4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
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5 * SPDX-License-Identifier: Apache-2.0
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7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
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8 * not use this file except in compliance with the License.
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9 * You may obtain a copy of the License at
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11 * http://www.apache.org/licenses/LICENSE-2.0
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13 * Unless required by applicable law or agreed to in writing, software
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14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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16 * See the License for the specific language governing permissions and
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17 * limitations under the License.
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19 * This file is part of mbed TLS (https://tls.mbed.org)
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25 * SEC1 http://www.secg.org/index.php?action=secg,docs_secg
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28 #if !defined(MBEDTLS_CONFIG_FILE)
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29 #include "mbedtls/config.h"
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31 #include MBEDTLS_CONFIG_FILE
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34 #if defined(MBEDTLS_ECDSA_C)
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36 #include "mbedtls/ecdsa.h"
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37 #include "mbedtls/asn1write.h"
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41 #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
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42 #include "mbedtls/hmac_drbg.h"
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45 #if defined(MBEDTLS_PLATFORM_C)
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46 #include "mbedtls/platform.h"
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49 #define mbedtls_calloc calloc
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50 #define mbedtls_free free
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53 #include "mbedtls/platform_util.h"
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55 /* Parameter validation macros based on platform_util.h */
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56 #define ECDSA_VALIDATE_RET( cond ) \
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57 MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
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58 #define ECDSA_VALIDATE( cond ) \
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59 MBEDTLS_INTERNAL_VALIDATE( cond )
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61 #if defined(MBEDTLS_ECP_RESTARTABLE)
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64 * Sub-context for ecdsa_verify()
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66 struct mbedtls_ecdsa_restart_ver
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68 mbedtls_mpi u1, u2; /* intermediate values */
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69 enum { /* what to do next? */
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70 ecdsa_ver_init = 0, /* getting started */
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71 ecdsa_ver_muladd, /* muladd step */
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76 * Init verify restart sub-context
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78 static void ecdsa_restart_ver_init( mbedtls_ecdsa_restart_ver_ctx *ctx )
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80 mbedtls_mpi_init( &ctx->u1 );
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81 mbedtls_mpi_init( &ctx->u2 );
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82 ctx->state = ecdsa_ver_init;
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86 * Free the components of a verify restart sub-context
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88 static void ecdsa_restart_ver_free( mbedtls_ecdsa_restart_ver_ctx *ctx )
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93 mbedtls_mpi_free( &ctx->u1 );
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94 mbedtls_mpi_free( &ctx->u2 );
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96 ecdsa_restart_ver_init( ctx );
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100 * Sub-context for ecdsa_sign()
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102 struct mbedtls_ecdsa_restart_sig
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106 mbedtls_mpi k; /* per-signature random */
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107 mbedtls_mpi r; /* r value */
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108 enum { /* what to do next? */
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109 ecdsa_sig_init = 0, /* getting started */
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110 ecdsa_sig_mul, /* doing ecp_mul() */
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111 ecdsa_sig_modn, /* mod N computations */
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116 * Init verify sign sub-context
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118 static void ecdsa_restart_sig_init( mbedtls_ecdsa_restart_sig_ctx *ctx )
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120 ctx->sign_tries = 0;
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121 ctx->key_tries = 0;
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122 mbedtls_mpi_init( &ctx->k );
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123 mbedtls_mpi_init( &ctx->r );
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124 ctx->state = ecdsa_sig_init;
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128 * Free the components of a sign restart sub-context
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130 static void ecdsa_restart_sig_free( mbedtls_ecdsa_restart_sig_ctx *ctx )
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135 mbedtls_mpi_free( &ctx->k );
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136 mbedtls_mpi_free( &ctx->r );
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139 #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
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141 * Sub-context for ecdsa_sign_det()
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143 struct mbedtls_ecdsa_restart_det
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145 mbedtls_hmac_drbg_context rng_ctx; /* DRBG state */
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146 enum { /* what to do next? */
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147 ecdsa_det_init = 0, /* getting started */
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148 ecdsa_det_sign, /* make signature */
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153 * Init verify sign_det sub-context
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155 static void ecdsa_restart_det_init( mbedtls_ecdsa_restart_det_ctx *ctx )
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157 mbedtls_hmac_drbg_init( &ctx->rng_ctx );
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158 ctx->state = ecdsa_det_init;
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162 * Free the components of a sign_det restart sub-context
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164 static void ecdsa_restart_det_free( mbedtls_ecdsa_restart_det_ctx *ctx )
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169 mbedtls_hmac_drbg_free( &ctx->rng_ctx );
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171 ecdsa_restart_det_init( ctx );
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173 #endif /* MBEDTLS_ECDSA_DETERMINISTIC */
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175 #define ECDSA_RS_ECP &rs_ctx->ecp
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177 /* Utility macro for checking and updating ops budget */
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178 #define ECDSA_BUDGET( ops ) \
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179 MBEDTLS_MPI_CHK( mbedtls_ecp_check_budget( grp, &rs_ctx->ecp, ops ) );
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181 /* Call this when entering a function that needs its own sub-context */
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182 #define ECDSA_RS_ENTER( SUB ) do { \
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183 /* reset ops count for this call if top-level */ \
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184 if( rs_ctx != NULL && rs_ctx->ecp.depth++ == 0 ) \
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185 rs_ctx->ecp.ops_done = 0; \
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187 /* set up our own sub-context if needed */ \
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188 if( mbedtls_ecp_restart_is_enabled() && \
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189 rs_ctx != NULL && rs_ctx->SUB == NULL ) \
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191 rs_ctx->SUB = mbedtls_calloc( 1, sizeof( *rs_ctx->SUB ) ); \
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192 if( rs_ctx->SUB == NULL ) \
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193 return( MBEDTLS_ERR_ECP_ALLOC_FAILED ); \
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195 ecdsa_restart_## SUB ##_init( rs_ctx->SUB ); \
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199 /* Call this when leaving a function that needs its own sub-context */
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200 #define ECDSA_RS_LEAVE( SUB ) do { \
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201 /* clear our sub-context when not in progress (done or error) */ \
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202 if( rs_ctx != NULL && rs_ctx->SUB != NULL && \
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203 ret != MBEDTLS_ERR_ECP_IN_PROGRESS ) \
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205 ecdsa_restart_## SUB ##_free( rs_ctx->SUB ); \
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206 mbedtls_free( rs_ctx->SUB ); \
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207 rs_ctx->SUB = NULL; \
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210 if( rs_ctx != NULL ) \
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211 rs_ctx->ecp.depth--; \
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214 #else /* MBEDTLS_ECP_RESTARTABLE */
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216 #define ECDSA_RS_ECP NULL
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218 #define ECDSA_BUDGET( ops ) /* no-op; for compatibility */
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220 #define ECDSA_RS_ENTER( SUB ) (void) rs_ctx
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221 #define ECDSA_RS_LEAVE( SUB ) (void) rs_ctx
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223 #endif /* MBEDTLS_ECP_RESTARTABLE */
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226 * Derive a suitable integer for group grp from a buffer of length len
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227 * SEC1 4.1.3 step 5 aka SEC1 4.1.4 step 3
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229 static int derive_mpi( const mbedtls_ecp_group *grp, mbedtls_mpi *x,
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230 const unsigned char *buf, size_t blen )
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233 size_t n_size = ( grp->nbits + 7 ) / 8;
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234 size_t use_size = blen > n_size ? n_size : blen;
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236 MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( x, buf, use_size ) );
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237 if( use_size * 8 > grp->nbits )
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238 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( x, use_size * 8 - grp->nbits ) );
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240 /* While at it, reduce modulo N */
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241 if( mbedtls_mpi_cmp_mpi( x, &grp->N ) >= 0 )
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242 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( x, x, &grp->N ) );
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248 #if !defined(MBEDTLS_ECDSA_SIGN_ALT)
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250 * Compute ECDSA signature of a hashed message (SEC1 4.1.3)
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251 * Obviously, compared to SEC1 4.1.3, we skip step 4 (hash message)
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253 static int ecdsa_sign_restartable( mbedtls_ecp_group *grp,
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254 mbedtls_mpi *r, mbedtls_mpi *s,
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255 const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
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256 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
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257 mbedtls_ecdsa_restart_ctx *rs_ctx )
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259 int ret, key_tries, sign_tries;
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260 int *p_sign_tries = &sign_tries, *p_key_tries = &key_tries;
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261 mbedtls_ecp_point R;
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262 mbedtls_mpi k, e, t;
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263 mbedtls_mpi *pk = &k, *pr = r;
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265 /* Fail cleanly on curves such as Curve25519 that can't be used for ECDSA */
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266 if( grp->N.p == NULL )
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267 return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
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269 /* Make sure d is in range 1..n-1 */
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270 if( mbedtls_mpi_cmp_int( d, 1 ) < 0 || mbedtls_mpi_cmp_mpi( d, &grp->N ) >= 0 )
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271 return( MBEDTLS_ERR_ECP_INVALID_KEY );
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273 mbedtls_ecp_point_init( &R );
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274 mbedtls_mpi_init( &k ); mbedtls_mpi_init( &e ); mbedtls_mpi_init( &t );
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276 ECDSA_RS_ENTER( sig );
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278 #if defined(MBEDTLS_ECP_RESTARTABLE)
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279 if( rs_ctx != NULL && rs_ctx->sig != NULL )
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281 /* redirect to our context */
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282 p_sign_tries = &rs_ctx->sig->sign_tries;
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283 p_key_tries = &rs_ctx->sig->key_tries;
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284 pk = &rs_ctx->sig->k;
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285 pr = &rs_ctx->sig->r;
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287 /* jump to current step */
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288 if( rs_ctx->sig->state == ecdsa_sig_mul )
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290 if( rs_ctx->sig->state == ecdsa_sig_modn )
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293 #endif /* MBEDTLS_ECP_RESTARTABLE */
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298 if( *p_sign_tries++ > 10 )
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300 ret = MBEDTLS_ERR_ECP_RANDOM_FAILED;
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305 * Steps 1-3: generate a suitable ephemeral keypair
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306 * and set r = xR mod n
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311 if( *p_key_tries++ > 10 )
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313 ret = MBEDTLS_ERR_ECP_RANDOM_FAILED;
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317 MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, pk, f_rng, p_rng ) );
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319 #if defined(MBEDTLS_ECP_RESTARTABLE)
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320 if( rs_ctx != NULL && rs_ctx->sig != NULL )
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321 rs_ctx->sig->state = ecdsa_sig_mul;
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325 MBEDTLS_MPI_CHK( mbedtls_ecp_mul_restartable( grp, &R, pk, &grp->G,
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326 f_rng, p_rng, ECDSA_RS_ECP ) );
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327 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( pr, &R.X, &grp->N ) );
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329 while( mbedtls_mpi_cmp_int( pr, 0 ) == 0 );
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331 #if defined(MBEDTLS_ECP_RESTARTABLE)
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332 if( rs_ctx != NULL && rs_ctx->sig != NULL )
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333 rs_ctx->sig->state = ecdsa_sig_modn;
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338 * Accounting for everything up to the end of the loop
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339 * (step 6, but checking now avoids saving e and t)
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341 ECDSA_BUDGET( MBEDTLS_ECP_OPS_INV + 4 );
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344 * Step 5: derive MPI from hashed message
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346 MBEDTLS_MPI_CHK( derive_mpi( grp, &e, buf, blen ) );
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349 * Generate a random value to blind inv_mod in next step,
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350 * avoiding a potential timing leak.
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352 MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, &t, f_rng, p_rng ) );
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355 * Step 6: compute s = (e + r * d) / k = t (e + rd) / (kt) mod n
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357 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( s, pr, d ) );
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358 MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &e, &e, s ) );
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359 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &e, &e, &t ) );
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360 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( pk, pk, &t ) );
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361 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( s, pk, &grp->N ) );
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362 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( s, s, &e ) );
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363 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( s, s, &grp->N ) );
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365 while( mbedtls_mpi_cmp_int( s, 0 ) == 0 );
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367 #if defined(MBEDTLS_ECP_RESTARTABLE)
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368 if( rs_ctx != NULL && rs_ctx->sig != NULL )
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369 mbedtls_mpi_copy( r, pr );
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373 mbedtls_ecp_point_free( &R );
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374 mbedtls_mpi_free( &k ); mbedtls_mpi_free( &e ); mbedtls_mpi_free( &t );
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376 ECDSA_RS_LEAVE( sig );
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382 * Compute ECDSA signature of a hashed message
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384 int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
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385 const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
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386 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
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388 ECDSA_VALIDATE_RET( grp != NULL );
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389 ECDSA_VALIDATE_RET( r != NULL );
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390 ECDSA_VALIDATE_RET( s != NULL );
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391 ECDSA_VALIDATE_RET( d != NULL );
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392 ECDSA_VALIDATE_RET( f_rng != NULL );
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393 ECDSA_VALIDATE_RET( buf != NULL || blen == 0 );
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395 return( ecdsa_sign_restartable( grp, r, s, d, buf, blen,
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396 f_rng, p_rng, NULL ) );
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398 #endif /* !MBEDTLS_ECDSA_SIGN_ALT */
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400 #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
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402 * Deterministic signature wrapper
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404 static int ecdsa_sign_det_restartable( mbedtls_ecp_group *grp,
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405 mbedtls_mpi *r, mbedtls_mpi *s,
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406 const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
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407 mbedtls_md_type_t md_alg,
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408 mbedtls_ecdsa_restart_ctx *rs_ctx )
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411 mbedtls_hmac_drbg_context rng_ctx;
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412 mbedtls_hmac_drbg_context *p_rng = &rng_ctx;
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413 unsigned char data[2 * MBEDTLS_ECP_MAX_BYTES];
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414 size_t grp_len = ( grp->nbits + 7 ) / 8;
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415 const mbedtls_md_info_t *md_info;
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418 if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL )
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419 return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
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421 mbedtls_mpi_init( &h );
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422 mbedtls_hmac_drbg_init( &rng_ctx );
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424 ECDSA_RS_ENTER( det );
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426 #if defined(MBEDTLS_ECP_RESTARTABLE)
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427 if( rs_ctx != NULL && rs_ctx->det != NULL )
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429 /* redirect to our context */
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430 p_rng = &rs_ctx->det->rng_ctx;
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432 /* jump to current step */
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433 if( rs_ctx->det->state == ecdsa_det_sign )
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436 #endif /* MBEDTLS_ECP_RESTARTABLE */
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438 /* Use private key and message hash (reduced) to initialize HMAC_DRBG */
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439 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( d, data, grp_len ) );
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440 MBEDTLS_MPI_CHK( derive_mpi( grp, &h, buf, blen ) );
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441 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &h, data + grp_len, grp_len ) );
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442 mbedtls_hmac_drbg_seed_buf( p_rng, md_info, data, 2 * grp_len );
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444 #if defined(MBEDTLS_ECP_RESTARTABLE)
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445 if( rs_ctx != NULL && rs_ctx->det != NULL )
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446 rs_ctx->det->state = ecdsa_det_sign;
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450 #if defined(MBEDTLS_ECDSA_SIGN_ALT)
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451 ret = mbedtls_ecdsa_sign( grp, r, s, d, buf, blen,
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452 mbedtls_hmac_drbg_random, p_rng );
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454 ret = ecdsa_sign_restartable( grp, r, s, d, buf, blen,
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455 mbedtls_hmac_drbg_random, p_rng, rs_ctx );
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456 #endif /* MBEDTLS_ECDSA_SIGN_ALT */
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459 mbedtls_hmac_drbg_free( &rng_ctx );
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460 mbedtls_mpi_free( &h );
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462 ECDSA_RS_LEAVE( det );
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468 * Deterministic signature wrapper
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470 int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
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471 const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
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472 mbedtls_md_type_t md_alg )
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474 ECDSA_VALIDATE_RET( grp != NULL );
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475 ECDSA_VALIDATE_RET( r != NULL );
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476 ECDSA_VALIDATE_RET( s != NULL );
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477 ECDSA_VALIDATE_RET( d != NULL );
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478 ECDSA_VALIDATE_RET( buf != NULL || blen == 0 );
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480 return( ecdsa_sign_det_restartable( grp, r, s, d, buf, blen, md_alg, NULL ) );
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482 #endif /* MBEDTLS_ECDSA_DETERMINISTIC */
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484 #if !defined(MBEDTLS_ECDSA_VERIFY_ALT)
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486 * Verify ECDSA signature of hashed message (SEC1 4.1.4)
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487 * Obviously, compared to SEC1 4.1.3, we skip step 2 (hash message)
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489 static int ecdsa_verify_restartable( mbedtls_ecp_group *grp,
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490 const unsigned char *buf, size_t blen,
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491 const mbedtls_ecp_point *Q,
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492 const mbedtls_mpi *r, const mbedtls_mpi *s,
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493 mbedtls_ecdsa_restart_ctx *rs_ctx )
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496 mbedtls_mpi e, s_inv, u1, u2;
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497 mbedtls_ecp_point R;
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498 mbedtls_mpi *pu1 = &u1, *pu2 = &u2;
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500 mbedtls_ecp_point_init( &R );
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501 mbedtls_mpi_init( &e ); mbedtls_mpi_init( &s_inv );
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502 mbedtls_mpi_init( &u1 ); mbedtls_mpi_init( &u2 );
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504 /* Fail cleanly on curves such as Curve25519 that can't be used for ECDSA */
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505 if( grp->N.p == NULL )
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506 return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
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508 ECDSA_RS_ENTER( ver );
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510 #if defined(MBEDTLS_ECP_RESTARTABLE)
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511 if( rs_ctx != NULL && rs_ctx->ver != NULL )
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513 /* redirect to our context */
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514 pu1 = &rs_ctx->ver->u1;
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515 pu2 = &rs_ctx->ver->u2;
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517 /* jump to current step */
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518 if( rs_ctx->ver->state == ecdsa_ver_muladd )
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521 #endif /* MBEDTLS_ECP_RESTARTABLE */
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524 * Step 1: make sure r and s are in range 1..n-1
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526 if( mbedtls_mpi_cmp_int( r, 1 ) < 0 || mbedtls_mpi_cmp_mpi( r, &grp->N ) >= 0 ||
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527 mbedtls_mpi_cmp_int( s, 1 ) < 0 || mbedtls_mpi_cmp_mpi( s, &grp->N ) >= 0 )
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529 ret = MBEDTLS_ERR_ECP_VERIFY_FAILED;
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534 * Step 3: derive MPI from hashed message
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536 MBEDTLS_MPI_CHK( derive_mpi( grp, &e, buf, blen ) );
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539 * Step 4: u1 = e / s mod n, u2 = r / s mod n
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541 ECDSA_BUDGET( MBEDTLS_ECP_OPS_CHK + MBEDTLS_ECP_OPS_INV + 2 );
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543 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &s_inv, s, &grp->N ) );
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545 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( pu1, &e, &s_inv ) );
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546 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( pu1, pu1, &grp->N ) );
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548 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( pu2, r, &s_inv ) );
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549 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( pu2, pu2, &grp->N ) );
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551 #if defined(MBEDTLS_ECP_RESTARTABLE)
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552 if( rs_ctx != NULL && rs_ctx->ver != NULL )
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553 rs_ctx->ver->state = ecdsa_ver_muladd;
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558 * Step 5: R = u1 G + u2 Q
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560 MBEDTLS_MPI_CHK( mbedtls_ecp_muladd_restartable( grp,
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561 &R, pu1, &grp->G, pu2, Q, ECDSA_RS_ECP ) );
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563 if( mbedtls_ecp_is_zero( &R ) )
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565 ret = MBEDTLS_ERR_ECP_VERIFY_FAILED;
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570 * Step 6: convert xR to an integer (no-op)
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571 * Step 7: reduce xR mod n (gives v)
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573 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &R.X, &R.X, &grp->N ) );
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576 * Step 8: check if v (that is, R.X) is equal to r
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578 if( mbedtls_mpi_cmp_mpi( &R.X, r ) != 0 )
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580 ret = MBEDTLS_ERR_ECP_VERIFY_FAILED;
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585 mbedtls_ecp_point_free( &R );
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586 mbedtls_mpi_free( &e ); mbedtls_mpi_free( &s_inv );
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587 mbedtls_mpi_free( &u1 ); mbedtls_mpi_free( &u2 );
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589 ECDSA_RS_LEAVE( ver );
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595 * Verify ECDSA signature of hashed message
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597 int mbedtls_ecdsa_verify( mbedtls_ecp_group *grp,
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598 const unsigned char *buf, size_t blen,
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599 const mbedtls_ecp_point *Q,
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600 const mbedtls_mpi *r,
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601 const mbedtls_mpi *s)
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603 ECDSA_VALIDATE_RET( grp != NULL );
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604 ECDSA_VALIDATE_RET( Q != NULL );
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605 ECDSA_VALIDATE_RET( r != NULL );
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606 ECDSA_VALIDATE_RET( s != NULL );
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607 ECDSA_VALIDATE_RET( buf != NULL || blen == 0 );
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609 return( ecdsa_verify_restartable( grp, buf, blen, Q, r, s, NULL ) );
\r
611 #endif /* !MBEDTLS_ECDSA_VERIFY_ALT */
\r
614 * Convert a signature (given by context) to ASN.1
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616 static int ecdsa_signature_to_asn1( const mbedtls_mpi *r, const mbedtls_mpi *s,
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617 unsigned char *sig, size_t *slen )
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620 unsigned char buf[MBEDTLS_ECDSA_MAX_LEN];
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621 unsigned char *p = buf + sizeof( buf );
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624 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &p, buf, s ) );
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625 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &p, buf, r ) );
\r
627 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, buf, len ) );
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628 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, buf,
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629 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
\r
631 memcpy( sig, p, len );
\r
638 * Compute and write signature
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640 int mbedtls_ecdsa_write_signature_restartable( mbedtls_ecdsa_context *ctx,
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641 mbedtls_md_type_t md_alg,
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642 const unsigned char *hash, size_t hlen,
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643 unsigned char *sig, size_t *slen,
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644 int (*f_rng)(void *, unsigned char *, size_t),
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646 mbedtls_ecdsa_restart_ctx *rs_ctx )
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650 ECDSA_VALIDATE_RET( ctx != NULL );
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651 ECDSA_VALIDATE_RET( hash != NULL );
\r
652 ECDSA_VALIDATE_RET( sig != NULL );
\r
653 ECDSA_VALIDATE_RET( slen != NULL );
\r
655 mbedtls_mpi_init( &r );
\r
656 mbedtls_mpi_init( &s );
\r
658 #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
\r
662 MBEDTLS_MPI_CHK( ecdsa_sign_det_restartable( &ctx->grp, &r, &s, &ctx->d,
\r
663 hash, hlen, md_alg, rs_ctx ) );
\r
667 #if defined(MBEDTLS_ECDSA_SIGN_ALT)
\r
668 MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign( &ctx->grp, &r, &s, &ctx->d,
\r
669 hash, hlen, f_rng, p_rng ) );
\r
671 MBEDTLS_MPI_CHK( ecdsa_sign_restartable( &ctx->grp, &r, &s, &ctx->d,
\r
672 hash, hlen, f_rng, p_rng, rs_ctx ) );
\r
673 #endif /* MBEDTLS_ECDSA_SIGN_ALT */
\r
674 #endif /* MBEDTLS_ECDSA_DETERMINISTIC */
\r
676 MBEDTLS_MPI_CHK( ecdsa_signature_to_asn1( &r, &s, sig, slen ) );
\r
679 mbedtls_mpi_free( &r );
\r
680 mbedtls_mpi_free( &s );
\r
686 * Compute and write signature
\r
688 int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx,
\r
689 mbedtls_md_type_t md_alg,
\r
690 const unsigned char *hash, size_t hlen,
\r
691 unsigned char *sig, size_t *slen,
\r
692 int (*f_rng)(void *, unsigned char *, size_t),
\r
695 ECDSA_VALIDATE_RET( ctx != NULL );
\r
696 ECDSA_VALIDATE_RET( hash != NULL );
\r
697 ECDSA_VALIDATE_RET( sig != NULL );
\r
698 ECDSA_VALIDATE_RET( slen != NULL );
\r
699 return( mbedtls_ecdsa_write_signature_restartable(
\r
700 ctx, md_alg, hash, hlen, sig, slen, f_rng, p_rng, NULL ) );
\r
703 #if !defined(MBEDTLS_DEPRECATED_REMOVED) && \
\r
704 defined(MBEDTLS_ECDSA_DETERMINISTIC)
\r
705 int mbedtls_ecdsa_write_signature_det( mbedtls_ecdsa_context *ctx,
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706 const unsigned char *hash, size_t hlen,
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707 unsigned char *sig, size_t *slen,
\r
708 mbedtls_md_type_t md_alg )
\r
710 ECDSA_VALIDATE_RET( ctx != NULL );
\r
711 ECDSA_VALIDATE_RET( hash != NULL );
\r
712 ECDSA_VALIDATE_RET( sig != NULL );
\r
713 ECDSA_VALIDATE_RET( slen != NULL );
\r
714 return( mbedtls_ecdsa_write_signature( ctx, md_alg, hash, hlen, sig, slen,
\r
720 * Read and check signature
\r
722 int mbedtls_ecdsa_read_signature( mbedtls_ecdsa_context *ctx,
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723 const unsigned char *hash, size_t hlen,
\r
724 const unsigned char *sig, size_t slen )
\r
726 ECDSA_VALIDATE_RET( ctx != NULL );
\r
727 ECDSA_VALIDATE_RET( hash != NULL );
\r
728 ECDSA_VALIDATE_RET( sig != NULL );
\r
729 return( mbedtls_ecdsa_read_signature_restartable(
\r
730 ctx, hash, hlen, sig, slen, NULL ) );
\r
734 * Restartable read and check signature
\r
736 int mbedtls_ecdsa_read_signature_restartable( mbedtls_ecdsa_context *ctx,
\r
737 const unsigned char *hash, size_t hlen,
\r
738 const unsigned char *sig, size_t slen,
\r
739 mbedtls_ecdsa_restart_ctx *rs_ctx )
\r
742 unsigned char *p = (unsigned char *) sig;
\r
743 const unsigned char *end = sig + slen;
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746 ECDSA_VALIDATE_RET( ctx != NULL );
\r
747 ECDSA_VALIDATE_RET( hash != NULL );
\r
748 ECDSA_VALIDATE_RET( sig != NULL );
\r
750 mbedtls_mpi_init( &r );
\r
751 mbedtls_mpi_init( &s );
\r
753 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
\r
754 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
\r
756 ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
\r
760 if( p + len != end )
\r
762 ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA +
\r
763 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
\r
767 if( ( ret = mbedtls_asn1_get_mpi( &p, end, &r ) ) != 0 ||
\r
768 ( ret = mbedtls_asn1_get_mpi( &p, end, &s ) ) != 0 )
\r
770 ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
\r
773 #if defined(MBEDTLS_ECDSA_VERIFY_ALT)
\r
774 if( ( ret = mbedtls_ecdsa_verify( &ctx->grp, hash, hlen,
\r
775 &ctx->Q, &r, &s ) ) != 0 )
\r
778 if( ( ret = ecdsa_verify_restartable( &ctx->grp, hash, hlen,
\r
779 &ctx->Q, &r, &s, rs_ctx ) ) != 0 )
\r
781 #endif /* MBEDTLS_ECDSA_VERIFY_ALT */
\r
783 /* At this point we know that the buffer starts with a valid signature.
\r
784 * Return 0 if the buffer just contains the signature, and a specific
\r
785 * error code if the valid signature is followed by more data. */
\r
787 ret = MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH;
\r
790 mbedtls_mpi_free( &r );
\r
791 mbedtls_mpi_free( &s );
\r
796 #if !defined(MBEDTLS_ECDSA_GENKEY_ALT)
\r
798 * Generate key pair
\r
800 int mbedtls_ecdsa_genkey( mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid,
\r
801 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
\r
804 ECDSA_VALIDATE_RET( ctx != NULL );
\r
805 ECDSA_VALIDATE_RET( f_rng != NULL );
\r
807 ret = mbedtls_ecp_group_load( &ctx->grp, gid );
\r
811 return( mbedtls_ecp_gen_keypair( &ctx->grp, &ctx->d,
\r
812 &ctx->Q, f_rng, p_rng ) );
\r
814 #endif /* !MBEDTLS_ECDSA_GENKEY_ALT */
\r
817 * Set context from an mbedtls_ecp_keypair
\r
819 int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx, const mbedtls_ecp_keypair *key )
\r
822 ECDSA_VALIDATE_RET( ctx != NULL );
\r
823 ECDSA_VALIDATE_RET( key != NULL );
\r
825 if( ( ret = mbedtls_ecp_group_copy( &ctx->grp, &key->grp ) ) != 0 ||
\r
826 ( ret = mbedtls_mpi_copy( &ctx->d, &key->d ) ) != 0 ||
\r
827 ( ret = mbedtls_ecp_copy( &ctx->Q, &key->Q ) ) != 0 )
\r
829 mbedtls_ecdsa_free( ctx );
\r
836 * Initialize context
\r
838 void mbedtls_ecdsa_init( mbedtls_ecdsa_context *ctx )
\r
840 ECDSA_VALIDATE( ctx != NULL );
\r
842 mbedtls_ecp_keypair_init( ctx );
\r
848 void mbedtls_ecdsa_free( mbedtls_ecdsa_context *ctx )
\r
853 mbedtls_ecp_keypair_free( ctx );
\r
856 #if defined(MBEDTLS_ECP_RESTARTABLE)
\r
858 * Initialize a restart context
\r
860 void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx )
\r
862 ECDSA_VALIDATE( ctx != NULL );
\r
864 mbedtls_ecp_restart_init( &ctx->ecp );
\r
868 #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
\r
874 * Free the components of a restart context
\r
876 void mbedtls_ecdsa_restart_free( mbedtls_ecdsa_restart_ctx *ctx )
\r
881 mbedtls_ecp_restart_free( &ctx->ecp );
\r
883 ecdsa_restart_ver_free( ctx->ver );
\r
884 mbedtls_free( ctx->ver );
\r
887 ecdsa_restart_sig_free( ctx->sig );
\r
888 mbedtls_free( ctx->sig );
\r
891 #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
\r
892 ecdsa_restart_det_free( ctx->det );
\r
893 mbedtls_free( ctx->det );
\r
897 #endif /* MBEDTLS_ECP_RESTARTABLE */
\r
899 #endif /* MBEDTLS_ECDSA_C */
\r