crypto/modes/siv128.c

   1 /*
   2  * Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <string.h>
  11 #include <stdlib.h>
  12 #include <openssl/crypto.h>
  13 #include "internal/modes_int.h"
  14 #include "modes_lcl.h"
  15
  16 #ifndef OPENSSL_NO_SIV
  17
  18 __owur static ossl_inline uint32_t rotl8(uint32_t x)
  19 {
  20     return (x << 8) | (x >> 24);
  21 }
  22
  23 __owur static ossl_inline uint32_t rotr8(uint32_t x)
  24 {
  25     return (x >> 8) | (x << 24);
  26 }
  27
  28 __owur static ossl_inline uint64_t byteswap8(uint64_t x)
  29 {
  30     uint32_t high = (uint32_t)(x >> 32);
  31     uint32_t low = (uint32_t)x;
  32
  33     high = (rotl8(high) & 0x00ff00ff) | (rotr8(high) & 0xff00ff00);
  34     low = (rotl8(low) & 0x00ff00ff) | (rotr8(low) & 0xff00ff00);
  35     return ((uint64_t)low) << 32 | (uint64_t)high;
  36 }
  37
  38 __owur static ossl_inline uint64_t siv128_getword(SIV_BLOCK const *b, size_t i)
  39 {
  40     const union {
  41         long one;
  42         char little;
  43     } is_endian = { 1 };
  44
  45     if (is_endian.little)
  46         return byteswap8(b->word[i]);
  47     return b->word[i];
  48 }
  49
  50 static ossl_inline void siv128_putword(SIV_BLOCK *b, size_t i, uint64_t x)
  51 {
  52     const union {
  53         long one;
  54         char little;
  55     } is_endian = { 1 };
  56
  57     if (is_endian.little)
  58         b->word[i] = byteswap8(x);
  59     else
  60         b->word[i] = x;
  61 }
  62
  63 static ossl_inline void siv128_xorblock(SIV_BLOCK *x,
  64                                         SIV_BLOCK const *y)
  65 {
  66     x->word[0] ^= y->word[0];
  67     x->word[1] ^= y->word[1];
  68 }
  69
  70 /*
  71  * Doubles |b|, which is 16 bytes representing an element
  72  * of GF(2**128) modulo the irreducible polynomial
  73  * x**128 + x**7 + x**2 + x + 1.
  74  * Assumes two's-complement arithmetic
  75  */
  76 static ossl_inline void siv128_dbl(SIV_BLOCK *b)
  77 {
  78     uint64_t high = siv128_getword(b, 0);
  79     uint64_t low = siv128_getword(b, 1);
  80     uint64_t high_carry = high & (((uint64_t)1) << 63);
  81     uint64_t low_carry = low & (((uint64_t)1) << 63);
  82     int64_t low_mask = -((int64_t)(high_carry >> 63)) & 0x87;
  83     uint64_t high_mask = low_carry >> 63;
  84
  85     high = (high << 1) | high_mask;
  86     low = (low << 1) ^ (uint64_t)low_mask;
  87     siv128_putword(b, 0, high);
  88     siv128_putword(b, 1, low);
  89 }
  90
  91 __owur static ossl_inline int siv128_do_s2v_p(SIV128_CONTEXT *ctx, SIV_BLOCK *out,
  92                                               unsigned char const* in, size_t len)
  93 {
  94     SIV_BLOCK t;
  95     size_t out_len = sizeof(out->byte);
  96     EVP_MAC_CTX *mac_ctx;
  97     int ret = 0;
  98
  99     mac_ctx = EVP_MAC_CTX_dup(ctx->mac_ctx_init);
 100     if (mac_ctx == NULL)
 101         return 0;
 102
 103     if (len >= SIV_LEN) {
 104         if (!EVP_MAC_update(mac_ctx, in, len - SIV_LEN))
 105             goto err;
 106         memcpy(&t, in + (len-SIV_LEN), SIV_LEN);
 107         siv128_xorblock(&t, &ctx->d);
 108         if (!EVP_MAC_update(mac_ctx, t.byte, SIV_LEN))
 109             goto err;
 110     } else {
 111         memset(&t, 0, sizeof(t));
 112         memcpy(&t, in, len);
 113         t.byte[len] = 0x80;
 114         siv128_dbl(&ctx->d);
 115         siv128_xorblock(&t, &ctx->d);
 116         if (!EVP_MAC_update(mac_ctx, t.byte, SIV_LEN))
 117             goto err;
 118     }
 119     if (!EVP_MAC_final(mac_ctx, out->byte, &out_len)
 120         || out_len != SIV_LEN)
 121         goto err;
 122
 123     ret = 1;
 124
 125 err:
 126     EVP_MAC_CTX_free(mac_ctx);
 127     return ret;
 128 }
 129
 130
 131 __owur static ossl_inline int siv128_do_encrypt(EVP_CIPHER_CTX *ctx, unsigned char *out,
 132                                              unsigned char const *in, size_t len,
 133                                              SIV_BLOCK *icv)
 134 {
 135     int out_len = (int)len;
 136
 137     if (!EVP_CipherInit_ex(ctx, NULL, NULL, NULL, icv->byte, 1))
 138         return 0;
 139     return EVP_EncryptUpdate(ctx, out, &out_len, in, out_len);
 140 }
 141
 142 /*
 143  * Create a new SIV128_CONTEXT
 144  */
 145 SIV128_CONTEXT *CRYPTO_siv128_new(const unsigned char *key, int klen, EVP_CIPHER* cbc, EVP_CIPHER* ctr)
 146 {
 147     SIV128_CONTEXT *ctx;
 148     int ret;
 149
 150     if ((ctx = OPENSSL_malloc(sizeof(*ctx))) != NULL) {
 151         ret = CRYPTO_siv128_init(ctx, key, klen, cbc, ctr);
 152         if (ret)
 153             return ctx;
 154         OPENSSL_free(ctx);
 155     }
 156
 157     return NULL;
 158 }
 159
 160 /*
 161  * Initialise an existing SIV128_CONTEXT
 162  */
 163 int CRYPTO_siv128_init(SIV128_CONTEXT *ctx, const unsigned char *key, int klen,
 164                        const EVP_CIPHER* cbc, const EVP_CIPHER* ctr)
 165 {
 166     static const unsigned char zero[SIV_LEN] = { 0 };
 167     size_t out_len = SIV_LEN;
 168     EVP_MAC_CTX *mac_ctx = NULL;
 169
 170     memset(&ctx->d, 0, sizeof(ctx->d));
 171     ctx->cipher_ctx = NULL;
 172     ctx->mac_ctx_init = NULL;
 173
 174     if (key == NULL || cbc == NULL || ctr == NULL
 175             || (ctx->cipher_ctx = EVP_CIPHER_CTX_new()) == NULL
 176             || (ctx->mac_ctx_init = EVP_MAC_CTX_new_id(EVP_MAC_CMAC)) == NULL
 177             || EVP_MAC_ctrl(ctx->mac_ctx_init, EVP_MAC_CTRL_SET_CIPHER, cbc) <= 0
 178             || EVP_MAC_ctrl(ctx->mac_ctx_init, EVP_MAC_CTRL_SET_KEY, key, klen) <= 0
 179             || !EVP_EncryptInit_ex(ctx->cipher_ctx, ctr, NULL, key + klen, NULL)
 180             || (mac_ctx = EVP_MAC_CTX_dup(ctx->mac_ctx_init)) == NULL
 181             || !EVP_MAC_update(mac_ctx, zero, sizeof(zero))
 182             || !EVP_MAC_final(mac_ctx, ctx->d.byte, &out_len)) {
 183         EVP_CIPHER_CTX_free(ctx->cipher_ctx);
 184         EVP_MAC_CTX_free(ctx->mac_ctx_init);
 185         EVP_MAC_CTX_free(mac_ctx);
 186         return 0;
 187     }
 188     EVP_MAC_CTX_free(mac_ctx);
 189
 190     ctx->final_ret = -1;
 191     ctx->crypto_ok = 1;
 192
 193     return 1;
 194 }
 195
 196 /*
 197  * Copy an SIV128_CONTEXT object
 198  */
 199 int CRYPTO_siv128_copy_ctx(SIV128_CONTEXT *dest, SIV128_CONTEXT *src)
 200 {
 201     memcpy(&dest->d, &src->d, sizeof(src->d));
 202     if (!EVP_CIPHER_CTX_copy(dest->cipher_ctx, src->cipher_ctx))
 203         return 0;
 204     EVP_MAC_CTX_free(dest->mac_ctx_init);
 205     dest->mac_ctx_init = EVP_MAC_CTX_dup(src->mac_ctx_init);
 206     if (dest->mac_ctx_init == NULL)
 207         return 0;
 208     return 1;
 209 }
 210
 211 /*
 212  * Provide any AAD. This can be called multiple times.
 213  * Per RFC5297, the last piece of associated data
 214  * is the nonce, but it's not treated special
 215  */
 216 int CRYPTO_siv128_aad(SIV128_CONTEXT *ctx, const unsigned char *aad,
 217                       size_t len)
 218 {
 219     SIV_BLOCK mac_out;
 220     size_t out_len = SIV_LEN;
 221     EVP_MAC_CTX *mac_ctx;
 222
 223     siv128_dbl(&ctx->d);
 224
 225     mac_ctx = EVP_MAC_CTX_dup(ctx->mac_ctx_init);
 226     if (mac_ctx == NULL
 227         || !EVP_MAC_update(mac_ctx, aad, len)
 228         || !EVP_MAC_final(mac_ctx, mac_out.byte, &out_len)
 229         || out_len != SIV_LEN) {
 230         EVP_MAC_CTX_free(mac_ctx);
 231         return 0;
 232     }
 233     EVP_MAC_CTX_free(mac_ctx);
 234
 235     siv128_xorblock(&ctx->d, &mac_out);
 236
 237     return 1;
 238 }
 239
 240 /*
 241  * Provide any data to be encrypted. This can be called once.
 242  */
 243 int CRYPTO_siv128_encrypt(SIV128_CONTEXT *ctx,
 244                           const unsigned char *in, unsigned char *out,
 245                           size_t len)
 246 {
 247     SIV_BLOCK q;
 248
 249     /* can only do one crypto operation */
 250     if (ctx->crypto_ok == 0)
 251         return 0;
 252     ctx->crypto_ok--;
 253
 254     if (!siv128_do_s2v_p(ctx, &q, in, len))
 255         return 0;
 256
 257     memcpy(ctx->tag.byte, &q, SIV_LEN);
 258     q.byte[8] &= 0x7f;
 259     q.byte[12] &= 0x7f;
 260
 261     if (!siv128_do_encrypt(ctx->cipher_ctx, out, in, len, &q))
 262         return 0;
 263     ctx->final_ret = 0;
 264     return len;
 265 }
 266
 267 /*
 268  * Provide any data to be decrypted. This can be called once.
 269  */
 270 int CRYPTO_siv128_decrypt(SIV128_CONTEXT *ctx,
 271                           const unsigned char *in, unsigned char *out,
 272                           size_t len)
 273 {
 274     unsigned char* p;
 275     SIV_BLOCK t, q;
 276     int i;
 277
 278     /* can only do one crypto operation */
 279     if (ctx->crypto_ok == 0)
 280         return 0;
 281     ctx->crypto_ok--;
 282
 283     memcpy(&q, ctx->tag.byte, SIV_LEN);
 284     q.byte[8] &= 0x7f;
 285     q.byte[12] &= 0x7f;
 286
 287     if (!siv128_do_encrypt(ctx->cipher_ctx, out, in, len, &q)
 288         || !siv128_do_s2v_p(ctx, &t, out, len))
 289         return 0;
 290
 291     p = ctx->tag.byte;
 292     for (i = 0; i < SIV_LEN; i++)
 293         t.byte[i] ^= p[i];
 294
 295     if ((t.word[0] | t.word[1]) != 0) {
 296         OPENSSL_cleanse(out, len);
 297         return 0;
 298     }
 299     ctx->final_ret = 0;
 300     return len;
 301 }
 302
 303 /*
 304  * Return the already calculated final result.
 305  */
 306 int CRYPTO_siv128_finish(SIV128_CONTEXT *ctx)
 307 {
 308     return ctx->final_ret;
 309 }
 310
 311 /*
 312  * Set the tag
 313  */
 314 int CRYPTO_siv128_set_tag(SIV128_CONTEXT *ctx, const unsigned char *tag, size_t len)
 315 {
 316     if (len != SIV_LEN)
 317         return 0;
 318
 319     /* Copy the tag from the supplied buffer */
 320     memcpy(ctx->tag.byte, tag, len);
 321     return 1;
 322 }
 323
 324 /*
 325  * Retrieve the calculated tag
 326  */
 327 int CRYPTO_siv128_get_tag(SIV128_CONTEXT *ctx, unsigned char *tag, size_t len)
 328 {
 329     if (len != SIV_LEN)
 330         return 0;
 331
 332     /* Copy the tag into the supplied buffer */
 333     memcpy(tag, ctx->tag.byte, len);
 334     return 1;
 335 }
 336
 337 /*
 338  * Release all resources
 339  */
 340 int CRYPTO_siv128_cleanup(SIV128_CONTEXT *ctx)
 341 {
 342     if (ctx != NULL) {
 343         EVP_CIPHER_CTX_free(ctx->cipher_ctx);
 344         ctx->cipher_ctx = NULL;
 345         EVP_MAC_CTX_free(ctx->mac_ctx_init);
 346         ctx->mac_ctx_init = NULL;
 347         OPENSSL_cleanse(&ctx->d, sizeof(ctx->d));
 348         OPENSSL_cleanse(&ctx->tag, sizeof(ctx->tag));
 349         ctx->final_ret = -1;
 350         ctx->crypto_ok = 1;
 351     }
 352     return 1;
 353 }
 354
 355 int CRYPTO_siv128_speed(SIV128_CONTEXT *ctx, int arg)
 356 {
 357     ctx->crypto_ok = (arg == 1) ? -1 : 1;
 358     return 1;
 359 }
 360
 361 #endif                          /* OPENSSL_NO_SIV */