1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ECB: Electronic CodeBook mode 4 * 5 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au> 6 */ 7 8 #include <crypto/algapi.h> 9 #include <crypto/internal/skcipher.h> 10 #include <linux/err.h> 11 #include <linux/init.h> 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 15 static int crypto_ecb_crypt(struct skcipher_request *req, 16 struct crypto_cipher *cipher, 17 void (*fn)(struct crypto_tfm *, u8 *, const u8 *)) 18 { 19 const unsigned int bsize = crypto_cipher_blocksize(cipher); 20 struct skcipher_walk walk; 21 unsigned int nbytes; 22 int err; 23 24 err = skcipher_walk_virt(&walk, req, false); 25 26 while ((nbytes = walk.nbytes) != 0) { 27 const u8 *src = walk.src.virt.addr; 28 u8 *dst = walk.dst.virt.addr; 29 30 do { 31 fn(crypto_cipher_tfm(cipher), dst, src); 32 33 src += bsize; 34 dst += bsize; 35 } while ((nbytes -= bsize) >= bsize); 36 37 err = skcipher_walk_done(&walk, nbytes); 38 } 39 40 return err; 41 } 42 43 static int crypto_ecb_encrypt(struct skcipher_request *req) 44 { 45 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 46 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm); 47 48 return crypto_ecb_crypt(req, cipher, 49 crypto_cipher_alg(cipher)->cia_encrypt); 50 } 51 52 static int crypto_ecb_decrypt(struct skcipher_request *req) 53 { 54 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 55 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm); 56 57 return crypto_ecb_crypt(req, cipher, 58 crypto_cipher_alg(cipher)->cia_decrypt); 59 } 60 61 static int crypto_ecb_create(struct crypto_template *tmpl, struct rtattr **tb) 62 { 63 struct skcipher_instance *inst; 64 int err; 65 66 inst = skcipher_alloc_instance_simple(tmpl, tb); 67 if (IS_ERR(inst)) 68 return PTR_ERR(inst); 69 70 inst->alg.ivsize = 0; /* ECB mode doesn't take an IV */ 71 72 inst->alg.encrypt = crypto_ecb_encrypt; 73 inst->alg.decrypt = crypto_ecb_decrypt; 74 75 err = skcipher_register_instance(tmpl, inst); 76 if (err) 77 inst->free(inst); 78 79 return err; 80 } 81 82 static struct crypto_template crypto_ecb_tmpl = { 83 .name = "ecb", 84 .create = crypto_ecb_create, 85 .module = THIS_MODULE, 86 }; 87 88 static int __init crypto_ecb_module_init(void) 89 { 90 return crypto_register_template(&crypto_ecb_tmpl); 91 } 92 93 static void __exit crypto_ecb_module_exit(void) 94 { 95 crypto_unregister_template(&crypto_ecb_tmpl); 96 } 97 98 subsys_initcall(crypto_ecb_module_init); 99 module_exit(crypto_ecb_module_exit); 100 101 MODULE_LICENSE("GPL"); 102 MODULE_DESCRIPTION("ECB block cipher mode of operation"); 103 MODULE_ALIAS_CRYPTO("ecb"); 104