crypto/shash.c

   1 /*
   2  * Synchronous Cryptographic Hash operations.
   3  *
   4  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <crypto/internal/hash.h>
  14 #include <linux/err.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/seq_file.h>
  19
  20 static inline struct crypto_shash *__crypto_shash_cast(struct crypto_tfm *tfm)
  21 {
  22         return container_of(tfm, struct crypto_shash, base);
  23 }
  24
  25 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  26                                   unsigned int keylen)
  27 {
  28         struct shash_alg *shash = crypto_shash_alg(tfm);
  29         unsigned long alignmask = crypto_shash_alignmask(tfm);
  30         unsigned long absize;
  31         u8 *buffer, *alignbuffer;
  32         int err;
  33
  34         absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
  35         buffer = kmalloc(absize, GFP_KERNEL);
  36         if (!buffer)
  37                 return -ENOMEM;
  38
  39         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  40         memcpy(alignbuffer, key, keylen);
  41         err = shash->setkey(tfm, alignbuffer, keylen);
  42         memset(alignbuffer, 0, keylen);
  43         kfree(buffer);
  44         return err;
  45 }
  46
  47 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  48                         unsigned int keylen)
  49 {
  50         struct shash_alg *shash = crypto_shash_alg(tfm);
  51         unsigned long alignmask = crypto_shash_alignmask(tfm);
  52
  53         if ((unsigned long)key & alignmask)
  54                 return shash_setkey_unaligned(tfm, key, keylen);
  55
  56         return shash->setkey(tfm, key, keylen);
  57 }
  58 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  59
  60 static inline unsigned int shash_align_buffer_size(unsigned len,
  61                                                    unsigned long mask)
  62 {
  63         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
  64 }
  65
  66 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  67                                   unsigned int len)
  68 {
  69         struct crypto_shash *tfm = desc->tfm;
  70         struct shash_alg *shash = crypto_shash_alg(tfm);
  71         unsigned long alignmask = crypto_shash_alignmask(tfm);
  72         unsigned int unaligned_len = alignmask + 1 -
  73                                      ((unsigned long)data & alignmask);
  74         u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
  75                 __attribute__ ((aligned));
  76
  77         memcpy(buf, data, unaligned_len);
  78
  79         return shash->update(desc, buf, unaligned_len) ?:
  80                shash->update(desc, data + unaligned_len, len - unaligned_len);
  81 }
  82
  83 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  84                         unsigned int len)
  85 {
  86         struct crypto_shash *tfm = desc->tfm;
  87         struct shash_alg *shash = crypto_shash_alg(tfm);
  88         unsigned long alignmask = crypto_shash_alignmask(tfm);
  89
  90         if ((unsigned long)data & alignmask)
  91                 return shash_update_unaligned(desc, data, len);
  92
  93         return shash->update(desc, data, len);
  94 }
  95 EXPORT_SYMBOL_GPL(crypto_shash_update);
  96
  97 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
  98 {
  99         struct crypto_shash *tfm = desc->tfm;
 100         unsigned long alignmask = crypto_shash_alignmask(tfm);
 101         struct shash_alg *shash = crypto_shash_alg(tfm);
 102         unsigned int ds = crypto_shash_digestsize(tfm);
 103         u8 buf[shash_align_buffer_size(ds, alignmask)]
 104                 __attribute__ ((aligned));
 105         int err;
 106
 107         err = shash->final(desc, buf);
 108         memcpy(out, buf, ds);
 109         return err;
 110 }
 111
 112 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 113 {
 114         struct crypto_shash *tfm = desc->tfm;
 115         struct shash_alg *shash = crypto_shash_alg(tfm);
 116         unsigned long alignmask = crypto_shash_alignmask(tfm);
 117
 118         if ((unsigned long)out & alignmask)
 119                 return shash_final_unaligned(desc, out);
 120
 121         return shash->final(desc, out);
 122 }
 123 EXPORT_SYMBOL_GPL(crypto_shash_final);
 124
 125 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 126                                  unsigned int len, u8 *out)
 127 {
 128         return crypto_shash_update(desc, data, len) ?:
 129                crypto_shash_final(desc, out);
 130 }
 131
 132 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 133                        unsigned int len, u8 *out)
 134 {
 135         struct crypto_shash *tfm = desc->tfm;
 136         struct shash_alg *shash = crypto_shash_alg(tfm);
 137         unsigned long alignmask = crypto_shash_alignmask(tfm);
 138
 139         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 140             !shash->finup)
 141                 return shash_finup_unaligned(desc, data, len, out);
 142
 143         return shash->finup(desc, data, len, out);
 144 }
 145 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 146
 147 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 148                                   unsigned int len, u8 *out)
 149 {
 150         return crypto_shash_init(desc) ?:
 151                crypto_shash_update(desc, data, len) ?:
 152                crypto_shash_final(desc, out);
 153 }
 154
 155 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 156                         unsigned int len, u8 *out)
 157 {
 158         struct crypto_shash *tfm = desc->tfm;
 159         struct shash_alg *shash = crypto_shash_alg(tfm);
 160         unsigned long alignmask = crypto_shash_alignmask(tfm);
 161
 162         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 163             !shash->digest)
 164                 return shash_digest_unaligned(desc, data, len, out);
 165
 166         return shash->digest(desc, data, len, out);
 167 }
 168 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 169
 170 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
 171                                  const struct crypto_type *frontend)
 172 {
 173         if (frontend->type != CRYPTO_ALG_TYPE_SHASH)
 174                 return -EINVAL;
 175         return 0;
 176 }
 177
 178 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
 179                                          const struct crypto_type *frontend)
 180 {
 181         return alg->cra_ctxsize;
 182 }
 183
 184 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 185         __attribute__ ((unused));
 186 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 187 {
 188         struct shash_alg *salg = __crypto_shash_alg(alg);
 189
 190         seq_printf(m, "type         : shash\n");
 191         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 192         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 193         seq_printf(m, "descsize     : %u\n", salg->descsize);
 194 }
 195
 196 static const struct crypto_type crypto_shash_type = {
 197         .extsize = crypto_shash_extsize,
 198         .init_tfm = crypto_shash_init_tfm,
 199 #ifdef CONFIG_PROC_FS
 200         .show = crypto_shash_show,
 201 #endif
 202         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 203         .maskset = CRYPTO_ALG_TYPE_MASK,
 204         .type = CRYPTO_ALG_TYPE_SHASH,
 205         .tfmsize = offsetof(struct crypto_shash, base),
 206 };
 207
 208 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 209                                         u32 mask)
 210 {
 211         return __crypto_shash_cast(
 212                 crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask));
 213 }
 214 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 215
 216 int crypto_register_shash(struct shash_alg *alg)
 217 {
 218         struct crypto_alg *base = &alg->base;
 219
 220         if (alg->digestsize > PAGE_SIZE / 8 ||
 221             alg->descsize > PAGE_SIZE / 8)
 222                 return -EINVAL;
 223
 224         base->cra_type = &crypto_shash_type;
 225         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 226         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 227
 228         return crypto_register_alg(base);
 229 }
 230 EXPORT_SYMBOL_GPL(crypto_register_shash);
 231
 232 int crypto_unregister_shash(struct shash_alg *alg)
 233 {
 234         return crypto_unregister_alg(&alg->base);
 235 }
 236 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 237
 238 MODULE_LICENSE("GPL");
 239 MODULE_DESCRIPTION("Synchronous cryptographic hash type");