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/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 } 253