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