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