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