1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AMD Cryptographic Coprocessor (CCP) RSA crypto API support 4 * 5 * Copyright (C) 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/scatterlist.h> 13 #include <linux/crypto.h> 14 #include <crypto/algapi.h> 15 #include <crypto/internal/rsa.h> 16 #include <crypto/internal/akcipher.h> 17 #include <crypto/akcipher.h> 18 #include <crypto/scatterwalk.h> 19 20 #include "ccp-crypto.h" 21 22 static inline struct akcipher_request *akcipher_request_cast( 23 struct crypto_async_request *req) 24 { 25 return container_of(req, struct akcipher_request, base); 26 } 27 28 static inline int ccp_copy_and_save_keypart(u8 **kpbuf, unsigned int *kplen, 29 const u8 *buf, size_t sz) 30 { 31 int nskip; 32 33 for (nskip = 0; nskip < sz; nskip++) 34 if (buf[nskip]) 35 break; 36 *kplen = sz - nskip; 37 *kpbuf = kmemdup(buf + nskip, *kplen, GFP_KERNEL); 38 if (!*kpbuf) 39 return -ENOMEM; 40 41 return 0; 42 } 43 44 static int ccp_rsa_complete(struct crypto_async_request *async_req, int ret) 45 { 46 struct akcipher_request *req = akcipher_request_cast(async_req); 47 struct ccp_rsa_req_ctx *rctx = akcipher_request_ctx_dma(req); 48 49 if (ret) 50 return ret; 51 52 req->dst_len = rctx->cmd.u.rsa.key_size >> 3; 53 54 return 0; 55 } 56 57 static unsigned int ccp_rsa_maxsize(struct crypto_akcipher *tfm) 58 { 59 struct ccp_ctx *ctx = akcipher_tfm_ctx_dma(tfm); 60 61 return ctx->u.rsa.n_len; 62 } 63 64 static int ccp_rsa_crypt(struct akcipher_request *req, bool encrypt) 65 { 66 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 67 struct ccp_ctx *ctx = akcipher_tfm_ctx_dma(tfm); 68 struct ccp_rsa_req_ctx *rctx = akcipher_request_ctx_dma(req); 69 int ret = 0; 70 71 memset(&rctx->cmd, 0, sizeof(rctx->cmd)); 72 INIT_LIST_HEAD(&rctx->cmd.entry); 73 rctx->cmd.engine = CCP_ENGINE_RSA; 74 75 rctx->cmd.u.rsa.key_size = ctx->u.rsa.key_len; /* in bits */ 76 if (encrypt) { 77 rctx->cmd.u.rsa.exp = &ctx->u.rsa.e_sg; 78 rctx->cmd.u.rsa.exp_len = ctx->u.rsa.e_len; 79 } else { 80 rctx->cmd.u.rsa.exp = &ctx->u.rsa.d_sg; 81 rctx->cmd.u.rsa.exp_len = ctx->u.rsa.d_len; 82 } 83 rctx->cmd.u.rsa.mod = &ctx->u.rsa.n_sg; 84 rctx->cmd.u.rsa.mod_len = ctx->u.rsa.n_len; 85 rctx->cmd.u.rsa.src = req->src; 86 rctx->cmd.u.rsa.src_len = req->src_len; 87 rctx->cmd.u.rsa.dst = req->dst; 88 89 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd); 90 91 return ret; 92 } 93 94 static int ccp_rsa_encrypt(struct akcipher_request *req) 95 { 96 return ccp_rsa_crypt(req, true); 97 } 98 99 static int ccp_rsa_decrypt(struct akcipher_request *req) 100 { 101 return ccp_rsa_crypt(req, false); 102 } 103 104 static int ccp_check_key_length(unsigned int len) 105 { 106 /* In bits */ 107 if (len < 8 || len > 4096) 108 return -EINVAL; 109 return 0; 110 } 111 112 static void ccp_rsa_free_key_bufs(struct ccp_ctx *ctx) 113 { 114 /* Clean up old key data */ 115 kfree_sensitive(ctx->u.rsa.e_buf); 116 ctx->u.rsa.e_buf = NULL; 117 ctx->u.rsa.e_len = 0; 118 kfree_sensitive(ctx->u.rsa.n_buf); 119 ctx->u.rsa.n_buf = NULL; 120 ctx->u.rsa.n_len = 0; 121 kfree_sensitive(ctx->u.rsa.d_buf); 122 ctx->u.rsa.d_buf = NULL; 123 ctx->u.rsa.d_len = 0; 124 } 125 126 static int ccp_rsa_setkey(struct crypto_akcipher *tfm, const void *key, 127 unsigned int keylen, bool private) 128 { 129 struct ccp_ctx *ctx = akcipher_tfm_ctx_dma(tfm); 130 struct rsa_key raw_key; 131 int ret; 132 133 ccp_rsa_free_key_bufs(ctx); 134 memset(&raw_key, 0, sizeof(raw_key)); 135 136 /* Code borrowed from crypto/rsa.c */ 137 if (private) 138 ret = rsa_parse_priv_key(&raw_key, key, keylen); 139 else 140 ret = rsa_parse_pub_key(&raw_key, key, keylen); 141 if (ret) 142 goto n_key; 143 144 ret = ccp_copy_and_save_keypart(&ctx->u.rsa.n_buf, &ctx->u.rsa.n_len, 145 raw_key.n, raw_key.n_sz); 146 if (ret) 147 goto key_err; 148 sg_init_one(&ctx->u.rsa.n_sg, ctx->u.rsa.n_buf, ctx->u.rsa.n_len); 149 150 ctx->u.rsa.key_len = ctx->u.rsa.n_len << 3; /* convert to bits */ 151 if (ccp_check_key_length(ctx->u.rsa.key_len)) { 152 ret = -EINVAL; 153 goto key_err; 154 } 155 156 ret = ccp_copy_and_save_keypart(&ctx->u.rsa.e_buf, &ctx->u.rsa.e_len, 157 raw_key.e, raw_key.e_sz); 158 if (ret) 159 goto key_err; 160 sg_init_one(&ctx->u.rsa.e_sg, ctx->u.rsa.e_buf, ctx->u.rsa.e_len); 161 162 if (private) { 163 ret = ccp_copy_and_save_keypart(&ctx->u.rsa.d_buf, 164 &ctx->u.rsa.d_len, 165 raw_key.d, raw_key.d_sz); 166 if (ret) 167 goto key_err; 168 sg_init_one(&ctx->u.rsa.d_sg, 169 ctx->u.rsa.d_buf, ctx->u.rsa.d_len); 170 } 171 172 return 0; 173 174 key_err: 175 ccp_rsa_free_key_bufs(ctx); 176 177 n_key: 178 return ret; 179 } 180 181 static int ccp_rsa_setprivkey(struct crypto_akcipher *tfm, const void *key, 182 unsigned int keylen) 183 { 184 return ccp_rsa_setkey(tfm, key, keylen, true); 185 } 186 187 static int ccp_rsa_setpubkey(struct crypto_akcipher *tfm, const void *key, 188 unsigned int keylen) 189 { 190 return ccp_rsa_setkey(tfm, key, keylen, false); 191 } 192 193 static int ccp_rsa_init_tfm(struct crypto_akcipher *tfm) 194 { 195 struct ccp_ctx *ctx = akcipher_tfm_ctx_dma(tfm); 196 197 akcipher_set_reqsize_dma(tfm, sizeof(struct ccp_rsa_req_ctx)); 198 ctx->complete = ccp_rsa_complete; 199 200 return 0; 201 } 202 203 static void ccp_rsa_exit_tfm(struct crypto_akcipher *tfm) 204 { 205 struct ccp_ctx *ctx = akcipher_tfm_ctx_dma(tfm); 206 207 ccp_rsa_free_key_bufs(ctx); 208 } 209 210 static struct akcipher_alg ccp_rsa_defaults = { 211 .encrypt = ccp_rsa_encrypt, 212 .decrypt = ccp_rsa_decrypt, 213 .set_pub_key = ccp_rsa_setpubkey, 214 .set_priv_key = ccp_rsa_setprivkey, 215 .max_size = ccp_rsa_maxsize, 216 .init = ccp_rsa_init_tfm, 217 .exit = ccp_rsa_exit_tfm, 218 .base = { 219 .cra_name = "rsa", 220 .cra_driver_name = "rsa-ccp", 221 .cra_priority = CCP_CRA_PRIORITY, 222 .cra_module = THIS_MODULE, 223 .cra_ctxsize = 2 * sizeof(struct ccp_ctx) + CRYPTO_DMA_PADDING, 224 }, 225 }; 226 227 struct ccp_rsa_def { 228 unsigned int version; 229 const char *name; 230 const char *driver_name; 231 unsigned int reqsize; 232 struct akcipher_alg *alg_defaults; 233 }; 234 235 static struct ccp_rsa_def rsa_algs[] = { 236 { 237 .version = CCP_VERSION(3, 0), 238 .name = "rsa", 239 .driver_name = "rsa-ccp", 240 .reqsize = sizeof(struct ccp_rsa_req_ctx), 241 .alg_defaults = &ccp_rsa_defaults, 242 } 243 }; 244 245 static int ccp_register_rsa_alg(struct list_head *head, 246 const struct ccp_rsa_def *def) 247 { 248 struct ccp_crypto_akcipher_alg *ccp_alg; 249 struct akcipher_alg *alg; 250 int ret; 251 252 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); 253 if (!ccp_alg) 254 return -ENOMEM; 255 256 INIT_LIST_HEAD(&ccp_alg->entry); 257 258 alg = &ccp_alg->alg; 259 *alg = *def->alg_defaults; 260 snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name); 261 snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s", 262 def->driver_name); 263 ret = crypto_register_akcipher(alg); 264 if (ret) { 265 pr_err("%s akcipher algorithm registration error (%d)\n", 266 alg->base.cra_name, ret); 267 kfree(ccp_alg); 268 return ret; 269 } 270 271 list_add(&ccp_alg->entry, head); 272 273 return 0; 274 } 275 276 int ccp_register_rsa_algs(struct list_head *head) 277 { 278 int i, ret; 279 unsigned int ccpversion = ccp_version(); 280 281 /* Register the RSA algorithm in standard mode 282 * This works for CCP v3 and later 283 */ 284 for (i = 0; i < ARRAY_SIZE(rsa_algs); i++) { 285 if (rsa_algs[i].version > ccpversion) 286 continue; 287 ret = ccp_register_rsa_alg(head, &rsa_algs[i]); 288 if (ret) 289 return ret; 290 } 291 292 return 0; 293 } 294