| Herbert Xu | 1ae9782 | 2007-08-30 15:36:14 +0800 | [diff] [blame] | 1 | /* |
| 2 | * AEAD: Authenticated Encryption with Associated Data |
| 3 | * |
| 4 | * This file provides API support for AEAD algorithms. |
| 5 | * |
| 6 | * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify it |
| 9 | * under the terms of the GNU General Public License as published by the Free |
| 10 | * Software Foundation; either version 2 of the License, or (at your option) |
| 11 | * any later version. |
| 12 | * |
| 13 | */ |
| 14 | |
| 15 | #include <crypto/algapi.h> |
| 16 | #include <linux/errno.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/slab.h> |
| 21 | #include <linux/seq_file.h> |
| 22 | |
| 23 | static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key, |
| 24 | unsigned int keylen) |
| 25 | { |
| 26 | struct aead_alg *aead = crypto_aead_alg(tfm); |
| 27 | unsigned long alignmask = crypto_aead_alignmask(tfm); |
| 28 | int ret; |
| 29 | u8 *buffer, *alignbuffer; |
| 30 | unsigned long absize; |
| 31 | |
| 32 | absize = keylen + alignmask; |
| 33 | buffer = kmalloc(absize, GFP_ATOMIC); |
| 34 | if (!buffer) |
| 35 | return -ENOMEM; |
| 36 | |
| 37 | alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); |
| 38 | memcpy(alignbuffer, key, keylen); |
| 39 | ret = aead->setkey(tfm, alignbuffer, keylen); |
| 40 | memset(alignbuffer, 0, keylen); |
| 41 | kfree(buffer); |
| 42 | return ret; |
| 43 | } |
| 44 | |
| 45 | static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen) |
| 46 | { |
| 47 | struct aead_alg *aead = crypto_aead_alg(tfm); |
| 48 | unsigned long alignmask = crypto_aead_alignmask(tfm); |
| 49 | |
| 50 | if ((unsigned long)key & alignmask) |
| 51 | return setkey_unaligned(tfm, key, keylen); |
| 52 | |
| 53 | return aead->setkey(tfm, key, keylen); |
| 54 | } |
| 55 | |
| 56 | static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type, |
| 57 | u32 mask) |
| 58 | { |
| 59 | return alg->cra_ctxsize; |
| 60 | } |
| 61 | |
| 62 | static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask) |
| 63 | { |
| 64 | struct aead_alg *alg = &tfm->__crt_alg->cra_aead; |
| 65 | struct aead_tfm *crt = &tfm->crt_aead; |
| 66 | |
| 67 | if (max(alg->authsize, alg->ivsize) > PAGE_SIZE / 8) |
| 68 | return -EINVAL; |
| 69 | |
| 70 | crt->setkey = setkey; |
| 71 | crt->encrypt = alg->encrypt; |
| 72 | crt->decrypt = alg->decrypt; |
| 73 | crt->ivsize = alg->ivsize; |
| 74 | crt->authsize = alg->authsize; |
| 75 | |
| 76 | return 0; |
| 77 | } |
| 78 | |
| 79 | static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg) |
| 80 | __attribute__ ((unused)); |
| 81 | static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg) |
| 82 | { |
| 83 | struct aead_alg *aead = &alg->cra_aead; |
| 84 | |
| 85 | seq_printf(m, "type : aead\n"); |
| 86 | seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); |
| 87 | seq_printf(m, "ivsize : %u\n", aead->ivsize); |
| 88 | seq_printf(m, "authsize : %u\n", aead->authsize); |
| 89 | } |
| 90 | |
| 91 | const struct crypto_type crypto_aead_type = { |
| 92 | .ctxsize = crypto_aead_ctxsize, |
| 93 | .init = crypto_init_aead_ops, |
| 94 | #ifdef CONFIG_PROC_FS |
| 95 | .show = crypto_aead_show, |
| 96 | #endif |
| 97 | }; |
| 98 | EXPORT_SYMBOL_GPL(crypto_aead_type); |
| 99 | |
| 100 | MODULE_LICENSE("GPL"); |
| 101 | MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)"); |