init( (mbedtls_rsa_context *) ctx, 0, 0 );
00161 
00162     return( ctx );
00163 }
00164 
00165 static void rsa_free_wrap( void *ctx )
00166 {
00167     mbedtls_rsa_free( (mbedtls_rsa_context *) ctx );
00168     mbedtls_free( ctx );
00169 }
00170 
00171 static void rsa_debug( const void *ctx, mbedtls_pk_debug_item *items )
00172 {
00173     items->type = MBEDTLS_PK_DEBUG_MPI;
00174     items->name = "rsa.N";
00175     items->value = &( ((mbedtls_rsa_context *) ctx)->N );
00176 
00177     items++;
00178 
00179     items->type = MBEDTLS_PK_DEBUG_MPI;
00180     items->name = "rsa.E";
00181     items->value = &( ((mbedtls_rsa_context *) ctx)->E );
00182 }
00183 
00184 const mbedtls_pk_info_t mbedtls_rsa_info = {
00185     MBEDTLS_PK_RSA,
00186     "RSA",
00187     rsa_get_bitlen,
00188     rsa_can_do,
00189     rsa_verify_wrap,
00190     rsa_sign_wrap,
00191     rsa_decrypt_wrap,
00192     rsa_encrypt_wrap,
00193     rsa_check_pair_wrap,
00194     rsa_alloc_wrap,
00195     rsa_free_wrap,
00196     rsa_debug,
00197 };
00198 #endif /* MBEDTLS_RSA_C */
00199 
00200 #if defined(MBEDTLS_ECP_C)
00201 /*
00202  * Generic EC key
00203  */
00204 static int eckey_can_do( mbedtls_pk_type_t type )
00205 {
00206     return( type == MBEDTLS_PK_ECKEY ||
00207             type == MBEDTLS_PK_ECKEY_DH ||
00208             type == MBEDTLS_PK_ECDSA );
00209 }
00210 
00211 static size_t eckey_get_bitlen( const void *ctx )
00212 {
00213     return( ((mbedtls_ecp_keypair *) ctx)->grp.pbits );
00214 }
00215 
00216 #if defined(MBEDTLS_ECDSA_C)
00217 /* Forward declarations */
00218 static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00219                        const unsigned char *hash, size_t hash_len,
00220                        const unsigned char *sig, size_t sig_len );
00221 
00222 static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00223                    const unsigned char *hash, size_t hash_len,
00224                    unsigned char *sig, size_t *sig_len,
00225                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
00226 
00227 static int eckey_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00228                        const unsigned char *hash, size_t hash_len,
00229                        const unsigned char *sig, size_t sig_len )
00230 {
00231     int ret;
00232     mbedtls_ecdsa_context ecdsa;
00233 
00234     mbedtls_ecdsa_init( &ecdsa );
00235 
00236     if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
00237         ret = ecdsa_verify_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len );
00238 
00239     mbedtls_ecdsa_free( &ecdsa );
00240 
00241     return( ret );
00242 }
00243 
00244 static int eckey_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00245                    const unsigned char *hash, size_t hash_len,
00246                    unsigned char *sig, size_t *sig_len,
00247                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00248 {
00249     int ret;
00250     mbedtls_ecdsa_context ecdsa;
00251 
00252     mbedtls_ecdsa_init( &ecdsa );
00253 
00254     if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
00255         ret = ecdsa_sign_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len,
00256                                f_rng, p_rng );
00257 
00258     mbedtls_ecdsa_free( &ecdsa );
00259 
00260     return( ret );
00261 }
00262 
00263 #endif /* MBEDTLS_ECDSA_C */
00264 
00265 static int eckey_check_pair( const void *pub, const void *prv )
00266 {
00267     return( mbedtls_ecp_check_pub_priv( (const mbedtls_ecp_keypair *) pub,
00268                                 (const mbedtls_ecp_keypair *) prv ) );
00269 }
00270 
00271 static void *eckey_alloc_wrap( void )
00272 {
00273     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );
00274 
00275     if( ctx != NULL )
00276         mbedtls_ecp_keypair_init( ctx );
00277 
00278     return( ctx );
00279 }
00280 
00281 static void eckey_free_wrap( void *ctx )
00282 {
00283     mbedtls_ecp_keypair_free( (mbedtls_ecp_keypair *) ctx );
00284     mbedtls_free( ctx );
00285 }
00286 
00287 static void eckey_debug( const void *ctx, mbedtls_pk_debug_item *items )
00288 {
00289     items->type = MBEDTLS_PK_DEBUG_ECP;
00290     items->name = "eckey.Q";
00291     items->value = &( ((mbedtls_ecp_keypair *) ctx)->Q );
00292 }
00293 
00294 const mbedtls_pk_info_t mbedtls_eckey_info = {
00295     MBEDTLS_PK_ECKEY,
00296     "EC",
00297     eckey_get_bitlen,
00298     eckey_can_do,
00299 #if defined(MBEDTLS_ECDSA_C)
00300     eckey_verify_wrap,
00301     eckey_sign_wrap,
00302 #else
00303     NULL,
00304     NULL,
00305 #endif
00306     NULL,
00307     NULL,
00308     eckey_check_pair,
00309     eckey_alloc_wrap,
00310     eckey_free_wrap,
00311     eckey_debug,
00312 };
00313 
00314 /*
00315  * EC key restricted to ECDH
00316  */
00317 static int eckeydh_can_do( mbedtls_pk_type_t type )
00318 {
00319     return( type == MBEDTLS_PK_ECKEY ||
00320             type == MBEDTLS_PK_ECKEY_DH );
00321 }
00322 
00323 const mbedtls_pk_info_t mbedtls_eckeydh_info = {
00324     MBEDTLS_PK_ECKEY_DH,
00325     "EC_DH",
00326     eckey_get_bitlen,         /* Same underlying key structure */
00327     eckeydh_can_do,
00328     NULL,
00329     NULL,
00330     NULL,
00331     NULL,
00332     eckey_check_pair,
00333     eckey_alloc_wrap,       /* Same underlying key structure */
00334     eckey_free_wrap,        /* Same underlying key structure */
00335     eckey_debug,            /* Same underlying key structure */
00336 };
00337 #endif /* MBEDTLS_ECP_C */
00338 
00339 #if defined(MBEDTLS_ECDSA_C)
00340 static int ecdsa_can_do( mbedtls_pk_type_t type )
00341 {
00342     return( type == MBEDTLS_PK_ECDSA );
00343 }
00344 
00345 static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
00346                        const unsigned char *hash, size_t hash_len,
00347                        const unsigned char *sig, size_t sig_len )
00348 {
00349     int ret;
00350     ((void) md_alg);
00351 
00352     ret = mbedtls_ecdsa_read_signature( (mbedtls_ecdsa_context *) ctx,
00353                                 hash, hash_len, sig, sig_len );
00354 
00355     if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
00356         return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
00357 
00358     return( ret );
00359 }
00360 
00361 static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00362                    const unsigned char *hash, size_t hash_len,
00363                    unsigned char *sig, size_t *sig_len,
00364                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00365 {
00366     return( mbedtls_ecdsa_write_signature( (mbedtls_ecdsa_context *) ctx,
00367                 md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng ) );
00368 }
00369 
00370 static void *ecdsa_alloc_wrap( void )
00371 {
00372     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_context ) );
00373 
00374     if( ctx != NULL )
00375         mbedtls_ecdsa_init( (mbedtls_ecdsa_context *) ctx );
00376 
00377     return( ctx );
00378 }
00379 
00380 static void ecdsa_free_wrap( void *ctx )
00381 {
00382     mbedtls_ecdsa_free( (mbedtls_ecdsa_context *) ctx );
00383     mbedtls_free( ctx );
00384 }
00385 
00386 const mbedtls_pk_info_t mbedtls_ecdsa_info = {
00387     MBEDTLS_PK_ECDSA,
00388     "ECDSA",
00389     eckey_get_bitlen,     /* Compatible key structures */
00390     ecdsa_can_do,
00391     ecdsa_verify_wrap,
00392     ecdsa_sign_wrap,
00393     NULL,
00394     NULL,
00395     eckey_check_pair,   /* Compatible key structures */
00396     ecdsa_alloc_wrap,
00397     ecdsa_free_wrap,
00398     eckey_debug,        /* Compatible key structures */
00399 };
00400 #endif /* MBEDTLS_ECDSA_C */
00401 
00402 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
00403 /*
00404  * Support for alternative RSA-private implementations
00405  */
00406 
00407 static int rsa_alt_can_do( mbedtls_pk_type_t type )
00408 {
00409     return( type == MBEDTLS_PK_RSA );
00410 }
00411 
00412 static size_t rsa_alt_get_bitlen( const void *ctx )
00413 {
00414     const mbedtls_rsa_alt_context *rsa_alt = (const mbedtls_rsa_alt_context *) ctx;
00415 
00416     return( 8 * rsa_alt->key_len_func( rsa_alt->key ) );
00417 }
00418 
00419 static int rsa_alt_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
00420                    const unsigned char *hash, size_t hash_len,
00421                    unsigned char *sig, size_t *sig_len,
00422                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00423 {
00424     mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
00425 
00426 #if SIZE_MAX > UINT_MAX
00427     if( UINT_MAX < hash_len )
00428         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
00429 #endif /* SIZE_MAX > UINT_MAX */
00430 
00431     *sig_len = rsa_alt->key_len_func( rsa_alt->key );
00432 
00433     return( rsa_alt->sign_func( rsa_alt->key, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
00434                 md_alg, (unsigned int) hash_len, hash, sig ) );
00435 }
00436 
00437 static int rsa_alt_decrypt_wrap( void *ctx,
00438                     const unsigned char *input, size_t ilen,
00439                     unsigned char *output, size_t *olen, size_t osize,
00440                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
00441 {
00442     mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
00443 
00444     ((void) f_rng);
00445     ((void) p_rng);
00446 
00447     if( ilen != rsa_alt->key_len_func( rsa_alt->key ) )
00448         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
00449 
00450     return( rsa_alt->decrypt_func( rsa_alt->key,
00451                 MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
00452 }
00453 
00454 #if defined(MBEDTLS_RSA_C)
00455 static int rsa_alt_check_pair( const void *pub, const void *prv )
00456 {
00457     unsigned char sig[MBEDTLS_MPI_MAX_SIZE];
00458     unsigned char hash[32];
00459     size_t sig_len = 0;
00460     int ret;
00461 
00462     if( rsa_alt_get_bitlen( prv ) != rsa_get_bitlen( pub ) )
00463         return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
00464 
00465     memset( hash, 0x2a, sizeof( hash ) );
00466 
00467     if( ( ret = rsa_alt_sign_wrap( (void *) prv, MBEDTLS_MD_NONE,
00468                                    hash, sizeof( hash ),
00469                                    sig, &sig_len, NULL, NULL ) ) != 0 )
00470     {
00471         return( ret );
00472     }
00473 
00474     if( rsa_verify_wrap( (void *) pub, MBEDTLS_MD_NONE,
00475                          hash, sizeof( hash ), sig, sig_len ) != 0 )
00476     {
00477         return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
00478     }
00479 
00480     return( 0 );
00481 }
00482 #endif /* MBEDTLS_RSA_C */
00483 
00484 static void *rsa_alt_alloc_wrap( void )
00485 {
00486     void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_alt_context ) );
00487 
00488     if( ctx != NULL )
00489         memset( ctx, 0, sizeof( mbedtls_rsa_alt_context ) );
00490 
00491     return( ctx );
00492 }
00493 
00494 static void rsa_alt_free_wrap( void *ctx )
00495 {
00496     mbedtls_zeroize( ctx, sizeof( mbedtls_rsa_alt_context ) );
00497     mbedtls_free( ctx );
00498 }
00499 
00500 const mbedtls_pk_info_t mbedtls_rsa_alt_info = {
00501     MBEDTLS_PK_RSA_ALT,
00502     "RSA-alt",
00503     rsa_alt_get_bitlen,
00504     rsa_alt_can_do,
00505     NULL,
00506     rsa_alt_sign_wrap,
00507     rsa_alt_decrypt_wrap,
00508     NULL,
00509 #if defined(MBEDTLS_RSA_C)
00510     rsa_alt_check_pair,
00511 #else
00512     NULL,
00513 #endif
00514     rsa_alt_alloc_wrap,
00515     rsa_alt_free_wrap,
00516     NULL,
00517 };
00518 
00519 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
00520 
00521 #endif /* MBEDTLS_PK_C */