providers/implementations/ciphers/ciphercommon_ccm.c

   1 /*
   2  * Copyright 2019 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 /* Dispatch functions for ccm mode */
  11
  12 #include "prov/ciphercommon.h"
  13 #include "prov/ciphercommon_ccm.h"
  14 #include "prov/providercommonerr.h"
  15
  16 static int ccm_cipher_internal(PROV_CCM_CTX *ctx, unsigned char *out,
  17                                size_t *padlen, const unsigned char *in,
  18                                size_t len);
  19
  20 static int ccm_tls_init(PROV_CCM_CTX *ctx, unsigned char *aad, size_t alen)
  21 {
  22     size_t len;
  23
  24     if (alen != EVP_AEAD_TLS1_AAD_LEN)
  25         return 0;
  26
  27     /* Save the aad for later use. */
  28     memcpy(ctx->buf, aad, alen);
  29     ctx->tls_aad_len = alen;
  30
  31     len = ctx->buf[alen - 2] << 8 | ctx->buf[alen - 1];
  32     if (len < EVP_CCM_TLS_EXPLICIT_IV_LEN)
  33         return 0;
  34
  35     /* Correct length for explicit iv. */
  36     len -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
  37
  38     if (!ctx->enc) {
  39         if (len < ctx->m)
  40             return 0;
  41         /* Correct length for tag. */
  42         len -= ctx->m;
  43     }
  44     ctx->buf[alen - 2] = (unsigned char)(len >> 8);
  45     ctx->buf[alen - 1] = (unsigned char)(len & 0xff);
  46
  47     /* Extra padding: tag appended to record. */
  48     return ctx->m;
  49 }
  50
  51 static int ccm_tls_iv_set_fixed(PROV_CCM_CTX *ctx, unsigned char *fixed,
  52                                 size_t flen)
  53 {
  54     if (flen != EVP_CCM_TLS_FIXED_IV_LEN)
  55         return 0;
  56
  57     /* Copy to first part of the iv. */
  58     memcpy(ctx->iv, fixed, flen);
  59     return 1;
  60 }
  61
  62 static size_t ccm_get_ivlen(PROV_CCM_CTX *ctx)
  63 {
  64     return 15 - ctx->l;
  65 }
  66
  67 int ccm_set_ctx_params(void *vctx, const OSSL_PARAM params[])
  68 {
  69     PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
  70     const OSSL_PARAM *p;
  71     size_t sz;
  72
  73     p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TAG);
  74     if (p != NULL) {
  75         if (p->data_type != OSSL_PARAM_OCTET_STRING) {
  76             ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
  77             return 0;
  78         }
  79         if ((p->data_size & 1) || (p->data_size < 4) || p->data_size > 16) {
  80             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_TAGLEN);
  81             return 0;
  82         }
  83
  84         if (p->data != NULL) {
  85             if (ctx->enc) {
  86                 ERR_raise(ERR_LIB_PROV, PROV_R_TAG_NOT_NEEDED);
  87                 return 0;
  88             }
  89             memcpy(ctx->buf, p->data, p->data_size);
  90             ctx->tag_set = 1;
  91         }
  92         ctx->m = p->data_size;
  93     }
  94
  95     p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_IVLEN);
  96     if (p != NULL) {
  97         size_t ivlen;
  98
  99         if (!OSSL_PARAM_get_size_t(p, &sz)) {
 100             ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
 101             return 0;
 102         }
 103         ivlen = 15 - sz;
 104         if (ivlen < 2 || ivlen > 8) {
 105             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IVLEN);
 106             return 0;
 107         }
 108         ctx->l = ivlen;
 109     }
 110
 111     p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_AAD);
 112     if (p != NULL) {
 113         if (p->data_type != OSSL_PARAM_OCTET_STRING) {
 114             ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
 115             return 0;
 116         }
 117         sz = ccm_tls_init(ctx, p->data, p->data_size);
 118         if (sz == 0) {
 119             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_DATA);
 120             return 0;
 121         }
 122         ctx->tls_aad_pad_sz = sz;
 123     }
 124
 125     p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_IV_FIXED);
 126     if (p != NULL) {
 127         if (p->data_type != OSSL_PARAM_OCTET_STRING) {
 128             ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
 129             return 0;
 130         }
 131         if (ccm_tls_iv_set_fixed(ctx, p->data, p->data_size) == 0) {
 132             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IVLEN);
 133             return 0;
 134         }
 135     }
 136
 137     return 1;
 138 }
 139
 140 int ccm_get_ctx_params(void *vctx, OSSL_PARAM params[])
 141 {
 142     PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
 143     OSSL_PARAM *p;
 144
 145     p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IVLEN);
 146     if (p != NULL && !OSSL_PARAM_set_size_t(p, ccm_get_ivlen(ctx))) {
 147         ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
 148         return 0;
 149     }
 150
 151     p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TAGLEN);
 152     if (p != NULL) {
 153         size_t m = ctx->m;
 154
 155         if (!OSSL_PARAM_set_size_t(p, m)) {
 156             ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
 157             return 0;
 158         }
 159     }
 160
 161     p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IV);
 162     if (p != NULL) {
 163         if (ccm_get_ivlen(ctx) != p->data_size) {
 164             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IVLEN);
 165             return 0;
 166         }
 167         if (!OSSL_PARAM_set_octet_string(p, ctx->iv, p->data_size)) {
 168             ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
 169             return 0;
 170         }
 171     }
 172
 173     p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_KEYLEN);
 174     if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->keylen)) {
 175         ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
 176         return 0;
 177     }
 178
 179     p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TLS1_AAD_PAD);
 180     if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->tls_aad_pad_sz)) {
 181         ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
 182         return 0;
 183     }
 184
 185     p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TAG);
 186     if (p != NULL) {
 187         if (!ctx->enc || !ctx->tag_set) {
 188             ERR_raise(ERR_LIB_PROV, PROV_R_TAG_NOTSET);
 189             return 0;
 190         }
 191         if (p->data_type != OSSL_PARAM_OCTET_STRING) {
 192             ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
 193             return 0;
 194         }
 195         if (!ctx->hw->gettag(ctx, p->data, p->data_size))
 196             return 0;
 197         ctx->tag_set = 0;
 198         ctx->iv_set = 0;
 199         ctx->len_set = 0;
 200     }
 201     return 1;
 202 }
 203
 204 static int ccm_init(void *vctx, const unsigned char *key, size_t keylen,
 205                     const unsigned char *iv, size_t ivlen, int enc)
 206 {
 207     PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
 208
 209     ctx->enc = enc;
 210
 211     if (iv != NULL) {
 212         if (ivlen != ccm_get_ivlen(ctx)) {
 213             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IVLEN);
 214             return 0;
 215         }
 216         memcpy(ctx->iv, iv, ivlen);
 217         ctx->iv_set = 1;
 218     }
 219     if (key != NULL) {
 220         if (keylen != ctx->keylen) {
 221             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEYLEN);
 222             return 0;
 223         }
 224         return ctx->hw->setkey(ctx, key, keylen);
 225     }
 226     return 1;
 227 }
 228
 229 int ccm_einit(void *vctx, const unsigned char *key, size_t keylen,
 230                      const unsigned char *iv, size_t ivlen)
 231 {
 232     return ccm_init(vctx, key, keylen, iv, ivlen, 1);
 233 }
 234
 235 int ccm_dinit(void *vctx, const unsigned char *key, size_t keylen,
 236                      const unsigned char *iv, size_t ivlen)
 237 {
 238     return ccm_init(vctx, key, keylen, iv, ivlen, 0);
 239 }
 240
 241 int ccm_stream_update(void *vctx, unsigned char *out, size_t *outl,
 242                              size_t outsize, const unsigned char *in,
 243                              size_t inl)
 244 {
 245     PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
 246
 247     if (outsize < inl) {
 248         ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
 249         return 0;
 250     }
 251
 252     if (!ccm_cipher_internal(ctx, out, outl, in, inl)) {
 253         ERR_raise(ERR_LIB_PROV, PROV_R_CIPHER_OPERATION_FAILED);
 254         return 0;
 255     }
 256     return 1;
 257 }
 258
 259 int ccm_stream_final(void *vctx, unsigned char *out, size_t *outl,
 260                             size_t outsize)
 261 {
 262     PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
 263     int i;
 264
 265     i = ccm_cipher_internal(ctx, out, outl, NULL, 0);
 266     if (i <= 0)
 267         return 0;
 268
 269     *outl = 0;
 270     return 1;
 271 }
 272
 273 int ccm_cipher(void *vctx,
 274                       unsigned char *out, size_t *outl, size_t outsize,
 275                       const unsigned char *in, size_t inl)
 276 {
 277     PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
 278
 279     if (outsize < inl) {
 280         ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
 281         return 0;
 282     }
 283
 284     if (ccm_cipher_internal(ctx, out, outl, in, inl) <= 0)
 285         return 0;
 286
 287     *outl = inl;
 288     return 1;
 289 }
 290
 291 /* Copy the buffered iv */
 292 static int ccm_set_iv(PROV_CCM_CTX *ctx, size_t mlen)
 293 {
 294     const PROV_CCM_HW *hw = ctx->hw;
 295
 296     if (!hw->setiv(ctx, ctx->iv, ccm_get_ivlen(ctx), mlen))
 297         return 0;
 298     ctx->len_set = 1;
 299     return 1;
 300 }
 301
 302 static int ccm_tls_cipher(PROV_CCM_CTX *ctx,
 303                           unsigned char *out, size_t *padlen,
 304                           const unsigned char *in, size_t len)
 305 {
 306     int rv = 0;
 307     size_t olen = 0;
 308
 309     /* Encrypt/decrypt must be performed in place */
 310     if (out != in || len < (EVP_CCM_TLS_EXPLICIT_IV_LEN + (size_t)ctx->m))
 311         goto err;
 312
 313     /* If encrypting set explicit IV from sequence number (start of AAD) */
 314     if (ctx->enc)
 315         memcpy(out, ctx->buf, EVP_CCM_TLS_EXPLICIT_IV_LEN);
 316     /* Get rest of IV from explicit IV */
 317     memcpy(ctx->iv + EVP_CCM_TLS_FIXED_IV_LEN, in, EVP_CCM_TLS_EXPLICIT_IV_LEN);
 318     /* Correct length value */
 319     len -= EVP_CCM_TLS_EXPLICIT_IV_LEN + ctx->m;
 320     if (!ccm_set_iv(ctx, len))
 321         goto err;
 322
 323     /* Use saved AAD */
 324     if (!ctx->hw->setaad(ctx, ctx->buf, ctx->tls_aad_len))
 325         goto err;
 326
 327     /* Fix buffer to point to payload */
 328     in += EVP_CCM_TLS_EXPLICIT_IV_LEN;
 329     out += EVP_CCM_TLS_EXPLICIT_IV_LEN;
 330     if (ctx->enc) {
 331         if (!ctx->hw->auth_encrypt(ctx, in, out, len,  out + len, ctx->m))
 332             goto err;
 333         olen = len + EVP_CCM_TLS_EXPLICIT_IV_LEN + ctx->m;
 334     } else {
 335         if (!ctx->hw->auth_decrypt(ctx, in, out, len,
 336                                    (unsigned char *)in + len, ctx->m))
 337             goto err;
 338         olen = len;
 339     }
 340     rv = 1;
 341 err:
 342     *padlen = olen;
 343     return rv;
 344 }
 345
 346 static int ccm_cipher_internal(PROV_CCM_CTX *ctx, unsigned char *out,
 347                                size_t *padlen, const unsigned char *in,
 348                                size_t len)
 349 {
 350     int rv = 0;
 351     size_t olen = 0;
 352     const PROV_CCM_HW *hw = ctx->hw;
 353
 354     /* If no key set, return error */
 355     if (!ctx->key_set)
 356         return 0;
 357
 358     if (ctx->tls_aad_len != UNINITIALISED_SIZET)
 359         return ccm_tls_cipher(ctx, out, padlen, in, len);
 360
 361     /* EVP_*Final() doesn't return any data */
 362     if (in == NULL && out != NULL)
 363         goto finish;
 364
 365     if (!ctx->iv_set)
 366         goto err;
 367
 368     if (out == NULL) {
 369         if (in == NULL) {
 370             if (!ccm_set_iv(ctx, len))
 371                 goto err;
 372         } else {
 373             /* If we have AAD, we need a message length */
 374             if (!ctx->len_set && len)
 375                 goto err;
 376             if (!hw->setaad(ctx, in, len))
 377                 goto err;
 378         }
 379     } else {
 380         /* If not set length yet do it */
 381         if (!ctx->len_set && !ccm_set_iv(ctx, len))
 382             goto err;
 383
 384         if (ctx->enc) {
 385             if (!hw->auth_encrypt(ctx, in, out, len, NULL, 0))
 386                 goto err;
 387             ctx->tag_set = 1;
 388         } else {
 389             /* The tag must be set before actually decrypting data */
 390             if (!ctx->tag_set)
 391                 goto err;
 392
 393             if (!hw->auth_decrypt(ctx, in, out, len, ctx->buf, ctx->m))
 394                 goto err;
 395             /* Finished - reset flags so calling this method again will fail */
 396             ctx->iv_set = 0;
 397             ctx->tag_set = 0;
 398             ctx->len_set = 0;
 399         }
 400     }
 401     olen = len;
 402 finish:
 403     rv = 1;
 404 err:
 405     *padlen = olen;
 406     return rv;
 407 }
 408
 409 void ccm_initctx(PROV_CCM_CTX *ctx, size_t keybits, const PROV_CCM_HW *hw)
 410 {
 411     ctx->keylen = keybits / 8;
 412     ctx->key_set = 0;
 413     ctx->iv_set = 0;
 414     ctx->tag_set = 0;
 415     ctx->len_set = 0;
 416     ctx->l = 8;
 417     ctx->m = 12;
 418     ctx->tls_aad_len = UNINITIALISED_SIZET;
 419     ctx->hw = hw;
 420 }
 421