[398] | 1 | /*
|
---|
| 2 | * Elliptic curve DSA
|
---|
| 3 | *
|
---|
| 4 | * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
|
---|
| 5 | * SPDX-License-Identifier: Apache-2.0
|
---|
| 6 | *
|
---|
| 7 | * Licensed under the Apache License, Version 2.0 (the "License"); you may
|
---|
| 8 | * not use this file except in compliance with the License.
|
---|
| 9 | * You may obtain a copy of the License at
|
---|
| 10 | *
|
---|
| 11 | * http://www.apache.org/licenses/LICENSE-2.0
|
---|
| 12 | *
|
---|
| 13 | * Unless required by applicable law or agreed to in writing, software
|
---|
| 14 | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
---|
| 15 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
---|
| 16 | * See the License for the specific language governing permissions and
|
---|
| 17 | * limitations under the License.
|
---|
| 18 | *
|
---|
| 19 | * This file is part of mbed TLS (https://tls.mbed.org)
|
---|
| 20 | */
|
---|
| 21 |
|
---|
| 22 | /*
|
---|
| 23 | * References:
|
---|
| 24 | *
|
---|
| 25 | * SEC1 http://www.secg.org/index.php?action=secg,docs_secg
|
---|
| 26 | */
|
---|
| 27 |
|
---|
| 28 | #if !defined(MBEDTLS_CONFIG_FILE)
|
---|
| 29 | #include "mbedtls/config.h"
|
---|
| 30 | #else
|
---|
| 31 | #include MBEDTLS_CONFIG_FILE
|
---|
| 32 | #endif
|
---|
| 33 |
|
---|
| 34 | #if defined(MBEDTLS_ECDSA_C)
|
---|
| 35 |
|
---|
| 36 | #include "mbedtls/ecdsa.h"
|
---|
| 37 | #include "mbedtls/asn1write.h"
|
---|
| 38 |
|
---|
| 39 | #include <string.h>
|
---|
| 40 |
|
---|
| 41 | #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
|
---|
| 42 | #include "mbedtls/hmac_drbg.h"
|
---|
| 43 | #endif
|
---|
| 44 |
|
---|
| 45 | #if defined(MBEDTLS_PLATFORM_C)
|
---|
| 46 | #include "mbedtls/platform.h"
|
---|
| 47 | #else
|
---|
| 48 | #include <stdlib.h>
|
---|
| 49 | #define mbedtls_calloc calloc
|
---|
| 50 | #define mbedtls_free free
|
---|
| 51 | #endif
|
---|
| 52 |
|
---|
| 53 | #include "mbedtls/platform_util.h"
|
---|
| 54 |
|
---|
| 55 | /* Parameter validation macros based on platform_util.h */
|
---|
| 56 | #define ECDSA_VALIDATE_RET( cond ) \
|
---|
| 57 | MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
|
---|
| 58 | #define ECDSA_VALIDATE( cond ) \
|
---|
| 59 | MBEDTLS_INTERNAL_VALIDATE( cond )
|
---|
| 60 |
|
---|
| 61 | #if defined(MBEDTLS_ECP_RESTARTABLE)
|
---|
| 62 |
|
---|
| 63 | /*
|
---|
| 64 | * Sub-context for ecdsa_verify()
|
---|
| 65 | */
|
---|
| 66 | struct mbedtls_ecdsa_restart_ver
|
---|
| 67 | {
|
---|
| 68 | mbedtls_mpi u1, u2; /* intermediate values */
|
---|
| 69 | enum { /* what to do next? */
|
---|
| 70 | ecdsa_ver_init = 0, /* getting started */
|
---|
| 71 | ecdsa_ver_muladd, /* muladd step */
|
---|
| 72 | } state;
|
---|
| 73 | };
|
---|
| 74 |
|
---|
| 75 | /*
|
---|
| 76 | * Init verify restart sub-context
|
---|
| 77 | */
|
---|
| 78 | static void ecdsa_restart_ver_init( mbedtls_ecdsa_restart_ver_ctx *ctx )
|
---|
| 79 | {
|
---|
| 80 | mbedtls_mpi_init( &ctx->u1 );
|
---|
| 81 | mbedtls_mpi_init( &ctx->u2 );
|
---|
| 82 | ctx->state = ecdsa_ver_init;
|
---|
| 83 | }
|
---|
| 84 |
|
---|
| 85 | /*
|
---|
| 86 | * Free the components of a verify restart sub-context
|
---|
| 87 | */
|
---|
| 88 | static void ecdsa_restart_ver_free( mbedtls_ecdsa_restart_ver_ctx *ctx )
|
---|
| 89 | {
|
---|
| 90 | if( ctx == NULL )
|
---|
| 91 | return;
|
---|
| 92 |
|
---|
| 93 | mbedtls_mpi_free( &ctx->u1 );
|
---|
| 94 | mbedtls_mpi_free( &ctx->u2 );
|
---|
| 95 |
|
---|
| 96 | ecdsa_restart_ver_init( ctx );
|
---|
| 97 | }
|
---|
| 98 |
|
---|
| 99 | /*
|
---|
| 100 | * Sub-context for ecdsa_sign()
|
---|
| 101 | */
|
---|
| 102 | struct mbedtls_ecdsa_restart_sig
|
---|
| 103 | {
|
---|
| 104 | int sign_tries;
|
---|
| 105 | int key_tries;
|
---|
| 106 | mbedtls_mpi k; /* per-signature random */
|
---|
| 107 | mbedtls_mpi r; /* r value */
|
---|
| 108 | enum { /* what to do next? */
|
---|
| 109 | ecdsa_sig_init = 0, /* getting started */
|
---|
| 110 | ecdsa_sig_mul, /* doing ecp_mul() */
|
---|
| 111 | ecdsa_sig_modn, /* mod N computations */
|
---|
| 112 | } state;
|
---|
| 113 | };
|
---|
| 114 |
|
---|
| 115 | /*
|
---|
| 116 | * Init verify sign sub-context
|
---|
| 117 | */
|
---|
| 118 | static void ecdsa_restart_sig_init( mbedtls_ecdsa_restart_sig_ctx *ctx )
|
---|
| 119 | {
|
---|
| 120 | ctx->sign_tries = 0;
|
---|
| 121 | ctx->key_tries = 0;
|
---|
| 122 | mbedtls_mpi_init( &ctx->k );
|
---|
| 123 | mbedtls_mpi_init( &ctx->r );
|
---|
| 124 | ctx->state = ecdsa_sig_init;
|
---|
| 125 | }
|
---|
| 126 |
|
---|
| 127 | /*
|
---|
| 128 | * Free the components of a sign restart sub-context
|
---|
| 129 | */
|
---|
| 130 | static void ecdsa_restart_sig_free( mbedtls_ecdsa_restart_sig_ctx *ctx )
|
---|
| 131 | {
|
---|
| 132 | if( ctx == NULL )
|
---|
| 133 | return;
|
---|
| 134 |
|
---|
| 135 | mbedtls_mpi_free( &ctx->k );
|
---|
| 136 | mbedtls_mpi_free( &ctx->r );
|
---|
| 137 | }
|
---|
| 138 |
|
---|
| 139 | #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
|
---|
| 140 | /*
|
---|
| 141 | * Sub-context for ecdsa_sign_det()
|
---|
| 142 | */
|
---|
| 143 | struct mbedtls_ecdsa_restart_det
|
---|
| 144 | {
|
---|
| 145 | mbedtls_hmac_drbg_context rng_ctx; /* DRBG state */
|
---|
| 146 | enum { /* what to do next? */
|
---|
| 147 | ecdsa_det_init = 0, /* getting started */
|
---|
| 148 | ecdsa_det_sign, /* make signature */
|
---|
| 149 | } state;
|
---|
| 150 | };
|
---|
| 151 |
|
---|
| 152 | /*
|
---|
| 153 | * Init verify sign_det sub-context
|
---|
| 154 | */
|
---|
| 155 | static void ecdsa_restart_det_init( mbedtls_ecdsa_restart_det_ctx *ctx )
|
---|
| 156 | {
|
---|
| 157 | mbedtls_hmac_drbg_init( &ctx->rng_ctx );
|
---|
| 158 | ctx->state = ecdsa_det_init;
|
---|
| 159 | }
|
---|
| 160 |
|
---|
| 161 | /*
|
---|
| 162 | * Free the components of a sign_det restart sub-context
|
---|
| 163 | */
|
---|
| 164 | static void ecdsa_restart_det_free( mbedtls_ecdsa_restart_det_ctx *ctx )
|
---|
| 165 | {
|
---|
| 166 | if( ctx == NULL )
|
---|
| 167 | return;
|
---|
| 168 |
|
---|
| 169 | mbedtls_hmac_drbg_free( &ctx->rng_ctx );
|
---|
| 170 |
|
---|
| 171 | ecdsa_restart_det_init( ctx );
|
---|
| 172 | }
|
---|
| 173 | #endif /* MBEDTLS_ECDSA_DETERMINISTIC */
|
---|
| 174 |
|
---|
| 175 | #define ECDSA_RS_ECP &rs_ctx->ecp
|
---|
| 176 |
|
---|
| 177 | /* Utility macro for checking and updating ops budget */
|
---|
| 178 | #define ECDSA_BUDGET( ops ) \
|
---|
| 179 | MBEDTLS_MPI_CHK( mbedtls_ecp_check_budget( grp, &rs_ctx->ecp, ops ) );
|
---|
| 180 |
|
---|
| 181 | /* Call this when entering a function that needs its own sub-context */
|
---|
| 182 | #define ECDSA_RS_ENTER( SUB ) do { \
|
---|
| 183 | /* reset ops count for this call if top-level */ \
|
---|
| 184 | if( rs_ctx != NULL && rs_ctx->ecp.depth++ == 0 ) \
|
---|
| 185 | rs_ctx->ecp.ops_done = 0; \
|
---|
| 186 | \
|
---|
| 187 | /* set up our own sub-context if needed */ \
|
---|
| 188 | if( mbedtls_ecp_restart_is_enabled() && \
|
---|
| 189 | rs_ctx != NULL && rs_ctx->SUB == NULL ) \
|
---|
| 190 | { \
|
---|
| 191 | rs_ctx->SUB = mbedtls_calloc( 1, sizeof( *rs_ctx->SUB ) ); \
|
---|
| 192 | if( rs_ctx->SUB == NULL ) \
|
---|
| 193 | return( MBEDTLS_ERR_ECP_ALLOC_FAILED ); \
|
---|
| 194 | \
|
---|
| 195 | ecdsa_restart_## SUB ##_init( rs_ctx->SUB ); \
|
---|
| 196 | } \
|
---|
| 197 | } while( 0 )
|
---|
| 198 |
|
---|
| 199 | /* Call this when leaving a function that needs its own sub-context */
|
---|
| 200 | #define ECDSA_RS_LEAVE( SUB ) do { \
|
---|
| 201 | /* clear our sub-context when not in progress (done or error) */ \
|
---|
| 202 | if( rs_ctx != NULL && rs_ctx->SUB != NULL && \
|
---|
| 203 | ret != MBEDTLS_ERR_ECP_IN_PROGRESS ) \
|
---|
| 204 | { \
|
---|
| 205 | ecdsa_restart_## SUB ##_free( rs_ctx->SUB ); \
|
---|
| 206 | mbedtls_free( rs_ctx->SUB ); \
|
---|
| 207 | rs_ctx->SUB = NULL; \
|
---|
| 208 | } \
|
---|
| 209 | \
|
---|
| 210 | if( rs_ctx != NULL ) \
|
---|
| 211 | rs_ctx->ecp.depth--; \
|
---|
| 212 | } while( 0 )
|
---|
| 213 |
|
---|
| 214 | #else /* MBEDTLS_ECP_RESTARTABLE */
|
---|
| 215 |
|
---|
| 216 | #define ECDSA_RS_ECP NULL
|
---|
| 217 |
|
---|
| 218 | #define ECDSA_BUDGET( ops ) /* no-op; for compatibility */
|
---|
| 219 |
|
---|
| 220 | #define ECDSA_RS_ENTER( SUB ) (void) rs_ctx
|
---|
| 221 | #define ECDSA_RS_LEAVE( SUB ) (void) rs_ctx
|
---|
| 222 |
|
---|
| 223 | #endif /* MBEDTLS_ECP_RESTARTABLE */
|
---|
| 224 |
|
---|
| 225 | /*
|
---|
| 226 | * Derive a suitable integer for group grp from a buffer of length len
|
---|
| 227 | * SEC1 4.1.3 step 5 aka SEC1 4.1.4 step 3
|
---|
| 228 | */
|
---|
| 229 | static int derive_mpi( const mbedtls_ecp_group *grp, mbedtls_mpi *x,
|
---|
| 230 | const unsigned char *buf, size_t blen )
|
---|
| 231 | {
|
---|
| 232 | int ret;
|
---|
| 233 | size_t n_size = ( grp->nbits + 7 ) / 8;
|
---|
| 234 | size_t use_size = blen > n_size ? n_size : blen;
|
---|
| 235 |
|
---|
| 236 | MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( x, buf, use_size ) );
|
---|
| 237 | if( use_size * 8 > grp->nbits )
|
---|
| 238 | MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( x, use_size * 8 - grp->nbits ) );
|
---|
| 239 |
|
---|
| 240 | /* While at it, reduce modulo N */
|
---|
| 241 | if( mbedtls_mpi_cmp_mpi( x, &grp->N ) >= 0 )
|
---|
| 242 | MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( x, x, &grp->N ) );
|
---|
| 243 |
|
---|
| 244 | cleanup:
|
---|
| 245 | return( ret );
|
---|
| 246 | }
|
---|
| 247 |
|
---|
| 248 | #if !defined(MBEDTLS_ECDSA_SIGN_ALT)
|
---|
| 249 | /*
|
---|
| 250 | * Compute ECDSA signature of a hashed message (SEC1 4.1.3)
|
---|
| 251 | * Obviously, compared to SEC1 4.1.3, we skip step 4 (hash message)
|
---|
| 252 | */
|
---|
| 253 | static int ecdsa_sign_restartable( mbedtls_ecp_group *grp,
|
---|
| 254 | mbedtls_mpi *r, mbedtls_mpi *s,
|
---|
| 255 | const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
|
---|
| 256 | int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
|
---|
| 257 | mbedtls_ecdsa_restart_ctx *rs_ctx )
|
---|
| 258 | {
|
---|
| 259 | int ret, key_tries, sign_tries;
|
---|
| 260 | int *p_sign_tries = &sign_tries, *p_key_tries = &key_tries;
|
---|
| 261 | mbedtls_ecp_point R;
|
---|
| 262 | mbedtls_mpi k, e, t;
|
---|
| 263 | mbedtls_mpi *pk = &k, *pr = r;
|
---|
| 264 |
|
---|
| 265 | /* Fail cleanly on curves such as Curve25519 that can't be used for ECDSA */
|
---|
| 266 | if( grp->N.p == NULL )
|
---|
| 267 | return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
|
---|
| 268 |
|
---|
| 269 | /* Make sure d is in range 1..n-1 */
|
---|
| 270 | if( mbedtls_mpi_cmp_int( d, 1 ) < 0 || mbedtls_mpi_cmp_mpi( d, &grp->N ) >= 0 )
|
---|
| 271 | return( MBEDTLS_ERR_ECP_INVALID_KEY );
|
---|
| 272 |
|
---|
| 273 | mbedtls_ecp_point_init( &R );
|
---|
| 274 | mbedtls_mpi_init( &k ); mbedtls_mpi_init( &e ); mbedtls_mpi_init( &t );
|
---|
| 275 |
|
---|
| 276 | ECDSA_RS_ENTER( sig );
|
---|
| 277 |
|
---|
| 278 | #if defined(MBEDTLS_ECP_RESTARTABLE)
|
---|
| 279 | if( rs_ctx != NULL && rs_ctx->sig != NULL )
|
---|
| 280 | {
|
---|
| 281 | /* redirect to our context */
|
---|
| 282 | p_sign_tries = &rs_ctx->sig->sign_tries;
|
---|
| 283 | p_key_tries = &rs_ctx->sig->key_tries;
|
---|
| 284 | pk = &rs_ctx->sig->k;
|
---|
| 285 | pr = &rs_ctx->sig->r;
|
---|
| 286 |
|
---|
| 287 | /* jump to current step */
|
---|
| 288 | if( rs_ctx->sig->state == ecdsa_sig_mul )
|
---|
| 289 | goto mul;
|
---|
| 290 | if( rs_ctx->sig->state == ecdsa_sig_modn )
|
---|
| 291 | goto modn;
|
---|
| 292 | }
|
---|
| 293 | #endif /* MBEDTLS_ECP_RESTARTABLE */
|
---|
| 294 |
|
---|
| 295 | *p_sign_tries = 0;
|
---|
| 296 | do
|
---|
| 297 | {
|
---|
| 298 | if( *p_sign_tries++ > 10 )
|
---|
| 299 | {
|
---|
| 300 | ret = MBEDTLS_ERR_ECP_RANDOM_FAILED;
|
---|
| 301 | goto cleanup;
|
---|
| 302 | }
|
---|
| 303 |
|
---|
| 304 | /*
|
---|
| 305 | * Steps 1-3: generate a suitable ephemeral keypair
|
---|
| 306 | * and set r = xR mod n
|
---|
| 307 | */
|
---|
| 308 | *p_key_tries = 0;
|
---|
| 309 | do
|
---|
| 310 | {
|
---|
| 311 | if( *p_key_tries++ > 10 )
|
---|
| 312 | {
|
---|
| 313 | ret = MBEDTLS_ERR_ECP_RANDOM_FAILED;
|
---|
| 314 | goto cleanup;
|
---|
| 315 | }
|
---|
| 316 |
|
---|
| 317 | MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, pk, f_rng, p_rng ) );
|
---|
| 318 |
|
---|
| 319 | #if defined(MBEDTLS_ECP_RESTARTABLE)
|
---|
| 320 | if( rs_ctx != NULL && rs_ctx->sig != NULL )
|
---|
| 321 | rs_ctx->sig->state = ecdsa_sig_mul;
|
---|
| 322 |
|
---|
| 323 | mul:
|
---|
| 324 | #endif
|
---|
| 325 | MBEDTLS_MPI_CHK( mbedtls_ecp_mul_restartable( grp, &R, pk, &grp->G,
|
---|
| 326 | f_rng, p_rng, ECDSA_RS_ECP ) );
|
---|
| 327 | MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( pr, &R.X, &grp->N ) );
|
---|
| 328 | }
|
---|
| 329 | while( mbedtls_mpi_cmp_int( pr, 0 ) == 0 );
|
---|
| 330 |
|
---|
| 331 | #if defined(MBEDTLS_ECP_RESTARTABLE)
|
---|
| 332 | if( rs_ctx != NULL && rs_ctx->sig != NULL )
|
---|
| 333 | rs_ctx->sig->state = ecdsa_sig_modn;
|
---|
| 334 |
|
---|
| 335 | modn:
|
---|
| 336 | #endif
|
---|
| 337 | /*
|
---|
| 338 | * Accounting for everything up to the end of the loop
|
---|
| 339 | * (step 6, but checking now avoids saving e and t)
|
---|
| 340 | */
|
---|
| 341 | ECDSA_BUDGET( MBEDTLS_ECP_OPS_INV + 4 );
|
---|
| 342 |
|
---|
| 343 | /*
|
---|
| 344 | * Step 5: derive MPI from hashed message
|
---|
| 345 | */
|
---|
| 346 | MBEDTLS_MPI_CHK( derive_mpi( grp, &e, buf, blen ) );
|
---|
| 347 |
|
---|
| 348 | /*
|
---|
| 349 | * Generate a random value to blind inv_mod in next step,
|
---|
| 350 | * avoiding a potential timing leak.
|
---|
| 351 | */
|
---|
| 352 | MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, &t, f_rng, p_rng ) );
|
---|
| 353 |
|
---|
| 354 | /*
|
---|
| 355 | * Step 6: compute s = (e + r * d) / k = t (e + rd) / (kt) mod n
|
---|
| 356 | */
|
---|
| 357 | MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( s, pr, d ) );
|
---|
| 358 | MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &e, &e, s ) );
|
---|
| 359 | MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &e, &e, &t ) );
|
---|
| 360 | MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( pk, pk, &t ) );
|
---|
| 361 | MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( s, pk, &grp->N ) );
|
---|
| 362 | MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( s, s, &e ) );
|
---|
| 363 | MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( s, s, &grp->N ) );
|
---|
| 364 | }
|
---|
| 365 | while( mbedtls_mpi_cmp_int( s, 0 ) == 0 );
|
---|
| 366 |
|
---|
| 367 | #if defined(MBEDTLS_ECP_RESTARTABLE)
|
---|
| 368 | if( rs_ctx != NULL && rs_ctx->sig != NULL )
|
---|
| 369 | mbedtls_mpi_copy( r, pr );
|
---|
| 370 | #endif
|
---|
| 371 |
|
---|
| 372 | cleanup:
|
---|
| 373 | mbedtls_ecp_point_free( &R );
|
---|
| 374 | mbedtls_mpi_free( &k ); mbedtls_mpi_free( &e ); mbedtls_mpi_free( &t );
|
---|
| 375 |
|
---|
| 376 | ECDSA_RS_LEAVE( sig );
|
---|
| 377 |
|
---|
| 378 | return( ret );
|
---|
| 379 | }
|
---|
| 380 |
|
---|
| 381 | /*
|
---|
| 382 | * Compute ECDSA signature of a hashed message
|
---|
| 383 | */
|
---|
| 384 | int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
|
---|
| 385 | const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
|
---|
| 386 | int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
|
---|
| 387 | {
|
---|
| 388 | ECDSA_VALIDATE_RET( grp != NULL );
|
---|
| 389 | ECDSA_VALIDATE_RET( r != NULL );
|
---|
| 390 | ECDSA_VALIDATE_RET( s != NULL );
|
---|
| 391 | ECDSA_VALIDATE_RET( d != NULL );
|
---|
| 392 | ECDSA_VALIDATE_RET( f_rng != NULL );
|
---|
| 393 | ECDSA_VALIDATE_RET( buf != NULL || blen == 0 );
|
---|
| 394 |
|
---|
| 395 | return( ecdsa_sign_restartable( grp, r, s, d, buf, blen,
|
---|
| 396 | f_rng, p_rng, NULL ) );
|
---|
| 397 | }
|
---|
| 398 | #endif /* !MBEDTLS_ECDSA_SIGN_ALT */
|
---|
| 399 |
|
---|
| 400 | #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
|
---|
| 401 | /*
|
---|
| 402 | * Deterministic signature wrapper
|
---|
| 403 | */
|
---|
| 404 | static int ecdsa_sign_det_restartable( mbedtls_ecp_group *grp,
|
---|
| 405 | mbedtls_mpi *r, mbedtls_mpi *s,
|
---|
| 406 | const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
|
---|
| 407 | mbedtls_md_type_t md_alg,
|
---|
| 408 | mbedtls_ecdsa_restart_ctx *rs_ctx )
|
---|
| 409 | {
|
---|
| 410 | int ret;
|
---|
| 411 | mbedtls_hmac_drbg_context rng_ctx;
|
---|
| 412 | mbedtls_hmac_drbg_context *p_rng = &rng_ctx;
|
---|
| 413 | unsigned char data[2 * MBEDTLS_ECP_MAX_BYTES];
|
---|
| 414 | size_t grp_len = ( grp->nbits + 7 ) / 8;
|
---|
| 415 | const mbedtls_md_info_t *md_info;
|
---|
| 416 | mbedtls_mpi h;
|
---|
| 417 |
|
---|
| 418 | if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL )
|
---|
| 419 | return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
|
---|
| 420 |
|
---|
| 421 | mbedtls_mpi_init( &h );
|
---|
| 422 | mbedtls_hmac_drbg_init( &rng_ctx );
|
---|
| 423 |
|
---|
| 424 | ECDSA_RS_ENTER( det );
|
---|
| 425 |
|
---|
| 426 | #if defined(MBEDTLS_ECP_RESTARTABLE)
|
---|
| 427 | if( rs_ctx != NULL && rs_ctx->det != NULL )
|
---|
| 428 | {
|
---|
| 429 | /* redirect to our context */
|
---|
| 430 | p_rng = &rs_ctx->det->rng_ctx;
|
---|
| 431 |
|
---|
| 432 | /* jump to current step */
|
---|
| 433 | if( rs_ctx->det->state == ecdsa_det_sign )
|
---|
| 434 | goto sign;
|
---|
| 435 | }
|
---|
| 436 | #endif /* MBEDTLS_ECP_RESTARTABLE */
|
---|
| 437 |
|
---|
| 438 | /* Use private key and message hash (reduced) to initialize HMAC_DRBG */
|
---|
| 439 | MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( d, data, grp_len ) );
|
---|
| 440 | MBEDTLS_MPI_CHK( derive_mpi( grp, &h, buf, blen ) );
|
---|
| 441 | MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &h, data + grp_len, grp_len ) );
|
---|
| 442 | mbedtls_hmac_drbg_seed_buf( p_rng, md_info, data, 2 * grp_len );
|
---|
| 443 |
|
---|
| 444 | #if defined(MBEDTLS_ECP_RESTARTABLE)
|
---|
| 445 | if( rs_ctx != NULL && rs_ctx->det != NULL )
|
---|
| 446 | rs_ctx->det->state = ecdsa_det_sign;
|
---|
| 447 |
|
---|
| 448 | sign:
|
---|
| 449 | #endif
|
---|
| 450 | #if defined(MBEDTLS_ECDSA_SIGN_ALT)
|
---|
| 451 | ret = mbedtls_ecdsa_sign( grp, r, s, d, buf, blen,
|
---|
| 452 | mbedtls_hmac_drbg_random, p_rng );
|
---|
| 453 | #else
|
---|
| 454 | ret = ecdsa_sign_restartable( grp, r, s, d, buf, blen,
|
---|
| 455 | mbedtls_hmac_drbg_random, p_rng, rs_ctx );
|
---|
| 456 | #endif /* MBEDTLS_ECDSA_SIGN_ALT */
|
---|
| 457 |
|
---|
| 458 | cleanup:
|
---|
| 459 | mbedtls_hmac_drbg_free( &rng_ctx );
|
---|
| 460 | mbedtls_mpi_free( &h );
|
---|
| 461 |
|
---|
| 462 | ECDSA_RS_LEAVE( det );
|
---|
| 463 |
|
---|
| 464 | return( ret );
|
---|
| 465 | }
|
---|
| 466 |
|
---|
| 467 | /*
|
---|
| 468 | * Deterministic signature wrapper
|
---|
| 469 | */
|
---|
| 470 | int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
|
---|
| 471 | const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
|
---|
| 472 | mbedtls_md_type_t md_alg )
|
---|
| 473 | {
|
---|
| 474 | ECDSA_VALIDATE_RET( grp != NULL );
|
---|
| 475 | ECDSA_VALIDATE_RET( r != NULL );
|
---|
| 476 | ECDSA_VALIDATE_RET( s != NULL );
|
---|
| 477 | ECDSA_VALIDATE_RET( d != NULL );
|
---|
| 478 | ECDSA_VALIDATE_RET( buf != NULL || blen == 0 );
|
---|
| 479 |
|
---|
| 480 | return( ecdsa_sign_det_restartable( grp, r, s, d, buf, blen, md_alg, NULL ) );
|
---|
| 481 | }
|
---|
| 482 | #endif /* MBEDTLS_ECDSA_DETERMINISTIC */
|
---|
| 483 |
|
---|
| 484 | #if !defined(MBEDTLS_ECDSA_VERIFY_ALT)
|
---|
| 485 | /*
|
---|
| 486 | * Verify ECDSA signature of hashed message (SEC1 4.1.4)
|
---|
| 487 | * Obviously, compared to SEC1 4.1.3, we skip step 2 (hash message)
|
---|
| 488 | */
|
---|
| 489 | static int ecdsa_verify_restartable( mbedtls_ecp_group *grp,
|
---|
| 490 | const unsigned char *buf, size_t blen,
|
---|
| 491 | const mbedtls_ecp_point *Q,
|
---|
| 492 | const mbedtls_mpi *r, const mbedtls_mpi *s,
|
---|
| 493 | mbedtls_ecdsa_restart_ctx *rs_ctx )
|
---|
| 494 | {
|
---|
| 495 | int ret;
|
---|
| 496 | mbedtls_mpi e, s_inv, u1, u2;
|
---|
| 497 | mbedtls_ecp_point R;
|
---|
| 498 | mbedtls_mpi *pu1 = &u1, *pu2 = &u2;
|
---|
| 499 |
|
---|
| 500 | mbedtls_ecp_point_init( &R );
|
---|
| 501 | mbedtls_mpi_init( &e ); mbedtls_mpi_init( &s_inv );
|
---|
| 502 | mbedtls_mpi_init( &u1 ); mbedtls_mpi_init( &u2 );
|
---|
| 503 |
|
---|
| 504 | /* Fail cleanly on curves such as Curve25519 that can't be used for ECDSA */
|
---|
| 505 | if( grp->N.p == NULL )
|
---|
| 506 | return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
|
---|
| 507 |
|
---|
| 508 | ECDSA_RS_ENTER( ver );
|
---|
| 509 |
|
---|
| 510 | #if defined(MBEDTLS_ECP_RESTARTABLE)
|
---|
| 511 | if( rs_ctx != NULL && rs_ctx->ver != NULL )
|
---|
| 512 | {
|
---|
| 513 | /* redirect to our context */
|
---|
| 514 | pu1 = &rs_ctx->ver->u1;
|
---|
| 515 | pu2 = &rs_ctx->ver->u2;
|
---|
| 516 |
|
---|
| 517 | /* jump to current step */
|
---|
| 518 | if( rs_ctx->ver->state == ecdsa_ver_muladd )
|
---|
| 519 | goto muladd;
|
---|
| 520 | }
|
---|
| 521 | #endif /* MBEDTLS_ECP_RESTARTABLE */
|
---|
| 522 |
|
---|
| 523 | /*
|
---|
| 524 | * Step 1: make sure r and s are in range 1..n-1
|
---|
| 525 | */
|
---|
| 526 | if( mbedtls_mpi_cmp_int( r, 1 ) < 0 || mbedtls_mpi_cmp_mpi( r, &grp->N ) >= 0 ||
|
---|
| 527 | mbedtls_mpi_cmp_int( s, 1 ) < 0 || mbedtls_mpi_cmp_mpi( s, &grp->N ) >= 0 )
|
---|
| 528 | {
|
---|
| 529 | ret = MBEDTLS_ERR_ECP_VERIFY_FAILED;
|
---|
| 530 | goto cleanup;
|
---|
| 531 | }
|
---|
| 532 |
|
---|
| 533 | /*
|
---|
| 534 | * Step 3: derive MPI from hashed message
|
---|
| 535 | */
|
---|
| 536 | MBEDTLS_MPI_CHK( derive_mpi( grp, &e, buf, blen ) );
|
---|
| 537 |
|
---|
| 538 | /*
|
---|
| 539 | * Step 4: u1 = e / s mod n, u2 = r / s mod n
|
---|
| 540 | */
|
---|
| 541 | ECDSA_BUDGET( MBEDTLS_ECP_OPS_CHK + MBEDTLS_ECP_OPS_INV + 2 );
|
---|
| 542 |
|
---|
| 543 | MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &s_inv, s, &grp->N ) );
|
---|
| 544 |
|
---|
| 545 | MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( pu1, &e, &s_inv ) );
|
---|
| 546 | MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( pu1, pu1, &grp->N ) );
|
---|
| 547 |
|
---|
| 548 | MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( pu2, r, &s_inv ) );
|
---|
| 549 | MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( pu2, pu2, &grp->N ) );
|
---|
| 550 |
|
---|
| 551 | #if defined(MBEDTLS_ECP_RESTARTABLE)
|
---|
| 552 | if( rs_ctx != NULL && rs_ctx->ver != NULL )
|
---|
| 553 | rs_ctx->ver->state = ecdsa_ver_muladd;
|
---|
| 554 |
|
---|
| 555 | muladd:
|
---|
| 556 | #endif
|
---|
| 557 | /*
|
---|
| 558 | * Step 5: R = u1 G + u2 Q
|
---|
| 559 | */
|
---|
| 560 | MBEDTLS_MPI_CHK( mbedtls_ecp_muladd_restartable( grp,
|
---|
| 561 | &R, pu1, &grp->G, pu2, Q, ECDSA_RS_ECP ) );
|
---|
| 562 |
|
---|
| 563 | if( mbedtls_ecp_is_zero( &R ) )
|
---|
| 564 | {
|
---|
| 565 | ret = MBEDTLS_ERR_ECP_VERIFY_FAILED;
|
---|
| 566 | goto cleanup;
|
---|
| 567 | }
|
---|
| 568 |
|
---|
| 569 | /*
|
---|
| 570 | * Step 6: convert xR to an integer (no-op)
|
---|
| 571 | * Step 7: reduce xR mod n (gives v)
|
---|
| 572 | */
|
---|
| 573 | MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &R.X, &R.X, &grp->N ) );
|
---|
| 574 |
|
---|
| 575 | /*
|
---|
| 576 | * Step 8: check if v (that is, R.X) is equal to r
|
---|
| 577 | */
|
---|
| 578 | if( mbedtls_mpi_cmp_mpi( &R.X, r ) != 0 )
|
---|
| 579 | {
|
---|
| 580 | ret = MBEDTLS_ERR_ECP_VERIFY_FAILED;
|
---|
| 581 | goto cleanup;
|
---|
| 582 | }
|
---|
| 583 |
|
---|
| 584 | cleanup:
|
---|
| 585 | mbedtls_ecp_point_free( &R );
|
---|
| 586 | mbedtls_mpi_free( &e ); mbedtls_mpi_free( &s_inv );
|
---|
| 587 | mbedtls_mpi_free( &u1 ); mbedtls_mpi_free( &u2 );
|
---|
| 588 |
|
---|
| 589 | ECDSA_RS_LEAVE( ver );
|
---|
| 590 |
|
---|
| 591 | return( ret );
|
---|
| 592 | }
|
---|
| 593 |
|
---|
| 594 | /*
|
---|
| 595 | * Verify ECDSA signature of hashed message
|
---|
| 596 | */
|
---|
| 597 | int mbedtls_ecdsa_verify( mbedtls_ecp_group *grp,
|
---|
| 598 | const unsigned char *buf, size_t blen,
|
---|
| 599 | const mbedtls_ecp_point *Q,
|
---|
| 600 | const mbedtls_mpi *r,
|
---|
| 601 | const mbedtls_mpi *s)
|
---|
| 602 | {
|
---|
| 603 | ECDSA_VALIDATE_RET( grp != NULL );
|
---|
| 604 | ECDSA_VALIDATE_RET( Q != NULL );
|
---|
| 605 | ECDSA_VALIDATE_RET( r != NULL );
|
---|
| 606 | ECDSA_VALIDATE_RET( s != NULL );
|
---|
| 607 | ECDSA_VALIDATE_RET( buf != NULL || blen == 0 );
|
---|
| 608 |
|
---|
| 609 | return( ecdsa_verify_restartable( grp, buf, blen, Q, r, s, NULL ) );
|
---|
| 610 | }
|
---|
| 611 | #endif /* !MBEDTLS_ECDSA_VERIFY_ALT */
|
---|
| 612 |
|
---|
| 613 | /*
|
---|
| 614 | * Convert a signature (given by context) to ASN.1
|
---|
| 615 | */
|
---|
| 616 | static int ecdsa_signature_to_asn1( const mbedtls_mpi *r, const mbedtls_mpi *s,
|
---|
| 617 | unsigned char *sig, size_t *slen )
|
---|
| 618 | {
|
---|
| 619 | int ret;
|
---|
| 620 | unsigned char buf[MBEDTLS_ECDSA_MAX_LEN];
|
---|
| 621 | unsigned char *p = buf + sizeof( buf );
|
---|
| 622 | size_t len = 0;
|
---|
| 623 |
|
---|
| 624 | MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &p, buf, s ) );
|
---|
| 625 | MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &p, buf, r ) );
|
---|
| 626 |
|
---|
| 627 | MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, buf, len ) );
|
---|
| 628 | MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, buf,
|
---|
| 629 | MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
|
---|
| 630 |
|
---|
| 631 | memcpy( sig, p, len );
|
---|
| 632 | *slen = len;
|
---|
| 633 |
|
---|
| 634 | return( 0 );
|
---|
| 635 | }
|
---|
| 636 |
|
---|
| 637 | /*
|
---|
| 638 | * Compute and write signature
|
---|
| 639 | */
|
---|
| 640 | int mbedtls_ecdsa_write_signature_restartable( mbedtls_ecdsa_context *ctx,
|
---|
| 641 | mbedtls_md_type_t md_alg,
|
---|
| 642 | const unsigned char *hash, size_t hlen,
|
---|
| 643 | unsigned char *sig, size_t *slen,
|
---|
| 644 | int (*f_rng)(void *, unsigned char *, size_t),
|
---|
| 645 | void *p_rng,
|
---|
| 646 | mbedtls_ecdsa_restart_ctx *rs_ctx )
|
---|
| 647 | {
|
---|
| 648 | int ret;
|
---|
| 649 | mbedtls_mpi r, s;
|
---|
| 650 | ECDSA_VALIDATE_RET( ctx != NULL );
|
---|
| 651 | ECDSA_VALIDATE_RET( hash != NULL );
|
---|
| 652 | ECDSA_VALIDATE_RET( sig != NULL );
|
---|
| 653 | ECDSA_VALIDATE_RET( slen != NULL );
|
---|
| 654 |
|
---|
| 655 | mbedtls_mpi_init( &r );
|
---|
| 656 | mbedtls_mpi_init( &s );
|
---|
| 657 |
|
---|
| 658 | #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
|
---|
| 659 | (void) f_rng;
|
---|
| 660 | (void) p_rng;
|
---|
| 661 |
|
---|
| 662 | MBEDTLS_MPI_CHK( ecdsa_sign_det_restartable( &ctx->grp, &r, &s, &ctx->d,
|
---|
| 663 | hash, hlen, md_alg, rs_ctx ) );
|
---|
| 664 | #else
|
---|
| 665 | (void) md_alg;
|
---|
| 666 |
|
---|
| 667 | #if defined(MBEDTLS_ECDSA_SIGN_ALT)
|
---|
| 668 | MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign( &ctx->grp, &r, &s, &ctx->d,
|
---|
| 669 | hash, hlen, f_rng, p_rng ) );
|
---|
| 670 | #else
|
---|
| 671 | MBEDTLS_MPI_CHK( ecdsa_sign_restartable( &ctx->grp, &r, &s, &ctx->d,
|
---|
| 672 | hash, hlen, f_rng, p_rng, rs_ctx ) );
|
---|
| 673 | #endif /* MBEDTLS_ECDSA_SIGN_ALT */
|
---|
| 674 | #endif /* MBEDTLS_ECDSA_DETERMINISTIC */
|
---|
| 675 |
|
---|
| 676 | MBEDTLS_MPI_CHK( ecdsa_signature_to_asn1( &r, &s, sig, slen ) );
|
---|
| 677 |
|
---|
| 678 | cleanup:
|
---|
| 679 | mbedtls_mpi_free( &r );
|
---|
| 680 | mbedtls_mpi_free( &s );
|
---|
| 681 |
|
---|
| 682 | return( ret );
|
---|
| 683 | }
|
---|
| 684 |
|
---|
| 685 | /*
|
---|
| 686 | * Compute and write signature
|
---|
| 687 | */
|
---|
| 688 | int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx,
|
---|
| 689 | mbedtls_md_type_t md_alg,
|
---|
| 690 | const unsigned char *hash, size_t hlen,
|
---|
| 691 | unsigned char *sig, size_t *slen,
|
---|
| 692 | int (*f_rng)(void *, unsigned char *, size_t),
|
---|
| 693 | void *p_rng )
|
---|
| 694 | {
|
---|
| 695 | ECDSA_VALIDATE_RET( ctx != NULL );
|
---|
| 696 | ECDSA_VALIDATE_RET( hash != NULL );
|
---|
| 697 | ECDSA_VALIDATE_RET( sig != NULL );
|
---|
| 698 | ECDSA_VALIDATE_RET( slen != NULL );
|
---|
| 699 | return( mbedtls_ecdsa_write_signature_restartable(
|
---|
| 700 | ctx, md_alg, hash, hlen, sig, slen, f_rng, p_rng, NULL ) );
|
---|
| 701 | }
|
---|
| 702 |
|
---|
| 703 | #if !defined(MBEDTLS_DEPRECATED_REMOVED) && \
|
---|
| 704 | defined(MBEDTLS_ECDSA_DETERMINISTIC)
|
---|
| 705 | int mbedtls_ecdsa_write_signature_det( mbedtls_ecdsa_context *ctx,
|
---|
| 706 | const unsigned char *hash, size_t hlen,
|
---|
| 707 | unsigned char *sig, size_t *slen,
|
---|
| 708 | mbedtls_md_type_t md_alg )
|
---|
| 709 | {
|
---|
| 710 | ECDSA_VALIDATE_RET( ctx != NULL );
|
---|
| 711 | ECDSA_VALIDATE_RET( hash != NULL );
|
---|
| 712 | ECDSA_VALIDATE_RET( sig != NULL );
|
---|
| 713 | ECDSA_VALIDATE_RET( slen != NULL );
|
---|
| 714 | return( mbedtls_ecdsa_write_signature( ctx, md_alg, hash, hlen, sig, slen,
|
---|
| 715 | NULL, NULL ) );
|
---|
| 716 | }
|
---|
| 717 | #endif
|
---|
| 718 |
|
---|
| 719 | /*
|
---|
| 720 | * Read and check signature
|
---|
| 721 | */
|
---|
| 722 | int mbedtls_ecdsa_read_signature( mbedtls_ecdsa_context *ctx,
|
---|
| 723 | const unsigned char *hash, size_t hlen,
|
---|
| 724 | const unsigned char *sig, size_t slen )
|
---|
| 725 | {
|
---|
| 726 | ECDSA_VALIDATE_RET( ctx != NULL );
|
---|
| 727 | ECDSA_VALIDATE_RET( hash != NULL );
|
---|
| 728 | ECDSA_VALIDATE_RET( sig != NULL );
|
---|
| 729 | return( mbedtls_ecdsa_read_signature_restartable(
|
---|
| 730 | ctx, hash, hlen, sig, slen, NULL ) );
|
---|
| 731 | }
|
---|
| 732 |
|
---|
| 733 | /*
|
---|
| 734 | * Restartable read and check signature
|
---|
| 735 | */
|
---|
| 736 | int mbedtls_ecdsa_read_signature_restartable( mbedtls_ecdsa_context *ctx,
|
---|
| 737 | const unsigned char *hash, size_t hlen,
|
---|
| 738 | const unsigned char *sig, size_t slen,
|
---|
| 739 | mbedtls_ecdsa_restart_ctx *rs_ctx )
|
---|
| 740 | {
|
---|
| 741 | int ret;
|
---|
| 742 | unsigned char *p = (unsigned char *) sig;
|
---|
| 743 | const unsigned char *end = sig + slen;
|
---|
| 744 | size_t len;
|
---|
| 745 | mbedtls_mpi r, s;
|
---|
| 746 | ECDSA_VALIDATE_RET( ctx != NULL );
|
---|
| 747 | ECDSA_VALIDATE_RET( hash != NULL );
|
---|
| 748 | ECDSA_VALIDATE_RET( sig != NULL );
|
---|
| 749 |
|
---|
| 750 | mbedtls_mpi_init( &r );
|
---|
| 751 | mbedtls_mpi_init( &s );
|
---|
| 752 |
|
---|
| 753 | if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
|
---|
| 754 | MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
|
---|
| 755 | {
|
---|
| 756 | ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
|
---|
| 757 | goto cleanup;
|
---|
| 758 | }
|
---|
| 759 |
|
---|
| 760 | if( p + len != end )
|
---|
| 761 | {
|
---|
| 762 | ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA +
|
---|
| 763 | MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
|
---|
| 764 | goto cleanup;
|
---|
| 765 | }
|
---|
| 766 |
|
---|
| 767 | if( ( ret = mbedtls_asn1_get_mpi( &p, end, &r ) ) != 0 ||
|
---|
| 768 | ( ret = mbedtls_asn1_get_mpi( &p, end, &s ) ) != 0 )
|
---|
| 769 | {
|
---|
| 770 | ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
|
---|
| 771 | goto cleanup;
|
---|
| 772 | }
|
---|
| 773 | #if defined(MBEDTLS_ECDSA_VERIFY_ALT)
|
---|
| 774 | if( ( ret = mbedtls_ecdsa_verify( &ctx->grp, hash, hlen,
|
---|
| 775 | &ctx->Q, &r, &s ) ) != 0 )
|
---|
| 776 | goto cleanup;
|
---|
| 777 | #else
|
---|
| 778 | if( ( ret = ecdsa_verify_restartable( &ctx->grp, hash, hlen,
|
---|
| 779 | &ctx->Q, &r, &s, rs_ctx ) ) != 0 )
|
---|
| 780 | goto cleanup;
|
---|
| 781 | #endif /* MBEDTLS_ECDSA_VERIFY_ALT */
|
---|
| 782 |
|
---|
| 783 | /* At this point we know that the buffer starts with a valid signature.
|
---|
| 784 | * Return 0 if the buffer just contains the signature, and a specific
|
---|
| 785 | * error code if the valid signature is followed by more data. */
|
---|
| 786 | if( p != end )
|
---|
| 787 | ret = MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH;
|
---|
| 788 |
|
---|
| 789 | cleanup:
|
---|
| 790 | mbedtls_mpi_free( &r );
|
---|
| 791 | mbedtls_mpi_free( &s );
|
---|
| 792 |
|
---|
| 793 | return( ret );
|
---|
| 794 | }
|
---|
| 795 |
|
---|
| 796 | #if !defined(MBEDTLS_ECDSA_GENKEY_ALT)
|
---|
| 797 | /*
|
---|
| 798 | * Generate key pair
|
---|
| 799 | */
|
---|
| 800 | int mbedtls_ecdsa_genkey( mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid,
|
---|
| 801 | int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
|
---|
| 802 | {
|
---|
| 803 | int ret = 0;
|
---|
| 804 | ECDSA_VALIDATE_RET( ctx != NULL );
|
---|
| 805 | ECDSA_VALIDATE_RET( f_rng != NULL );
|
---|
| 806 |
|
---|
| 807 | ret = mbedtls_ecp_group_load( &ctx->grp, gid );
|
---|
| 808 | if( ret != 0 )
|
---|
| 809 | return( ret );
|
---|
| 810 |
|
---|
| 811 | return( mbedtls_ecp_gen_keypair( &ctx->grp, &ctx->d,
|
---|
| 812 | &ctx->Q, f_rng, p_rng ) );
|
---|
| 813 | }
|
---|
| 814 | #endif /* !MBEDTLS_ECDSA_GENKEY_ALT */
|
---|
| 815 |
|
---|
| 816 | /*
|
---|
| 817 | * Set context from an mbedtls_ecp_keypair
|
---|
| 818 | */
|
---|
| 819 | int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx, const mbedtls_ecp_keypair *key )
|
---|
| 820 | {
|
---|
| 821 | int ret;
|
---|
| 822 | ECDSA_VALIDATE_RET( ctx != NULL );
|
---|
| 823 | ECDSA_VALIDATE_RET( key != NULL );
|
---|
| 824 |
|
---|
| 825 | if( ( ret = mbedtls_ecp_group_copy( &ctx->grp, &key->grp ) ) != 0 ||
|
---|
| 826 | ( ret = mbedtls_mpi_copy( &ctx->d, &key->d ) ) != 0 ||
|
---|
| 827 | ( ret = mbedtls_ecp_copy( &ctx->Q, &key->Q ) ) != 0 )
|
---|
| 828 | {
|
---|
| 829 | mbedtls_ecdsa_free( ctx );
|
---|
| 830 | }
|
---|
| 831 |
|
---|
| 832 | return( ret );
|
---|
| 833 | }
|
---|
| 834 |
|
---|
| 835 | /*
|
---|
| 836 | * Initialize context
|
---|
| 837 | */
|
---|
| 838 | void mbedtls_ecdsa_init( mbedtls_ecdsa_context *ctx )
|
---|
| 839 | {
|
---|
| 840 | ECDSA_VALIDATE( ctx != NULL );
|
---|
| 841 |
|
---|
| 842 | mbedtls_ecp_keypair_init( ctx );
|
---|
| 843 | }
|
---|
| 844 |
|
---|
| 845 | /*
|
---|
| 846 | * Free context
|
---|
| 847 | */
|
---|
| 848 | void mbedtls_ecdsa_free( mbedtls_ecdsa_context *ctx )
|
---|
| 849 | {
|
---|
| 850 | if( ctx == NULL )
|
---|
| 851 | return;
|
---|
| 852 |
|
---|
| 853 | mbedtls_ecp_keypair_free( ctx );
|
---|
| 854 | }
|
---|
| 855 |
|
---|
| 856 | #if defined(MBEDTLS_ECP_RESTARTABLE)
|
---|
| 857 | /*
|
---|
| 858 | * Initialize a restart context
|
---|
| 859 | */
|
---|
| 860 | void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx )
|
---|
| 861 | {
|
---|
| 862 | ECDSA_VALIDATE( ctx != NULL );
|
---|
| 863 |
|
---|
| 864 | mbedtls_ecp_restart_init( &ctx->ecp );
|
---|
| 865 |
|
---|
| 866 | ctx->ver = NULL;
|
---|
| 867 | ctx->sig = NULL;
|
---|
| 868 | #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
|
---|
| 869 | ctx->det = NULL;
|
---|
| 870 | #endif
|
---|
| 871 | }
|
---|
| 872 |
|
---|
| 873 | /*
|
---|
| 874 | * Free the components of a restart context
|
---|
| 875 | */
|
---|
| 876 | void mbedtls_ecdsa_restart_free( mbedtls_ecdsa_restart_ctx *ctx )
|
---|
| 877 | {
|
---|
| 878 | if( ctx == NULL )
|
---|
| 879 | return;
|
---|
| 880 |
|
---|
| 881 | mbedtls_ecp_restart_free( &ctx->ecp );
|
---|
| 882 |
|
---|
| 883 | ecdsa_restart_ver_free( ctx->ver );
|
---|
| 884 | mbedtls_free( ctx->ver );
|
---|
| 885 | ctx->ver = NULL;
|
---|
| 886 |
|
---|
| 887 | ecdsa_restart_sig_free( ctx->sig );
|
---|
| 888 | mbedtls_free( ctx->sig );
|
---|
| 889 | ctx->sig = NULL;
|
---|
| 890 |
|
---|
| 891 | #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
|
---|
| 892 | ecdsa_restart_det_free( ctx->det );
|
---|
| 893 | mbedtls_free( ctx->det );
|
---|
| 894 | ctx->det = NULL;
|
---|
| 895 | #endif
|
---|
| 896 | }
|
---|
| 897 | #endif /* MBEDTLS_ECP_RESTARTABLE */
|
---|
| 898 |
|
---|
| 899 | #endif /* MBEDTLS_ECDSA_C */
|
---|