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grub/lib/crypto.c
Vladimir 'phcoder' Serbinenko 7316783f35 Crypto module autoloading
2009-12-23 17:33:35 +01:00

447 lines
10 KiB
C
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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006
* 2007, 2008, 2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/crypto.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/term.h>
struct grub_crypto_hmac_handle
{
const struct gcry_md_spec *md;
void *ctx;
void *opad;
};
static gcry_cipher_spec_t *grub_ciphers = NULL;
static gcry_md_spec_t *grub_digests = NULL;
void (*grub_crypto_autoload_hook) (const char *name) = NULL;
/* Based on libgcrypt-1.4.4/src/misc.c. */
void
grub_burn_stack (grub_size_t size)
{
char buf[64];
grub_memset (buf, 0, sizeof (buf));
if (size > sizeof (buf))
grub_burn_stack (size - sizeof (buf));
}
void
grub_cipher_register (gcry_cipher_spec_t *cipher)
{
cipher->next = grub_ciphers;
grub_ciphers = cipher;
}
void
grub_cipher_unregister (gcry_cipher_spec_t *cipher)
{
gcry_cipher_spec_t **ciph;
for (ciph = &grub_ciphers; *ciph; ciph = &((*ciph)->next))
if (*ciph == cipher)
*ciph = (*ciph)->next;
}
void
grub_md_register (gcry_md_spec_t *digest)
{
digest->next = grub_digests;
grub_digests = digest;
}
void
grub_md_unregister (gcry_md_spec_t *cipher)
{
gcry_md_spec_t **ciph;
for (ciph = &grub_digests; *ciph; ciph = &((*ciph)->next))
if (*ciph == cipher)
*ciph = (*ciph)->next;
}
void
grub_crypto_hash (const gcry_md_spec_t *hash, void *out, const void *in,
grub_size_t inlen)
{
grub_uint8_t ctx[hash->contextsize];
hash->init (&ctx);
hash->write (&ctx, in, inlen);
hash->final (&ctx);
grub_memcpy (out, hash->read (&ctx), hash->mdlen);
}
const gcry_md_spec_t *
grub_crypto_lookup_md_by_name (const char *name)
{
const gcry_md_spec_t *md;
int first = 1;
while (1)
{
for (md = grub_digests; md; md = md->next)
if (grub_strcasecmp (name, md->name) == 0)
return md;
if (grub_crypto_autoload_hook && first)
grub_crypto_autoload_hook (name);
else
return NULL;
first = 0;
}
}
const gcry_cipher_spec_t *
grub_crypto_lookup_cipher_by_name (const char *name)
{
const gcry_cipher_spec_t *ciph;
int first = 1;
while (1)
{
for (ciph = grub_ciphers; ciph; ciph = ciph->next)
{
const char **alias;
if (grub_strcasecmp (name, ciph->name) == 0)
return ciph;
if (!ciph->aliases)
continue;
for (alias = ciph->aliases; *alias; alias++)
if (grub_strcasecmp (name, *alias) == 0)
return ciph;
}
if (grub_crypto_autoload_hook && first)
grub_crypto_autoload_hook (name);
else
return NULL;
first = 0;
}
}
grub_crypto_cipher_handle_t
grub_crypto_cipher_open (const struct gcry_cipher_spec *cipher)
{
grub_crypto_cipher_handle_t ret;
ret = grub_malloc (sizeof (*ret) + cipher->contextsize);
if (!ret)
return NULL;
ret->cipher = cipher;
return ret;
}
gcry_err_code_t
grub_crypto_cipher_set_key (grub_crypto_cipher_handle_t cipher,
const unsigned char *key,
unsigned keylen)
{
return cipher->cipher->setkey (cipher->ctx, key, keylen);
}
void
grub_crypto_cipher_close (grub_crypto_cipher_handle_t cipher)
{
grub_free (cipher);
}
void
grub_crypto_xor (void *out, const void *in1, const void *in2, grub_size_t size)
{
const grub_uint8_t *in1ptr = in1, *in2ptr = in2;
grub_uint8_t *outptr = out;
while (size--)
{
*outptr = *in1ptr ^ *in2ptr;
in1ptr++;
in2ptr++;
outptr++;
}
}
gcry_err_code_t
grub_crypto_ecb_decrypt (grub_crypto_cipher_handle_t cipher,
void *out, void *in, grub_size_t size)
{
grub_uint8_t *inptr, *outptr, *end;
if (!cipher->cipher->decrypt)
return GPG_ERR_NOT_SUPPORTED;
if (size % cipher->cipher->blocksize != 0)
return GPG_ERR_INV_ARG;
end = (grub_uint8_t *) in + size;
for (inptr = in, outptr = out; inptr < end;
inptr += cipher->cipher->blocksize, outptr += cipher->cipher->blocksize)
cipher->cipher->decrypt (cipher->ctx, outptr, inptr);
return GPG_ERR_NO_ERROR;
}
gcry_err_code_t
grub_crypto_ecb_encrypt (grub_crypto_cipher_handle_t cipher,
void *out, void *in, grub_size_t size)
{
grub_uint8_t *inptr, *outptr, *end;
if (!cipher->cipher->encrypt)
return GPG_ERR_NOT_SUPPORTED;
if (size % cipher->cipher->blocksize != 0)
return GPG_ERR_INV_ARG;
end = (grub_uint8_t *) in + size;
for (inptr = in, outptr = out; inptr < end;
inptr += cipher->cipher->blocksize, outptr += cipher->cipher->blocksize)
cipher->cipher->encrypt (cipher->ctx, outptr, inptr);
return GPG_ERR_NO_ERROR;
}
gcry_err_code_t
grub_crypto_cbc_encrypt (grub_crypto_cipher_handle_t cipher,
void *out, void *in, grub_size_t size,
void *iv_in)
{
grub_uint8_t *inptr, *outptr, *end;
void *iv;
if (!cipher->cipher->decrypt)
return GPG_ERR_NOT_SUPPORTED;
if (size % cipher->cipher->blocksize != 0)
return GPG_ERR_INV_ARG;
end = (grub_uint8_t *) in + size;
iv = iv_in;
for (inptr = in, outptr = out; inptr < end;
inptr += cipher->cipher->blocksize, outptr += cipher->cipher->blocksize)
{
grub_crypto_xor (outptr, inptr, iv, cipher->cipher->blocksize);
cipher->cipher->encrypt (cipher->ctx, outptr, outptr);
iv = outptr;
}
grub_memcpy (iv_in, iv, cipher->cipher->blocksize);
return GPG_ERR_NO_ERROR;
}
gcry_err_code_t
grub_crypto_cbc_decrypt (grub_crypto_cipher_handle_t cipher,
void *out, void *in, grub_size_t size,
void *iv)
{
grub_uint8_t *inptr, *outptr, *end;
grub_uint8_t ivt[cipher->cipher->blocksize];
if (!cipher->cipher->decrypt)
return GPG_ERR_NOT_SUPPORTED;
if (size % cipher->cipher->blocksize != 0)
return GPG_ERR_INV_ARG;
end = (grub_uint8_t *) in + size;
for (inptr = in, outptr = out; inptr < end;
inptr += cipher->cipher->blocksize, outptr += cipher->cipher->blocksize)
{
grub_memcpy (ivt, inptr, cipher->cipher->blocksize);
cipher->cipher->decrypt (cipher->ctx, outptr, inptr);
grub_crypto_xor (outptr, outptr, iv, cipher->cipher->blocksize);
grub_memcpy (iv, ivt, cipher->cipher->blocksize);
}
return GPG_ERR_NO_ERROR;
}
/* Based on gcry/cipher/md.c. */
struct grub_crypto_hmac_handle *
grub_crypto_hmac_init (const struct gcry_md_spec *md,
const void *key, grub_size_t keylen)
{
grub_uint8_t *helpkey = NULL;
grub_uint8_t *ipad = NULL, *opad = NULL;
void *ctx = NULL;
struct grub_crypto_hmac_handle *ret = NULL;
unsigned i;
if (md->mdlen > md->blocksize)
return NULL;
ctx = grub_malloc (md->contextsize);
if (!ctx)
goto err;
if ( keylen > md->blocksize )
{
helpkey = grub_malloc (md->mdlen);
if (!helpkey)
goto err;
grub_crypto_hash (md, helpkey, key, keylen);
key = helpkey;
keylen = md->mdlen;
}
ipad = grub_zalloc (md->blocksize);
if (!ipad)
goto err;
opad = grub_zalloc (md->blocksize);
if (!opad)
goto err;
grub_memcpy ( ipad, key, keylen );
grub_memcpy ( opad, key, keylen );
for (i=0; i < md->blocksize; i++ )
{
ipad[i] ^= 0x36;
opad[i] ^= 0x5c;
}
grub_free (helpkey);
helpkey = NULL;
md->init (ctx);
md->write (ctx, ipad, md->blocksize); /* inner pad */
grub_memset (ipad, 0, md->blocksize);
grub_free (ipad);
ipad = NULL;
ret = grub_malloc (sizeof (*ret));
if (!ret)
goto err;
ret->md = md;
ret->ctx = ctx;
ret->opad = opad;
return ret;
err:
grub_free (helpkey);
grub_free (ctx);
grub_free (ipad);
grub_free (opad);
return NULL;
}
void
grub_crypto_hmac_write (struct grub_crypto_hmac_handle *hnd, void *data,
grub_size_t datalen)
{
hnd->md->write (hnd->ctx, data, datalen);
}
gcry_err_code_t
grub_crypto_hmac_fini (struct grub_crypto_hmac_handle *hnd, void *out)
{
grub_uint8_t *p;
grub_uint8_t *ctx2;
ctx2 = grub_malloc (hnd->md->contextsize);
if (!ctx2)
return GPG_ERR_OUT_OF_MEMORY;
hnd->md->final (hnd->ctx);
hnd->md->read (hnd->ctx);
p = hnd->md->read (hnd->ctx);
hnd->md->init (ctx2);
hnd->md->write (ctx2, hnd->opad, hnd->md->blocksize);
hnd->md->write (ctx2, p, hnd->md->mdlen);
hnd->md->final (ctx2);
grub_memset (hnd->opad, 0, hnd->md->blocksize);
grub_free (hnd->opad);
grub_memset (hnd->ctx, 0, hnd->md->contextsize);
grub_free (hnd->ctx);
grub_memcpy (out, hnd->md->read (ctx2), hnd->md->mdlen);
grub_memset (ctx2, 0, hnd->md->contextsize);
grub_free (ctx2);
grub_memset (hnd, 0, sizeof (*hnd));
grub_free (hnd);
return GPG_ERR_NO_ERROR;
}
gcry_err_code_t
grub_crypto_hmac_buffer (const struct gcry_md_spec *md,
const void *key, grub_size_t keylen,
void *data, grub_size_t datalen, void *out)
{
struct grub_crypto_hmac_handle *hnd;
hnd = grub_crypto_hmac_init (md, key, keylen);
if (!hnd)
return GPG_ERR_OUT_OF_MEMORY;
grub_crypto_hmac_write (hnd, data, datalen);
return grub_crypto_hmac_fini (hnd, out);
}
grub_err_t
grub_crypto_gcry_error (gcry_err_code_t in)
{
if (in == GPG_ERR_NO_ERROR)
return GRUB_ERR_NONE;
return GRUB_ACCESS_DENIED;
}
int
grub_crypto_memcmp (const void *a, const void *b, grub_size_t n)
{
register grub_size_t counter = 0;
const grub_uint8_t *pa, *pb;
for (pa = a, pb = b; n; pa++, pb++, n--)
{
if (*pa != *pb)
counter++;
}
return !!counter;
}
#ifndef GRUB_MKPASSWD
int
grub_password_get (char buf[], unsigned buf_size)
{
unsigned cur_len = 0;
int key;
while (1)
{
key = GRUB_TERM_ASCII_CHAR (grub_getkey ());
if (key == '\n' || key == '\r')
break;
if (key == '\e')
{
cur_len = 0;
break;
}
if (key == '\b')
{
cur_len--;
continue;
}
if (!grub_isprint (key))
continue;
if (cur_len + 2 < buf_size)
buf[cur_len++] = key;
}
grub_memset (buf + cur_len, 0, buf_size - cur_len);
grub_putchar ('\n');
grub_refresh ();
return (key != '\e');
}
#endif
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