| 1 | /* |
| 2 | * Cryptographic API. |
| 3 | * |
| 4 | * Digest operations. |
| 5 | * |
| 6 | * Copyright (c) 2002 James Morris <jmorris@intercode.com.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/scatterwalk.h> |
| 16 | #include <linux/mm.h> |
| 17 | #include <linux/errno.h> |
| 18 | #include <linux/hardirq.h> |
| 19 | #include <linux/highmem.h> |
| 20 | #include <linux/kernel.h> |
| 21 | #include <linux/module.h> |
| 22 | #include <linux/scatterlist.h> |
| 23 | |
| 24 | #include "internal.h" |
| 25 | |
| 26 | static int init(struct hash_desc *desc) |
| 27 | { |
| 28 | struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm); |
| 29 | |
| 30 | tfm->__crt_alg->cra_digest.dia_init(tfm); |
| 31 | return 0; |
| 32 | } |
| 33 | |
| 34 | static int update2(struct hash_desc *desc, |
| 35 | struct scatterlist *sg, unsigned int nbytes) |
| 36 | { |
| 37 | struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm); |
| 38 | unsigned int alignmask = crypto_tfm_alg_alignmask(tfm); |
| 39 | |
| 40 | if (!nbytes) |
| 41 | return 0; |
| 42 | |
| 43 | for (;;) { |
| 44 | struct page *pg = sg_page(sg); |
| 45 | unsigned int offset = sg->offset; |
| 46 | unsigned int l = sg->length; |
| 47 | |
| 48 | if (unlikely(l > nbytes)) |
| 49 | l = nbytes; |
| 50 | nbytes -= l; |
| 51 | |
| 52 | do { |
| 53 | unsigned int bytes_from_page = min(l, ((unsigned int) |
| 54 | (PAGE_SIZE)) - |
| 55 | offset); |
| 56 | char *src = crypto_kmap(pg, 0); |
| 57 | char *p = src + offset; |
| 58 | |
| 59 | if (unlikely(offset & alignmask)) { |
| 60 | unsigned int bytes = |
| 61 | alignmask + 1 - (offset & alignmask); |
| 62 | bytes = min(bytes, bytes_from_page); |
| 63 | tfm->__crt_alg->cra_digest.dia_update(tfm, p, |
| 64 | bytes); |
| 65 | p += bytes; |
| 66 | bytes_from_page -= bytes; |
| 67 | l -= bytes; |
| 68 | } |
| 69 | tfm->__crt_alg->cra_digest.dia_update(tfm, p, |
| 70 | bytes_from_page); |
| 71 | crypto_kunmap(src, 0); |
| 72 | crypto_yield(desc->flags); |
| 73 | offset = 0; |
| 74 | pg++; |
| 75 | l -= bytes_from_page; |
| 76 | } while (l > 0); |
| 77 | |
| 78 | if (!nbytes) |
| 79 | break; |
| 80 | sg = scatterwalk_sg_next(sg); |
| 81 | } |
| 82 | |
| 83 | return 0; |
| 84 | } |
| 85 | |
| 86 | static int update(struct hash_desc *desc, |
| 87 | struct scatterlist *sg, unsigned int nbytes) |
| 88 | { |
| 89 | if (WARN_ON_ONCE(in_irq())) |
| 90 | return -EDEADLK; |
| 91 | return update2(desc, sg, nbytes); |
| 92 | } |
| 93 | |
| 94 | static int final(struct hash_desc *desc, u8 *out) |
| 95 | { |
| 96 | struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm); |
| 97 | unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); |
| 98 | struct digest_alg *digest = &tfm->__crt_alg->cra_digest; |
| 99 | |
| 100 | if (unlikely((unsigned long)out & alignmask)) { |
| 101 | unsigned long align = alignmask + 1; |
| 102 | unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm); |
| 103 | u8 *dst = (u8 *)ALIGN(addr, align) + |
| 104 | ALIGN(tfm->__crt_alg->cra_ctxsize, align); |
| 105 | |
| 106 | digest->dia_final(tfm, dst); |
| 107 | memcpy(out, dst, digest->dia_digestsize); |
| 108 | } else |
| 109 | digest->dia_final(tfm, out); |
| 110 | |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen) |
| 115 | { |
| 116 | crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK); |
| 117 | return -ENOSYS; |
| 118 | } |
| 119 | |
| 120 | static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen) |
| 121 | { |
| 122 | struct crypto_tfm *tfm = crypto_hash_tfm(hash); |
| 123 | |
| 124 | crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK); |
| 125 | return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen); |
| 126 | } |
| 127 | |
| 128 | static int digest(struct hash_desc *desc, |
| 129 | struct scatterlist *sg, unsigned int nbytes, u8 *out) |
| 130 | { |
| 131 | if (WARN_ON_ONCE(in_irq())) |
| 132 | return -EDEADLK; |
| 133 | |
| 134 | init(desc); |
| 135 | update2(desc, sg, nbytes); |
| 136 | return final(desc, out); |
| 137 | } |
| 138 | |
| 139 | int crypto_init_digest_ops(struct crypto_tfm *tfm) |
| 140 | { |
| 141 | struct hash_tfm *ops = &tfm->crt_hash; |
| 142 | struct digest_alg *dalg = &tfm->__crt_alg->cra_digest; |
| 143 | |
| 144 | if (dalg->dia_digestsize > crypto_tfm_alg_blocksize(tfm)) |
| 145 | return -EINVAL; |
| 146 | |
| 147 | ops->init = init; |
| 148 | ops->update = update; |
| 149 | ops->final = final; |
| 150 | ops->digest = digest; |
| 151 | ops->setkey = dalg->dia_setkey ? setkey : nosetkey; |
| 152 | ops->digestsize = dalg->dia_digestsize; |
| 153 | |
| 154 | return 0; |
| 155 | } |
| 156 | |
| 157 | void crypto_exit_digest_ops(struct crypto_tfm *tfm) |
| 158 | { |
| 159 | } |