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 } 252