1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Public Key Encryption 4 * 5 * Copyright (c) 2015, Intel Corporation 6 * Authors: Tadeusz Struk <tadeusz.struk@intel.com> 7 */ 8 #include <crypto/internal/akcipher.h> 9 #include <linux/cryptouser.h> 10 #include <linux/errno.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/scatterlist.h> 14 #include <linux/seq_file.h> 15 #include <linux/slab.h> 16 #include <linux/string.h> 17 #include <net/netlink.h> 18 19 #include "internal.h" 20 21 #define CRYPTO_ALG_TYPE_AHASH_MASK 0x0000000e 22 23 struct crypto_akcipher_sync_data { 24 struct crypto_akcipher *tfm; 25 const void *src; 26 void *dst; 27 unsigned int slen; 28 unsigned int dlen; 29 30 struct akcipher_request *req; 31 struct crypto_wait cwait; 32 struct scatterlist sg; 33 u8 *buf; 34 }; 35 36 static int __maybe_unused crypto_akcipher_report( 37 struct sk_buff *skb, struct crypto_alg *alg) 38 { 39 struct crypto_report_akcipher rakcipher; 40 41 memset(&rakcipher, 0, sizeof(rakcipher)); 42 43 strscpy(rakcipher.type, "akcipher", sizeof(rakcipher.type)); 44 45 return nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER, 46 sizeof(rakcipher), &rakcipher); 47 } 48 49 static void __maybe_unused crypto_akcipher_show(struct seq_file *m, 50 struct crypto_alg *alg) 51 { 52 seq_puts(m, "type : akcipher\n"); 53 } 54 55 static void crypto_akcipher_exit_tfm(struct crypto_tfm *tfm) 56 { 57 struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm); 58 struct akcipher_alg *alg = crypto_akcipher_alg(akcipher); 59 60 alg->exit(akcipher); 61 } 62 63 static int crypto_akcipher_init_tfm(struct crypto_tfm *tfm) 64 { 65 struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm); 66 struct akcipher_alg *alg = crypto_akcipher_alg(akcipher); 67 68 if (alg->exit) 69 akcipher->base.exit = crypto_akcipher_exit_tfm; 70 71 if (alg->init) 72 return alg->init(akcipher); 73 74 return 0; 75 } 76 77 static void crypto_akcipher_free_instance(struct crypto_instance *inst) 78 { 79 struct akcipher_instance *akcipher = akcipher_instance(inst); 80 81 akcipher->free(akcipher); 82 } 83 84 static const struct crypto_type crypto_akcipher_type = { 85 .extsize = crypto_alg_extsize, 86 .init_tfm = crypto_akcipher_init_tfm, 87 .free = crypto_akcipher_free_instance, 88 #ifdef CONFIG_PROC_FS 89 .show = crypto_akcipher_show, 90 #endif 91 #if IS_ENABLED(CONFIG_CRYPTO_USER) 92 .report = crypto_akcipher_report, 93 #endif 94 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 95 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, 96 .type = CRYPTO_ALG_TYPE_AKCIPHER, 97 .tfmsize = offsetof(struct crypto_akcipher, base), 98 .algsize = offsetof(struct akcipher_alg, base), 99 }; 100 101 int crypto_grab_akcipher(struct crypto_akcipher_spawn *spawn, 102 struct crypto_instance *inst, 103 const char *name, u32 type, u32 mask) 104 { 105 spawn->base.frontend = &crypto_akcipher_type; 106 return crypto_grab_spawn(&spawn->base, inst, name, type, mask); 107 } 108 EXPORT_SYMBOL_GPL(crypto_grab_akcipher); 109 110 struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type, 111 u32 mask) 112 { 113 return crypto_alloc_tfm(alg_name, &crypto_akcipher_type, type, mask); 114 } 115 EXPORT_SYMBOL_GPL(crypto_alloc_akcipher); 116 117 static void akcipher_prepare_alg(struct akcipher_alg *alg) 118 { 119 struct crypto_alg *base = &alg->base; 120 121 base->cra_type = &crypto_akcipher_type; 122 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 123 base->cra_flags |= CRYPTO_ALG_TYPE_AKCIPHER; 124 } 125 126 static int akcipher_default_op(struct akcipher_request *req) 127 { 128 return -ENOSYS; 129 } 130 131 static int akcipher_default_set_key(struct crypto_akcipher *tfm, 132 const void *key, unsigned int keylen) 133 { 134 return -ENOSYS; 135 } 136 137 int crypto_register_akcipher(struct akcipher_alg *alg) 138 { 139 struct crypto_alg *base = &alg->base; 140 141 if (!alg->encrypt) 142 alg->encrypt = akcipher_default_op; 143 if (!alg->decrypt) 144 alg->decrypt = akcipher_default_op; 145 if (!alg->set_priv_key) 146 alg->set_priv_key = akcipher_default_set_key; 147 148 akcipher_prepare_alg(alg); 149 return crypto_register_alg(base); 150 } 151 EXPORT_SYMBOL_GPL(crypto_register_akcipher); 152 153 void crypto_unregister_akcipher(struct akcipher_alg *alg) 154 { 155 crypto_unregister_alg(&alg->base); 156 } 157 EXPORT_SYMBOL_GPL(crypto_unregister_akcipher); 158 159 int akcipher_register_instance(struct crypto_template *tmpl, 160 struct akcipher_instance *inst) 161 { 162 if (WARN_ON(!inst->free)) 163 return -EINVAL; 164 akcipher_prepare_alg(&inst->alg); 165 return crypto_register_instance(tmpl, akcipher_crypto_instance(inst)); 166 } 167 EXPORT_SYMBOL_GPL(akcipher_register_instance); 168 169 static int crypto_akcipher_sync_prep(struct crypto_akcipher_sync_data *data) 170 { 171 unsigned int reqsize = crypto_akcipher_reqsize(data->tfm); 172 struct akcipher_request *req; 173 struct scatterlist *sg; 174 unsigned int mlen; 175 unsigned int len; 176 u8 *buf; 177 178 mlen = max(data->slen, data->dlen); 179 180 len = sizeof(*req) + reqsize + mlen; 181 if (len < mlen) 182 return -EOVERFLOW; 183 184 req = kzalloc(len, GFP_KERNEL); 185 if (!req) 186 return -ENOMEM; 187 188 data->req = req; 189 akcipher_request_set_tfm(req, data->tfm); 190 191 buf = (u8 *)(req + 1) + reqsize; 192 data->buf = buf; 193 memcpy(buf, data->src, data->slen); 194 195 sg = &data->sg; 196 sg_init_one(sg, buf, mlen); 197 akcipher_request_set_crypt(req, sg, sg, data->slen, data->dlen); 198 199 crypto_init_wait(&data->cwait); 200 akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, 201 crypto_req_done, &data->cwait); 202 203 return 0; 204 } 205 206 static int crypto_akcipher_sync_post(struct crypto_akcipher_sync_data *data, 207 int err) 208 { 209 err = crypto_wait_req(err, &data->cwait); 210 memcpy(data->dst, data->buf, data->dlen); 211 data->dlen = data->req->dst_len; 212 kfree_sensitive(data->req); 213 return err; 214 } 215 216 int crypto_akcipher_sync_encrypt(struct crypto_akcipher *tfm, 217 const void *src, unsigned int slen, 218 void *dst, unsigned int dlen) 219 { 220 struct crypto_akcipher_sync_data data = { 221 .tfm = tfm, 222 .src = src, 223 .dst = dst, 224 .slen = slen, 225 .dlen = dlen, 226 }; 227 228 return crypto_akcipher_sync_prep(&data) ?: 229 crypto_akcipher_sync_post(&data, 230 crypto_akcipher_encrypt(data.req)); 231 } 232 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_encrypt); 233 234 int crypto_akcipher_sync_decrypt(struct crypto_akcipher *tfm, 235 const void *src, unsigned int slen, 236 void *dst, unsigned int dlen) 237 { 238 struct crypto_akcipher_sync_data data = { 239 .tfm = tfm, 240 .src = src, 241 .dst = dst, 242 .slen = slen, 243 .dlen = dlen, 244 }; 245 246 return crypto_akcipher_sync_prep(&data) ?: 247 crypto_akcipher_sync_post(&data, 248 crypto_akcipher_decrypt(data.req)) ?: 249 data.dlen; 250 } 251 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_decrypt); 252 253 MODULE_LICENSE("GPL"); 254 MODULE_DESCRIPTION("Generic public key cipher type"); 255