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, const u8 *iv, unsigned int assoclen)
 170 {
 171         int rc;
 172         struct nx_crypto_ctx *nx_ctx =
 173                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 174         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 175         struct nx_sg *nx_sg;
 176         unsigned int nbytes = assoclen;
 177         unsigned int processed = 0, to_process;
 178         unsigned int max_sg_len;
 179
 180         /* Set GMAC mode */
 181         csbcpb->cpb.hdr.mode = NX_MODE_AES_GMAC;
 182
 183         NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
 184
 185         /* page_limit: number of sg entries that fit on one page */
 186         max_sg_len = min_t(u64, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
 187                            nx_ctx->ap->sglen);
 188         max_sg_len = min_t(u64, max_sg_len,
 189                            nx_ctx->ap->databytelen/NX_PAGE_SIZE);
 190
 191         /* Copy IV */
 192         memcpy(csbcpb->cpb.aes_gcm.iv_or_cnt, iv, AES_BLOCK_SIZE);
 193
 194         do {
 195                 /*
 196                  * to_process: the data chunk to process in this update.
 197                  * This value is bound by sg list limits.
 198                  */
 199                 to_process = min_t(u64, nbytes - processed,
 200                                    nx_ctx->ap->databytelen);
 201                 to_process = min_t(u64, to_process,
 202                                    NX_PAGE_SIZE * (max_sg_len - 1));
 203
 204                 nx_sg = nx_walk_and_build(nx_ctx->in_sg, max_sg_len,
 205                                           req->src, processed, &to_process);
 206
 207                 if ((to_process + processed) < nbytes)
 208                         NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 209                 else
 210                         NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 211
 212                 nx_ctx->op.inlen = (nx_ctx->in_sg - nx_sg)
 213                                         * sizeof(struct nx_sg);
 214
 215                 csbcpb->cpb.aes_gcm.bit_length_data = 0;
 216                 csbcpb->cpb.aes_gcm.bit_length_aad = 8 * nbytes;
 217
 218                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 219                                 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 220                 if (rc)
 221                         goto out;
 222
 223                 memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad,
 224                         csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE);
 225                 memcpy(csbcpb->cpb.aes_gcm.in_s0,
 226                         csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE);
 227
 228                 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
 229
 230                 atomic_inc(&(nx_ctx->stats->aes_ops));
 231                 atomic64_add(assoclen, &(nx_ctx->stats->aes_bytes));
 232
 233                 processed += to_process;
 234         } while (processed < nbytes);
 235
 236 out:
 237         /* Restore GCM mode */
 238         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
 239         return rc;
 240 }
 241
 242 static int gcm_empty(struct aead_request *req, const u8 *iv, int enc)
 243 {
 244         int rc;
 245         struct nx_crypto_ctx *nx_ctx =
 246                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 247         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 248         char out[AES_BLOCK_SIZE];
 249         struct nx_sg *in_sg, *out_sg;
 250         int len;
 251
 252         /* For scenarios where the input message is zero length, AES CTR mode
 253          * may be used. Set the source data to be a single block (16B) of all
 254          * zeros, and set the input IV value to be the same as the GMAC IV
 255          * value. - nx_wb 4.8.1.3 */
 256
 257         /* Change to ECB mode */
 258         csbcpb->cpb.hdr.mode = NX_MODE_AES_ECB;
 259         memcpy(csbcpb->cpb.aes_ecb.key, csbcpb->cpb.aes_gcm.key,
 260                         sizeof(csbcpb->cpb.aes_ecb.key));
 261         if (enc)
 262                 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
 263         else
 264                 NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 265
 266         len = AES_BLOCK_SIZE;
 267
 268         /* Encrypt the counter/IV */
 269         in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) iv,
 270                                  &len, nx_ctx->ap->sglen);
 271
 272         if (len != AES_BLOCK_SIZE)
 273                 return -EINVAL;
 274
 275         len = sizeof(out);
 276         out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *) out, &len,
 277                                   nx_ctx->ap->sglen);
 278
 279         if (len != sizeof(out))
 280                 return -EINVAL;
 281
 282         nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
 283         nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
 284
 285         rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 286                            req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 287         if (rc)
 288                 goto out;
 289         atomic_inc(&(nx_ctx->stats->aes_ops));
 290
 291         /* Copy out the auth tag */
 292         memcpy(csbcpb->cpb.aes_gcm.out_pat_or_mac, out,
 293                         crypto_aead_authsize(crypto_aead_reqtfm(req)));
 294 out:
 295         /* Restore XCBC mode */
 296         csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
 297
 298         /*
 299          * ECB key uses the same region that GCM AAD and counter, so it's safe
 300          * to just fill it with zeroes.
 301          */
 302         memset(csbcpb->cpb.aes_ecb.key, 0, sizeof(csbcpb->cpb.aes_ecb.key));
 303
 304         return rc;
 305 }
 306
 307 static int gcm_aes_nx_crypt(struct aead_request *req, int enc,
 308                             unsigned int assoclen)
 309 {
 310         struct nx_crypto_ctx *nx_ctx =
 311                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 312         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 313         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 314         unsigned int nbytes = req->cryptlen;
 315         unsigned int processed = 0, to_process;
 316         unsigned long irq_flags;
 317         int rc = -EINVAL;
 318
 319         spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 320
 321         /* initialize the counter */
 322         *(u32 *)&rctx->iv[NX_GCM_CTR_OFFSET] = 1;
 323
 324         if (nbytes == 0) {
 325                 if (assoclen == 0)
 326                         rc = gcm_empty(req, rctx->iv, enc);
 327                 else
 328                         rc = gmac(req, rctx->iv, assoclen);
 329                 if (rc)
 330                         goto out;
 331                 else
 332                         goto mac;
 333         }
 334
 335         /* Process associated data */
 336         csbcpb->cpb.aes_gcm.bit_length_aad = assoclen * 8;
 337         if (assoclen) {
 338                 rc = nx_gca(nx_ctx, req, csbcpb->cpb.aes_gcm.in_pat_or_aad,
 339                             assoclen);
 340                 if (rc)
 341                         goto out;
 342         }
 343
 344         /* Set flags for encryption */
 345         NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
 346         if (enc) {
 347                 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
 348         } else {
 349                 NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 350                 nbytes -= crypto_aead_authsize(crypto_aead_reqtfm(req));
 351         }
 352
 353         do {
 354                 to_process = nbytes - processed;
 355
 356                 csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8;
 357                 rc = nx_build_sg_lists(nx_ctx, rctx->iv, req->dst,
 358                                        req->src, &to_process,
 359                                        processed + req->assoclen,
 360                                        csbcpb->cpb.aes_gcm.iv_or_cnt);
 361
 362                 if (rc)
 363                         goto out;
 364
 365                 if ((to_process + processed) < nbytes)
 366                         NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 367                 else
 368                         NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 369
 370
 371                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 372                                    req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 373                 if (rc)
 374                         goto out;
 375
 376                 memcpy(rctx->iv, csbcpb->cpb.aes_gcm.out_cnt, AES_BLOCK_SIZE);
 377                 memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad,
 378                         csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE);
 379                 memcpy(csbcpb->cpb.aes_gcm.in_s0,
 380                         csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE);
 381
 382                 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
 383
 384                 atomic_inc(&(nx_ctx->stats->aes_ops));
 385                 atomic64_add(csbcpb->csb.processed_byte_count,
 386                              &(nx_ctx->stats->aes_bytes));
 387
 388                 processed += to_process;
 389         } while (processed < nbytes);
 390
 391 mac:
 392         if (enc) {
 393                 /* copy out the auth tag */
 394                 scatterwalk_map_and_copy(
 395                         csbcpb->cpb.aes_gcm.out_pat_or_mac,
 396                         req->dst, req->assoclen + nbytes,
 397                         crypto_aead_authsize(crypto_aead_reqtfm(req)),
 398                         SCATTERWALK_TO_SG);
 399         } else {
 400                 u8 *itag = nx_ctx->priv.gcm.iauth_tag;
 401                 u8 *otag = csbcpb->cpb.aes_gcm.out_pat_or_mac;
 402
 403                 scatterwalk_map_and_copy(
 404                         itag, req->src, req->assoclen + nbytes,
 405                         crypto_aead_authsize(crypto_aead_reqtfm(req)),
 406                         SCATTERWALK_FROM_SG);
 407                 rc = crypto_memneq(itag, otag,
 408                             crypto_aead_authsize(crypto_aead_reqtfm(req))) ?
 409                      -EBADMSG : 0;
 410         }
 411 out:
 412         spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 413         return rc;
 414 }
 415
 416 static int gcm_aes_nx_encrypt(struct aead_request *req)
 417 {
 418         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 419         char *iv = rctx->iv;
 420
 421         memcpy(iv, req->iv, GCM_AES_IV_SIZE);
 422
 423         return gcm_aes_nx_crypt(req, 1, req->assoclen);
 424 }
 425
 426 static int gcm_aes_nx_decrypt(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, GCM_AES_IV_SIZE);
 432
 433         return gcm_aes_nx_crypt(req, 0, req->assoclen);
 434 }
 435
 436 static int gcm4106_aes_nx_encrypt(struct aead_request *req)
 437 {
 438         struct nx_crypto_ctx *nx_ctx =
 439                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 440         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 441         char *iv = rctx->iv;
 442         char *nonce = nx_ctx->priv.gcm.nonce;
 443
 444         memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
 445         memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);
 446
 447         if (req->assoclen < 8)
 448                 return -EINVAL;
 449
 450         return gcm_aes_nx_crypt(req, 1, req->assoclen - 8);
 451 }
 452
 453 static int gcm4106_aes_nx_decrypt(struct aead_request *req)
 454 {
 455         struct nx_crypto_ctx *nx_ctx =
 456                 crypto_aead_ctx(crypto_aead_reqtfm(req));
 457         struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 458         char *iv = rctx->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         if (req->assoclen < 8)
 465                 return -EINVAL;
 466
 467         return gcm_aes_nx_crypt(req, 0, req->assoclen - 8);
 468 }
 469
 470 struct aead_alg nx_gcm_aes_alg = {
 471         .base = {
 472                 .cra_name        = "gcm(aes)",
 473                 .cra_driver_name = "gcm-aes-nx",
 474                 .cra_priority    = 300,
 475                 .cra_blocksize   = 1,
 476                 .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 477                 .cra_module      = THIS_MODULE,
 478         },
 479         .init        = nx_crypto_ctx_aes_gcm_init,
 480         .exit        = nx_crypto_ctx_aead_exit,
 481         .ivsize      = GCM_AES_IV_SIZE,
 482         .maxauthsize = AES_BLOCK_SIZE,
 483         .setkey      = gcm_aes_nx_set_key,
 484         .encrypt     = gcm_aes_nx_encrypt,
 485         .decrypt     = gcm_aes_nx_decrypt,
 486 };
 487
 488 struct aead_alg nx_gcm4106_aes_alg = {
 489         .base = {
 490                 .cra_name        = "rfc4106(gcm(aes))",
 491                 .cra_driver_name = "rfc4106-gcm-aes-nx",
 492                 .cra_priority    = 300,
 493                 .cra_blocksize   = 1,
 494                 .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 495                 .cra_module      = THIS_MODULE,
 496         },
 497         .init        = nx_crypto_ctx_aes_gcm_init,
 498         .exit        = nx_crypto_ctx_aead_exit,
 499         .ivsize      = GCM_RFC4106_IV_SIZE,
 500         .maxauthsize = AES_BLOCK_SIZE,
 501         .setkey      = gcm4106_aes_nx_set_key,
 502         .setauthsize = gcm4106_aes_nx_setauthsize,
 503         .encrypt     = gcm4106_aes_nx_encrypt,
 504         .decrypt     = gcm4106_aes_nx_decrypt,
 505 };