linux/drivers/crypto/nx/nx-aes-gcm.c
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   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
  35static 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
  74static 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);
  92out:
  93        return rc;
  94}
  95
  96static 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
 107static 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
 124static 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
 193static 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
 259out:
 260        /* Restore GCM mode */
 261        csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
 262        return rc;
 263}
 264
 265static 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)));
 317out:
 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
 330static 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_gcm_rctx *rctx = aead_request_ctx(req);
 334        struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 335        struct blkcipher_desc desc;
 336        unsigned int nbytes = req->cryptlen;
 337        unsigned int processed = 0, to_process;
 338        unsigned long irq_flags;
 339        int rc = -EINVAL;
 340
 341        spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 342
 343        desc.info = rctx->iv;
 344        /* initialize the counter */
 345        *(u32 *)(desc.info + NX_GCM_CTR_OFFSET) = 1;
 346
 347        if (nbytes == 0) {
 348                if (req->assoclen == 0)
 349                        rc = gcm_empty(req, &desc, enc);
 350                else
 351                        rc = gmac(req, &desc);
 352                if (rc)
 353                        goto out;
 354                else
 355                        goto mac;
 356        }
 357
 358        /* Process associated data */
 359        csbcpb->cpb.aes_gcm.bit_length_aad = req->assoclen * 8;
 360        if (req->assoclen) {
 361                rc = nx_gca(nx_ctx, req, csbcpb->cpb.aes_gcm.in_pat_or_aad);
 362                if (rc)
 363                        goto out;
 364        }
 365
 366        /* Set flags for encryption */
 367        NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
 368        if (enc) {
 369                NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
 370        } else {
 371                NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 372                nbytes -= crypto_aead_authsize(crypto_aead_reqtfm(req));
 373        }
 374
 375        do {
 376                to_process = nbytes - processed;
 377
 378                csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8;
 379                desc.tfm = (struct crypto_blkcipher *) req->base.tfm;
 380                rc = nx_build_sg_lists(nx_ctx, &desc, req->dst,
 381                                       req->src, &to_process, processed,
 382                                       csbcpb->cpb.aes_gcm.iv_or_cnt);
 383
 384                if (rc)
 385                        goto out;
 386
 387                if ((to_process + processed) < nbytes)
 388                        NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 389                else
 390                        NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 391
 392
 393                rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 394                                   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 395                if (rc)
 396                        goto out;
 397
 398                memcpy(desc.info, csbcpb->cpb.aes_gcm.out_cnt, AES_BLOCK_SIZE);
 399                memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad,
 400                        csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE);
 401                memcpy(csbcpb->cpb.aes_gcm.in_s0,
 402                        csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE);
 403
 404                NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
 405
 406                atomic_inc(&(nx_ctx->stats->aes_ops));
 407                atomic64_add(csbcpb->csb.processed_byte_count,
 408                             &(nx_ctx->stats->aes_bytes));
 409
 410                processed += to_process;
 411        } while (processed < nbytes);
 412
 413mac:
 414        if (enc) {
 415                /* copy out the auth tag */
 416                scatterwalk_map_and_copy(csbcpb->cpb.aes_gcm.out_pat_or_mac,
 417                                 req->dst, nbytes,
 418                                 crypto_aead_authsize(crypto_aead_reqtfm(req)),
 419                                 SCATTERWALK_TO_SG);
 420        } else {
 421                u8 *itag = nx_ctx->priv.gcm.iauth_tag;
 422                u8 *otag = csbcpb->cpb.aes_gcm.out_pat_or_mac;
 423
 424                scatterwalk_map_and_copy(itag, req->src, nbytes,
 425                                 crypto_aead_authsize(crypto_aead_reqtfm(req)),
 426                                 SCATTERWALK_FROM_SG);
 427                rc = memcmp(itag, otag,
 428                            crypto_aead_authsize(crypto_aead_reqtfm(req))) ?
 429                     -EBADMSG : 0;
 430        }
 431out:
 432        spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 433        return rc;
 434}
 435
 436static int gcm_aes_nx_encrypt(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, 1);
 444}
 445
 446static int gcm_aes_nx_decrypt(struct aead_request *req)
 447{
 448        struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 449        char *iv = rctx->iv;
 450
 451        memcpy(iv, req->iv, 12);
 452
 453        return gcm_aes_nx_crypt(req, 0);
 454}
 455
 456static int gcm4106_aes_nx_encrypt(struct aead_request *req)
 457{
 458        struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
 459        struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 460        char *iv = rctx->iv;
 461        char *nonce = nx_ctx->priv.gcm.nonce;
 462
 463        memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
 464        memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);
 465
 466        return gcm_aes_nx_crypt(req, 1);
 467}
 468
 469static int gcm4106_aes_nx_decrypt(struct aead_request *req)
 470{
 471        struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
 472        struct nx_gcm_rctx *rctx = aead_request_ctx(req);
 473        char *iv = rctx->iv;
 474        char *nonce = nx_ctx->priv.gcm.nonce;
 475
 476        memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
 477        memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);
 478
 479        return gcm_aes_nx_crypt(req, 0);
 480}
 481
 482/* tell the block cipher walk routines that this is a stream cipher by
 483 * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block
 484 * during encrypt/decrypt doesn't solve this problem, because it calls
 485 * blkcipher_walk_done under the covers, which doesn't use walk->blocksize,
 486 * but instead uses this tfm->blocksize. */
 487struct crypto_alg nx_gcm_aes_alg = {
 488        .cra_name        = "gcm(aes)",
 489        .cra_driver_name = "gcm-aes-nx",
 490        .cra_priority    = 300,
 491        .cra_flags       = CRYPTO_ALG_TYPE_AEAD,
 492        .cra_blocksize   = 1,
 493        .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 494        .cra_type        = &crypto_aead_type,
 495        .cra_module      = THIS_MODULE,
 496        .cra_init        = nx_crypto_ctx_aes_gcm_init,
 497        .cra_exit        = nx_crypto_ctx_exit,
 498        .cra_aead = {
 499                .ivsize      = AES_BLOCK_SIZE,
 500                .maxauthsize = AES_BLOCK_SIZE,
 501                .setkey      = gcm_aes_nx_set_key,
 502                .setauthsize = gcm_aes_nx_setauthsize,
 503                .encrypt     = gcm_aes_nx_encrypt,
 504                .decrypt     = gcm_aes_nx_decrypt,
 505        }
 506};
 507
 508struct crypto_alg nx_gcm4106_aes_alg = {
 509        .cra_name        = "rfc4106(gcm(aes))",
 510        .cra_driver_name = "rfc4106-gcm-aes-nx",
 511        .cra_priority    = 300,
 512        .cra_flags       = CRYPTO_ALG_TYPE_AEAD,
 513        .cra_blocksize   = 1,
 514        .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 515        .cra_type        = &crypto_nivaead_type,
 516        .cra_module      = THIS_MODULE,
 517        .cra_init        = nx_crypto_ctx_aes_gcm_init,
 518        .cra_exit        = nx_crypto_ctx_exit,
 519        .cra_aead = {
 520                .ivsize      = 8,
 521                .maxauthsize = AES_BLOCK_SIZE,
 522                .geniv       = "seqiv",
 523                .setkey      = gcm4106_aes_nx_set_key,
 524                .setauthsize = gcm4106_aes_nx_setauthsize,
 525                .encrypt     = gcm4106_aes_nx_encrypt,
 526                .decrypt     = gcm4106_aes_nx_decrypt,
 527        }
 528};
 529