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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /**
   3  * AES GCM routines supporting the Power 7+ Nest Accelerators driver
   4  *
   5  * Copyright (C) 2012 International Business Machines Inc.
   6  *
   7  * Author: Kent Yoder <yoder1@us.ibm.com>
   8  */
   9
  10 #include <crypto/internal/aead.h>
  11 #include <crypto/aes.h>
  12 #include <crypto/algapi.h>
  13 #include <crypto/gcm.h>
  14 #include <crypto/scatterwalk.h>
  15 #include <linux/module.h>
  16 #include <linux/types.h>
  17 #include <asm/vio.h>
  18
  19 #include "nx_csbcpb.h"
  20 #include "nx.h"
  21
  22
  23 static int gcm_aes_nx_set_key(struct crypto_aead *tfm,
  24                               const u8           *in_key,
  25                               unsigned int        key_len)
  26 {
  27         struct nx_crypto_ctx *nx_ctx = crypto_aead_ctx(tfm);
  28         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  29         struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
  30
  31         nx_ctx_init(nx_ctx, HCOP_FC_AES);
  32
  33         switch (key_len) {
  34         case AES_KEYSIZE_128:
  35                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
  36                 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_128);
  37                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
  38                 break;
  39         case AES_KEYSIZE_192:
  40                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
  41                 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_192);
  42                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
  43                 break;
  44         case AES_KEYSIZE_256:
  45                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
  46                 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_256);
  47                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
  48                 break;
  49         default:
  50                 return -EINVAL;
  51         }
  52
  53         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
  54         memcpy(csbcpb->cpb.aes_gcm.key, in_key, key_len);
  55
  56         csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_GCA;
  57         memcpy(csbcpb_aead->cpb.aes_gca.key, in_key, key_len);
  58
  59         return 0;
  60 }
  61
  62 static int gcm4106_aes_nx_set_key(struct crypto_aead *tfm,
  63                                   const u8           *in_key,
  64                                   unsigned int        key_len)
  65 {
  66         struct nx_crypto_ctx *nx_ctx = crypto_aead_ctx(tfm);
  67         char *nonce = nx_ctx->priv.gcm.nonce;
  68         int rc;
  69
  70         if (key_len < 4)
  71                 return -EINVAL;
  72
  73         key_len -= 4;
  74
  75         rc = gcm_aes_nx_set_key(tfm, in_key, key_len);
  76         if (rc)
  77                 goto out;
  78
  79         memcpy(nonce, in_key + key_len, 4);
  80 out:
  81         return rc;
  82 }
  83
  84 static int gcm4106_aes_nx_setauthsize(struct crypto_aead *tfm,
  85                                       unsigned int authsize)
  86 {
  87         switch (authsize) {
  88         case 8:
  89         case 12:
  90         case 16:
  91                 break;
  92         default:
  93                 return -EINVAL;
  94         }
  95
  96         return 0;
  97 }
  98
  99 static int nx_gca(struct nx_crypto_ctx  *nx_ctx,
 100                   struct aead_request   *req,
 101                   u8                    *out,
 102                   unsigned int assoclen)
 103 {
 104         int rc;
 105         struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
 106         struct scatter_walk walk;
 107         struct nx_sg *nx_sg = nx_ctx->in_sg;
 108         unsigned int nbytes = assoclen;
 109         unsigned int processed = 0, to_process;
 110         unsigned int max_sg_len;
 111
 112         if (nbytes <= AES_BLOCK_SIZE) {
 113                 scatterwalk_start(&walk, req->src);
 114                 scatterwalk_copychunks(out, &walk, nbytes, SCATTERWALK_FROM_SG);
 115                 scatterwalk_done(&walk, SCATTERWALK_FROM_SG, 0);
 116                 return 0;
 117         }
 118
 119         NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_CONTINUATION;
 120
 121         /* page_limit: number of sg entries that fit on one page */
 122         max_sg_len = min_t(u64, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
 123                            nx_ctx->ap->sglen);
 124         max_sg_len = min_t(u64, max_sg_len,
 125                            nx_ctx->ap->databytelen/NX_PAGE_SIZE);
 126
 127         do {
 128                 /*
 129                  * to_process: the data chunk to process in this update.
 130                  * This value is bound by sg list limits.
 131                  */
 132                 to_process = min_t(u64, nbytes - processed,
 133                                    nx_ctx->ap->databytelen);
 134                 to_process = min_t(u64, to_process,
 135                                    NX_PAGE_SIZE * (max_sg_len - 1));
 136
 137                 nx_sg = nx_walk_and_build(nx_ctx->in_sg, max_sg_len,
 138                                           req->src, processed, &to_process);
 139
 140                 if ((to_process + processed) < nbytes)
 141                         NX_CPB_FDM(csbcpb_aead) |= NX_FDM_INTERMEDIATE;
 142                 else
 143                         NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_INTERMEDIATE;
 144
 145                 nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_sg)
 146                                         * sizeof(struct nx_sg);
 147
 148                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead,
 149                                 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 150                 if (rc)
 151                         return rc;
 152
 153                 memcpy(csbcpb_aead->cpb.aes_gca.in_pat,
 154                                 csbcpb_aead->cpb.aes_gca.out_pat,
 155                                 AES_BLOCK_SIZE);
 156                 NX_CPB_FDM(csbcpb_aead) |= NX_FDM_CONTINUATION;
 157
 158                 atomic_inc(&(nx_ctx->stats->aes_ops));
 159                 atomic64_add(assoclen, &(nx_ctx->stats->aes_bytes));
 160
 161                 processed += to_process;
 162         } while (processed < nbytes);
 163
 164         memcpy(out, csbcpb_aead->cpb.aes_gca.out_pat, AES_BLOCK_SIZE);
 165
 166         return rc;
 167 }
 168
 169 static int gmac(struct aead_request *req, struct blkcipher_desc *desc,
 170                 unsigned int assoclen)
 171 {
 172         int rc;
 173         struct nx_crypto_ctx *nx_ctx =
 174                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 175         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 176         struct nx_sg *nx_sg;
 177         unsigned int nbytes = assoclen;
 178         unsigned int processed = 0, to_process;
 179         unsigned int max_sg_len;
 180
 181         /* Set GMAC mode */
 182         csbcpb->cpb.hdr.mode = NX_MODE_AES_GMAC;
 183
 184         NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
 185
 186         /* page_limit: number of sg entries that fit on one page */
 187         max_sg_len = min_t(u64, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
 188                            nx_ctx->ap->sglen);
 189         max_sg_len = min_t(u64, max_sg_len,
 190                            nx_ctx->ap->databytelen/NX_PAGE_SIZE);
 191
 192         /* Copy IV */
 193         memcpy(csbcpb->cpb.aes_gcm.iv_or_cnt, desc->info, AES_BLOCK_SIZE);
 194
 195         do {
 196                 /*
 197                  * to_process: the data chunk to process in this update.
 198                  * This value is bound by sg list limits.
 199                  */
 200                 to_process = min_t(u64, nbytes - processed,
 201                                    nx_ctx->ap->databytelen);
 202                 to_process = min_t(u64, to_process,
 203                                    NX_PAGE_SIZE * (max_sg_len - 1));
 204
 205                 nx_sg = nx_walk_and_build(nx_ctx->in_sg, max_sg_len,
 206                                           req->src, processed, &to_process);
 207
 208                 if ((to_process + processed) < nbytes)
 209                         NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 210                 else
 211                         NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 212
 213                 nx_ctx->op.inlen = (nx_ctx->in_sg - nx_sg)
 214                                         * sizeof(struct nx_sg);
 215
 216                 csbcpb->cpb.aes_gcm.bit_length_data = 0;
 217                 csbcpb->cpb.aes_gcm.bit_length_aad = 8 * nbytes;
 218
 219                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 220                                 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 221                 if (rc)
 222                         goto out;
 223
 224                 memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad,
 225                         csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE);
 226                 memcpy(csbcpb->cpb.aes_gcm.in_s0,
 227                         csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE);
 228
 229                 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
 230
 231                 atomic_inc(&(nx_ctx->stats->aes_ops));
 232                 atomic64_add(assoclen, &(nx_ctx->stats->aes_bytes));
 233
 234                 processed += to_process;
 235         } while (processed < nbytes);
 236
 237 out:
 238         /* Restore GCM mode */
 239         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
 240         return rc;
 241 }
 242
 243 static int gcm_empty(struct aead_request *req, struct blkcipher_desc *desc,
 244                      int enc)
 245 {
 246         int rc;
 247         struct nx_crypto_ctx *nx_ctx =
 248                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 249         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 250         char out[AES_BLOCK_SIZE];
 251         struct nx_sg *in_sg, *out_sg;
 252         int len;
 253
 254         /* For scenarios where the input message is zero length, AES CTR mode
 255          * may be used. Set the source data to be a single block (16B) of all
 256          * zeros, and set the input IV value to be the same as the GMAC IV
 257          * value. - nx_wb 4.8.1.3 */
 258
 259         /* Change to ECB mode */
 260         csbcpb->cpb.hdr.mode = NX_MODE_AES_ECB;
 261         memcpy(csbcpb->cpb.aes_ecb.key, csbcpb->cpb.aes_gcm.key,
 262                         sizeof(csbcpb->cpb.aes_ecb.key));
 263         if (enc)
 264                 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
 265         else
 266                 NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 267
 268         len = AES_BLOCK_SIZE;
 269
 270         /* Encrypt the counter/IV */
 271         in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) desc->info,
 272                                  &len, nx_ctx->ap->sglen);
 273
 274         if (len != AES_BLOCK_SIZE)
 275                 return -EINVAL;
 276
 277         len = sizeof(out);
 278         out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *) out, &len,
 279                                   nx_ctx->ap->sglen);
 280
 281         if (len != sizeof(out))
 282                 return -EINVAL;
 283
 284         nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
 285         nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
 286
 287         rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 288                            desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 289         if (rc)
 290                 goto out;
 291         atomic_inc(&(nx_ctx->stats->aes_ops));
 292
 293         /* Copy out the auth tag */
 294         memcpy(csbcpb->cpb.aes_gcm.out_pat_or_mac, out,
 295                         crypto_aead_authsize(crypto_aead_reqtfm(req)));
 296 out:
 297         /* Restore XCBC mode */
 298         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
 299
 300         /*
 301          * ECB key uses the same region that GCM AAD and counter, so it's safe
 302          * to just fill it with zeroes.
 303          */
 304         memset(csbcpb->cpb.aes_ecb.key, 0, sizeof(csbcpb->cpb.aes_ecb.key));
 305
 306         return rc;
 307 }
 308
 309 static int gcm_aes_nx_crypt(struct aead_request *req, int enc,
 310                             unsigned int assoclen)
 311 {
 312         struct nx_crypto_ctx *nx_ctx =
 313                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 314         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 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         int rc = -EINVAL;
 321
 322         spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 323
 324         desc.info = rctx->iv;
 325         /* initialize the counter */
 326         *(u32 *)(desc.info + NX_GCM_CTR_OFFSET) = 1;
 327
 328         if (nbytes == 0) {
 329                 if (assoclen == 0)
 330                         rc = gcm_empty(req, &desc, enc);
 331                 else
 332                         rc = gmac(req, &desc, assoclen);
 333                 if (rc)
 334                         goto out;
 335                 else
 336                         goto mac;
 337         }
 338
 339         /* Process associated data */
 340         csbcpb->cpb.aes_gcm.bit_length_aad = assoclen * 8;
 341         if (assoclen) {
 342                 rc = nx_gca(nx_ctx, req, csbcpb->cpb.aes_gcm.in_pat_or_aad,
 343                             assoclen);
 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         do {
 358                 to_process = nbytes - processed;
 359
 360                 csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8;
 361                 rc = nx_build_sg_lists(nx_ctx, &desc, req->dst,
 362                                        req->src, &to_process,
 363                                        processed + req->assoclen,
 364                                        csbcpb->cpb.aes_gcm.iv_or_cnt);
 365
 366                 if (rc)
 367                         goto out;
 368
 369                 if ((to_process + processed) < nbytes)
 370                         NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 371                 else
 372                         NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 373
 374
 375                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 376                                    req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 377                 if (rc)
 378                         goto out;
 379
 380                 memcpy(desc.info, csbcpb->cpb.aes_gcm.out_cnt, AES_BLOCK_SIZE);
 381                 memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad,
 382                         csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE);
 383                 memcpy(csbcpb->cpb.aes_gcm.in_s0,
 384                         csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE);
 385
 386                 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
 387
 388                 atomic_inc(&(nx_ctx->stats->aes_ops));
 389                 atomic64_add(csbcpb->csb.processed_byte_count,
 390                              &(nx_ctx->stats->aes_bytes));
 391
 392                 processed += to_process;
 393         } while (processed < nbytes);
 394
 395 mac:
 396         if (enc) {
 397                 /* copy out the auth tag */
 398                 scatterwalk_map_and_copy(
 399                         csbcpb->cpb.aes_gcm.out_pat_or_mac,
 400                         req->dst, req->assoclen + nbytes,
 401                         crypto_aead_authsize(crypto_aead_reqtfm(req)),
 402                         SCATTERWALK_TO_SG);
 403         } else {
 404                 u8 *itag = nx_ctx->priv.gcm.iauth_tag;
 405                 u8 *otag = csbcpb->cpb.aes_gcm.out_pat_or_mac;
 406
 407                 scatterwalk_map_and_copy(
 408                         itag, req->src, req->assoclen + nbytes,
 409                         crypto_aead_authsize(crypto_aead_reqtfm(req)),
 410                         SCATTERWALK_FROM_SG);
 411                 rc = crypto_memneq(itag, otag,
 412                             crypto_aead_authsize(crypto_aead_reqtfm(req))) ?
 413                      -EBADMSG : 0;
 414         }
 415 out:
 416         spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 417         return rc;
 418 }
 419
 420 static int gcm_aes_nx_encrypt(struct aead_request *req)
 421 {
 422         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 423         char *iv = rctx->iv;
 424
 425         memcpy(iv, req->iv, GCM_AES_IV_SIZE);
 426
 427         return gcm_aes_nx_crypt(req, 1, req->assoclen);
 428 }
 429
 430 static int gcm_aes_nx_decrypt(struct aead_request *req)
 431 {
 432         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 433         char *iv = rctx->iv;
 434
 435         memcpy(iv, req->iv, GCM_AES_IV_SIZE);
 436
 437         return gcm_aes_nx_crypt(req, 0, req->assoclen);
 438 }
 439
 440 static int gcm4106_aes_nx_encrypt(struct aead_request *req)
 441 {
 442         struct nx_crypto_ctx *nx_ctx =
 443                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 444         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 445         char *iv = rctx->iv;
 446         char *nonce = nx_ctx->priv.gcm.nonce;
 447
 448         memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
 449         memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);
 450
 451         if (req->assoclen < 8)
 452                 return -EINVAL;
 453
 454         return gcm_aes_nx_crypt(req, 1, req->assoclen - 8);
 455 }
 456
 457 static int gcm4106_aes_nx_decrypt(struct aead_request *req)
 458 {
 459         struct nx_crypto_ctx *nx_ctx =
 460                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 461         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 462         char *iv = rctx->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         if (req->assoclen < 8)
 469                 return -EINVAL;
 470
 471         return gcm_aes_nx_crypt(req, 0, req->assoclen - 8);
 472 }
 473
 474 /* tell the block cipher walk routines that this is a stream cipher by
 475  * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block
 476  * during encrypt/decrypt doesn't solve this problem, because it calls
 477  * blkcipher_walk_done under the covers, which doesn't use walk->blocksize,
 478  * but instead uses this tfm->blocksize. */
 479 struct aead_alg nx_gcm_aes_alg = {
 480         .base = {
 481                 .cra_name        = "gcm(aes)",
 482                 .cra_driver_name = "gcm-aes-nx",
 483                 .cra_priority    = 300,
 484                 .cra_blocksize   = 1,
 485                 .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 486                 .cra_module      = THIS_MODULE,
 487         },
 488         .init        = nx_crypto_ctx_aes_gcm_init,
 489         .exit        = nx_crypto_ctx_aead_exit,
 490         .ivsize      = GCM_AES_IV_SIZE,
 491         .maxauthsize = AES_BLOCK_SIZE,
 492         .setkey      = gcm_aes_nx_set_key,
 493         .encrypt     = gcm_aes_nx_encrypt,
 494         .decrypt     = gcm_aes_nx_decrypt,
 495 };
 496
 497 struct aead_alg nx_gcm4106_aes_alg = {
 498         .base = {
 499                 .cra_name        = "rfc4106(gcm(aes))",
 500                 .cra_driver_name = "rfc4106-gcm-aes-nx",
 501                 .cra_priority    = 300,
 502                 .cra_blocksize   = 1,
 503                 .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 504                 .cra_module      = THIS_MODULE,
 505         },
 506         .init        = nx_crypto_ctx_aes_gcm_init,
 507         .exit        = nx_crypto_ctx_aead_exit,
 508         .ivsize      = GCM_RFC4106_IV_SIZE,
 509         .maxauthsize = AES_BLOCK_SIZE,
 510         .setkey      = gcm4106_aes_nx_set_key,
 511         .setauthsize = gcm4106_aes_nx_setauthsize,
 512         .encrypt     = gcm4106_aes_nx_encrypt,
 513         .decrypt     = gcm4106_aes_nx_decrypt,
 514 };