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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AES XCBC routines supporting the Power 7+ Nest Accelerators driver
   4  *
   5  * Copyright (C) 2011-2012 International Business Machines Inc.
   6  *
   7  * Author: Kent Yoder <[email protected]>
   8  */
   9
  10 #include <crypto/internal/hash.h>
  11 #include <crypto/aes.h>
  12 #include <crypto/algapi.h>
  13 #include <linux/module.h>
  14 #include <linux/types.h>
  15 #include <linux/crypto.h>
  16 #include <asm/vio.h>
  17
  18 #include "nx_csbcpb.h"
  19 #include "nx.h"
  20
  21
  22 struct xcbc_state {
  23         u8 state[AES_BLOCK_SIZE];
  24         unsigned int count;
  25         u8 buffer[AES_BLOCK_SIZE];
  26 };
  27
  28 static int nx_xcbc_set_key(struct crypto_shash *desc,
  29                            const u8            *in_key,
  30                            unsigned int         key_len)
  31 {
  32         struct nx_crypto_ctx *nx_ctx = crypto_shash_ctx(desc);
  33         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  34
  35         switch (key_len) {
  36         case AES_KEYSIZE_128:
  37                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
  38                 break;
  39         default:
  40                 return -EINVAL;
  41         }
  42
  43         memcpy(csbcpb->cpb.aes_xcbc.key, in_key, key_len);
  44
  45         return 0;
  46 }
  47
  48 /*
  49  * Based on RFC 3566, for a zero-length message:
  50  *
  51  * n = 1
  52  * K1 = E(K, 0x01010101010101010101010101010101)
  53  * K3 = E(K, 0x03030303030303030303030303030303)
  54  * E[0] = 0x00000000000000000000000000000000
  55  * M[1] = 0x80000000000000000000000000000000 (0 length message with padding)
  56  * E[1] = (K1, M[1] ^ E[0] ^ K3)
  57  * Tag = M[1]
  58  */
  59 static int nx_xcbc_empty(struct shash_desc *desc, u8 *out)
  60 {
  61         struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
  62         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  63         struct nx_sg *in_sg, *out_sg;
  64         u8 keys[2][AES_BLOCK_SIZE];
  65         u8 key[32];
  66         int rc = 0;
  67         int len;
  68
  69         /* Change to ECB mode */
  70         csbcpb->cpb.hdr.mode = NX_MODE_AES_ECB;
  71         memcpy(key, csbcpb->cpb.aes_xcbc.key, AES_BLOCK_SIZE);
  72         memcpy(csbcpb->cpb.aes_ecb.key, key, AES_BLOCK_SIZE);
  73         NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
  74
  75         /* K1 and K3 base patterns */
  76         memset(keys[0], 0x01, sizeof(keys[0]));
  77         memset(keys[1], 0x03, sizeof(keys[1]));
  78
  79         len = sizeof(keys);
  80         /* Generate K1 and K3 encrypting the patterns */
  81         in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) keys, &len,
  82                                  nx_ctx->ap->sglen);
  83
  84         if (len != sizeof(keys))
  85                 return -EINVAL;
  86
  87         out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *) keys, &len,
  88                                   nx_ctx->ap->sglen);
  89
  90         if (len != sizeof(keys))
  91                 return -EINVAL;
  92
  93         nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
  94         nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
  95
  96         rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 0);
  97         if (rc)
  98                 goto out;
  99         atomic_inc(&(nx_ctx->stats->aes_ops));
 100
 101         /* XOr K3 with the padding for a 0 length message */
 102         keys[1][0] ^= 0x80;
 103
 104         len = sizeof(keys[1]);
 105
 106         /* Encrypt the final result */
 107         memcpy(csbcpb->cpb.aes_ecb.key, keys[0], AES_BLOCK_SIZE);
 108         in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) keys[1], &len,
 109                                  nx_ctx->ap->sglen);
 110
 111         if (len != sizeof(keys[1]))
 112                 return -EINVAL;
 113
 114         len = AES_BLOCK_SIZE;
 115         out_sg = nx_build_sg_list(nx_ctx->out_sg, out, &len,
 116                                   nx_ctx->ap->sglen);
 117
 118         if (len != AES_BLOCK_SIZE)
 119                 return -EINVAL;
 120
 121         nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
 122         nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
 123
 124         rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 0);
 125         if (rc)
 126                 goto out;
 127         atomic_inc(&(nx_ctx->stats->aes_ops));
 128
 129 out:
 130         /* Restore XCBC mode */
 131         csbcpb->cpb.hdr.mode = NX_MODE_AES_XCBC_MAC;
 132         memcpy(csbcpb->cpb.aes_xcbc.key, key, AES_BLOCK_SIZE);
 133         NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 134
 135         return rc;
 136 }
 137
 138 static int nx_crypto_ctx_aes_xcbc_init2(struct crypto_tfm *tfm)
 139 {
 140         struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
 141         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 142         int err;
 143
 144         err = nx_crypto_ctx_aes_xcbc_init(tfm);
 145         if (err)
 146                 return err;
 147
 148         nx_ctx_init(nx_ctx, HCOP_FC_AES);
 149
 150         NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
 151         csbcpb->cpb.hdr.mode = NX_MODE_AES_XCBC_MAC;
 152
 153         return 0;
 154 }
 155
 156 static int nx_xcbc_init(struct shash_desc *desc)
 157 {
 158         struct xcbc_state *sctx = shash_desc_ctx(desc);
 159
 160         memset(sctx, 0, sizeof *sctx);
 161
 162         return 0;
 163 }
 164
 165 static int nx_xcbc_update(struct shash_desc *desc,
 166                           const u8          *data,
 167                           unsigned int       len)
 168 {
 169         struct xcbc_state *sctx = shash_desc_ctx(desc);
 170         struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
 171         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 172         struct nx_sg *in_sg;
 173         struct nx_sg *out_sg;
 174         u32 to_process = 0, leftover, total;
 175         unsigned int max_sg_len;
 176         unsigned long irq_flags;
 177         int rc = 0;
 178         int data_len;
 179
 180         spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 181
 182
 183         total = sctx->count + len;
 184
 185         /* 2 cases for total data len:
 186          *  1: <= AES_BLOCK_SIZE: copy into state, return 0
 187          *  2: > AES_BLOCK_SIZE: process X blocks, copy in leftover
 188          */
 189         if (total <= AES_BLOCK_SIZE) {
 190                 memcpy(sctx->buffer + sctx->count, data, len);
 191                 sctx->count += len;
 192                 goto out;
 193         }
 194
 195         in_sg = nx_ctx->in_sg;
 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         data_len = AES_BLOCK_SIZE;
 202         out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state,
 203                                   &len, nx_ctx->ap->sglen);
 204
 205         if (data_len != AES_BLOCK_SIZE) {
 206                 rc = -EINVAL;
 207                 goto out;
 208         }
 209
 210         nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
 211
 212         do {
 213                 to_process = total - to_process;
 214                 to_process = to_process & ~(AES_BLOCK_SIZE - 1);
 215
 216                 leftover = total - to_process;
 217
 218                 /* the hardware will not accept a 0 byte operation for this
 219                  * algorithm and the operation MUST be finalized to be correct.
 220                  * So if we happen to get an update that falls on a block sized
 221                  * boundary, we must save off the last block to finalize with
 222                  * later. */
 223                 if (!leftover) {
 224                         to_process -= AES_BLOCK_SIZE;
 225                         leftover = AES_BLOCK_SIZE;
 226                 }
 227
 228                 if (sctx->count) {
 229                         data_len = sctx->count;
 230                         in_sg = nx_build_sg_list(nx_ctx->in_sg,
 231                                                 (u8 *) sctx->buffer,
 232                                                 &data_len,
 233                                                 max_sg_len);
 234                         if (data_len != sctx->count) {
 235                                 rc = -EINVAL;
 236                                 goto out;
 237                         }
 238                 }
 239
 240                 data_len = to_process - sctx->count;
 241                 in_sg = nx_build_sg_list(in_sg,
 242                                         (u8 *) data,
 243                                         &data_len,
 244                                         max_sg_len);
 245
 246                 if (data_len != to_process - sctx->count) {
 247                         rc = -EINVAL;
 248                         goto out;
 249                 }
 250
 251                 nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) *
 252                                         sizeof(struct nx_sg);
 253
 254                 /* we've hit the nx chip previously and we're updating again,
 255                  * so copy over the partial digest */
 256                 if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
 257                         memcpy(csbcpb->cpb.aes_xcbc.cv,
 258                                 csbcpb->cpb.aes_xcbc.out_cv_mac,
 259                                 AES_BLOCK_SIZE);
 260                 }
 261
 262                 NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
 263                 if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
 264                         rc = -EINVAL;
 265                         goto out;
 266                 }
 267
 268                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 0);
 269                 if (rc)
 270                         goto out;
 271
 272                 atomic_inc(&(nx_ctx->stats->aes_ops));
 273
 274                 /* everything after the first update is continuation */
 275                 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
 276
 277                 total -= to_process;
 278                 data += to_process - sctx->count;
 279                 sctx->count = 0;
 280                 in_sg = nx_ctx->in_sg;
 281         } while (leftover > AES_BLOCK_SIZE);
 282
 283         /* copy the leftover back into the state struct */
 284         memcpy(sctx->buffer, data, leftover);
 285         sctx->count = leftover;
 286
 287 out:
 288         spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 289         return rc;
 290 }
 291
 292 static int nx_xcbc_final(struct shash_desc *desc, u8 *out)
 293 {
 294         struct xcbc_state *sctx = shash_desc_ctx(desc);
 295         struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
 296         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 297         struct nx_sg *in_sg, *out_sg;
 298         unsigned long irq_flags;
 299         int rc = 0;
 300         int len;
 301
 302         spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 303
 304         if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
 305                 /* we've hit the nx chip previously, now we're finalizing,
 306                  * so copy over the partial digest */
 307                 memcpy(csbcpb->cpb.aes_xcbc.cv,
 308                        csbcpb->cpb.aes_xcbc.out_cv_mac, AES_BLOCK_SIZE);
 309         } else if (sctx->count == 0) {
 310                 /*
 311                  * we've never seen an update, so this is a 0 byte op. The
 312                  * hardware cannot handle a 0 byte op, so just ECB to
 313                  * generate the hash.
 314                  */
 315                 rc = nx_xcbc_empty(desc, out);
 316                 goto out;
 317         }
 318
 319         /* final is represented by continuing the operation and indicating that
 320          * this is not an intermediate operation */
 321         NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 322
 323         len = sctx->count;
 324         in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)sctx->buffer,
 325                                  &len, nx_ctx->ap->sglen);
 326
 327         if (len != sctx->count) {
 328                 rc = -EINVAL;
 329                 goto out;
 330         }
 331
 332         len = AES_BLOCK_SIZE;
 333         out_sg = nx_build_sg_list(nx_ctx->out_sg, out, &len,
 334                                   nx_ctx->ap->sglen);
 335
 336         if (len != AES_BLOCK_SIZE) {
 337                 rc = -EINVAL;
 338                 goto out;
 339         }
 340
 341         nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
 342         nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
 343
 344         if (!nx_ctx->op.outlen) {
 345                 rc = -EINVAL;
 346                 goto out;
 347         }
 348
 349         rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 0);
 350         if (rc)
 351                 goto out;
 352
 353         atomic_inc(&(nx_ctx->stats->aes_ops));
 354
 355         memcpy(out, csbcpb->cpb.aes_xcbc.out_cv_mac, AES_BLOCK_SIZE);
 356 out:
 357         spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 358         return rc;
 359 }
 360
 361 struct shash_alg nx_shash_aes_xcbc_alg = {
 362         .digestsize = AES_BLOCK_SIZE,
 363         .init       = nx_xcbc_init,
 364         .update     = nx_xcbc_update,
 365         .final      = nx_xcbc_final,
 366         .setkey     = nx_xcbc_set_key,
 367         .descsize   = sizeof(struct xcbc_state),
 368         .statesize  = sizeof(struct xcbc_state),
 369         .base       = {
 370                 .cra_name        = "xcbc(aes)",
 371                 .cra_driver_name = "xcbc-aes-nx",
 372                 .cra_priority    = 300,
 373                 .cra_blocksize   = AES_BLOCK_SIZE,
 374                 .cra_module      = THIS_MODULE,
 375                 .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 376                 .cra_init        = nx_crypto_ctx_aes_xcbc_init2,
 377                 .cra_exit        = nx_crypto_ctx_exit,
 378         }
 379 };