drivers/crypto/ccp/ccp-crypto-aes-galois.c

   1 /*
   2  * AMD Cryptographic Coprocessor (CCP) AES GCM crypto API support
   3  *
   4  * Copyright (C) 2016,2017 Advanced Micro Devices, Inc.
   5  *
   6  * Author: Gary R Hook <gary.hook@amd.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/sched.h>
  15 #include <linux/delay.h>
  16 #include <linux/scatterlist.h>
  17 #include <linux/crypto.h>
  18 #include <crypto/internal/aead.h>
  19 #include <crypto/algapi.h>
  20 #include <crypto/aes.h>
  21 #include <crypto/ctr.h>
  22 #include <crypto/gcm.h>
  23 #include <crypto/scatterwalk.h>
  24 #include <linux/delay.h>
  25
  26 #include "ccp-crypto.h"
  27
  28 static int ccp_aes_gcm_complete(struct crypto_async_request *async_req, int ret)
  29 {
  30         return ret;
  31 }
  32
  33 static int ccp_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
  34                               unsigned int key_len)
  35 {
  36         struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
  37
  38         switch (key_len) {
  39         case AES_KEYSIZE_128:
  40                 ctx->u.aes.type = CCP_AES_TYPE_128;
  41                 break;
  42         case AES_KEYSIZE_192:
  43                 ctx->u.aes.type = CCP_AES_TYPE_192;
  44                 break;
  45         case AES_KEYSIZE_256:
  46                 ctx->u.aes.type = CCP_AES_TYPE_256;
  47                 break;
  48         default:
  49                 crypto_aead_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
  50                 return -EINVAL;
  51         }
  52
  53         ctx->u.aes.mode = CCP_AES_MODE_GCM;
  54         ctx->u.aes.key_len = key_len;
  55
  56         memcpy(ctx->u.aes.key, key, key_len);
  57         sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
  58
  59         return 0;
  60 }
  61
  62 static int ccp_aes_gcm_setauthsize(struct crypto_aead *tfm,
  63                                    unsigned int authsize)
  64 {
  65         return 0;
  66 }
  67
  68 static int ccp_aes_gcm_crypt(struct aead_request *req, bool encrypt)
  69 {
  70         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
  71         struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
  72         struct ccp_aes_req_ctx *rctx = aead_request_ctx(req);
  73         struct scatterlist *iv_sg = NULL;
  74         unsigned int iv_len = 0;
  75         int i;
  76         int ret = 0;
  77
  78         if (!ctx->u.aes.key_len)
  79                 return -EINVAL;
  80
  81         if (ctx->u.aes.mode != CCP_AES_MODE_GCM)
  82                 return -EINVAL;
  83
  84         if (!req->iv)
  85                 return -EINVAL;
  86
  87         /*
  88          * 5 parts:
  89          *   plaintext/ciphertext input
  90          *   AAD
  91          *   key
  92          *   IV
  93          *   Destination+tag buffer
  94          */
  95
  96         /* Prepare the IV: 12 bytes + an integer (counter) */
  97         memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE);
  98         for (i = 0; i < 3; i++)
  99                 rctx->iv[i + GCM_AES_IV_SIZE] = 0;
 100         rctx->iv[AES_BLOCK_SIZE - 1] = 1;
 101
 102         /* Set up a scatterlist for the IV */
 103         iv_sg = &rctx->iv_sg;
 104         iv_len = AES_BLOCK_SIZE;
 105         sg_init_one(iv_sg, rctx->iv, iv_len);
 106
 107         /* The AAD + plaintext are concatenated in the src buffer */
 108         memset(&rctx->cmd, 0, sizeof(rctx->cmd));
 109         INIT_LIST_HEAD(&rctx->cmd.entry);
 110         rctx->cmd.engine = CCP_ENGINE_AES;
 111         rctx->cmd.u.aes.type = ctx->u.aes.type;
 112         rctx->cmd.u.aes.mode = ctx->u.aes.mode;
 113         rctx->cmd.u.aes.action = encrypt;
 114         rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
 115         rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
 116         rctx->cmd.u.aes.iv = iv_sg;
 117         rctx->cmd.u.aes.iv_len = iv_len;
 118         rctx->cmd.u.aes.src = req->src;
 119         rctx->cmd.u.aes.src_len = req->cryptlen;
 120         rctx->cmd.u.aes.aad_len = req->assoclen;
 121
 122         /* The cipher text + the tag are in the dst buffer */
 123         rctx->cmd.u.aes.dst = req->dst;
 124
 125         ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
 126
 127         return ret;
 128 }
 129
 130 static int ccp_aes_gcm_encrypt(struct aead_request *req)
 131 {
 132         return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_ENCRYPT);
 133 }
 134
 135 static int ccp_aes_gcm_decrypt(struct aead_request *req)
 136 {
 137         return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_DECRYPT);
 138 }
 139
 140 static int ccp_aes_gcm_cra_init(struct crypto_aead *tfm)
 141 {
 142         struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
 143
 144         ctx->complete = ccp_aes_gcm_complete;
 145         ctx->u.aes.key_len = 0;
 146
 147         crypto_aead_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx));
 148
 149         return 0;
 150 }
 151
 152 static void ccp_aes_gcm_cra_exit(struct crypto_tfm *tfm)
 153 {
 154 }
 155
 156 static struct aead_alg ccp_aes_gcm_defaults = {
 157         .setkey = ccp_aes_gcm_setkey,
 158         .setauthsize = ccp_aes_gcm_setauthsize,
 159         .encrypt = ccp_aes_gcm_encrypt,
 160         .decrypt = ccp_aes_gcm_decrypt,
 161         .init = ccp_aes_gcm_cra_init,
 162         .ivsize = GCM_AES_IV_SIZE,
 163         .maxauthsize = AES_BLOCK_SIZE,
 164         .base = {
 165                 .cra_flags      = CRYPTO_ALG_TYPE_ABLKCIPHER |
 166                                   CRYPTO_ALG_ASYNC |
 167                                   CRYPTO_ALG_KERN_DRIVER_ONLY |
 168                                   CRYPTO_ALG_NEED_FALLBACK,
 169                 .cra_blocksize  = AES_BLOCK_SIZE,
 170                 .cra_ctxsize    = sizeof(struct ccp_ctx),
 171                 .cra_priority   = CCP_CRA_PRIORITY,
 172                 .cra_type       = &crypto_ablkcipher_type,
 173                 .cra_exit       = ccp_aes_gcm_cra_exit,
 174                 .cra_module     = THIS_MODULE,
 175         },
 176 };
 177
 178 struct ccp_aes_aead_def {
 179         enum ccp_aes_mode mode;
 180         unsigned int version;
 181         const char *name;
 182         const char *driver_name;
 183         unsigned int blocksize;
 184         unsigned int ivsize;
 185         struct aead_alg *alg_defaults;
 186 };
 187
 188 static struct ccp_aes_aead_def aes_aead_algs[] = {
 189         {
 190                 .mode           = CCP_AES_MODE_GHASH,
 191                 .version        = CCP_VERSION(5, 0),
 192                 .name           = "gcm(aes)",
 193                 .driver_name    = "gcm-aes-ccp",
 194                 .blocksize      = 1,
 195                 .ivsize         = AES_BLOCK_SIZE,
 196                 .alg_defaults   = &ccp_aes_gcm_defaults,
 197         },
 198 };
 199
 200 static int ccp_register_aes_aead(struct list_head *head,
 201                                  const struct ccp_aes_aead_def *def)
 202 {
 203         struct ccp_crypto_aead *ccp_aead;
 204         struct aead_alg *alg;
 205         int ret;
 206
 207         ccp_aead = kzalloc(sizeof(*ccp_aead), GFP_KERNEL);
 208         if (!ccp_aead)
 209                 return -ENOMEM;
 210
 211         INIT_LIST_HEAD(&ccp_aead->entry);
 212
 213         ccp_aead->mode = def->mode;
 214
 215         /* Copy the defaults and override as necessary */
 216         alg = &ccp_aead->alg;
 217         *alg = *def->alg_defaults;
 218         snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
 219         snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
 220                  def->driver_name);
 221         alg->base.cra_blocksize = def->blocksize;
 222         alg->base.cra_ablkcipher.ivsize = def->ivsize;
 223
 224         ret = crypto_register_aead(alg);
 225         if (ret) {
 226                 pr_err("%s ablkcipher algorithm registration error (%d)\n",
 227                        alg->base.cra_name, ret);
 228                 kfree(ccp_aead);
 229                 return ret;
 230         }
 231
 232         list_add(&ccp_aead->entry, head);
 233
 234         return 0;
 235 }
 236
 237 int ccp_register_aes_aeads(struct list_head *head)
 238 {
 239         int i, ret;
 240         unsigned int ccpversion = ccp_version();
 241
 242         for (i = 0; i < ARRAY_SIZE(aes_aead_algs); i++) {
 243                 if (aes_aead_algs[i].version > ccpversion)
 244                         continue;
 245                 ret = ccp_register_aes_aead(head, &aes_aead_algs[i]);
 246                 if (ret)
 247                         return ret;
 248         }
 249
 250         return 0;
 251 }