drivers/crypto/ccp/ccp-crypto-sha.c

   1 /*
   2  * AMD Cryptographic Coprocessor (CCP) SHA crypto API support
   3  *
   4  * Copyright (C) 2013 Advanced Micro Devices, Inc.
   5  *
   6  * Author: Tom Lendacky <thomas.lendacky@amd.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/sched.h>
  15 #include <linux/delay.h>
  16 #include <linux/scatterlist.h>
  17 #include <linux/crypto.h>
  18 #include <crypto/algapi.h>
  19 #include <crypto/hash.h>
  20 #include <crypto/internal/hash.h>
  21 #include <crypto/sha.h>
  22 #include <crypto/scatterwalk.h>
  23
  24 #include "ccp-crypto.h"
  25
  26 static int ccp_sha_complete(struct crypto_async_request *async_req, int ret)
  27 {
  28         struct ahash_request *req = ahash_request_cast(async_req);
  29         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
  30         struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
  31         unsigned int digest_size = crypto_ahash_digestsize(tfm);
  32
  33         if (ret)
  34                 goto e_free;
  35
  36         if (rctx->hash_rem) {
  37                 /* Save remaining data to buffer */
  38                 unsigned int offset = rctx->nbytes - rctx->hash_rem;
  39
  40                 scatterwalk_map_and_copy(rctx->buf, rctx->src,
  41                                          offset, rctx->hash_rem, 0);
  42                 rctx->buf_count = rctx->hash_rem;
  43         } else {
  44                 rctx->buf_count = 0;
  45         }
  46
  47         /* Update result area if supplied */
  48         if (req->result)
  49                 memcpy(req->result, rctx->ctx, digest_size);
  50
  51 e_free:
  52         sg_free_table(&rctx->data_sg);
  53
  54         return ret;
  55 }
  56
  57 static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
  58                              unsigned int final)
  59 {
  60         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
  61         struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
  62         struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
  63         struct scatterlist *sg;
  64         unsigned int block_size =
  65                 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
  66         unsigned int sg_count;
  67         gfp_t gfp;
  68         u64 len;
  69         int ret;
  70
  71         len = (u64)rctx->buf_count + (u64)nbytes;
  72
  73         if (!final && (len <= block_size)) {
  74                 scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src,
  75                                          0, nbytes, 0);
  76                 rctx->buf_count += nbytes;
  77
  78                 return 0;
  79         }
  80
  81         rctx->src = req->src;
  82         rctx->nbytes = nbytes;
  83
  84         rctx->final = final;
  85         rctx->hash_rem = final ? 0 : len & (block_size - 1);
  86         rctx->hash_cnt = len - rctx->hash_rem;
  87         if (!final && !rctx->hash_rem) {
  88                 /* CCP can't do zero length final, so keep some data around */
  89                 rctx->hash_cnt -= block_size;
  90                 rctx->hash_rem = block_size;
  91         }
  92
  93         /* Initialize the context scatterlist */
  94         sg_init_one(&rctx->ctx_sg, rctx->ctx, sizeof(rctx->ctx));
  95
  96         sg = NULL;
  97         if (rctx->buf_count && nbytes) {
  98                 /* Build the data scatterlist table - allocate enough entries
  99                  * for both data pieces (buffer and input data)
 100                  */
 101                 gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
 102                         GFP_KERNEL : GFP_ATOMIC;
 103                 sg_count = sg_nents(req->src) + 1;
 104                 ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp);
 105                 if (ret)
 106                         return ret;
 107
 108                 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
 109                 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg);
 110                 if (!sg) {
 111                         ret = -EINVAL;
 112                         goto e_free;
 113                 }
 114                 sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src);
 115                 if (!sg) {
 116                         ret = -EINVAL;
 117                         goto e_free;
 118                 }
 119                 sg_mark_end(sg);
 120
 121                 sg = rctx->data_sg.sgl;
 122         } else if (rctx->buf_count) {
 123                 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
 124
 125                 sg = &rctx->buf_sg;
 126         } else if (nbytes) {
 127                 sg = req->src;
 128         }
 129
 130         rctx->msg_bits += (rctx->hash_cnt << 3);        /* Total in bits */
 131
 132         memset(&rctx->cmd, 0, sizeof(rctx->cmd));
 133         INIT_LIST_HEAD(&rctx->cmd.entry);
 134         rctx->cmd.engine = CCP_ENGINE_SHA;
 135         rctx->cmd.u.sha.type = rctx->type;
 136         rctx->cmd.u.sha.ctx = &rctx->ctx_sg;
 137         rctx->cmd.u.sha.ctx_len = sizeof(rctx->ctx);
 138         rctx->cmd.u.sha.src = sg;
 139         rctx->cmd.u.sha.src_len = rctx->hash_cnt;
 140         rctx->cmd.u.sha.opad = ctx->u.sha.key_len ?
 141                 &ctx->u.sha.opad_sg : NULL;
 142         rctx->cmd.u.sha.opad_len = ctx->u.sha.key_len ?
 143                 ctx->u.sha.opad_count : 0;
 144         rctx->cmd.u.sha.first = rctx->first;
 145         rctx->cmd.u.sha.final = rctx->final;
 146         rctx->cmd.u.sha.msg_bits = rctx->msg_bits;
 147
 148         rctx->first = 0;
 149
 150         ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
 151
 152         return ret;
 153
 154 e_free:
 155         sg_free_table(&rctx->data_sg);
 156
 157         return ret;
 158 }
 159
 160 static int ccp_sha_init(struct ahash_request *req)
 161 {
 162         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 163         struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
 164         struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
 165         struct ccp_crypto_ahash_alg *alg =
 166                 ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm));
 167         unsigned int block_size =
 168                 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
 169
 170         memset(rctx, 0, sizeof(*rctx));
 171
 172         rctx->type = alg->type;
 173         rctx->first = 1;
 174
 175         if (ctx->u.sha.key_len) {
 176                 /* Buffer the HMAC key for first update */
 177                 memcpy(rctx->buf, ctx->u.sha.ipad, block_size);
 178                 rctx->buf_count = block_size;
 179         }
 180
 181         return 0;
 182 }
 183
 184 static int ccp_sha_update(struct ahash_request *req)
 185 {
 186         return ccp_do_sha_update(req, req->nbytes, 0);
 187 }
 188
 189 static int ccp_sha_final(struct ahash_request *req)
 190 {
 191         return ccp_do_sha_update(req, 0, 1);
 192 }
 193
 194 static int ccp_sha_finup(struct ahash_request *req)
 195 {
 196         return ccp_do_sha_update(req, req->nbytes, 1);
 197 }
 198
 199 static int ccp_sha_digest(struct ahash_request *req)
 200 {
 201         int ret;
 202
 203         ret = ccp_sha_init(req);
 204         if (ret)
 205                 return ret;
 206
 207         return ccp_sha_finup(req);
 208 }
 209
 210 static int ccp_sha_export(struct ahash_request *req, void *out)
 211 {
 212         struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
 213         struct ccp_sha_exp_ctx *state = out;
 214
 215         state->type = rctx->type;
 216         state->msg_bits = rctx->msg_bits;
 217         state->first = rctx->first;
 218         memcpy(state->ctx, rctx->ctx, sizeof(state->ctx));
 219         state->buf_count = rctx->buf_count;
 220         memcpy(state->buf, rctx->buf, sizeof(state->buf));
 221
 222         return 0;
 223 }
 224
 225 static int ccp_sha_import(struct ahash_request *req, const void *in)
 226 {
 227         struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
 228         const struct ccp_sha_exp_ctx *state = in;
 229
 230         rctx->type = state->type;
 231         rctx->msg_bits = state->msg_bits;
 232         rctx->first = state->first;
 233         memcpy(rctx->ctx, state->ctx, sizeof(rctx->ctx));
 234         rctx->buf_count = state->buf_count;
 235         memcpy(rctx->buf, state->buf, sizeof(rctx->buf));
 236
 237         return 0;
 238 }
 239
 240 static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
 241                           unsigned int key_len)
 242 {
 243         struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
 244         struct crypto_shash *shash = ctx->u.sha.hmac_tfm;
 245
 246         SHASH_DESC_ON_STACK(sdesc, shash);
 247
 248         unsigned int block_size = crypto_shash_blocksize(shash);
 249         unsigned int digest_size = crypto_shash_digestsize(shash);
 250         int i, ret;
 251
 252         /* Set to zero until complete */
 253         ctx->u.sha.key_len = 0;
 254
 255         /* Clear key area to provide zero padding for keys smaller
 256          * than the block size
 257          */
 258         memset(ctx->u.sha.key, 0, sizeof(ctx->u.sha.key));
 259
 260         if (key_len > block_size) {
 261                 /* Must hash the input key */
 262                 sdesc->tfm = shash;
 263                 sdesc->flags = crypto_ahash_get_flags(tfm) &
 264                         CRYPTO_TFM_REQ_MAY_SLEEP;
 265
 266                 ret = crypto_shash_digest(sdesc, key, key_len,
 267                                           ctx->u.sha.key);
 268                 if (ret) {
 269                         crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 270                         return -EINVAL;
 271                 }
 272
 273                 key_len = digest_size;
 274         } else {
 275                 memcpy(ctx->u.sha.key, key, key_len);
 276         }
 277
 278         for (i = 0; i < block_size; i++) {
 279                 ctx->u.sha.ipad[i] = ctx->u.sha.key[i] ^ 0x36;
 280                 ctx->u.sha.opad[i] = ctx->u.sha.key[i] ^ 0x5c;
 281         }
 282
 283         sg_init_one(&ctx->u.sha.opad_sg, ctx->u.sha.opad, block_size);
 284         ctx->u.sha.opad_count = block_size;
 285
 286         ctx->u.sha.key_len = key_len;
 287
 288         return 0;
 289 }
 290
 291 static int ccp_sha_cra_init(struct crypto_tfm *tfm)
 292 {
 293         struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 294         struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);
 295
 296         ctx->complete = ccp_sha_complete;
 297         ctx->u.sha.key_len = 0;
 298
 299         crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_sha_req_ctx));
 300
 301         return 0;
 302 }
 303
 304 static void ccp_sha_cra_exit(struct crypto_tfm *tfm)
 305 {
 306 }
 307
 308 static int ccp_hmac_sha_cra_init(struct crypto_tfm *tfm)
 309 {
 310         struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 311         struct ccp_crypto_ahash_alg *alg = ccp_crypto_ahash_alg(tfm);
 312         struct crypto_shash *hmac_tfm;
 313
 314         hmac_tfm = crypto_alloc_shash(alg->child_alg, 0, 0);
 315         if (IS_ERR(hmac_tfm)) {
 316                 pr_warn("could not load driver %s need for HMAC support\n",
 317                         alg->child_alg);
 318                 return PTR_ERR(hmac_tfm);
 319         }
 320
 321         ctx->u.sha.hmac_tfm = hmac_tfm;
 322
 323         return ccp_sha_cra_init(tfm);
 324 }
 325
 326 static void ccp_hmac_sha_cra_exit(struct crypto_tfm *tfm)
 327 {
 328         struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 329
 330         if (ctx->u.sha.hmac_tfm)
 331                 crypto_free_shash(ctx->u.sha.hmac_tfm);
 332
 333         ccp_sha_cra_exit(tfm);
 334 }
 335
 336 struct ccp_sha_def {
 337         const char *name;
 338         const char *drv_name;
 339         enum ccp_sha_type type;
 340         u32 digest_size;
 341         u32 block_size;
 342 };
 343
 344 static struct ccp_sha_def sha_algs[] = {
 345         {
 346                 .name           = "sha1",
 347                 .drv_name       = "sha1-ccp",
 348                 .type           = CCP_SHA_TYPE_1,
 349                 .digest_size    = SHA1_DIGEST_SIZE,
 350                 .block_size     = SHA1_BLOCK_SIZE,
 351         },
 352         {
 353                 .name           = "sha224",
 354                 .drv_name       = "sha224-ccp",
 355                 .type           = CCP_SHA_TYPE_224,
 356                 .digest_size    = SHA224_DIGEST_SIZE,
 357                 .block_size     = SHA224_BLOCK_SIZE,
 358         },
 359         {
 360                 .name           = "sha256",
 361                 .drv_name       = "sha256-ccp",
 362                 .type           = CCP_SHA_TYPE_256,
 363                 .digest_size    = SHA256_DIGEST_SIZE,
 364                 .block_size     = SHA256_BLOCK_SIZE,
 365         },
 366 };
 367
 368 static int ccp_register_hmac_alg(struct list_head *head,
 369                                  const struct ccp_sha_def *def,
 370                                  const struct ccp_crypto_ahash_alg *base_alg)
 371 {
 372         struct ccp_crypto_ahash_alg *ccp_alg;
 373         struct ahash_alg *alg;
 374         struct hash_alg_common *halg;
 375         struct crypto_alg *base;
 376         int ret;
 377
 378         ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
 379         if (!ccp_alg)
 380                 return -ENOMEM;
 381
 382         /* Copy the base algorithm and only change what's necessary */
 383         *ccp_alg = *base_alg;
 384         INIT_LIST_HEAD(&ccp_alg->entry);
 385
 386         strncpy(ccp_alg->child_alg, def->name, CRYPTO_MAX_ALG_NAME);
 387
 388         alg = &ccp_alg->alg;
 389         alg->setkey = ccp_sha_setkey;
 390
 391         halg = &alg->halg;
 392
 393         base = &halg->base;
 394         snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", def->name);
 395         snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "hmac-%s",
 396                  def->drv_name);
 397         base->cra_init = ccp_hmac_sha_cra_init;
 398         base->cra_exit = ccp_hmac_sha_cra_exit;
 399
 400         ret = crypto_register_ahash(alg);
 401         if (ret) {
 402                 pr_err("%s ahash algorithm registration error (%d)\n",
 403                        base->cra_name, ret);
 404                 kfree(ccp_alg);
 405                 return ret;
 406         }
 407
 408         list_add(&ccp_alg->entry, head);
 409
 410         return ret;
 411 }
 412
 413 static int ccp_register_sha_alg(struct list_head *head,
 414                                 const struct ccp_sha_def *def)
 415 {
 416         struct ccp_crypto_ahash_alg *ccp_alg;
 417         struct ahash_alg *alg;
 418         struct hash_alg_common *halg;
 419         struct crypto_alg *base;
 420         int ret;
 421
 422         ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
 423         if (!ccp_alg)
 424                 return -ENOMEM;
 425
 426         INIT_LIST_HEAD(&ccp_alg->entry);
 427
 428         ccp_alg->type = def->type;
 429
 430         alg = &ccp_alg->alg;
 431         alg->init = ccp_sha_init;
 432         alg->update = ccp_sha_update;
 433         alg->final = ccp_sha_final;
 434         alg->finup = ccp_sha_finup;
 435         alg->digest = ccp_sha_digest;
 436         alg->export = ccp_sha_export;
 437         alg->import = ccp_sha_import;
 438
 439         halg = &alg->halg;
 440         halg->digestsize = def->digest_size;
 441         halg->statesize = sizeof(struct ccp_sha_exp_ctx);
 442
 443         base = &halg->base;
 444         snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
 445         snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
 446                  def->drv_name);
 447         base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC |
 448                           CRYPTO_ALG_KERN_DRIVER_ONLY |
 449                           CRYPTO_ALG_NEED_FALLBACK;
 450         base->cra_blocksize = def->block_size;
 451         base->cra_ctxsize = sizeof(struct ccp_ctx);
 452         base->cra_priority = CCP_CRA_PRIORITY;
 453         base->cra_type = &crypto_ahash_type;
 454         base->cra_init = ccp_sha_cra_init;
 455         base->cra_exit = ccp_sha_cra_exit;
 456         base->cra_module = THIS_MODULE;
 457
 458         ret = crypto_register_ahash(alg);
 459         if (ret) {
 460                 pr_err("%s ahash algorithm registration error (%d)\n",
 461                        base->cra_name, ret);
 462                 kfree(ccp_alg);
 463                 return ret;
 464         }
 465
 466         list_add(&ccp_alg->entry, head);
 467
 468         ret = ccp_register_hmac_alg(head, def, ccp_alg);
 469
 470         return ret;
 471 }
 472
 473 int ccp_register_sha_algs(struct list_head *head)
 474 {
 475         int i, ret;
 476
 477         for (i = 0; i < ARRAY_SIZE(sha_algs); i++) {
 478                 ret = ccp_register_sha_alg(head, &sha_algs[i]);
 479                 if (ret)
 480                         return ret;
 481         }
 482
 483         return 0;
 484 }