1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AMD Cryptographic Coprocessor (CCP) AES GCM crypto API support 4 * 5 * Copyright (C) 2016,2017 Advanced Micro Devices, Inc. 6 * 7 * Author: Gary R Hook <gary.hook@amd.com> 8 */ 9 10 #include <linux/module.h> 11 #include <linux/sched.h> 12 #include <linux/delay.h> 13 #include <linux/scatterlist.h> 14 #include <linux/crypto.h> 15 #include <crypto/internal/aead.h> 16 #include <crypto/algapi.h> 17 #include <crypto/aes.h> 18 #include <crypto/ctr.h> 19 #include <crypto/gcm.h> 20 #include <crypto/scatterwalk.h> 21 22 #include "ccp-crypto.h" 23 24 static int ccp_aes_gcm_complete(struct crypto_async_request *async_req, int ret) 25 { 26 return ret; 27 } 28 29 static int ccp_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key, 30 unsigned int key_len) 31 { 32 struct ccp_ctx *ctx = crypto_aead_ctx(tfm); 33 34 switch (key_len) { 35 case AES_KEYSIZE_128: 36 ctx->u.aes.type = CCP_AES_TYPE_128; 37 break; 38 case AES_KEYSIZE_192: 39 ctx->u.aes.type = CCP_AES_TYPE_192; 40 break; 41 case AES_KEYSIZE_256: 42 ctx->u.aes.type = CCP_AES_TYPE_256; 43 break; 44 default: 45 crypto_aead_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 46 return -EINVAL; 47 } 48 49 ctx->u.aes.mode = CCP_AES_MODE_GCM; 50 ctx->u.aes.key_len = key_len; 51 52 memcpy(ctx->u.aes.key, key, key_len); 53 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len); 54 55 return 0; 56 } 57 58 static int ccp_aes_gcm_setauthsize(struct crypto_aead *tfm, 59 unsigned int authsize) 60 { 61 switch (authsize) { 62 case 16: 63 case 15: 64 case 14: 65 case 13: 66 case 12: 67 case 8: 68 case 4: 69 break; 70 default: 71 return -EINVAL; 72 } 73 74 return 0; 75 } 76 77 static int ccp_aes_gcm_crypt(struct aead_request *req, bool encrypt) 78 { 79 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 80 struct ccp_ctx *ctx = crypto_aead_ctx(tfm); 81 struct ccp_aes_req_ctx *rctx = aead_request_ctx(req); 82 struct scatterlist *iv_sg = NULL; 83 unsigned int iv_len = 0; 84 int i; 85 int ret = 0; 86 87 if (!ctx->u.aes.key_len) 88 return -EINVAL; 89 90 if (ctx->u.aes.mode != CCP_AES_MODE_GCM) 91 return -EINVAL; 92 93 if (!req->iv) 94 return -EINVAL; 95 96 /* 97 * 5 parts: 98 * plaintext/ciphertext input 99 * AAD 100 * key 101 * IV 102 * Destination+tag buffer 103 */ 104 105 /* Prepare the IV: 12 bytes + an integer (counter) */ 106 memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE); 107 for (i = 0; i < 3; i++) 108 rctx->iv[i + GCM_AES_IV_SIZE] = 0; 109 rctx->iv[AES_BLOCK_SIZE - 1] = 1; 110 111 /* Set up a scatterlist for the IV */ 112 iv_sg = &rctx->iv_sg; 113 iv_len = AES_BLOCK_SIZE; 114 sg_init_one(iv_sg, rctx->iv, iv_len); 115 116 /* The AAD + plaintext are concatenated in the src buffer */ 117 memset(&rctx->cmd, 0, sizeof(rctx->cmd)); 118 INIT_LIST_HEAD(&rctx->cmd.entry); 119 rctx->cmd.engine = CCP_ENGINE_AES; 120 rctx->cmd.u.aes.authsize = crypto_aead_authsize(tfm); 121 rctx->cmd.u.aes.type = ctx->u.aes.type; 122 rctx->cmd.u.aes.mode = ctx->u.aes.mode; 123 rctx->cmd.u.aes.action = encrypt; 124 rctx->cmd.u.aes.key = &ctx->u.aes.key_sg; 125 rctx->cmd.u.aes.key_len = ctx->u.aes.key_len; 126 rctx->cmd.u.aes.iv = iv_sg; 127 rctx->cmd.u.aes.iv_len = iv_len; 128 rctx->cmd.u.aes.src = req->src; 129 rctx->cmd.u.aes.src_len = req->cryptlen; 130 rctx->cmd.u.aes.aad_len = req->assoclen; 131 132 /* The cipher text + the tag are in the dst buffer */ 133 rctx->cmd.u.aes.dst = req->dst; 134 135 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd); 136 137 return ret; 138 } 139 140 static int ccp_aes_gcm_encrypt(struct aead_request *req) 141 { 142 return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_ENCRYPT); 143 } 144 145 static int ccp_aes_gcm_decrypt(struct aead_request *req) 146 { 147 return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_DECRYPT); 148 } 149 150 static int ccp_aes_gcm_cra_init(struct crypto_aead *tfm) 151 { 152 struct ccp_ctx *ctx = crypto_aead_ctx(tfm); 153 154 ctx->complete = ccp_aes_gcm_complete; 155 ctx->u.aes.key_len = 0; 156 157 crypto_aead_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx)); 158 159 return 0; 160 } 161 162 static void ccp_aes_gcm_cra_exit(struct crypto_tfm *tfm) 163 { 164 } 165 166 static struct aead_alg ccp_aes_gcm_defaults = { 167 .setkey = ccp_aes_gcm_setkey, 168 .setauthsize = ccp_aes_gcm_setauthsize, 169 .encrypt = ccp_aes_gcm_encrypt, 170 .decrypt = ccp_aes_gcm_decrypt, 171 .init = ccp_aes_gcm_cra_init, 172 .ivsize = GCM_AES_IV_SIZE, 173 .maxauthsize = AES_BLOCK_SIZE, 174 .base = { 175 .cra_flags = CRYPTO_ALG_ASYNC | 176 CRYPTO_ALG_KERN_DRIVER_ONLY | 177 CRYPTO_ALG_NEED_FALLBACK, 178 .cra_blocksize = AES_BLOCK_SIZE, 179 .cra_ctxsize = sizeof(struct ccp_ctx), 180 .cra_priority = CCP_CRA_PRIORITY, 181 .cra_exit = ccp_aes_gcm_cra_exit, 182 .cra_module = THIS_MODULE, 183 }, 184 }; 185 186 struct ccp_aes_aead_def { 187 enum ccp_aes_mode mode; 188 unsigned int version; 189 const char *name; 190 const char *driver_name; 191 unsigned int blocksize; 192 unsigned int ivsize; 193 struct aead_alg *alg_defaults; 194 }; 195 196 static struct ccp_aes_aead_def aes_aead_algs[] = { 197 { 198 .mode = CCP_AES_MODE_GHASH, 199 .version = CCP_VERSION(5, 0), 200 .name = "gcm(aes)", 201 .driver_name = "gcm-aes-ccp", 202 .blocksize = 1, 203 .ivsize = AES_BLOCK_SIZE, 204 .alg_defaults = &ccp_aes_gcm_defaults, 205 }, 206 }; 207 208 static int ccp_register_aes_aead(struct list_head *head, 209 const struct ccp_aes_aead_def *def) 210 { 211 struct ccp_crypto_aead *ccp_aead; 212 struct aead_alg *alg; 213 int ret; 214 215 ccp_aead = kzalloc(sizeof(*ccp_aead), GFP_KERNEL); 216 if (!ccp_aead) 217 return -ENOMEM; 218 219 INIT_LIST_HEAD(&ccp_aead->entry); 220 221 ccp_aead->mode = def->mode; 222 223 /* Copy the defaults and override as necessary */ 224 alg = &ccp_aead->alg; 225 *alg = *def->alg_defaults; 226 snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name); 227 snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s", 228 def->driver_name); 229 alg->base.cra_blocksize = def->blocksize; 230 231 ret = crypto_register_aead(alg); 232 if (ret) { 233 pr_err("%s aead algorithm registration error (%d)\n", 234 alg->base.cra_name, ret); 235 kfree(ccp_aead); 236 return ret; 237 } 238 239 list_add(&ccp_aead->entry, head); 240 241 return 0; 242 } 243 244 int ccp_register_aes_aeads(struct list_head *head) 245 { 246 int i, ret; 247 unsigned int ccpversion = ccp_version(); 248 249 for (i = 0; i < ARRAY_SIZE(aes_aead_algs); i++) { 250 if (aes_aead_algs[i].version > ccpversion) 251 continue; 252 ret = ccp_register_aes_aead(head, &aes_aead_algs[i]); 253 if (ret) 254 return ret; 255 } 256 257 return 0; 258 } 259