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/*
* Copyright (C) 2012 Red Hat Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above
* copyright notice, this list of conditions and the
* following disclaimer.
* * Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and
* the following disclaimer in the documentation and/or
* other materials provided with the distribution.
* * The names of contributors to this software may not be
* used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
* THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* Author: Stef Walter <stefw@redhat.com>
*/
#include "config.h"
#include "compat.h"
#include "base64.h"
#include "debug.h"
#include "pem.h"
#include <assert.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#define ARMOR_SUFF "-----"
#define ARMOR_SUFF_L 5
#define ARMOR_PREF_BEGIN "-----BEGIN "
#define ARMOR_PREF_BEGIN_L 11
#define ARMOR_PREF_END "-----END "
#define ARMOR_PREF_END_L 9
enum {
NONE = 0,
TRUSTED_CERTIFICATE,
CERTIFICATE
};
static const char *
pem_find_begin (const char *data,
size_t n_data,
char **type)
{
const char *pref, *suff;
/* Look for a prefix */
pref = strnstr ((char *)data, ARMOR_PREF_BEGIN, n_data);
if (!pref)
return NULL;
n_data -= (pref - data) + ARMOR_PREF_BEGIN_L;
data = pref + ARMOR_PREF_BEGIN_L;
/* Look for the end of that begin */
suff = strnstr ((char *)data, ARMOR_SUFF, n_data);
if (!suff)
return NULL;
/* Make sure on the same line */
if (memchr (pref, '\n', suff - pref))
return NULL;
if (type) {
pref += ARMOR_PREF_BEGIN_L;
assert (suff > pref);
*type = malloc (suff - pref + 1);
return_val_if_fail (*type != NULL, NULL);
memcpy (*type, pref, suff - pref);
(*type)[suff - pref] = 0;
}
/* The byte after this ---BEGIN--- */
return suff + ARMOR_SUFF_L;
}
static const char *
pem_find_end (const char *data,
size_t n_data,
const char *type)
{
const char *pref;
size_t n_type;
/* Look for a prefix */
pref = strnstr (data, ARMOR_PREF_END, n_data);
if (!pref)
return NULL;
n_data -= (pref - data) + ARMOR_PREF_END_L;
data = pref + ARMOR_PREF_END_L;
/* Next comes the type string */
n_type = strlen (type);
if (n_type > n_data || strncmp ((char *)data, type, n_type) != 0)
return NULL;
n_data -= n_type;
data += n_type;
/* Next comes the suffix */
if (ARMOR_SUFF_L > n_data && strncmp ((char *)data, ARMOR_SUFF, ARMOR_SUFF_L) != 0)
return NULL;
/* The end of the data */
return pref;
}
static unsigned char *
pem_parse_block (const char *data,
size_t n_data,
size_t *n_decoded)
{
const char *x, *hbeg, *hend;
const char *p, *end;
unsigned char *decoded;
size_t length;
int ret;
assert (data != NULL);
assert (n_data != 0);
assert (n_decoded != NULL);
p = data;
end = p + n_data;
hbeg = hend = NULL;
/* Try and find a pair of blank lines with only white space between */
while (hend == NULL) {
x = memchr (p, '\n', end - p);
if (!x)
break;
++x;
while (isspace (*x)) {
/* Found a second line, with only spaces between */
if (*x == '\n') {
hbeg = data;
hend = x;
break;
/* Found a space between two lines */
} else {
++x;
}
}
/* Try next line */
p = x;
}
/* Headers found? */
if (hbeg && hend) {
data = hend;
n_data = end - data;
}
length = (n_data * 3) / 4 + 1;
decoded = malloc (length);
return_val_if_fail (decoded != NULL, 0);
ret = p11_b64_pton (data, n_data, decoded, length);
if (ret < 0) {
free (decoded);
return NULL;
}
/* No need to parse headers for our use cases */
*n_decoded = ret;
return decoded;
}
unsigned int
p11_pem_parse (const char *data,
size_t n_data,
p11_pem_sink sink,
void *user_data)
{
const char *beg, *end;
unsigned int nfound = 0;
unsigned char *decoded = NULL;
size_t n_decoded = 0;
char *type;
assert (data != NULL);
while (n_data > 0) {
/* This returns the first character after the PEM BEGIN header */
beg = pem_find_begin (data, n_data, &type);
if (beg == NULL)
break;
assert (type != NULL);
/* This returns the character position before the PEM END header */
end = pem_find_end (beg, n_data - (beg - data), type);
if (end == NULL) {
free (type);
break;
}
if (beg != end) {
decoded = pem_parse_block (beg, end - beg, &n_decoded);
if (decoded) {
if (sink != NULL)
(sink) (type, decoded, n_decoded, user_data);
++nfound;
}
}
free (type);
/* Try for another block */
end += ARMOR_SUFF_L;
n_data -= (const char *)end - (const char *)data;
data = end;
}
return nfound;
}
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