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                 sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src);
 111                 sg_mark_end(sg);
 112
 113                 sg = rctx->data_sg.sgl;
 114         } else if (rctx->buf_count) {
 115                 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
 116
 117                 sg = &rctx->buf_sg;
 118         } else if (nbytes) {
 119                 sg = req->src;
 120         }
 121
 122         rctx->msg_bits += (rctx->hash_cnt << 3);        /* Total in bits */
 123
 124         memset(&rctx->cmd, 0, sizeof(rctx->cmd));
 125         INIT_LIST_HEAD(&rctx->cmd.entry);
 126         rctx->cmd.engine = CCP_ENGINE_SHA;
 127         rctx->cmd.u.sha.type = rctx->type;
 128         rctx->cmd.u.sha.ctx = &rctx->ctx_sg;
 129         rctx->cmd.u.sha.ctx_len = sizeof(rctx->ctx);
 130         rctx->cmd.u.sha.src = sg;
 131         rctx->cmd.u.sha.src_len = rctx->hash_cnt;
 132         rctx->cmd.u.sha.opad = ctx->u.sha.key_len ?
 133                 &ctx->u.sha.opad_sg : NULL;
 134         rctx->cmd.u.sha.opad_len = ctx->u.sha.key_len ?
 135                 ctx->u.sha.opad_count : 0;
 136         rctx->cmd.u.sha.first = rctx->first;
 137         rctx->cmd.u.sha.final = rctx->final;
 138         rctx->cmd.u.sha.msg_bits = rctx->msg_bits;
 139
 140         rctx->first = 0;
 141
 142         ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
 143
 144         return ret;
 145 }
 146
 147 static int ccp_sha_init(struct ahash_request *req)
 148 {
 149         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 150         struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
 151         struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
 152         struct ccp_crypto_ahash_alg *alg =
 153                 ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm));
 154         unsigned int block_size =
 155                 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
 156
 157         memset(rctx, 0, sizeof(*rctx));
 158
 159         rctx->type = alg->type;
 160         rctx->first = 1;
 161
 162         if (ctx->u.sha.key_len) {
 163                 /* Buffer the HMAC key for first update */
 164                 memcpy(rctx->buf, ctx->u.sha.ipad, block_size);
 165                 rctx->buf_count = block_size;
 166         }
 167
 168         return 0;
 169 }
 170
 171 static int ccp_sha_update(struct ahash_request *req)
 172 {
 173         return ccp_do_sha_update(req, req->nbytes, 0);
 174 }
 175
 176 static int ccp_sha_final(struct ahash_request *req)
 177 {
 178         return ccp_do_sha_update(req, 0, 1);
 179 }
 180
 181 static int ccp_sha_finup(struct ahash_request *req)
 182 {
 183         return ccp_do_sha_update(req, req->nbytes, 1);
 184 }
 185
 186 static int ccp_sha_digest(struct ahash_request *req)
 187 {
 188         int ret;
 189
 190         ret = ccp_sha_init(req);
 191         if (ret)
 192                 return ret;
 193
 194         return ccp_sha_finup(req);
 195 }
 196
 197 static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
 198                           unsigned int key_len)
 199 {
 200         struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
 201         struct crypto_shash *shash = ctx->u.sha.hmac_tfm;
 202
 203         SHASH_DESC_ON_STACK(sdesc, shash);
 204
 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                 sdesc->tfm = shash;
 220                 sdesc->flags = crypto_ahash_get_flags(tfm) &
 221                         CRYPTO_TFM_REQ_MAY_SLEEP;
 222
 223                 ret = crypto_shash_digest(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
 235         for (i = 0; i < block_size; i++) {
 236                 ctx->u.sha.ipad[i] = ctx->u.sha.key[i] ^ 0x36;
 237                 ctx->u.sha.opad[i] = ctx->u.sha.key[i] ^ 0x5c;
 238         }
 239
 240         sg_init_one(&ctx->u.sha.opad_sg, ctx->u.sha.opad, block_size);
 241         ctx->u.sha.opad_count = block_size;
 242
 243         ctx->u.sha.key_len = key_len;
 244
 245         return 0;
 246 }
 247
 248 static int ccp_sha_cra_init(struct crypto_tfm *tfm)
 249 {
 250         struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 251         struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);
 252
 253         ctx->complete = ccp_sha_complete;
 254         ctx->u.sha.key_len = 0;
 255
 256         crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_sha_req_ctx));
 257
 258         return 0;
 259 }
 260
 261 static void ccp_sha_cra_exit(struct crypto_tfm *tfm)
 262 {
 263 }
 264
 265 static int ccp_hmac_sha_cra_init(struct crypto_tfm *tfm)
 266 {
 267         struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 268         struct ccp_crypto_ahash_alg *alg = ccp_crypto_ahash_alg(tfm);
 269         struct crypto_shash *hmac_tfm;
 270
 271         hmac_tfm = crypto_alloc_shash(alg->child_alg, 0, 0);
 272         if (IS_ERR(hmac_tfm)) {
 273                 pr_warn("could not load driver %s need for HMAC support\n",
 274                         alg->child_alg);
 275                 return PTR_ERR(hmac_tfm);
 276         }
 277
 278         ctx->u.sha.hmac_tfm = hmac_tfm;
 279
 280         return ccp_sha_cra_init(tfm);
 281 }
 282
 283 static void ccp_hmac_sha_cra_exit(struct crypto_tfm *tfm)
 284 {
 285         struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 286
 287         if (ctx->u.sha.hmac_tfm)
 288                 crypto_free_shash(ctx->u.sha.hmac_tfm);
 289
 290         ccp_sha_cra_exit(tfm);
 291 }
 292
 293 struct ccp_sha_def {
 294         const char *name;
 295         const char *drv_name;
 296         enum ccp_sha_type type;
 297         u32 digest_size;
 298         u32 block_size;
 299 };
 300
 301 static struct ccp_sha_def sha_algs[] = {
 302         {
 303                 .name           = "sha1",
 304                 .drv_name       = "sha1-ccp",
 305                 .type           = CCP_SHA_TYPE_1,
 306                 .digest_size    = SHA1_DIGEST_SIZE,
 307                 .block_size     = SHA1_BLOCK_SIZE,
 308         },
 309         {
 310                 .name           = "sha224",
 311                 .drv_name       = "sha224-ccp",
 312                 .type           = CCP_SHA_TYPE_224,
 313                 .digest_size    = SHA224_DIGEST_SIZE,
 314                 .block_size     = SHA224_BLOCK_SIZE,
 315         },
 316         {
 317                 .name           = "sha256",
 318                 .drv_name       = "sha256-ccp",
 319                 .type           = CCP_SHA_TYPE_256,
 320                 .digest_size    = SHA256_DIGEST_SIZE,
 321                 .block_size     = SHA256_BLOCK_SIZE,
 322         },
 323 };
 324
 325 static int ccp_register_hmac_alg(struct list_head *head,
 326                                  const struct ccp_sha_def *def,
 327                                  const struct ccp_crypto_ahash_alg *base_alg)
 328 {
 329         struct ccp_crypto_ahash_alg *ccp_alg;
 330         struct ahash_alg *alg;
 331         struct hash_alg_common *halg;
 332         struct crypto_alg *base;
 333         int ret;
 334
 335         ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
 336         if (!ccp_alg)
 337                 return -ENOMEM;
 338
 339         /* Copy the base algorithm and only change what's necessary */
 340         *ccp_alg = *base_alg;
 341         INIT_LIST_HEAD(&ccp_alg->entry);
 342
 343         strncpy(ccp_alg->child_alg, def->name, CRYPTO_MAX_ALG_NAME);
 344
 345         alg = &ccp_alg->alg;
 346         alg->setkey = ccp_sha_setkey;
 347
 348         halg = &alg->halg;
 349
 350         base = &halg->base;
 351         snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", def->name);
 352         snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "hmac-%s",
 353                  def->drv_name);
 354         base->cra_init = ccp_hmac_sha_cra_init;
 355         base->cra_exit = ccp_hmac_sha_cra_exit;
 356
 357         ret = crypto_register_ahash(alg);
 358         if (ret) {
 359                 pr_err("%s ahash algorithm registration error (%d)\n",
 360                        base->cra_name, ret);
 361                 kfree(ccp_alg);
 362                 return ret;
 363         }
 364
 365         list_add(&ccp_alg->entry, head);
 366
 367         return ret;
 368 }
 369
 370 static int ccp_register_sha_alg(struct list_head *head,
 371                                 const struct ccp_sha_def *def)
 372 {
 373         struct ccp_crypto_ahash_alg *ccp_alg;
 374         struct ahash_alg *alg;
 375         struct hash_alg_common *halg;
 376         struct crypto_alg *base;
 377         int ret;
 378
 379         ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
 380         if (!ccp_alg)
 381                 return -ENOMEM;
 382
 383         INIT_LIST_HEAD(&ccp_alg->entry);
 384
 385         ccp_alg->type = def->type;
 386
 387         alg = &ccp_alg->alg;
 388         alg->init = ccp_sha_init;
 389         alg->update = ccp_sha_update;
 390         alg->final = ccp_sha_final;
 391         alg->finup = ccp_sha_finup;
 392         alg->digest = ccp_sha_digest;
 393
 394         halg = &alg->halg;
 395         halg->digestsize = def->digest_size;
 396
 397         base = &halg->base;
 398         snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
 399         snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
 400                  def->drv_name);
 401         base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC |
 402                           CRYPTO_ALG_KERN_DRIVER_ONLY |
 403                           CRYPTO_ALG_NEED_FALLBACK;
 404         base->cra_blocksize = def->block_size;
 405         base->cra_ctxsize = sizeof(struct ccp_ctx);
 406         base->cra_priority = CCP_CRA_PRIORITY;
 407         base->cra_type = &crypto_ahash_type;
 408         base->cra_init = ccp_sha_cra_init;
 409         base->cra_exit = ccp_sha_cra_exit;
 410         base->cra_module = THIS_MODULE;
 411
 412         ret = crypto_register_ahash(alg);
 413         if (ret) {
 414                 pr_err("%s ahash algorithm registration error (%d)\n",
 415                        base->cra_name, ret);
 416                 kfree(ccp_alg);
 417                 return ret;
 418         }
 419
 420         list_add(&ccp_alg->entry, head);
 421
 422         ret = ccp_register_hmac_alg(head, def, ccp_alg);
 423
 424         return ret;
 425 }
 426
 427 int ccp_register_sha_algs(struct list_head *head)
 428 {
 429         int i, ret;
 430
 431         for (i = 0; i < ARRAY_SIZE(sha_algs); i++) {
 432                 ret = ccp_register_sha_alg(head, &sha_algs[i]);
 433                 if (ret)
 434                         return ret;
 435         }
 436
 437         return 0;
 438 }