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

   1 /*
   2  * AMD Cryptographic Coprocessor (CCP) AES GCM crypto API support
   3  *
   4  * Copyright (C) 2016 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/scatterwalk.h>
  23 #include <linux/delay.h>
  24
  25 #include "ccp-crypto.h"
  26
  27 #define AES_GCM_IVSIZE  12
  28
  29 static int ccp_aes_gcm_complete(struct crypto_async_request *async_req, int ret)
  30 {
  31         return ret;
  32 }
  33
  34 static int ccp_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
  35                               unsigned int key_len)
  36 {
  37         struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
  38
  39         switch (key_len) {
  40         case AES_KEYSIZE_128:
  41                 ctx->u.aes.type = CCP_AES_TYPE_128;
  42                 break;
  43         case AES_KEYSIZE_192:
  44                 ctx->u.aes.type = CCP_AES_TYPE_192;
  45                 break;
  46         case AES_KEYSIZE_256:
  47                 ctx->u.aes.type = CCP_AES_TYPE_256;
  48                 break;
  49         default:
  50                 crypto_aead_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
  51                 return -EINVAL;
  52         }
  53
  54         ctx->u.aes.mode = CCP_AES_MODE_GCM;
  55         ctx->u.aes.key_len = key_len;
  56
  57         memcpy(ctx->u.aes.key, key, key_len);
  58         sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
  59
  60         return 0;
  61 }
  62
  63 static int ccp_aes_gcm_setauthsize(struct crypto_aead *tfm,
  64                                    unsigned int authsize)
  65 {
  66         return 0;
  67 }
  68
  69 static int ccp_aes_gcm_crypt(struct aead_request *req, bool encrypt)
  70 {
  71         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
  72         struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
  73         struct ccp_aes_req_ctx *rctx = aead_request_ctx(req);
  74         struct scatterlist *iv_sg = NULL;
  75         unsigned int iv_len = 0;
  76         int i;
  77         int ret = 0;
  78
  79         if (!ctx->u.aes.key_len)
  80                 return -EINVAL;
  81
  82         if (ctx->u.aes.mode != CCP_AES_MODE_GCM)
  83                 return -EINVAL;
  84
  85         if (!req->iv)
  86                 return -EINVAL;
  87
  88         /*
  89          * 5 parts:
  90          *   plaintext/ciphertext input
  91          *   AAD
  92          *   key
  93          *   IV
  94          *   Destination+tag buffer
  95          */
  96
  97         /* Prepare the IV: 12 bytes + an integer (counter) */
  98         memcpy(rctx->iv, req->iv, AES_GCM_IVSIZE);
  99         for (i = 0; i < 3; i++)
 100                 rctx->iv[i + AES_GCM_IVSIZE] = 0;
 101         rctx->iv[AES_BLOCK_SIZE - 1] = 1;
 102
 103         /* Set up a scatterlist for the IV */
 104         iv_sg = &rctx->iv_sg;
 105         iv_len = AES_BLOCK_SIZE;
 106         sg_init_one(iv_sg, rctx->iv, iv_len);
 107
 108         /* The AAD + plaintext are concatenated in the src buffer */
 109         memset(&rctx->cmd, 0, sizeof(rctx->cmd));
 110         INIT_LIST_HEAD(&rctx->cmd.entry);
 111         rctx->cmd.engine = CCP_ENGINE_AES;
 112         rctx->cmd.u.aes.type = ctx->u.aes.type;
 113         rctx->cmd.u.aes.mode = ctx->u.aes.mode;
 114         rctx->cmd.u.aes.action = encrypt;
 115         rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
 116         rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
 117         rctx->cmd.u.aes.iv = iv_sg;
 118         rctx->cmd.u.aes.iv_len = iv_len;
 119         rctx->cmd.u.aes.src = req->src;
 120         rctx->cmd.u.aes.src_len = req->cryptlen;
 121         rctx->cmd.u.aes.aad_len = req->assoclen;
 122
 123         /* The cipher text + the tag are in the dst buffer */
 124         rctx->cmd.u.aes.dst = req->dst;
 125
 126         ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
 127
 128         return ret;
 129 }
 130
 131 static int ccp_aes_gcm_encrypt(struct aead_request *req)
 132 {
 133         return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_ENCRYPT);
 134 }
 135
 136 static int ccp_aes_gcm_decrypt(struct aead_request *req)
 137 {
 138         return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_DECRYPT);
 139 }
 140
 141 static int ccp_aes_gcm_cra_init(struct crypto_aead *tfm)
 142 {
 143         struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
 144
 145         ctx->complete = ccp_aes_gcm_complete;
 146         ctx->u.aes.key_len = 0;
 147
 148         crypto_aead_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx));
 149
 150         return 0;
 151 }
 152
 153 static void ccp_aes_gcm_cra_exit(struct crypto_tfm *tfm)
 154 {
 155 }
 156
 157 static struct aead_alg ccp_aes_gcm_defaults = {
 158         .setkey = ccp_aes_gcm_setkey,
 159         .setauthsize = ccp_aes_gcm_setauthsize,
 160         .encrypt = ccp_aes_gcm_encrypt,
 161         .decrypt = ccp_aes_gcm_decrypt,
 162         .init = ccp_aes_gcm_cra_init,
 163         .ivsize = AES_GCM_IVSIZE,
 164         .maxauthsize = AES_BLOCK_SIZE,
 165         .base = {
 166                 .cra_flags      = CRYPTO_ALG_TYPE_ABLKCIPHER |
 167                                   CRYPTO_ALG_ASYNC |
 168                                   CRYPTO_ALG_KERN_DRIVER_ONLY |
 169                                   CRYPTO_ALG_NEED_FALLBACK,
 170                 .cra_blocksize  = AES_BLOCK_SIZE,
 171                 .cra_ctxsize    = sizeof(struct ccp_ctx),
 172                 .cra_priority   = CCP_CRA_PRIORITY,
 173                 .cra_type       = &crypto_ablkcipher_type,
 174                 .cra_exit       = ccp_aes_gcm_cra_exit,
 175                 .cra_module     = THIS_MODULE,
 176         },
 177 };
 178
 179 struct ccp_aes_aead_def {
 180         enum ccp_aes_mode mode;
 181         unsigned int version;
 182         const char *name;
 183         const char *driver_name;
 184         unsigned int blocksize;
 185         unsigned int ivsize;
 186         struct aead_alg *alg_defaults;
 187 };
 188
 189 static struct ccp_aes_aead_def aes_aead_algs[] = {
 190         {
 191                 .mode           = CCP_AES_MODE_GHASH,
 192                 .version        = CCP_VERSION(5, 0),
 193                 .name           = "gcm(aes)",
 194                 .driver_name    = "gcm-aes-ccp",
 195                 .blocksize      = 1,
 196                 .ivsize         = AES_BLOCK_SIZE,
 197                 .alg_defaults   = &ccp_aes_gcm_defaults,
 198         },
 199 };
 200
 201 static int ccp_register_aes_aead(struct list_head *head,
 202                                  const struct ccp_aes_aead_def *def)
 203 {
 204         struct ccp_crypto_aead *ccp_aead;
 205         struct aead_alg *alg;
 206         int ret;
 207
 208         ccp_aead = kzalloc(sizeof(*ccp_aead), GFP_KERNEL);
 209         if (!ccp_aead)
 210                 return -ENOMEM;
 211
 212         INIT_LIST_HEAD(&ccp_aead->entry);
 213
 214         ccp_aead->mode = def->mode;
 215
 216         /* Copy the defaults and override as necessary */
 217         alg = &ccp_aead->alg;
 218         *alg = *def->alg_defaults;
 219         snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
 220         snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
 221                  def->driver_name);
 222         alg->base.cra_blocksize = def->blocksize;
 223         alg->base.cra_ablkcipher.ivsize = def->ivsize;
 224
 225         ret = crypto_register_aead(alg);
 226         if (ret) {
 227                 pr_err("%s ablkcipher algorithm registration error (%d)\n",
 228                        alg->base.cra_name, ret);
 229                 kfree(ccp_aead);
 230                 return ret;
 231         }
 232
 233         list_add(&ccp_aead->entry, head);
 234
 235         return 0;
 236 }
 237
 238 int ccp_register_aes_aeads(struct list_head *head)
 239 {
 240         int i, ret;
 241         unsigned int ccpversion = ccp_version();
 242
 243         for (i = 0; i < ARRAY_SIZE(aes_aead_algs); i++) {
 244                 if (aes_aead_algs[i].version > ccpversion)
 245                         continue;
 246                 ret = ccp_register_aes_aead(head, &aes_aead_algs[i]);
 247                 if (ret)
 248                         return ret;
 249         }
 250
 251         return 0;
 252 }