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 <linux/mm.h> 16#include <linux/errno.h> 17#include <linux/hardirq.h> 18#include <linux/highmem.h> 19#include <linux/kernel.h> 20#include <linux/module.h> 21#include <linux/scatterlist.h> 22 23#include "internal.h" 24#include "scatterwalk.h" 25 26static 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 34static 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; 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 = sg_next(sg); 81 } 82 83 return 0; 84} 85 86static 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 94static 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 114static 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 120static 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 128static 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 139int 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 157void crypto_exit_digest_ops(struct crypto_tfm *tfm) 158{ 159} 160