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
  25 #include "ccp-crypto.h"
  26
  27 static int ccp_aes_gcm_complete(struct crypto_async_request *async_req, int ret)
  28 {
  29         return ret;
  30 }
  31
  32 static int ccp_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
  33                               unsigned int key_len)
  34 {
  35         struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
  36
  37         switch (key_len) {
  38         case AES_KEYSIZE_128:
  39                 ctx->u.aes.type = CCP_AES_TYPE_128;
  40                 break;
  41         case AES_KEYSIZE_192:
  42                 ctx->u.aes.type = CCP_AES_TYPE_192;
  43                 break;
  44         case AES_KEYSIZE_256:
  45                 ctx->u.aes.type = CCP_AES_TYPE_256;
  46                 break;
  47         default:
  48                 crypto_aead_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
  49                 return -EINVAL;
  50         }
  51
  52         ctx->u.aes.mode = CCP_AES_MODE_GCM;
  53         ctx->u.aes.key_len = key_len;
  54
  55         memcpy(ctx->u.aes.key, key, key_len);
  56         sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
  57
  58         return 0;
  59 }
  60
  61 static int ccp_aes_gcm_setauthsize(struct crypto_aead *tfm,
  62                                    unsigned int authsize)
  63 {
  64         switch (authsize) {
  65         case 16:
  66         case 15:
  67         case 14:
  68         case 13:
  69         case 12:
  70         case 8:
  71         case 4:
  72                 break;
  73         default:
  74                 return -EINVAL;
  75         }
  76
  77         return 0;
  78 }
  79
  80 static int ccp_aes_gcm_crypt(struct aead_request *req, bool encrypt)
  81 {
  82         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
  83         struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
  84         struct ccp_aes_req_ctx *rctx = aead_request_ctx(req);
  85         struct scatterlist *iv_sg = NULL;
  86         unsigned int iv_len = 0;
  87         int i;
  88         int ret = 0;
  89
  90         if (!ctx->u.aes.key_len)
  91                 return -EINVAL;
  92
  93         if (ctx->u.aes.mode != CCP_AES_MODE_GCM)
  94                 return -EINVAL;
  95
  96         if (!req->iv)
  97                 return -EINVAL;
  98
  99         /*
 100          * 5 parts:
 101          *   plaintext/ciphertext input
 102          *   AAD
 103          *   key
 104          *   IV
 105          *   Destination+tag buffer
 106          */
 107
 108         /* Prepare the IV: 12 bytes + an integer (counter) */
 109         memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE);
 110         for (i = 0; i < 3; i++)
 111                 rctx->iv[i + GCM_AES_IV_SIZE] = 0;
 112         rctx->iv[AES_BLOCK_SIZE - 1] = 1;
 113
 114         /* Set up a scatterlist for the IV */
 115         iv_sg = &rctx->iv_sg;
 116         iv_len = AES_BLOCK_SIZE;
 117         sg_init_one(iv_sg, rctx->iv, iv_len);
 118
 119         /* The AAD + plaintext are concatenated in the src buffer */
 120         memset(&rctx->cmd, 0, sizeof(rctx->cmd));
 121         INIT_LIST_HEAD(&rctx->cmd.entry);
 122         rctx->cmd.engine = CCP_ENGINE_AES;
 123         rctx->cmd.u.aes.authsize = crypto_aead_authsize(tfm);
 124         rctx->cmd.u.aes.type = ctx->u.aes.type;
 125         rctx->cmd.u.aes.mode = ctx->u.aes.mode;
 126         rctx->cmd.u.aes.action = encrypt;
 127         rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
 128         rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
 129         rctx->cmd.u.aes.iv = iv_sg;
 130         rctx->cmd.u.aes.iv_len = iv_len;
 131         rctx->cmd.u.aes.src = req->src;
 132         rctx->cmd.u.aes.src_len = req->cryptlen;
 133         rctx->cmd.u.aes.aad_len = req->assoclen;
 134
 135         /* The cipher text + the tag are in the dst buffer */
 136         rctx->cmd.u.aes.dst = req->dst;
 137
 138         ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
 139
 140         return ret;
 141 }
 142
 143 static int ccp_aes_gcm_encrypt(struct aead_request *req)
 144 {
 145         return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_ENCRYPT);
 146 }
 147
 148 static int ccp_aes_gcm_decrypt(struct aead_request *req)
 149 {
 150         return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_DECRYPT);
 151 }
 152
 153 static int ccp_aes_gcm_cra_init(struct crypto_aead *tfm)
 154 {
 155         struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
 156
 157         ctx->complete = ccp_aes_gcm_complete;
 158         ctx->u.aes.key_len = 0;
 159
 160         crypto_aead_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx));
 161
 162         return 0;
 163 }
 164
 165 static void ccp_aes_gcm_cra_exit(struct crypto_tfm *tfm)
 166 {
 167 }
 168
 169 static struct aead_alg ccp_aes_gcm_defaults = {
 170         .setkey = ccp_aes_gcm_setkey,
 171         .setauthsize = ccp_aes_gcm_setauthsize,
 172         .encrypt = ccp_aes_gcm_encrypt,
 173         .decrypt = ccp_aes_gcm_decrypt,
 174         .init = ccp_aes_gcm_cra_init,
 175         .ivsize = GCM_AES_IV_SIZE,
 176         .maxauthsize = AES_BLOCK_SIZE,
 177         .base = {
 178                 .cra_flags      = CRYPTO_ALG_TYPE_ABLKCIPHER |
 179                                   CRYPTO_ALG_ASYNC |
 180                                   CRYPTO_ALG_KERN_DRIVER_ONLY |
 181                                   CRYPTO_ALG_NEED_FALLBACK,
 182                 .cra_blocksize  = AES_BLOCK_SIZE,
 183                 .cra_ctxsize    = sizeof(struct ccp_ctx),
 184                 .cra_priority   = CCP_CRA_PRIORITY,
 185                 .cra_type       = &crypto_ablkcipher_type,
 186                 .cra_exit       = ccp_aes_gcm_cra_exit,
 187                 .cra_module     = THIS_MODULE,
 188         },
 189 };
 190
 191 struct ccp_aes_aead_def {
 192         enum ccp_aes_mode mode;
 193         unsigned int version;
 194         const char *name;
 195         const char *driver_name;
 196         unsigned int blocksize;
 197         unsigned int ivsize;
 198         struct aead_alg *alg_defaults;
 199 };
 200
 201 static struct ccp_aes_aead_def aes_aead_algs[] = {
 202         {
 203                 .mode           = CCP_AES_MODE_GHASH,
 204                 .version        = CCP_VERSION(5, 0),
 205                 .name           = "gcm(aes)",
 206                 .driver_name    = "gcm-aes-ccp",
 207                 .blocksize      = 1,
 208                 .ivsize         = AES_BLOCK_SIZE,
 209                 .alg_defaults   = &ccp_aes_gcm_defaults,
 210         },
 211 };
 212
 213 static int ccp_register_aes_aead(struct list_head *head,
 214                                  const struct ccp_aes_aead_def *def)
 215 {
 216         struct ccp_crypto_aead *ccp_aead;
 217         struct aead_alg *alg;
 218         int ret;
 219
 220         ccp_aead = kzalloc(sizeof(*ccp_aead), GFP_KERNEL);
 221         if (!ccp_aead)
 222                 return -ENOMEM;
 223
 224         INIT_LIST_HEAD(&ccp_aead->entry);
 225
 226         ccp_aead->mode = def->mode;
 227
 228         /* Copy the defaults and override as necessary */
 229         alg = &ccp_aead->alg;
 230         *alg = *def->alg_defaults;
 231         snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
 232         snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
 233                  def->driver_name);
 234         alg->base.cra_blocksize = def->blocksize;
 235         alg->base.cra_ablkcipher.ivsize = def->ivsize;
 236
 237         ret = crypto_register_aead(alg);
 238         if (ret) {
 239                 pr_err("%s ablkcipher algorithm registration error (%d)\n",
 240                        alg->base.cra_name, ret);
 241                 kfree(ccp_aead);
 242                 return ret;
 243         }
 244
 245         list_add(&ccp_aead->entry, head);
 246
 247         return 0;
 248 }
 249
 250 int ccp_register_aes_aeads(struct list_head *head)
 251 {
 252         int i, ret;
 253         unsigned int ccpversion = ccp_version();
 254
 255         for (i = 0; i < ARRAY_SIZE(aes_aead_algs); i++) {
 256                 if (aes_aead_algs[i].version > ccpversion)
 257                         continue;
 258                 ret = ccp_register_aes_aead(head, &aes_aead_algs[i]);
 259                 if (ret)
 260                         return ret;
 261         }
 262
 263         return 0;
 264 }