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/* Taken from minip12
*/
#include <gnutls_int.h>
#ifdef ENABLE_PKI
#include <gcrypt.h>
#include <gnutls_errors.h>
#include <ctype.h>
/* Returns 0 if the password is ok, or a negative error
* code instead.
*/
int _pkcs12_check_pass( const char* pass, size_t plen)
{
const unsigned char* p = pass;
int i;
for (i=0;i<plen;i++) {
if ( p[i] < 128) continue;
return GNUTLS_E_INVALID_PASSWORD;
}
return 0;
}
int
_pkcs12_string_to_key (int id, const char *salt, int salt_size, int iter, const char *pw,
int req_keylen, unsigned char *keybuf)
{
int rc, i, j;
GcryMDHd md;
GcryMPI num_b1 = NULL;
int pwlen;
unsigned char hash[20], buf_b[64], buf_i[128], *p;
size_t cur_keylen;
size_t n;
cur_keylen = 0;
pwlen = strlen (pw);
if (pwlen > 63/2 || salt_size > 8) {
gnutls_assert();
return GNUTLS_E_INVALID_REQUEST;
}
if ((rc=_pkcs12_check_pass( pw, pwlen)) < 0) {
gnutls_assert();
return rc;
}
/* Store salt and password in BUF_I */
p = buf_i;
for(i=0; i < 64; i++)
*p++ = salt [i%8];
for(i=j=0; i < 64; i += 2)
{
*p++ = 0;
*p++ = pw[j];
if (++j > pwlen) /* Note, that we include the trailing zero */
j = 0;
}
for (;;)
{
md = gcry_md_open (GCRY_MD_SHA1, 0);
if (!md)
{
return GNUTLS_E_DECRYPTION_FAILED;
}
for(i=0; i < 64; i++)
gcry_md_putc (md, id);
gcry_md_write (md, buf_i, 128);
memcpy (hash, gcry_md_read (md, 0), 20);
gcry_md_close (md);
for (i=1; i < iter; i++)
gcry_md_hash_buffer (GCRY_MD_SHA1, hash, hash, 20);
for (i=0; i < 20 && cur_keylen < req_keylen; i++)
keybuf[cur_keylen++] = hash[i];
if (cur_keylen == req_keylen)
{
gcry_mpi_release (num_b1);
return 0; /* ready */
}
/* need more bytes. */
for(i=0; i < 64; i++)
buf_b[i] = hash[i % 20];
n = 64;
rc = gcry_mpi_scan (&num_b1, GCRYMPI_FMT_USG, buf_b, &n);
if (rc)
{
return GNUTLS_E_DECRYPTION_FAILED;
}
gcry_mpi_add_ui (num_b1, num_b1, 1);
for (i=0; i < 128; i += 64)
{
GcryMPI num_ij;
n = 64;
rc = gcry_mpi_scan (&num_ij, GCRYMPI_FMT_USG, buf_i + i, &n);
if (rc)
{
return GNUTLS_E_DECRYPTION_FAILED;
}
gcry_mpi_add (num_ij, num_ij, num_b1);
gcry_mpi_clear_highbit (num_ij, 64*8);
n = 64;
rc = gcry_mpi_print (GCRYMPI_FMT_USG, buf_i + i, &n, num_ij);
if (rc)
{
return GNUTLS_E_DECRYPTION_FAILED;
}
gcry_mpi_release (num_ij);
}
}
}
#endif /* ENABLE_PKI */
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