Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 1 | /* Originally written by Bodo Moeller for the OpenSSL project. |
| 2 | * ==================================================================== |
| 3 | * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in |
| 14 | * the documentation and/or other materials provided with the |
| 15 | * distribution. |
| 16 | * |
| 17 | * 3. All advertising materials mentioning features or use of this |
| 18 | * software must display the following acknowledgment: |
| 19 | * "This product includes software developed by the OpenSSL Project |
| 20 | * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" |
| 21 | * |
| 22 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
| 23 | * endorse or promote products derived from this software without |
| 24 | * prior written permission. For written permission, please contact |
| 25 | * openssl-core@openssl.org. |
| 26 | * |
| 27 | * 5. Products derived from this software may not be called "OpenSSL" |
| 28 | * nor may "OpenSSL" appear in their names without prior written |
| 29 | * permission of the OpenSSL Project. |
| 30 | * |
| 31 | * 6. Redistributions of any form whatsoever must retain the following |
| 32 | * acknowledgment: |
| 33 | * "This product includes software developed by the OpenSSL Project |
| 34 | * for use in the OpenSSL Toolkit (http://www.openssl.org/)" |
| 35 | * |
| 36 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
| 37 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 38 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 39 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
| 40 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 41 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 42 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 43 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 44 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 45 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 46 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| 47 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
| 48 | * ==================================================================== |
| 49 | * |
| 50 | * This product includes cryptographic software written by Eric Young |
| 51 | * (eay@cryptsoft.com). This product includes software written by Tim |
| 52 | * Hudson (tjh@cryptsoft.com). |
| 53 | * |
| 54 | */ |
| 55 | /* ==================================================================== |
| 56 | * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. |
| 57 | * |
| 58 | * Portions of the attached software ("Contribution") are developed by |
| 59 | * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. |
| 60 | * |
| 61 | * The Contribution is licensed pursuant to the OpenSSL open source |
| 62 | * license provided above. |
| 63 | * |
| 64 | * The elliptic curve binary polynomial software is originally written by |
| 65 | * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems |
| 66 | * Laboratories. */ |
| 67 | |
| 68 | #include <openssl/ec.h> |
| 69 | |
| 70 | #include <string.h> |
| 71 | |
| 72 | #include <openssl/bn.h> |
| 73 | #include <openssl/err.h> |
| 74 | #include <openssl/mem.h> |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 75 | #include <openssl/thread.h> |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 76 | |
| 77 | #include "internal.h" |
Robert Sloan | 8ff0355 | 2017-06-14 12:40:58 -0700 | [diff] [blame] | 78 | #include "../../internal.h" |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 79 | |
| 80 | |
Robert Sloan | 8ff0355 | 2017-06-14 12:40:58 -0700 | [diff] [blame] | 81 | /* This file implements the wNAF-based interleaving multi-exponentiation method |
| 82 | * at: |
| 83 | * http://link.springer.com/chapter/10.1007%2F3-540-45537-X_13 |
| 84 | * http://www.bmoeller.de/pdf/TI-01-08.multiexp.pdf */ |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 85 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 86 | /* Determine the modified width-(w+1) Non-Adjacent Form (wNAF) of 'scalar'. |
| 87 | * This is an array r[] of values that are either zero or odd with an |
| 88 | * absolute value less than 2^w satisfying |
| 89 | * scalar = \sum_j r[j]*2^j |
| 90 | * where at most one of any w+1 consecutive digits is non-zero |
| 91 | * with the exception that the most significant digit may be only |
| 92 | * w-1 zeros away from that next non-zero digit. |
| 93 | */ |
David Benjamin | 1b24967 | 2016-12-06 18:25:50 -0500 | [diff] [blame] | 94 | static int8_t *compute_wNAF(const BIGNUM *scalar, int w, size_t *ret_len) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 95 | int window_val; |
| 96 | int ok = 0; |
David Benjamin | 1b24967 | 2016-12-06 18:25:50 -0500 | [diff] [blame] | 97 | int8_t *r = NULL; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 98 | int sign = 1; |
| 99 | int bit, next_bit, mask; |
| 100 | size_t len = 0, j; |
| 101 | |
| 102 | if (BN_is_zero(scalar)) { |
| 103 | r = OPENSSL_malloc(1); |
| 104 | if (!r) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 105 | OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 106 | goto err; |
| 107 | } |
| 108 | r[0] = 0; |
| 109 | *ret_len = 1; |
| 110 | return r; |
| 111 | } |
| 112 | |
David Benjamin | 1b24967 | 2016-12-06 18:25:50 -0500 | [diff] [blame] | 113 | /* 'int8_t' can represent integers with absolute values less than 2^7. */ |
| 114 | if (w <= 0 || w > 7) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 115 | OPENSSL_PUT_ERROR(EC, ERR_R_INTERNAL_ERROR); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 116 | goto err; |
| 117 | } |
| 118 | bit = 1 << w; /* at most 128 */ |
| 119 | next_bit = bit << 1; /* at most 256 */ |
| 120 | mask = next_bit - 1; /* at most 255 */ |
| 121 | |
| 122 | if (BN_is_negative(scalar)) { |
| 123 | sign = -1; |
| 124 | } |
| 125 | |
| 126 | if (scalar->d == NULL || scalar->top == 0) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 127 | OPENSSL_PUT_ERROR(EC, ERR_R_INTERNAL_ERROR); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 128 | goto err; |
| 129 | } |
| 130 | |
| 131 | len = BN_num_bits(scalar); |
David Benjamin | 1b24967 | 2016-12-06 18:25:50 -0500 | [diff] [blame] | 132 | /* The modified wNAF may be one digit longer than binary representation |
| 133 | * (*ret_len will be set to the actual length, i.e. at most |
| 134 | * BN_num_bits(scalar) + 1). */ |
| 135 | r = OPENSSL_malloc(len + 1); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 136 | if (r == NULL) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 137 | OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 138 | goto err; |
| 139 | } |
| 140 | window_val = scalar->d[0] & mask; |
| 141 | j = 0; |
David Benjamin | 1b24967 | 2016-12-06 18:25:50 -0500 | [diff] [blame] | 142 | /* If j+w+1 >= len, window_val will not increase. */ |
| 143 | while (window_val != 0 || j + w + 1 < len) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 144 | int digit = 0; |
| 145 | |
| 146 | /* 0 <= window_val <= 2^(w+1) */ |
| 147 | |
| 148 | if (window_val & 1) { |
| 149 | /* 0 < window_val < 2^(w+1) */ |
| 150 | |
| 151 | if (window_val & bit) { |
| 152 | digit = window_val - next_bit; /* -2^w < digit < 0 */ |
| 153 | |
| 154 | #if 1 /* modified wNAF */ |
| 155 | if (j + w + 1 >= len) { |
| 156 | /* special case for generating modified wNAFs: |
| 157 | * no new bits will be added into window_val, |
| 158 | * so using a positive digit here will decrease |
| 159 | * the total length of the representation */ |
| 160 | |
| 161 | digit = window_val & (mask >> 1); /* 0 < digit < 2^w */ |
| 162 | } |
| 163 | #endif |
| 164 | } else { |
| 165 | digit = window_val; /* 0 < digit < 2^w */ |
| 166 | } |
| 167 | |
| 168 | if (digit <= -bit || digit >= bit || !(digit & 1)) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 169 | OPENSSL_PUT_ERROR(EC, ERR_R_INTERNAL_ERROR); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 170 | goto err; |
| 171 | } |
| 172 | |
| 173 | window_val -= digit; |
| 174 | |
David Benjamin | 1b24967 | 2016-12-06 18:25:50 -0500 | [diff] [blame] | 175 | /* Now window_val is 0 or 2^(w+1) in standard wNAF generation; |
| 176 | * for modified window NAFs, it may also be 2^w. */ |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 177 | if (window_val != 0 && window_val != next_bit && window_val != bit) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 178 | OPENSSL_PUT_ERROR(EC, ERR_R_INTERNAL_ERROR); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 179 | goto err; |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | r[j++] = sign * digit; |
| 184 | |
| 185 | window_val >>= 1; |
| 186 | window_val += bit * BN_is_bit_set(scalar, j + w); |
| 187 | |
| 188 | if (window_val > next_bit) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 189 | OPENSSL_PUT_ERROR(EC, ERR_R_INTERNAL_ERROR); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 190 | goto err; |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | if (j > len + 1) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 195 | OPENSSL_PUT_ERROR(EC, ERR_R_INTERNAL_ERROR); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 196 | goto err; |
| 197 | } |
| 198 | len = j; |
| 199 | ok = 1; |
| 200 | |
| 201 | err: |
| 202 | if (!ok) { |
| 203 | OPENSSL_free(r); |
| 204 | r = NULL; |
| 205 | } |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 206 | if (ok) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 207 | *ret_len = len; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 208 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 209 | return r; |
| 210 | } |
| 211 | |
| 212 | |
| 213 | /* TODO: table should be optimised for the wNAF-based implementation, |
| 214 | * sometimes smaller windows will give better performance |
| 215 | * (thus the boundaries should be increased) |
| 216 | */ |
David Benjamin | 1b24967 | 2016-12-06 18:25:50 -0500 | [diff] [blame] | 217 | static size_t window_bits_for_scalar_size(size_t b) { |
| 218 | if (b >= 2000) { |
| 219 | return 6; |
| 220 | } |
| 221 | |
| 222 | if (b >= 800) { |
| 223 | return 5; |
| 224 | } |
| 225 | |
| 226 | if (b >= 300) { |
| 227 | return 4; |
| 228 | } |
| 229 | |
| 230 | if (b >= 70) { |
| 231 | return 3; |
| 232 | } |
| 233 | |
| 234 | if (b >= 20) { |
| 235 | return 2; |
| 236 | } |
| 237 | |
| 238 | return 1; |
| 239 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 240 | |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 241 | int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar, |
| 242 | const EC_POINT *p, const BIGNUM *p_scalar, BN_CTX *ctx) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 243 | BN_CTX *new_ctx = NULL; |
| 244 | const EC_POINT *generator = NULL; |
| 245 | EC_POINT *tmp = NULL; |
Steven Valdez | b0b45c6 | 2017-01-17 16:23:54 -0500 | [diff] [blame] | 246 | size_t total_num = 0; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 247 | size_t i, j; |
| 248 | int k; |
| 249 | int r_is_inverted = 0; |
| 250 | int r_is_at_infinity = 1; |
| 251 | size_t *wsize = NULL; /* individual window sizes */ |
David Benjamin | 1b24967 | 2016-12-06 18:25:50 -0500 | [diff] [blame] | 252 | int8_t **wNAF = NULL; /* individual wNAFs */ |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 253 | size_t *wNAF_len = NULL; |
| 254 | size_t max_len = 0; |
Steven Valdez | b0b45c6 | 2017-01-17 16:23:54 -0500 | [diff] [blame] | 255 | size_t num_val = 0; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 256 | EC_POINT **val = NULL; /* precomputation */ |
| 257 | EC_POINT **v; |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 258 | EC_POINT ***val_sub = NULL; /* pointers to sub-arrays of 'val' */ |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 259 | int ret = 0; |
| 260 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 261 | if (ctx == NULL) { |
| 262 | ctx = new_ctx = BN_CTX_new(); |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 263 | if (ctx == NULL) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 264 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 265 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 266 | } |
| 267 | |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 268 | /* TODO: This function used to take |points| and |scalars| as arrays of |
| 269 | * |num| elements. The code below should be simplified to work in terms of |p| |
| 270 | * and |p_scalar|. */ |
| 271 | size_t num = p != NULL ? 1 : 0; |
| 272 | const EC_POINT **points = p != NULL ? &p : NULL; |
| 273 | const BIGNUM **scalars = p != NULL ? &p_scalar : NULL; |
| 274 | |
| 275 | total_num = num; |
| 276 | |
| 277 | if (g_scalar != NULL) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 278 | generator = EC_GROUP_get0_generator(group); |
| 279 | if (generator == NULL) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 280 | OPENSSL_PUT_ERROR(EC, EC_R_UNDEFINED_GENERATOR); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 281 | goto err; |
| 282 | } |
| 283 | |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 284 | ++total_num; /* treat 'g_scalar' like 'num'-th element of 'scalars' */ |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 285 | } |
| 286 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 287 | |
Steven Valdez | b0b45c6 | 2017-01-17 16:23:54 -0500 | [diff] [blame] | 288 | wsize = OPENSSL_malloc(total_num * sizeof(wsize[0])); |
| 289 | wNAF_len = OPENSSL_malloc(total_num * sizeof(wNAF_len[0])); |
| 290 | wNAF = OPENSSL_malloc(total_num * sizeof(wNAF[0])); |
| 291 | val_sub = OPENSSL_malloc(total_num * sizeof(val_sub[0])); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 292 | |
| 293 | /* Ensure wNAF is initialised in case we end up going to err. */ |
Steven Valdez | b0b45c6 | 2017-01-17 16:23:54 -0500 | [diff] [blame] | 294 | if (wNAF != NULL) { |
| 295 | OPENSSL_memset(wNAF, 0, total_num * sizeof(wNAF[0])); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 296 | } |
| 297 | |
| 298 | if (!wsize || !wNAF_len || !wNAF || !val_sub) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 299 | OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 300 | goto err; |
| 301 | } |
| 302 | |
| 303 | /* num_val will be the total number of temporarily precomputed points */ |
| 304 | num_val = 0; |
| 305 | |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 306 | for (i = 0; i < total_num; i++) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 307 | size_t bits; |
| 308 | |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 309 | bits = i < num ? BN_num_bits(scalars[i]) : BN_num_bits(g_scalar); |
David Benjamin | 1b24967 | 2016-12-06 18:25:50 -0500 | [diff] [blame] | 310 | wsize[i] = window_bits_for_scalar_size(bits); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 311 | num_val += (size_t)1 << (wsize[i] - 1); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 312 | wNAF[i] = |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 313 | compute_wNAF((i < num ? scalars[i] : g_scalar), wsize[i], &wNAF_len[i]); |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 314 | if (wNAF[i] == NULL) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 315 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 316 | } |
| 317 | if (wNAF_len[i] > max_len) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 318 | max_len = wNAF_len[i]; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 319 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 320 | } |
| 321 | |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 322 | /* All points we precompute now go into a single array 'val'. 'val_sub[i]' is |
| 323 | * a pointer to the subarray for the i-th point. */ |
Steven Valdez | b0b45c6 | 2017-01-17 16:23:54 -0500 | [diff] [blame] | 324 | val = OPENSSL_malloc(num_val * sizeof(val[0])); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 325 | if (val == NULL) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 326 | OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 327 | goto err; |
| 328 | } |
Steven Valdez | b0b45c6 | 2017-01-17 16:23:54 -0500 | [diff] [blame] | 329 | OPENSSL_memset(val, 0, num_val * sizeof(val[0])); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 330 | |
| 331 | /* allocate points for precomputation */ |
| 332 | v = val; |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 333 | for (i = 0; i < total_num; i++) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 334 | val_sub[i] = v; |
| 335 | for (j = 0; j < ((size_t)1 << (wsize[i] - 1)); j++) { |
| 336 | *v = EC_POINT_new(group); |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 337 | if (*v == NULL) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 338 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 339 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 340 | v++; |
| 341 | } |
| 342 | } |
| 343 | if (!(v == val + num_val)) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 344 | OPENSSL_PUT_ERROR(EC, ERR_R_INTERNAL_ERROR); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 345 | goto err; |
| 346 | } |
| 347 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 348 | if (!(tmp = EC_POINT_new(group))) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 349 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 350 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 351 | |
| 352 | /* prepare precomputed values: |
| 353 | * val_sub[i][0] := points[i] |
| 354 | * val_sub[i][1] := 3 * points[i] |
| 355 | * val_sub[i][2] := 5 * points[i] |
| 356 | * ... |
| 357 | */ |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 358 | for (i = 0; i < total_num; i++) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 359 | if (i < num) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 360 | if (!EC_POINT_copy(val_sub[i][0], points[i])) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 361 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 362 | } |
| 363 | } else if (!EC_POINT_copy(val_sub[i][0], generator)) { |
| 364 | goto err; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 365 | } |
| 366 | |
| 367 | if (wsize[i] > 1) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 368 | if (!EC_POINT_dbl(group, tmp, val_sub[i][0], ctx)) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 369 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 370 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 371 | for (j = 1; j < ((size_t)1 << (wsize[i] - 1)); j++) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 372 | if (!EC_POINT_add(group, val_sub[i][j], val_sub[i][j - 1], tmp, ctx)) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 373 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 374 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 375 | } |
| 376 | } |
| 377 | } |
| 378 | |
David Benjamin | 1b24967 | 2016-12-06 18:25:50 -0500 | [diff] [blame] | 379 | #if 1 /* optional; window_bits_for_scalar_size assumes we do this step */ |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 380 | if (!EC_POINTs_make_affine(group, num_val, val, ctx)) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 381 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 382 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 383 | #endif |
| 384 | |
| 385 | r_is_at_infinity = 1; |
| 386 | |
| 387 | for (k = max_len - 1; k >= 0; k--) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 388 | if (!r_is_at_infinity && !EC_POINT_dbl(group, r, r, ctx)) { |
| 389 | goto err; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 390 | } |
| 391 | |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 392 | for (i = 0; i < total_num; i++) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 393 | if (wNAF_len[i] > (size_t)k) { |
| 394 | int digit = wNAF[i][k]; |
| 395 | int is_neg; |
| 396 | |
| 397 | if (digit) { |
| 398 | is_neg = digit < 0; |
| 399 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 400 | if (is_neg) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 401 | digit = -digit; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 402 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 403 | |
| 404 | if (is_neg != r_is_inverted) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 405 | if (!r_is_at_infinity && !EC_POINT_invert(group, r, ctx)) { |
| 406 | goto err; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 407 | } |
| 408 | r_is_inverted = !r_is_inverted; |
| 409 | } |
| 410 | |
| 411 | /* digit > 0 */ |
| 412 | |
| 413 | if (r_is_at_infinity) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 414 | if (!EC_POINT_copy(r, val_sub[i][digit >> 1])) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 415 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 416 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 417 | r_is_at_infinity = 0; |
| 418 | } else { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 419 | if (!EC_POINT_add(group, r, r, val_sub[i][digit >> 1], ctx)) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 420 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 421 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 422 | } |
| 423 | } |
| 424 | } |
| 425 | } |
| 426 | } |
| 427 | |
| 428 | if (r_is_at_infinity) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 429 | if (!EC_POINT_set_to_infinity(group, r)) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 430 | goto err; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 431 | } |
| 432 | } else if (r_is_inverted && !EC_POINT_invert(group, r, ctx)) { |
| 433 | goto err; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 434 | } |
| 435 | |
| 436 | ret = 1; |
| 437 | |
| 438 | err: |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 439 | BN_CTX_free(new_ctx); |
| 440 | EC_POINT_free(tmp); |
| 441 | OPENSSL_free(wsize); |
| 442 | OPENSSL_free(wNAF_len); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 443 | if (wNAF != NULL) { |
Steven Valdez | b0b45c6 | 2017-01-17 16:23:54 -0500 | [diff] [blame] | 444 | for (i = 0; i < total_num; i++) { |
| 445 | OPENSSL_free(wNAF[i]); |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 446 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 447 | |
| 448 | OPENSSL_free(wNAF); |
| 449 | } |
| 450 | if (val != NULL) { |
Steven Valdez | b0b45c6 | 2017-01-17 16:23:54 -0500 | [diff] [blame] | 451 | for (i = 0; i < num_val; i++) { |
| 452 | EC_POINT_clear_free(val[i]); |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 453 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 454 | |
| 455 | OPENSSL_free(val); |
| 456 | } |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 457 | OPENSSL_free(val_sub); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 458 | return ret; |
| 459 | } |