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_setkey(struct crypto_ahash *tfm, const u8 *key,
 211                           unsigned int key_len)
 212 {
 213         struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
 214         struct crypto_shash *shash = ctx->u.sha.hmac_tfm;
 215
 216         SHASH_DESC_ON_STACK(sdesc, shash);
 217
 218         unsigned int block_size = crypto_shash_blocksize(shash);
 219         unsigned int digest_size = crypto_shash_digestsize(shash);
 220         int i, ret;
 221
 222         /* Set to zero until complete */
 223         ctx->u.sha.key_len = 0;
 224
 225         /* Clear key area to provide zero padding for keys smaller
 226          * than the block size
 227          */
 228         memset(ctx->u.sha.key, 0, sizeof(ctx->u.sha.key));
 229
 230         if (key_len > block_size) {
 231                 /* Must hash the input key */
 232                 sdesc->tfm = shash;
 233                 sdesc->flags = crypto_ahash_get_flags(tfm) &
 234                         CRYPTO_TFM_REQ_MAY_SLEEP;
 235
 236                 ret = crypto_shash_digest(sdesc, key, key_len,
 237                                           ctx->u.sha.key);
 238                 if (ret) {
 239                         crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 240                         return -EINVAL;
 241                 }
 242
 243                 key_len = digest_size;
 244         } else {
 245                 memcpy(ctx->u.sha.key, key, key_len);
 246         }
 247
 248         for (i = 0; i < block_size; i++) {
 249                 ctx->u.sha.ipad[i] = ctx->u.sha.key[i] ^ 0x36;
 250                 ctx->u.sha.opad[i] = ctx->u.sha.key[i] ^ 0x5c;
 251         }
 252
 253         sg_init_one(&ctx->u.sha.opad_sg, ctx->u.sha.opad, block_size);
 254         ctx->u.sha.opad_count = block_size;
 255
 256         ctx->u.sha.key_len = key_len;
 257
 258         return 0;
 259 }
 260
 261 static int ccp_sha_cra_init(struct crypto_tfm *tfm)
 262 {
 263         struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 264         struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);
 265
 266         ctx->complete = ccp_sha_complete;
 267         ctx->u.sha.key_len = 0;
 268
 269         crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_sha_req_ctx));
 270
 271         return 0;
 272 }
 273
 274 static void ccp_sha_cra_exit(struct crypto_tfm *tfm)
 275 {
 276 }
 277
 278 static int ccp_hmac_sha_cra_init(struct crypto_tfm *tfm)
 279 {
 280         struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 281         struct ccp_crypto_ahash_alg *alg = ccp_crypto_ahash_alg(tfm);
 282         struct crypto_shash *hmac_tfm;
 283
 284         hmac_tfm = crypto_alloc_shash(alg->child_alg, 0, 0);
 285         if (IS_ERR(hmac_tfm)) {
 286                 pr_warn("could not load driver %s need for HMAC support\n",
 287                         alg->child_alg);
 288                 return PTR_ERR(hmac_tfm);
 289         }
 290
 291         ctx->u.sha.hmac_tfm = hmac_tfm;
 292
 293         return ccp_sha_cra_init(tfm);
 294 }
 295
 296 static void ccp_hmac_sha_cra_exit(struct crypto_tfm *tfm)
 297 {
 298         struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 299
 300         if (ctx->u.sha.hmac_tfm)
 301                 crypto_free_shash(ctx->u.sha.hmac_tfm);
 302
 303         ccp_sha_cra_exit(tfm);
 304 }
 305
 306 struct ccp_sha_def {
 307         const char *name;
 308         const char *drv_name;
 309         enum ccp_sha_type type;
 310         u32 digest_size;
 311         u32 block_size;
 312 };
 313
 314 static struct ccp_sha_def sha_algs[] = {
 315         {
 316                 .name           = "sha1",
 317                 .drv_name       = "sha1-ccp",
 318                 .type           = CCP_SHA_TYPE_1,
 319                 .digest_size    = SHA1_DIGEST_SIZE,
 320                 .block_size     = SHA1_BLOCK_SIZE,
 321         },
 322         {
 323                 .name           = "sha224",
 324                 .drv_name       = "sha224-ccp",
 325                 .type           = CCP_SHA_TYPE_224,
 326                 .digest_size    = SHA224_DIGEST_SIZE,
 327                 .block_size     = SHA224_BLOCK_SIZE,
 328         },
 329         {
 330                 .name           = "sha256",
 331                 .drv_name       = "sha256-ccp",
 332                 .type           = CCP_SHA_TYPE_256,
 333                 .digest_size    = SHA256_DIGEST_SIZE,
 334                 .block_size     = SHA256_BLOCK_SIZE,
 335         },
 336 };
 337
 338 static int ccp_register_hmac_alg(struct list_head *head,
 339                                  const struct ccp_sha_def *def,
 340                                  const struct ccp_crypto_ahash_alg *base_alg)
 341 {
 342         struct ccp_crypto_ahash_alg *ccp_alg;
 343         struct ahash_alg *alg;
 344         struct hash_alg_common *halg;
 345         struct crypto_alg *base;
 346         int ret;
 347
 348         ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
 349         if (!ccp_alg)
 350                 return -ENOMEM;
 351
 352         /* Copy the base algorithm and only change what's necessary */
 353         *ccp_alg = *base_alg;
 354         INIT_LIST_HEAD(&ccp_alg->entry);
 355
 356         strncpy(ccp_alg->child_alg, def->name, CRYPTO_MAX_ALG_NAME);
 357
 358         alg = &ccp_alg->alg;
 359         alg->setkey = ccp_sha_setkey;
 360
 361         halg = &alg->halg;
 362
 363         base = &halg->base;
 364         snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", def->name);
 365         snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "hmac-%s",
 366                  def->drv_name);
 367         base->cra_init = ccp_hmac_sha_cra_init;
 368         base->cra_exit = ccp_hmac_sha_cra_exit;
 369
 370         ret = crypto_register_ahash(alg);
 371         if (ret) {
 372                 pr_err("%s ahash algorithm registration error (%d)\n",
 373                        base->cra_name, ret);
 374                 kfree(ccp_alg);
 375                 return ret;
 376         }
 377
 378         list_add(&ccp_alg->entry, head);
 379
 380         return ret;
 381 }
 382
 383 static int ccp_register_sha_alg(struct list_head *head,
 384                                 const struct ccp_sha_def *def)
 385 {
 386         struct ccp_crypto_ahash_alg *ccp_alg;
 387         struct ahash_alg *alg;
 388         struct hash_alg_common *halg;
 389         struct crypto_alg *base;
 390         int ret;
 391
 392         ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
 393         if (!ccp_alg)
 394                 return -ENOMEM;
 395
 396         INIT_LIST_HEAD(&ccp_alg->entry);
 397
 398         ccp_alg->type = def->type;
 399
 400         alg = &ccp_alg->alg;
 401         alg->init = ccp_sha_init;
 402         alg->update = ccp_sha_update;
 403         alg->final = ccp_sha_final;
 404         alg->finup = ccp_sha_finup;
 405         alg->digest = ccp_sha_digest;
 406
 407         halg = &alg->halg;
 408         halg->digestsize = def->digest_size;
 409
 410         base = &halg->base;
 411         snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
 412         snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
 413                  def->drv_name);
 414         base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC |
 415                           CRYPTO_ALG_KERN_DRIVER_ONLY |
 416                           CRYPTO_ALG_NEED_FALLBACK;
 417         base->cra_blocksize = def->block_size;
 418         base->cra_ctxsize = sizeof(struct ccp_ctx);
 419         base->cra_priority = CCP_CRA_PRIORITY;
 420         base->cra_type = &crypto_ahash_type;
 421         base->cra_init = ccp_sha_cra_init;
 422         base->cra_exit = ccp_sha_cra_exit;
 423         base->cra_module = THIS_MODULE;
 424
 425         ret = crypto_register_ahash(alg);
 426         if (ret) {
 427                 pr_err("%s ahash algorithm registration error (%d)\n",
 428                        base->cra_name, ret);
 429                 kfree(ccp_alg);
 430                 return ret;
 431         }
 432
 433         list_add(&ccp_alg->entry, head);
 434
 435         ret = ccp_register_hmac_alg(head, def, ccp_alg);
 436
 437         return ret;
 438 }
 439
 440 int ccp_register_sha_algs(struct list_head *head)
 441 {
 442         int i, ret;
 443
 444         for (i = 0; i < ARRAY_SIZE(sha_algs); i++) {
 445                 ret = ccp_register_sha_alg(head, &sha_algs[i]);
 446                 if (ret)
 447                         return ret;
 448         }
 449
 450         return 0;
 451 }