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/gcm.h>
  26 #include <crypto/scatterwalk.h>
  27 #include <linux/module.h>
  28 #include <linux/types.h>
  29 #include <asm/vio.h>
  30
  31 #include "nx_csbcpb.h"
  32 #include "nx.h"
  33
  34
  35 static int gcm_aes_nx_set_key(struct crypto_aead *tfm,
  36                               const u8           *in_key,
  37                               unsigned int        key_len)
  38 {
  39         struct nx_crypto_ctx *nx_ctx = crypto_aead_ctx(tfm);
  40         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  41         struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
  42
  43         nx_ctx_init(nx_ctx, HCOP_FC_AES);
  44
  45         switch (key_len) {
  46         case AES_KEYSIZE_128:
  47                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
  48                 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_128);
  49                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
  50                 break;
  51         case AES_KEYSIZE_192:
  52                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
  53                 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_192);
  54                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
  55                 break;
  56         case AES_KEYSIZE_256:
  57                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
  58                 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_256);
  59                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
  60                 break;
  61         default:
  62                 return -EINVAL;
  63         }
  64
  65         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
  66         memcpy(csbcpb->cpb.aes_gcm.key, in_key, key_len);
  67
  68         csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_GCA;
  69         memcpy(csbcpb_aead->cpb.aes_gca.key, in_key, key_len);
  70
  71         return 0;
  72 }
  73
  74 static int gcm4106_aes_nx_set_key(struct crypto_aead *tfm,
  75                                   const u8           *in_key,
  76                                   unsigned int        key_len)
  77 {
  78         struct nx_crypto_ctx *nx_ctx = crypto_aead_ctx(tfm);
  79         char *nonce = nx_ctx->priv.gcm.nonce;
  80         int rc;
  81
  82         if (key_len < 4)
  83                 return -EINVAL;
  84
  85         key_len -= 4;
  86
  87         rc = gcm_aes_nx_set_key(tfm, in_key, key_len);
  88         if (rc)
  89                 goto out;
  90
  91         memcpy(nonce, in_key + key_len, 4);
  92 out:
  93         return rc;
  94 }
  95
  96 static int gcm4106_aes_nx_setauthsize(struct crypto_aead *tfm,
  97                                       unsigned int authsize)
  98 {
  99         switch (authsize) {
 100         case 8:
 101         case 12:
 102         case 16:
 103                 break;
 104         default:
 105                 return -EINVAL;
 106         }
 107
 108         return 0;
 109 }
 110
 111 static int nx_gca(struct nx_crypto_ctx  *nx_ctx,
 112                   struct aead_request   *req,
 113                   u8                    *out,
 114                   unsigned int assoclen)
 115 {
 116         int rc;
 117         struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
 118         struct scatter_walk walk;
 119         struct nx_sg *nx_sg = nx_ctx->in_sg;
 120         unsigned int nbytes = assoclen;
 121         unsigned int processed = 0, to_process;
 122         unsigned int max_sg_len;
 123
 124         if (nbytes <= AES_BLOCK_SIZE) {
 125                 scatterwalk_start(&walk, req->src);
 126                 scatterwalk_copychunks(out, &walk, nbytes, SCATTERWALK_FROM_SG);
 127                 scatterwalk_done(&walk, SCATTERWALK_FROM_SG, 0);
 128                 return 0;
 129         }
 130
 131         NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_CONTINUATION;
 132
 133         /* page_limit: number of sg entries that fit on one page */
 134         max_sg_len = min_t(u64, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
 135                            nx_ctx->ap->sglen);
 136         max_sg_len = min_t(u64, max_sg_len,
 137                            nx_ctx->ap->databytelen/NX_PAGE_SIZE);
 138
 139         do {
 140                 /*
 141                  * to_process: the data chunk to process in this update.
 142                  * This value is bound by sg list limits.
 143                  */
 144                 to_process = min_t(u64, nbytes - processed,
 145                                    nx_ctx->ap->databytelen);
 146                 to_process = min_t(u64, to_process,
 147                                    NX_PAGE_SIZE * (max_sg_len - 1));
 148
 149                 nx_sg = nx_walk_and_build(nx_ctx->in_sg, max_sg_len,
 150                                           req->src, processed, &to_process);
 151
 152                 if ((to_process + processed) < nbytes)
 153                         NX_CPB_FDM(csbcpb_aead) |= NX_FDM_INTERMEDIATE;
 154                 else
 155                         NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_INTERMEDIATE;
 156
 157                 nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_sg)
 158                                         * sizeof(struct nx_sg);
 159
 160                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead,
 161                                 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 162                 if (rc)
 163                         return rc;
 164
 165                 memcpy(csbcpb_aead->cpb.aes_gca.in_pat,
 166                                 csbcpb_aead->cpb.aes_gca.out_pat,
 167                                 AES_BLOCK_SIZE);
 168                 NX_CPB_FDM(csbcpb_aead) |= NX_FDM_CONTINUATION;
 169
 170                 atomic_inc(&(nx_ctx->stats->aes_ops));
 171                 atomic64_add(assoclen, &(nx_ctx->stats->aes_bytes));
 172
 173                 processed += to_process;
 174         } while (processed < nbytes);
 175
 176         memcpy(out, csbcpb_aead->cpb.aes_gca.out_pat, AES_BLOCK_SIZE);
 177
 178         return rc;
 179 }
 180
 181 static int gmac(struct aead_request *req, struct blkcipher_desc *desc,
 182                 unsigned int assoclen)
 183 {
 184         int rc;
 185         struct nx_crypto_ctx *nx_ctx =
 186                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 187         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 188         struct nx_sg *nx_sg;
 189         unsigned int nbytes = assoclen;
 190         unsigned int processed = 0, to_process;
 191         unsigned int max_sg_len;
 192
 193         /* Set GMAC mode */
 194         csbcpb->cpb.hdr.mode = NX_MODE_AES_GMAC;
 195
 196         NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
 197
 198         /* page_limit: number of sg entries that fit on one page */
 199         max_sg_len = min_t(u64, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
 200                            nx_ctx->ap->sglen);
 201         max_sg_len = min_t(u64, max_sg_len,
 202                            nx_ctx->ap->databytelen/NX_PAGE_SIZE);
 203
 204         /* Copy IV */
 205         memcpy(csbcpb->cpb.aes_gcm.iv_or_cnt, desc->info, AES_BLOCK_SIZE);
 206
 207         do {
 208                 /*
 209                  * to_process: the data chunk to process in this update.
 210                  * This value is bound by sg list limits.
 211                  */
 212                 to_process = min_t(u64, nbytes - processed,
 213                                    nx_ctx->ap->databytelen);
 214                 to_process = min_t(u64, to_process,
 215                                    NX_PAGE_SIZE * (max_sg_len - 1));
 216
 217                 nx_sg = nx_walk_and_build(nx_ctx->in_sg, max_sg_len,
 218                                           req->src, processed, &to_process);
 219
 220                 if ((to_process + processed) < nbytes)
 221                         NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 222                 else
 223                         NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 224
 225                 nx_ctx->op.inlen = (nx_ctx->in_sg - nx_sg)
 226                                         * sizeof(struct nx_sg);
 227
 228                 csbcpb->cpb.aes_gcm.bit_length_data = 0;
 229                 csbcpb->cpb.aes_gcm.bit_length_aad = 8 * nbytes;
 230
 231                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 232                                 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 233                 if (rc)
 234                         goto out;
 235
 236                 memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad,
 237                         csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE);
 238                 memcpy(csbcpb->cpb.aes_gcm.in_s0,
 239                         csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE);
 240
 241                 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
 242
 243                 atomic_inc(&(nx_ctx->stats->aes_ops));
 244                 atomic64_add(assoclen, &(nx_ctx->stats->aes_bytes));
 245
 246                 processed += to_process;
 247         } while (processed < nbytes);
 248
 249 out:
 250         /* Restore GCM mode */
 251         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
 252         return rc;
 253 }
 254
 255 static int gcm_empty(struct aead_request *req, struct blkcipher_desc *desc,
 256                      int enc)
 257 {
 258         int rc;
 259         struct nx_crypto_ctx *nx_ctx =
 260                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 261         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 262         char out[AES_BLOCK_SIZE];
 263         struct nx_sg *in_sg, *out_sg;
 264         int len;
 265
 266         /* For scenarios where the input message is zero length, AES CTR mode
 267          * may be used. Set the source data to be a single block (16B) of all
 268          * zeros, and set the input IV value to be the same as the GMAC IV
 269          * value. - nx_wb 4.8.1.3 */
 270
 271         /* Change to ECB mode */
 272         csbcpb->cpb.hdr.mode = NX_MODE_AES_ECB;
 273         memcpy(csbcpb->cpb.aes_ecb.key, csbcpb->cpb.aes_gcm.key,
 274                         sizeof(csbcpb->cpb.aes_ecb.key));
 275         if (enc)
 276                 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
 277         else
 278                 NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 279
 280         len = AES_BLOCK_SIZE;
 281
 282         /* Encrypt the counter/IV */
 283         in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) desc->info,
 284                                  &len, nx_ctx->ap->sglen);
 285
 286         if (len != AES_BLOCK_SIZE)
 287                 return -EINVAL;
 288
 289         len = sizeof(out);
 290         out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *) out, &len,
 291                                   nx_ctx->ap->sglen);
 292
 293         if (len != sizeof(out))
 294                 return -EINVAL;
 295
 296         nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
 297         nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
 298
 299         rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 300                            desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 301         if (rc)
 302                 goto out;
 303         atomic_inc(&(nx_ctx->stats->aes_ops));
 304
 305         /* Copy out the auth tag */
 306         memcpy(csbcpb->cpb.aes_gcm.out_pat_or_mac, out,
 307                         crypto_aead_authsize(crypto_aead_reqtfm(req)));
 308 out:
 309         /* Restore XCBC mode */
 310         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
 311
 312         /*
 313          * ECB key uses the same region that GCM AAD and counter, so it's safe
 314          * to just fill it with zeroes.
 315          */
 316         memset(csbcpb->cpb.aes_ecb.key, 0, sizeof(csbcpb->cpb.aes_ecb.key));
 317
 318         return rc;
 319 }
 320
 321 static int gcm_aes_nx_crypt(struct aead_request *req, int enc,
 322                             unsigned int assoclen)
 323 {
 324         struct nx_crypto_ctx *nx_ctx =
 325                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 326         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 327         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 328         struct blkcipher_desc desc;
 329         unsigned int nbytes = req->cryptlen;
 330         unsigned int processed = 0, to_process;
 331         unsigned long irq_flags;
 332         int rc = -EINVAL;
 333
 334         spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 335
 336         desc.info = rctx->iv;
 337         /* initialize the counter */
 338         *(u32 *)(desc.info + NX_GCM_CTR_OFFSET) = 1;
 339
 340         if (nbytes == 0) {
 341                 if (assoclen == 0)
 342                         rc = gcm_empty(req, &desc, enc);
 343                 else
 344                         rc = gmac(req, &desc, assoclen);
 345                 if (rc)
 346                         goto out;
 347                 else
 348                         goto mac;
 349         }
 350
 351         /* Process associated data */
 352         csbcpb->cpb.aes_gcm.bit_length_aad = assoclen * 8;
 353         if (assoclen) {
 354                 rc = nx_gca(nx_ctx, req, csbcpb->cpb.aes_gcm.in_pat_or_aad,
 355                             assoclen);
 356                 if (rc)
 357                         goto out;
 358         }
 359
 360         /* Set flags for encryption */
 361         NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
 362         if (enc) {
 363                 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
 364         } else {
 365                 NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 366                 nbytes -= crypto_aead_authsize(crypto_aead_reqtfm(req));
 367         }
 368
 369         do {
 370                 to_process = nbytes - processed;
 371
 372                 csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8;
 373                 rc = nx_build_sg_lists(nx_ctx, &desc, req->dst,
 374                                        req->src, &to_process,
 375                                        processed + req->assoclen,
 376                                        csbcpb->cpb.aes_gcm.iv_or_cnt);
 377
 378                 if (rc)
 379                         goto out;
 380
 381                 if ((to_process + processed) < nbytes)
 382                         NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 383                 else
 384                         NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 385
 386
 387                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 388                                    req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 389                 if (rc)
 390                         goto out;
 391
 392                 memcpy(desc.info, csbcpb->cpb.aes_gcm.out_cnt, AES_BLOCK_SIZE);
 393                 memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad,
 394                         csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE);
 395                 memcpy(csbcpb->cpb.aes_gcm.in_s0,
 396                         csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE);
 397
 398                 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
 399
 400                 atomic_inc(&(nx_ctx->stats->aes_ops));
 401                 atomic64_add(csbcpb->csb.processed_byte_count,
 402                              &(nx_ctx->stats->aes_bytes));
 403
 404                 processed += to_process;
 405         } while (processed < nbytes);
 406
 407 mac:
 408         if (enc) {
 409                 /* copy out the auth tag */
 410                 scatterwalk_map_and_copy(
 411                         csbcpb->cpb.aes_gcm.out_pat_or_mac,
 412                         req->dst, req->assoclen + nbytes,
 413                         crypto_aead_authsize(crypto_aead_reqtfm(req)),
 414                         SCATTERWALK_TO_SG);
 415         } else {
 416                 u8 *itag = nx_ctx->priv.gcm.iauth_tag;
 417                 u8 *otag = csbcpb->cpb.aes_gcm.out_pat_or_mac;
 418
 419                 scatterwalk_map_and_copy(
 420                         itag, req->src, req->assoclen + nbytes,
 421                         crypto_aead_authsize(crypto_aead_reqtfm(req)),
 422                         SCATTERWALK_FROM_SG);
 423                 rc = crypto_memneq(itag, otag,
 424                             crypto_aead_authsize(crypto_aead_reqtfm(req))) ?
 425                      -EBADMSG : 0;
 426         }
 427 out:
 428         spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 429         return rc;
 430 }
 431
 432 static int gcm_aes_nx_encrypt(struct aead_request *req)
 433 {
 434         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 435         char *iv = rctx->iv;
 436
 437         memcpy(iv, req->iv, GCM_AES_IV_SIZE);
 438
 439         return gcm_aes_nx_crypt(req, 1, req->assoclen);
 440 }
 441
 442 static int gcm_aes_nx_decrypt(struct aead_request *req)
 443 {
 444         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 445         char *iv = rctx->iv;
 446
 447         memcpy(iv, req->iv, GCM_AES_IV_SIZE);
 448
 449         return gcm_aes_nx_crypt(req, 0, req->assoclen);
 450 }
 451
 452 static int gcm4106_aes_nx_encrypt(struct aead_request *req)
 453 {
 454         struct nx_crypto_ctx *nx_ctx =
 455                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 456         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 457         char *iv = rctx->iv;
 458         char *nonce = nx_ctx->priv.gcm.nonce;
 459
 460         memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
 461         memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);
 462
 463         if (req->assoclen < 8)
 464                 return -EINVAL;
 465
 466         return gcm_aes_nx_crypt(req, 1, req->assoclen - 8);
 467 }
 468
 469 static int gcm4106_aes_nx_decrypt(struct aead_request *req)
 470 {
 471         struct nx_crypto_ctx *nx_ctx =
 472                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 473         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 474         char *iv = rctx->iv;
 475         char *nonce = nx_ctx->priv.gcm.nonce;
 476
 477         memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
 478         memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);
 479
 480         if (req->assoclen < 8)
 481                 return -EINVAL;
 482
 483         return gcm_aes_nx_crypt(req, 0, req->assoclen - 8);
 484 }
 485
 486 /* tell the block cipher walk routines that this is a stream cipher by
 487  * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block
 488  * during encrypt/decrypt doesn't solve this problem, because it calls
 489  * blkcipher_walk_done under the covers, which doesn't use walk->blocksize,
 490  * but instead uses this tfm->blocksize. */
 491 struct aead_alg nx_gcm_aes_alg = {
 492         .base = {
 493                 .cra_name        = "gcm(aes)",
 494                 .cra_driver_name = "gcm-aes-nx",
 495                 .cra_priority    = 300,
 496                 .cra_blocksize   = 1,
 497                 .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 498                 .cra_module      = THIS_MODULE,
 499         },
 500         .init        = nx_crypto_ctx_aes_gcm_init,
 501         .exit        = nx_crypto_ctx_aead_exit,
 502         .ivsize      = GCM_AES_IV_SIZE,
 503         .maxauthsize = AES_BLOCK_SIZE,
 504         .setkey      = gcm_aes_nx_set_key,
 505         .encrypt     = gcm_aes_nx_encrypt,
 506         .decrypt     = gcm_aes_nx_decrypt,
 507 };
 508
 509 struct aead_alg nx_gcm4106_aes_alg = {
 510         .base = {
 511                 .cra_name        = "rfc4106(gcm(aes))",
 512                 .cra_driver_name = "rfc4106-gcm-aes-nx",
 513                 .cra_priority    = 300,
 514                 .cra_blocksize   = 1,
 515                 .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 516                 .cra_module      = THIS_MODULE,
 517         },
 518         .init        = nx_crypto_ctx_aes_gcm_init,
 519         .exit        = nx_crypto_ctx_aead_exit,
 520         .ivsize      = GCM_RFC4106_IV_SIZE,
 521         .maxauthsize = AES_BLOCK_SIZE,
 522         .setkey      = gcm4106_aes_nx_set_key,
 523         .setauthsize = gcm4106_aes_nx_setauthsize,
 524         .encrypt     = gcm4106_aes_nx_encrypt,
 525         .decrypt     = gcm4106_aes_nx_decrypt,
 526 };