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