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