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 crypto_akcipher_show(struct seq_file *m, struct crypto_alg *alg) 50 __maybe_unused; 51 52 static void crypto_akcipher_show(struct seq_file *m, struct crypto_alg *alg) 53 { 54 seq_puts(m, "type : akcipher\n"); 55 } 56 57 static void crypto_akcipher_exit_tfm(struct crypto_tfm *tfm) 58 { 59 struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm); 60 struct akcipher_alg *alg = crypto_akcipher_alg(akcipher); 61 62 alg->exit(akcipher); 63 } 64 65 static int crypto_akcipher_init_tfm(struct crypto_tfm *tfm) 66 { 67 struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm); 68 struct akcipher_alg *alg = crypto_akcipher_alg(akcipher); 69 70 if (alg->exit) 71 akcipher->base.exit = crypto_akcipher_exit_tfm; 72 73 if (alg->init) 74 return alg->init(akcipher); 75 76 return 0; 77 } 78 79 static void crypto_akcipher_free_instance(struct crypto_instance *inst) 80 { 81 struct akcipher_instance *akcipher = akcipher_instance(inst); 82 83 akcipher->free(akcipher); 84 } 85 86 static const struct crypto_type crypto_akcipher_type = { 87 .extsize = crypto_alg_extsize, 88 .init_tfm = crypto_akcipher_init_tfm, 89 .free = crypto_akcipher_free_instance, 90 #ifdef CONFIG_PROC_FS 91 .show = crypto_akcipher_show, 92 #endif 93 #if IS_ENABLED(CONFIG_CRYPTO_USER) 94 .report = crypto_akcipher_report, 95 #endif 96 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 97 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, 98 .type = CRYPTO_ALG_TYPE_AKCIPHER, 99 .tfmsize = offsetof(struct crypto_akcipher, base), 100 }; 101 102 int crypto_grab_akcipher(struct crypto_akcipher_spawn *spawn, 103 struct crypto_instance *inst, 104 const char *name, u32 type, u32 mask) 105 { 106 spawn->base.frontend = &crypto_akcipher_type; 107 return crypto_grab_spawn(&spawn->base, inst, name, type, mask); 108 } 109 EXPORT_SYMBOL_GPL(crypto_grab_akcipher); 110 111 struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type, 112 u32 mask) 113 { 114 return crypto_alloc_tfm(alg_name, &crypto_akcipher_type, type, mask); 115 } 116 EXPORT_SYMBOL_GPL(crypto_alloc_akcipher); 117 118 static void akcipher_prepare_alg(struct akcipher_alg *alg) 119 { 120 struct crypto_alg *base = &alg->base; 121 122 base->cra_type = &crypto_akcipher_type; 123 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 124 base->cra_flags |= CRYPTO_ALG_TYPE_AKCIPHER; 125 } 126 127 static int akcipher_default_op(struct akcipher_request *req) 128 { 129 return -ENOSYS; 130 } 131 132 static int akcipher_default_set_key(struct crypto_akcipher *tfm, 133 const void *key, unsigned int keylen) 134 { 135 return -ENOSYS; 136 } 137 138 int crypto_register_akcipher(struct akcipher_alg *alg) 139 { 140 struct crypto_alg *base = &alg->base; 141 142 if (!alg->encrypt) 143 alg->encrypt = akcipher_default_op; 144 if (!alg->decrypt) 145 alg->decrypt = akcipher_default_op; 146 if (!alg->set_priv_key) 147 alg->set_priv_key = akcipher_default_set_key; 148 149 akcipher_prepare_alg(alg); 150 return crypto_register_alg(base); 151 } 152 EXPORT_SYMBOL_GPL(crypto_register_akcipher); 153 154 void crypto_unregister_akcipher(struct akcipher_alg *alg) 155 { 156 crypto_unregister_alg(&alg->base); 157 } 158 EXPORT_SYMBOL_GPL(crypto_unregister_akcipher); 159 160 int akcipher_register_instance(struct crypto_template *tmpl, 161 struct akcipher_instance *inst) 162 { 163 if (WARN_ON(!inst->free)) 164 return -EINVAL; 165 akcipher_prepare_alg(&inst->alg); 166 return crypto_register_instance(tmpl, akcipher_crypto_instance(inst)); 167 } 168 EXPORT_SYMBOL_GPL(akcipher_register_instance); 169 170 static int crypto_akcipher_sync_prep(struct crypto_akcipher_sync_data *data) 171 { 172 unsigned int reqsize = crypto_akcipher_reqsize(data->tfm); 173 struct akcipher_request *req; 174 struct scatterlist *sg; 175 unsigned int mlen; 176 unsigned int len; 177 u8 *buf; 178 179 mlen = max(data->slen, data->dlen); 180 181 len = sizeof(*req) + reqsize + mlen; 182 if (len < mlen) 183 return -EOVERFLOW; 184 185 req = kzalloc(len, GFP_KERNEL); 186 if (!req) 187 return -ENOMEM; 188 189 data->req = req; 190 akcipher_request_set_tfm(req, data->tfm); 191 192 buf = (u8 *)(req + 1) + reqsize; 193 data->buf = buf; 194 memcpy(buf, data->src, data->slen); 195 196 sg = &data->sg; 197 sg_init_one(sg, buf, mlen); 198 akcipher_request_set_crypt(req, sg, sg, data->slen, data->dlen); 199 200 crypto_init_wait(&data->cwait); 201 akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, 202 crypto_req_done, &data->cwait); 203 204 return 0; 205 } 206 207 static int crypto_akcipher_sync_post(struct crypto_akcipher_sync_data *data, 208 int err) 209 { 210 err = crypto_wait_req(err, &data->cwait); 211 memcpy(data->dst, data->buf, data->dlen); 212 data->dlen = data->req->dst_len; 213 kfree_sensitive(data->req); 214 return err; 215 } 216 217 int crypto_akcipher_sync_encrypt(struct crypto_akcipher *tfm, 218 const void *src, unsigned int slen, 219 void *dst, unsigned int dlen) 220 { 221 struct crypto_akcipher_sync_data data = { 222 .tfm = tfm, 223 .src = src, 224 .dst = dst, 225 .slen = slen, 226 .dlen = dlen, 227 }; 228 229 return crypto_akcipher_sync_prep(&data) ?: 230 crypto_akcipher_sync_post(&data, 231 crypto_akcipher_encrypt(data.req)); 232 } 233 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_encrypt); 234 235 int crypto_akcipher_sync_decrypt(struct crypto_akcipher *tfm, 236 const void *src, unsigned int slen, 237 void *dst, unsigned int dlen) 238 { 239 struct crypto_akcipher_sync_data data = { 240 .tfm = tfm, 241 .src = src, 242 .dst = dst, 243 .slen = slen, 244 .dlen = dlen, 245 }; 246 247 return crypto_akcipher_sync_prep(&data) ?: 248 crypto_akcipher_sync_post(&data, 249 crypto_akcipher_decrypt(data.req)) ?: 250 data.dlen; 251 } 252 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_decrypt); 253 254 MODULE_LICENSE("GPL"); 255 MODULE_DESCRIPTION("Generic public key cipher type"); 256