drivers/crypto/nx/nx-aes-gcm.c

   1 /**
   2  * AES GCM routines supporting the Power 7+ Nest Accelerators driver
   3  *
   4  * Copyright (C) 2012 International Business Machines Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 only.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  * Author: Kent Yoder <yoder1@us.ibm.com>
  20  */
  21
  22 #include <crypto/internal/aead.h>
  23 #include <crypto/aes.h>
  24 #include <crypto/algapi.h>
  25 #include <crypto/scatterwalk.h>
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <asm/vio.h>
  29
  30 #include "nx_csbcpb.h"
  31 #include "nx.h"
  32
  33
  34 static int gcm_aes_nx_set_key(struct crypto_aead *tfm,
  35                               const u8           *in_key,
  36                               unsigned int        key_len)
  37 {
  38         struct nx_crypto_ctx *nx_ctx = crypto_aead_ctx(tfm);
  39         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  40         struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
  41
  42         nx_ctx_init(nx_ctx, HCOP_FC_AES);
  43
  44         switch (key_len) {
  45         case AES_KEYSIZE_128:
  46                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
  47                 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_128);
  48                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
  49                 break;
  50         case AES_KEYSIZE_192:
  51                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
  52                 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_192);
  53                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
  54                 break;
  55         case AES_KEYSIZE_256:
  56                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
  57                 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_256);
  58                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
  59                 break;
  60         default:
  61                 return -EINVAL;
  62         }
  63
  64         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
  65         memcpy(csbcpb->cpb.aes_gcm.key, in_key, key_len);
  66
  67         csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_GCA;
  68         memcpy(csbcpb_aead->cpb.aes_gca.key, in_key, key_len);
  69
  70         return 0;
  71 }
  72
  73 static int gcm4106_aes_nx_set_key(struct crypto_aead *tfm,
  74                                   const u8           *in_key,
  75                                   unsigned int        key_len)
  76 {
  77         struct nx_crypto_ctx *nx_ctx = crypto_aead_ctx(tfm);
  78         char *nonce = nx_ctx->priv.gcm.nonce;
  79         int rc;
  80
  81         if (key_len < 4)
  82                 return -EINVAL;
  83
  84         key_len -= 4;
  85
  86         rc = gcm_aes_nx_set_key(tfm, in_key, key_len);
  87         if (rc)
  88                 goto out;
  89
  90         memcpy(nonce, in_key + key_len, 4);
  91 out:
  92         return rc;
  93 }
  94
  95 static int gcm4106_aes_nx_setauthsize(struct crypto_aead *tfm,
  96                                       unsigned int authsize)
  97 {
  98         switch (authsize) {
  99         case 8:
 100         case 12:
 101         case 16:
 102                 break;
 103         default:
 104                 return -EINVAL;
 105         }
 106
 107         return 0;
 108 }
 109
 110 static int nx_gca(struct nx_crypto_ctx  *nx_ctx,
 111                   struct aead_request   *req,
 112                   u8                    *out,
 113                   unsigned int assoclen)
 114 {
 115         int rc;
 116         struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
 117         struct scatter_walk walk;
 118         struct nx_sg *nx_sg = nx_ctx->in_sg;
 119         unsigned int nbytes = assoclen;
 120         unsigned int processed = 0, to_process;
 121         unsigned int max_sg_len;
 122
 123         if (nbytes <= AES_BLOCK_SIZE) {
 124                 scatterwalk_start(&walk, req->src);
 125                 scatterwalk_copychunks(out, &walk, nbytes, SCATTERWALK_FROM_SG);
 126                 scatterwalk_done(&walk, SCATTERWALK_FROM_SG, 0);
 127                 return 0;
 128         }
 129
 130         NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_CONTINUATION;
 131
 132         /* page_limit: number of sg entries that fit on one page */
 133         max_sg_len = min_t(u64, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
 134                            nx_ctx->ap->sglen);
 135         max_sg_len = min_t(u64, max_sg_len,
 136                            nx_ctx->ap->databytelen/NX_PAGE_SIZE);
 137
 138         do {
 139                 /*
 140                  * to_process: the data chunk to process in this update.
 141                  * This value is bound by sg list limits.
 142                  */
 143                 to_process = min_t(u64, nbytes - processed,
 144                                    nx_ctx->ap->databytelen);
 145                 to_process = min_t(u64, to_process,
 146                                    NX_PAGE_SIZE * (max_sg_len - 1));
 147
 148                 nx_sg = nx_walk_and_build(nx_ctx->in_sg, max_sg_len,
 149                                           req->src, processed, &to_process);
 150
 151                 if ((to_process + processed) < nbytes)
 152                         NX_CPB_FDM(csbcpb_aead) |= NX_FDM_INTERMEDIATE;
 153                 else
 154                         NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_INTERMEDIATE;
 155
 156                 nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_sg)
 157                                         * sizeof(struct nx_sg);
 158
 159                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead,
 160                                 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 161                 if (rc)
 162                         return rc;
 163
 164                 memcpy(csbcpb_aead->cpb.aes_gca.in_pat,
 165                                 csbcpb_aead->cpb.aes_gca.out_pat,
 166                                 AES_BLOCK_SIZE);
 167                 NX_CPB_FDM(csbcpb_aead) |= NX_FDM_CONTINUATION;
 168
 169                 atomic_inc(&(nx_ctx->stats->aes_ops));
 170                 atomic64_add(assoclen, &(nx_ctx->stats->aes_bytes));
 171
 172                 processed += to_process;
 173         } while (processed < nbytes);
 174
 175         memcpy(out, csbcpb_aead->cpb.aes_gca.out_pat, AES_BLOCK_SIZE);
 176
 177         return rc;
 178 }
 179
 180 static int gmac(struct aead_request *req, struct blkcipher_desc *desc,
 181                 unsigned int assoclen)
 182 {
 183         int rc;
 184         struct nx_crypto_ctx *nx_ctx =
 185                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 186         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 187         struct nx_sg *nx_sg;
 188         unsigned int nbytes = assoclen;
 189         unsigned int processed = 0, to_process;
 190         unsigned int max_sg_len;
 191
 192         /* Set GMAC mode */
 193         csbcpb->cpb.hdr.mode = NX_MODE_AES_GMAC;
 194
 195         NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
 196
 197         /* page_limit: number of sg entries that fit on one page */
 198         max_sg_len = min_t(u64, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
 199                            nx_ctx->ap->sglen);
 200         max_sg_len = min_t(u64, max_sg_len,
 201                            nx_ctx->ap->databytelen/NX_PAGE_SIZE);
 202
 203         /* Copy IV */
 204         memcpy(csbcpb->cpb.aes_gcm.iv_or_cnt, desc->info, AES_BLOCK_SIZE);
 205
 206         do {
 207                 /*
 208                  * to_process: the data chunk to process in this update.
 209                  * This value is bound by sg list limits.
 210                  */
 211                 to_process = min_t(u64, nbytes - processed,
 212                                    nx_ctx->ap->databytelen);
 213                 to_process = min_t(u64, to_process,
 214                                    NX_PAGE_SIZE * (max_sg_len - 1));
 215
 216                 nx_sg = nx_walk_and_build(nx_ctx->in_sg, max_sg_len,
 217                                           req->src, processed, &to_process);
 218
 219                 if ((to_process + processed) < nbytes)
 220                         NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 221                 else
 222                         NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 223
 224                 nx_ctx->op.inlen = (nx_ctx->in_sg - nx_sg)
 225                                         * sizeof(struct nx_sg);
 226
 227                 csbcpb->cpb.aes_gcm.bit_length_data = 0;
 228                 csbcpb->cpb.aes_gcm.bit_length_aad = 8 * nbytes;
 229
 230                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 231                                 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 232                 if (rc)
 233                         goto out;
 234
 235                 memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad,
 236                         csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE);
 237                 memcpy(csbcpb->cpb.aes_gcm.in_s0,
 238                         csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE);
 239
 240                 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
 241
 242                 atomic_inc(&(nx_ctx->stats->aes_ops));
 243                 atomic64_add(assoclen, &(nx_ctx->stats->aes_bytes));
 244
 245                 processed += to_process;
 246         } while (processed < nbytes);
 247
 248 out:
 249         /* Restore GCM mode */
 250         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
 251         return rc;
 252 }
 253
 254 static int gcm_empty(struct aead_request *req, struct blkcipher_desc *desc,
 255                      int enc)
 256 {
 257         int rc;
 258         struct nx_crypto_ctx *nx_ctx =
 259                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 260         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 261         char out[AES_BLOCK_SIZE];
 262         struct nx_sg *in_sg, *out_sg;
 263         int len;
 264
 265         /* For scenarios where the input message is zero length, AES CTR mode
 266          * may be used. Set the source data to be a single block (16B) of all
 267          * zeros, and set the input IV value to be the same as the GMAC IV
 268          * value. - nx_wb 4.8.1.3 */
 269
 270         /* Change to ECB mode */
 271         csbcpb->cpb.hdr.mode = NX_MODE_AES_ECB;
 272         memcpy(csbcpb->cpb.aes_ecb.key, csbcpb->cpb.aes_gcm.key,
 273                         sizeof(csbcpb->cpb.aes_ecb.key));
 274         if (enc)
 275                 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
 276         else
 277                 NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 278
 279         len = AES_BLOCK_SIZE;
 280
 281         /* Encrypt the counter/IV */
 282         in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) desc->info,
 283                                  &len, nx_ctx->ap->sglen);
 284
 285         if (len != AES_BLOCK_SIZE)
 286                 return -EINVAL;
 287
 288         len = sizeof(out);
 289         out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *) out, &len,
 290                                   nx_ctx->ap->sglen);
 291
 292         if (len != sizeof(out))
 293                 return -EINVAL;
 294
 295         nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
 296         nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
 297
 298         rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 299                            desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 300         if (rc)
 301                 goto out;
 302         atomic_inc(&(nx_ctx->stats->aes_ops));
 303
 304         /* Copy out the auth tag */
 305         memcpy(csbcpb->cpb.aes_gcm.out_pat_or_mac, out,
 306                         crypto_aead_authsize(crypto_aead_reqtfm(req)));
 307 out:
 308         /* Restore XCBC mode */
 309         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
 310
 311         /*
 312          * ECB key uses the same region that GCM AAD and counter, so it's safe
 313          * to just fill it with zeroes.
 314          */
 315         memset(csbcpb->cpb.aes_ecb.key, 0, sizeof(csbcpb->cpb.aes_ecb.key));
 316
 317         return rc;
 318 }
 319
 320 static int gcm_aes_nx_crypt(struct aead_request *req, int enc,
 321                             unsigned int assoclen)
 322 {
 323         struct nx_crypto_ctx *nx_ctx =
 324                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 325         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 326         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 327         struct blkcipher_desc desc;
 328         unsigned int nbytes = req->cryptlen;
 329         unsigned int processed = 0, to_process;
 330         unsigned long irq_flags;
 331         int rc = -EINVAL;
 332
 333         spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 334
 335         desc.info = rctx->iv;
 336         /* initialize the counter */
 337         *(u32 *)(desc.info + NX_GCM_CTR_OFFSET) = 1;
 338
 339         if (nbytes == 0) {
 340                 if (assoclen == 0)
 341                         rc = gcm_empty(req, &desc, enc);
 342                 else
 343                         rc = gmac(req, &desc, assoclen);
 344                 if (rc)
 345                         goto out;
 346                 else
 347                         goto mac;
 348         }
 349
 350         /* Process associated data */
 351         csbcpb->cpb.aes_gcm.bit_length_aad = assoclen * 8;
 352         if (assoclen) {
 353                 rc = nx_gca(nx_ctx, req, csbcpb->cpb.aes_gcm.in_pat_or_aad,
 354                             assoclen);
 355                 if (rc)
 356                         goto out;
 357         }
 358
 359         /* Set flags for encryption */
 360         NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
 361         if (enc) {
 362                 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
 363         } else {
 364                 NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 365                 nbytes -= crypto_aead_authsize(crypto_aead_reqtfm(req));
 366         }
 367
 368         do {
 369                 to_process = nbytes - processed;
 370
 371                 csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8;
 372                 rc = nx_build_sg_lists(nx_ctx, &desc, req->dst,
 373                                        req->src, &to_process,
 374                                        processed + req->assoclen,
 375                                        csbcpb->cpb.aes_gcm.iv_or_cnt);
 376
 377                 if (rc)
 378                         goto out;
 379
 380                 if ((to_process + processed) < nbytes)
 381                         NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 382                 else
 383                         NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 384
 385
 386                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 387                                    req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 388                 if (rc)
 389                         goto out;
 390
 391                 memcpy(desc.info, csbcpb->cpb.aes_gcm.out_cnt, AES_BLOCK_SIZE);
 392                 memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad,
 393                         csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE);
 394                 memcpy(csbcpb->cpb.aes_gcm.in_s0,
 395                         csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE);
 396
 397                 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
 398
 399                 atomic_inc(&(nx_ctx->stats->aes_ops));
 400                 atomic64_add(csbcpb->csb.processed_byte_count,
 401                              &(nx_ctx->stats->aes_bytes));
 402
 403                 processed += to_process;
 404         } while (processed < nbytes);
 405
 406 mac:
 407         if (enc) {
 408                 /* copy out the auth tag */
 409                 scatterwalk_map_and_copy(
 410                         csbcpb->cpb.aes_gcm.out_pat_or_mac,
 411                         req->dst, req->assoclen + nbytes,
 412                         crypto_aead_authsize(crypto_aead_reqtfm(req)),
 413                         SCATTERWALK_TO_SG);
 414         } else {
 415                 u8 *itag = nx_ctx->priv.gcm.iauth_tag;
 416                 u8 *otag = csbcpb->cpb.aes_gcm.out_pat_or_mac;
 417
 418                 scatterwalk_map_and_copy(
 419                         itag, req->src, req->assoclen + nbytes,
 420                         crypto_aead_authsize(crypto_aead_reqtfm(req)),
 421                         SCATTERWALK_FROM_SG);
 422                 rc = crypto_memneq(itag, otag,
 423                             crypto_aead_authsize(crypto_aead_reqtfm(req))) ?
 424                      -EBADMSG : 0;
 425         }
 426 out:
 427         spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 428         return rc;
 429 }
 430
 431 static int gcm_aes_nx_encrypt(struct aead_request *req)
 432 {
 433         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 434         char *iv = rctx->iv;
 435
 436         memcpy(iv, req->iv, 12);
 437
 438         return gcm_aes_nx_crypt(req, 1, req->assoclen);
 439 }
 440
 441 static int gcm_aes_nx_decrypt(struct aead_request *req)
 442 {
 443         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 444         char *iv = rctx->iv;
 445
 446         memcpy(iv, req->iv, 12);
 447
 448         return gcm_aes_nx_crypt(req, 0, req->assoclen);
 449 }
 450
 451 static int gcm4106_aes_nx_encrypt(struct aead_request *req)
 452 {
 453         struct nx_crypto_ctx *nx_ctx =
 454                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 455         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 456         char *iv = rctx->iv;
 457         char *nonce = nx_ctx->priv.gcm.nonce;
 458
 459         memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
 460         memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);
 461
 462         if (req->assoclen < 8)
 463                 return -EINVAL;
 464
 465         return gcm_aes_nx_crypt(req, 1, req->assoclen - 8);
 466 }
 467
 468 static int gcm4106_aes_nx_decrypt(struct aead_request *req)
 469 {
 470         struct nx_crypto_ctx *nx_ctx =
 471                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 472         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 473         char *iv = rctx->iv;
 474         char *nonce = nx_ctx->priv.gcm.nonce;
 475
 476         memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
 477         memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);
 478
 479         if (req->assoclen < 8)
 480                 return -EINVAL;
 481
 482         return gcm_aes_nx_crypt(req, 0, req->assoclen - 8);
 483 }
 484
 485 /* tell the block cipher walk routines that this is a stream cipher by
 486  * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block
 487  * during encrypt/decrypt doesn't solve this problem, because it calls
 488  * blkcipher_walk_done under the covers, which doesn't use walk->blocksize,
 489  * but instead uses this tfm->blocksize. */
 490 struct aead_alg nx_gcm_aes_alg = {
 491         .base = {
 492                 .cra_name        = "gcm(aes)",
 493                 .cra_driver_name = "gcm-aes-nx",
 494                 .cra_priority    = 300,
 495                 .cra_blocksize   = 1,
 496                 .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 497                 .cra_module      = THIS_MODULE,
 498         },
 499         .init        = nx_crypto_ctx_aes_gcm_init,
 500         .exit        = nx_crypto_ctx_aead_exit,
 501         .ivsize      = 12,
 502         .maxauthsize = AES_BLOCK_SIZE,
 503         .setkey      = gcm_aes_nx_set_key,
 504         .encrypt     = gcm_aes_nx_encrypt,
 505         .decrypt     = gcm_aes_nx_decrypt,
 506 };
 507
 508 struct aead_alg nx_gcm4106_aes_alg = {
 509         .base = {
 510                 .cra_name        = "rfc4106(gcm(aes))",
 511                 .cra_driver_name = "rfc4106-gcm-aes-nx",
 512                 .cra_priority    = 300,
 513                 .cra_blocksize   = 1,
 514                 .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 515                 .cra_module      = THIS_MODULE,
 516         },
 517         .init        = nx_crypto_ctx_aes_gcm_init,
 518         .exit        = nx_crypto_ctx_aead_exit,
 519         .ivsize      = 8,
 520         .maxauthsize = AES_BLOCK_SIZE,
 521         .setkey      = gcm4106_aes_nx_set_key,
 522         .setauthsize = gcm4106_aes_nx_setauthsize,
 523         .encrypt     = gcm4106_aes_nx_encrypt,
 524         .decrypt     = gcm4106_aes_nx_decrypt,
 525 };