providers/implementations/ciphers/cipher_chacha20_poly1305_hw.c

   1 /*
   2  * Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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 /* chacha20_poly1305 cipher implementation */
  11
  12 #include "internal/endian.h"
  13 #include "cipher_chacha20_poly1305.h"
  14
  15 static int chacha_poly1305_tls_init(PROV_CIPHER_CTX *bctx,
  16                                     unsigned char *aad, size_t alen)
  17 {
  18     unsigned int len;
  19     PROV_CHACHA20_POLY1305_CTX *ctx = (PROV_CHACHA20_POLY1305_CTX *)bctx;
  20
  21     if (alen != EVP_AEAD_TLS1_AAD_LEN)
  22         return 0;
  23
  24     memcpy(ctx->tls_aad, aad, EVP_AEAD_TLS1_AAD_LEN);
  25     len = aad[EVP_AEAD_TLS1_AAD_LEN - 2] << 8 | aad[EVP_AEAD_TLS1_AAD_LEN - 1];
  26     aad = ctx->tls_aad;
  27     if (!bctx->enc) {
  28         if (len < POLY1305_BLOCK_SIZE)
  29             return 0;
  30         len -= POLY1305_BLOCK_SIZE; /* discount attached tag */
  31         aad[EVP_AEAD_TLS1_AAD_LEN - 2] = (unsigned char)(len >> 8);
  32         aad[EVP_AEAD_TLS1_AAD_LEN - 1] = (unsigned char)len;
  33     }
  34     ctx->tls_payload_length = len;
  35
  36     /* merge record sequence number as per RFC7905 */
  37     ctx->chacha.counter[1] = ctx->nonce[0];
  38     ctx->chacha.counter[2] = ctx->nonce[1] ^ CHACHA_U8TOU32(aad);
  39     ctx->chacha.counter[3] = ctx->nonce[2] ^ CHACHA_U8TOU32(aad+4);
  40     ctx->mac_inited = 0;
  41
  42     return POLY1305_BLOCK_SIZE;         /* tag length */
  43 }
  44
  45 static int chacha_poly1305_tls_iv_set_fixed(PROV_CIPHER_CTX *bctx,
  46                                             unsigned char *fixed, size_t flen)
  47 {
  48     PROV_CHACHA20_POLY1305_CTX *ctx = (PROV_CHACHA20_POLY1305_CTX *)bctx;
  49
  50     if (flen != CHACHA20_POLY1305_IVLEN)
  51         return 0;
  52     ctx->nonce[0] = ctx->chacha.counter[1] = CHACHA_U8TOU32(fixed);
  53     ctx->nonce[1] = ctx->chacha.counter[2] = CHACHA_U8TOU32(fixed + 4);
  54     ctx->nonce[2] = ctx->chacha.counter[3] = CHACHA_U8TOU32(fixed + 8);
  55     return 1;
  56 }
  57
  58
  59 static int chacha20_poly1305_initkey(PROV_CIPHER_CTX *bctx,
  60                                      const unsigned char *key, size_t keylen)
  61 {
  62     PROV_CHACHA20_POLY1305_CTX *ctx = (PROV_CHACHA20_POLY1305_CTX *)bctx;
  63
  64     ctx->len.aad = 0;
  65     ctx->len.text = 0;
  66     ctx->aad = 0;
  67     ctx->mac_inited = 0;
  68     ctx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH;
  69
  70     if (bctx->enc)
  71         return chacha20_einit(&ctx->chacha, key, keylen, NULL, 0);
  72     else
  73         return chacha20_dinit(&ctx->chacha, key, keylen, NULL, 0);
  74 }
  75
  76 static int chacha20_poly1305_initiv(PROV_CIPHER_CTX *bctx)
  77 {
  78     PROV_CHACHA20_POLY1305_CTX *ctx = (PROV_CHACHA20_POLY1305_CTX *)bctx;
  79     unsigned char tempiv[CHACHA_CTR_SIZE] = { 0 };
  80     int ret = 1;
  81
  82     ctx->len.aad = 0;
  83     ctx->len.text = 0;
  84     ctx->aad = 0;
  85     ctx->mac_inited = 0;
  86     ctx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH;
  87
  88         /* pad on the left */
  89     if (ctx->nonce_len <= CHACHA_CTR_SIZE) {
  90             memcpy(tempiv + CHACHA_CTR_SIZE - ctx->nonce_len, bctx->oiv,
  91                    ctx->nonce_len);
  92
  93         if (bctx->enc)
  94             ret = chacha20_einit(&ctx->chacha, NULL, 0, tempiv, sizeof(tempiv));
  95         else
  96             ret = chacha20_dinit(&ctx->chacha, NULL, 0, tempiv, sizeof(tempiv));
  97         ctx->nonce[0] = ctx->chacha.counter[1];
  98         ctx->nonce[1] = ctx->chacha.counter[2];
  99         ctx->nonce[2] = ctx->chacha.counter[3];
 100         bctx->iv_set = 1;
 101     }
 102     return ret;
 103 }
 104
 105 #if !defined(OPENSSL_SMALL_FOOTPRINT)
 106
 107 # if defined(POLY1305_ASM) && (defined(__x86_64) || defined(__x86_64__) \
 108      || defined(_M_AMD64) || defined(_M_X64))
 109 #  define XOR128_HELPERS
 110 void *xor128_encrypt_n_pad(void *out, const void *inp, void *otp, size_t len);
 111 void *xor128_decrypt_n_pad(void *out, const void *inp, void *otp, size_t len);
 112 static const unsigned char zero[4 * CHACHA_BLK_SIZE] = { 0 };
 113 # else
 114 static const unsigned char zero[2 * CHACHA_BLK_SIZE] = { 0 };
 115 # endif
 116
 117 static int chacha20_poly1305_tls_cipher(PROV_CIPHER_CTX *bctx,
 118                                         unsigned char *out,
 119                                         size_t *out_padlen,
 120                                         const unsigned char *in, size_t len)
 121 {
 122     PROV_CHACHA20_POLY1305_CTX *ctx = (PROV_CHACHA20_POLY1305_CTX *)bctx;
 123     POLY1305 *poly = &ctx->poly1305;
 124     size_t tail, tohash_len, buf_len, plen = ctx->tls_payload_length;
 125     unsigned char *buf, *tohash, *ctr, storage[sizeof(zero) + 32];
 126
 127     DECLARE_IS_ENDIAN;
 128
 129     buf = storage + ((0 - (size_t)storage) & 15);   /* align */
 130     ctr = buf + CHACHA_BLK_SIZE;
 131     tohash = buf + CHACHA_BLK_SIZE - POLY1305_BLOCK_SIZE;
 132
 133 # ifdef XOR128_HELPERS
 134     if (plen <= 3 * CHACHA_BLK_SIZE) {
 135         ctx->chacha.counter[0] = 0;
 136         buf_len = (plen + 2 * CHACHA_BLK_SIZE - 1) & (0 - CHACHA_BLK_SIZE);
 137         ChaCha20_ctr32(buf, zero, buf_len, ctx->chacha.key.d, ctx->chacha.counter);
 138         Poly1305_Init(poly, buf);
 139         ctx->chacha.partial_len = 0;
 140         memcpy(tohash, ctx->tls_aad, POLY1305_BLOCK_SIZE);
 141         tohash_len = POLY1305_BLOCK_SIZE;
 142         ctx->len.aad = EVP_AEAD_TLS1_AAD_LEN;
 143         ctx->len.text = plen;
 144
 145         if (plen) {
 146             if (bctx->enc)
 147                 ctr = xor128_encrypt_n_pad(out, in, ctr, plen);
 148             else
 149                 ctr = xor128_decrypt_n_pad(out, in, ctr, plen);
 150
 151             in += plen;
 152             out += plen;
 153             tohash_len = (size_t)(ctr - tohash);
 154         }
 155     }
 156 # else
 157     if (plen <= CHACHA_BLK_SIZE) {
 158         size_t i;
 159
 160         ctx->chacha.counter[0] = 0;
 161         ChaCha20_ctr32(buf, zero, (buf_len = 2 * CHACHA_BLK_SIZE),
 162                        ctx->chacha.key.d, ctx->chacha.counter);
 163         Poly1305_Init(poly, buf);
 164         ctx->chacha.partial_len = 0;
 165         memcpy(tohash, ctx->tls_aad, POLY1305_BLOCK_SIZE);
 166         tohash_len = POLY1305_BLOCK_SIZE;
 167         ctx->len.aad = EVP_AEAD_TLS1_AAD_LEN;
 168         ctx->len.text = plen;
 169
 170         if (bctx->enc) {
 171             for (i = 0; i < plen; i++)
 172                 out[i] = ctr[i] ^= in[i];
 173         } else {
 174             for (i = 0; i < plen; i++) {
 175                 unsigned char c = in[i];
 176
 177                 out[i] = ctr[i] ^ c;
 178                 ctr[i] = c;
 179             }
 180         }
 181
 182         in += i;
 183         out += i;
 184
 185         tail = (0 - i) & (POLY1305_BLOCK_SIZE - 1);
 186         memset(ctr + i, 0, tail);
 187         ctr += i + tail;
 188         tohash_len += i + tail;
 189     }
 190 # endif
 191     else {
 192         ctx->chacha.counter[0] = 0;
 193         ChaCha20_ctr32(buf, zero, (buf_len = CHACHA_BLK_SIZE),
 194                        ctx->chacha.key.d, ctx->chacha.counter);
 195         Poly1305_Init(poly, buf);
 196         ctx->chacha.counter[0] = 1;
 197         ctx->chacha.partial_len = 0;
 198         Poly1305_Update(poly, ctx->tls_aad, POLY1305_BLOCK_SIZE);
 199         tohash = ctr;
 200         tohash_len = 0;
 201         ctx->len.aad = EVP_AEAD_TLS1_AAD_LEN;
 202         ctx->len.text = plen;
 203
 204         if (bctx->enc) {
 205             ChaCha20_ctr32(out, in, plen, ctx->chacha.key.d, ctx->chacha.counter);
 206             Poly1305_Update(poly, out, plen);
 207         } else {
 208             Poly1305_Update(poly, in, plen);
 209             ChaCha20_ctr32(out, in, plen, ctx->chacha.key.d, ctx->chacha.counter);
 210         }
 211
 212         in += plen;
 213         out += plen;
 214         tail = (0 - plen) & (POLY1305_BLOCK_SIZE - 1);
 215         Poly1305_Update(poly, zero, tail);
 216     }
 217
 218     if (IS_LITTLE_ENDIAN) {
 219         memcpy(ctr, (unsigned char *)&ctx->len, POLY1305_BLOCK_SIZE);
 220     } else {
 221         ctr[0]  = (unsigned char)(ctx->len.aad);
 222         ctr[1]  = (unsigned char)(ctx->len.aad>>8);
 223         ctr[2]  = (unsigned char)(ctx->len.aad>>16);
 224         ctr[3]  = (unsigned char)(ctx->len.aad>>24);
 225         ctr[4]  = (unsigned char)(ctx->len.aad>>32);
 226         ctr[5]  = (unsigned char)(ctx->len.aad>>40);
 227         ctr[6]  = (unsigned char)(ctx->len.aad>>48);
 228         ctr[7]  = (unsigned char)(ctx->len.aad>>56);
 229
 230         ctr[8]  = (unsigned char)(ctx->len.text);
 231         ctr[9]  = (unsigned char)(ctx->len.text>>8);
 232         ctr[10] = (unsigned char)(ctx->len.text>>16);
 233         ctr[11] = (unsigned char)(ctx->len.text>>24);
 234         ctr[12] = (unsigned char)(ctx->len.text>>32);
 235         ctr[13] = (unsigned char)(ctx->len.text>>40);
 236         ctr[14] = (unsigned char)(ctx->len.text>>48);
 237         ctr[15] = (unsigned char)(ctx->len.text>>56);
 238     }
 239     tohash_len += POLY1305_BLOCK_SIZE;
 240
 241     Poly1305_Update(poly, tohash, tohash_len);
 242     OPENSSL_cleanse(buf, buf_len);
 243     Poly1305_Final(poly, bctx->enc ? ctx->tag : tohash);
 244
 245     ctx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH;
 246
 247     if (bctx->enc) {
 248         memcpy(out, ctx->tag, POLY1305_BLOCK_SIZE);
 249     } else {
 250         if (CRYPTO_memcmp(tohash, in, POLY1305_BLOCK_SIZE)) {
 251             if (len > POLY1305_BLOCK_SIZE)
 252                 memset(out - (len - POLY1305_BLOCK_SIZE), 0,
 253                        len - POLY1305_BLOCK_SIZE);
 254             return 0;
 255         }
 256         /* Strip the tag */
 257         len -= POLY1305_BLOCK_SIZE;
 258     }
 259
 260     *out_padlen = len;
 261     return 1;
 262 }
 263 #else
 264 static const unsigned char zero[CHACHA_BLK_SIZE] = { 0 };
 265 #endif /* OPENSSL_SMALL_FOOTPRINT */
 266
 267 static int chacha20_poly1305_aead_cipher(PROV_CIPHER_CTX *bctx,
 268                                          unsigned char *out, size_t *outl,
 269                                          const unsigned char *in, size_t inl)
 270 {
 271     PROV_CHACHA20_POLY1305_CTX *ctx = (PROV_CHACHA20_POLY1305_CTX *)bctx;
 272     POLY1305 *poly = &ctx->poly1305;
 273     size_t rem, plen = ctx->tls_payload_length;
 274     size_t olen = 0;
 275     int rv = 0;
 276
 277     DECLARE_IS_ENDIAN;
 278
 279     if (!ctx->mac_inited) {
 280         if (plen != NO_TLS_PAYLOAD_LENGTH && out != NULL) {
 281             if (inl != plen + POLY1305_BLOCK_SIZE)
 282                 return 0;
 283 #if !defined(OPENSSL_SMALL_FOOTPRINT)
 284             return chacha20_poly1305_tls_cipher(bctx, out, outl, in, inl);
 285 #endif
 286         }
 287
 288         ctx->chacha.counter[0] = 0;
 289         ChaCha20_ctr32(ctx->chacha.buf, zero, CHACHA_BLK_SIZE,
 290                        ctx->chacha.key.d, ctx->chacha.counter);
 291         Poly1305_Init(poly, ctx->chacha.buf);
 292         ctx->chacha.counter[0] = 1;
 293         ctx->chacha.partial_len = 0;
 294         ctx->len.aad = ctx->len.text = 0;
 295         ctx->mac_inited = 1;
 296         if (plen != NO_TLS_PAYLOAD_LENGTH) {
 297             Poly1305_Update(poly, ctx->tls_aad, EVP_AEAD_TLS1_AAD_LEN);
 298             ctx->len.aad = EVP_AEAD_TLS1_AAD_LEN;
 299             ctx->aad = 1;
 300         }
 301     }
 302
 303     if (in != NULL) { /* aad or text */
 304         if (out == NULL) { /* aad */
 305             Poly1305_Update(poly, in, inl);
 306             ctx->len.aad += inl;
 307             ctx->aad = 1;
 308             goto finish;
 309         } else { /* plain- or ciphertext */
 310             if (ctx->aad) { /* wrap up aad */
 311                 if ((rem = (size_t)ctx->len.aad % POLY1305_BLOCK_SIZE))
 312                     Poly1305_Update(poly, zero, POLY1305_BLOCK_SIZE - rem);
 313                 ctx->aad = 0;
 314             }
 315
 316             ctx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH;
 317             if (plen == NO_TLS_PAYLOAD_LENGTH)
 318                 plen = inl;
 319             else if (inl != plen + POLY1305_BLOCK_SIZE)
 320                 goto err;
 321
 322             if (bctx->enc) { /* plaintext */
 323                 ctx->chacha.base.hw->cipher(&ctx->chacha.base, out, in, plen);
 324                 Poly1305_Update(poly, out, plen);
 325                 in += plen;
 326                 out += plen;
 327                 ctx->len.text += plen;
 328             } else { /* ciphertext */
 329                 Poly1305_Update(poly, in, plen);
 330                 ctx->chacha.base.hw->cipher(&ctx->chacha.base, out, in, plen);
 331                 in += plen;
 332                 out += plen;
 333                 ctx->len.text += plen;
 334             }
 335         }
 336     }
 337     /* explicit final, or tls mode */
 338     if (in == NULL || inl != plen) {
 339
 340         unsigned char temp[POLY1305_BLOCK_SIZE];
 341
 342         if (ctx->aad) {                        /* wrap up aad */
 343             if ((rem = (size_t)ctx->len.aad % POLY1305_BLOCK_SIZE))
 344                 Poly1305_Update(poly, zero, POLY1305_BLOCK_SIZE - rem);
 345             ctx->aad = 0;
 346         }
 347
 348         if ((rem = (size_t)ctx->len.text % POLY1305_BLOCK_SIZE))
 349             Poly1305_Update(poly, zero, POLY1305_BLOCK_SIZE - rem);
 350
 351         if (IS_LITTLE_ENDIAN) {
 352             Poly1305_Update(poly, (unsigned char *)&ctx->len,
 353                             POLY1305_BLOCK_SIZE);
 354         } else {
 355             temp[0]  = (unsigned char)(ctx->len.aad);
 356             temp[1]  = (unsigned char)(ctx->len.aad>>8);
 357             temp[2]  = (unsigned char)(ctx->len.aad>>16);
 358             temp[3]  = (unsigned char)(ctx->len.aad>>24);
 359             temp[4]  = (unsigned char)(ctx->len.aad>>32);
 360             temp[5]  = (unsigned char)(ctx->len.aad>>40);
 361             temp[6]  = (unsigned char)(ctx->len.aad>>48);
 362             temp[7]  = (unsigned char)(ctx->len.aad>>56);
 363             temp[8]  = (unsigned char)(ctx->len.text);
 364             temp[9]  = (unsigned char)(ctx->len.text>>8);
 365             temp[10] = (unsigned char)(ctx->len.text>>16);
 366             temp[11] = (unsigned char)(ctx->len.text>>24);
 367             temp[12] = (unsigned char)(ctx->len.text>>32);
 368             temp[13] = (unsigned char)(ctx->len.text>>40);
 369             temp[14] = (unsigned char)(ctx->len.text>>48);
 370             temp[15] = (unsigned char)(ctx->len.text>>56);
 371             Poly1305_Update(poly, temp, POLY1305_BLOCK_SIZE);
 372         }
 373         Poly1305_Final(poly, bctx->enc ? ctx->tag : temp);
 374         ctx->mac_inited = 0;
 375
 376         if (in != NULL && inl != plen) {
 377             if (bctx->enc) {
 378                 memcpy(out, ctx->tag, POLY1305_BLOCK_SIZE);
 379             } else {
 380                 if (CRYPTO_memcmp(temp, in, POLY1305_BLOCK_SIZE)) {
 381                     memset(out - plen, 0, plen);
 382                     goto err;
 383                 }
 384                 /* Strip the tag */
 385                 inl -= POLY1305_BLOCK_SIZE;
 386             }
 387         }
 388         else if (!bctx->enc) {
 389             if (CRYPTO_memcmp(temp, ctx->tag, ctx->tag_len))
 390                 goto err;
 391         }
 392     }
 393 finish:
 394     olen = inl;
 395     rv = 1;
 396 err:
 397     *outl = olen;
 398     return rv;
 399 }
 400
 401 static const PROV_CIPHER_HW_CHACHA20_POLY1305 chacha20poly1305_hw =
 402 {
 403     { chacha20_poly1305_initkey, NULL },
 404     chacha20_poly1305_aead_cipher,
 405     chacha20_poly1305_initiv,
 406     chacha_poly1305_tls_init,
 407     chacha_poly1305_tls_iv_set_fixed
 408 };
 409
 410 const PROV_CIPHER_HW *ossl_prov_cipher_hw_chacha20_poly1305(size_t keybits)
 411 {
 412     return (PROV_CIPHER_HW *)&chacha20poly1305_hw;
 413 }