greenplumn pgp-armor 源码
greenplumn pgp-armor 代码
文件路径：/contrib/pgcrypto/pgp-armor.c
/*
* pgp-armor.c
* PGP ascii-armor.
*
* Copyright (c) 2005 Marko Kreen
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* contrib/pgcrypto/pgp-armor.c
*/
#include "postgres.h"
#include "px.h"
#include "pgp.h"
/*
* BASE64 - duplicated :(
*/
static const unsigned char _base64[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static int
pg_base64_encode(const uint8 *src, unsigned len, uint8 *dst)
{
uint8 *p,
*lend = dst + 76;
const uint8 *s,
*end = src + len;
int pos = 2;
unsigned long buf = 0;
s = src;
p = dst;
while (s < end)
{
buf |= *s << (pos << 3);
pos--;
s++;
/*
* write it out
*/
if (pos < 0)
{
*p++ = _base64[(buf >> 18) & 0x3f];
*p++ = _base64[(buf >> 12) & 0x3f];
*p++ = _base64[(buf >> 6) & 0x3f];
*p++ = _base64[buf & 0x3f];
pos = 2;
buf = 0;
}
if (p >= lend)
{
*p++ = '\n';
lend = p + 76;
}
}
if (pos != 2)
{
*p++ = _base64[(buf >> 18) & 0x3f];
*p++ = _base64[(buf >> 12) & 0x3f];
*p++ = (pos == 0) ? _base64[(buf >> 6) & 0x3f] : '=';
*p++ = '=';
}
return p - dst;
}
/* probably should use lookup table */
static int
pg_base64_decode(const uint8 *src, unsigned len, uint8 *dst)
{
const uint8 *srcend = src + len,
*s = src;
uint8 *p = dst;
char c;
unsigned b = 0;
unsigned long buf = 0;
int pos = 0,
end = 0;
while (s < srcend)
{
c = *s++;
if (c >= 'A' && c <= 'Z')
b = c - 'A';
else if (c >= 'a' && c <= 'z')
b = c - 'a' + 26;
else if (c >= '0' && c <= '9')
b = c - '0' + 52;
else if (c == '+')
b = 62;
else if (c == '/')
b = 63;
else if (c == '=')
{
/*
* end sequence
*/
if (!end)
{
if (pos == 2)
end = 1;
else if (pos == 3)
end = 2;
else
return PXE_PGP_CORRUPT_ARMOR;
}
b = 0;
}
else if (c == ' ' || c == '\t' || c == '\n' || c == '\r')
continue;
else
return PXE_PGP_CORRUPT_ARMOR;
/*
* add it to buffer
*/
buf = (buf << 6) + b;
pos++;
if (pos == 4)
{
*p++ = (buf >> 16) & 255;
if (end == 0 || end > 1)
*p++ = (buf >> 8) & 255;
if (end == 0 || end > 2)
*p++ = buf & 255;
buf = 0;
pos = 0;
}
}
if (pos != 0)
return PXE_PGP_CORRUPT_ARMOR;
return p - dst;
}
static unsigned
pg_base64_enc_len(unsigned srclen)
{
/*
* 3 bytes will be converted to 4, linefeed after 76 chars
*/
return (srclen + 2) * 4 / 3 + srclen / (76 * 3 / 4);
}
static unsigned
pg_base64_dec_len(unsigned srclen)
{
return (srclen * 3) >> 2;
}
/*
* PGP armor
*/
static const char *armor_header = "-----BEGIN PGP MESSAGE-----\n";
static const char *armor_footer = "\n-----END PGP MESSAGE-----\n";
/* CRC24 implementation from rfc2440 */
#define CRC24_INIT 0x00b704ceL
#define CRC24_POLY 0x01864cfbL
static long
crc24(const uint8 *data, unsigned len)
{
unsigned crc = CRC24_INIT;
int i;
while (len--)
{
crc ^= (*data++) << 16;
for (i = 0; i < 8; i++)
{
crc <<= 1;
if (crc & 0x1000000)
crc ^= CRC24_POLY;
}
}
return crc & 0xffffffL;
}
void
pgp_armor_encode(const uint8 *src, unsigned len, StringInfo dst,
int num_headers, char **keys, char **values)
{
int n;
int res;
unsigned b64len;
unsigned crc = crc24(src, len);
appendStringInfoString(dst, armor_header);
for (n = 0; n < num_headers; n++)
appendStringInfo(dst, "%s: %s\n", keys[n], values[n]);
appendStringInfoChar(dst, '\n');
/* make sure we have enough room to pg_base64_encode() */
b64len = pg_base64_enc_len(len);
enlargeStringInfo(dst, (int) b64len);
res = pg_base64_encode(src, len, (uint8 *) dst->data + dst->len);
if (res > b64len)
elog(FATAL, "overflow - encode estimate too small");
dst->len += res;
if (*(dst->data + dst->len - 1) != '\n')
appendStringInfoChar(dst, '\n');
appendStringInfoChar(dst, '=');
appendStringInfoChar(dst, _base64[(crc >> 18) & 0x3f]);
appendStringInfoChar(dst, _base64[(crc >> 12) & 0x3f]);
appendStringInfoChar(dst, _base64[(crc >> 6) & 0x3f]);
appendStringInfoChar(dst, _base64[crc & 0x3f]);
appendStringInfoString(dst, armor_footer);
}
static const uint8 *
find_str(const uint8 *data, const uint8 *data_end, const char *str, int strlen)
{
const uint8 *p = data;
if (!strlen)
return NULL;
if (data_end - data < strlen)
return NULL;
while (p < data_end)
{
p = memchr(p, str[0], data_end - p);
if (p == NULL)
return NULL;
if (p + strlen > data_end)
return NULL;
if (memcmp(p, str, strlen) == 0)
return p;
p++;
}
return NULL;
}
static int
find_header(const uint8 *data, const uint8 *datend,
const uint8 **start_p, int is_end)
{
const uint8 *p = data;
static const char *start_sep = "-----BEGIN";
static const char *end_sep = "-----END";
const char *sep = is_end ? end_sep : start_sep;
/* find header line */
while (1)
{
p = find_str(p, datend, sep, strlen(sep));
if (p == NULL)
return PXE_PGP_CORRUPT_ARMOR;
/* it must start at beginning of line */
if (p == data || *(p - 1) == '\n')
break;
p += strlen(sep);
}
*start_p = p;
p += strlen(sep);
/* check if header text ok */
for (; p < datend && *p != '-'; p++)
{
/* various junk can be there, but definitely not line-feed */
if (*p >= ' ')
continue;
return PXE_PGP_CORRUPT_ARMOR;
}
if (datend - p < 5 || memcmp(p, sep, 5) != 0)
return PXE_PGP_CORRUPT_ARMOR;
p += 5;
/* check if at end of line */
if (p < datend)
{
if (*p != '\n' && *p != '\r')
return PXE_PGP_CORRUPT_ARMOR;
if (*p == '\r')
p++;
if (p < datend && *p == '\n')
p++;
}
return p - *start_p;
}
int
pgp_armor_decode(const uint8 *src, int len, StringInfo dst)
{
const uint8 *p = src;
const uint8 *data_end = src + len;
long crc;
const uint8 *base64_start,
*armor_end;
const uint8 *base64_end = NULL;
uint8 buf[4];
int hlen;
int blen;
int res = PXE_PGP_CORRUPT_ARMOR;
/* armor start */
hlen = find_header(src, data_end, &p, 0);
if (hlen <= 0)
goto out;
p += hlen;
/* armor end */
hlen = find_header(p, data_end, &armor_end, 1);
if (hlen <= 0)
goto out;
/* skip comments - find empty line */
while (p < armor_end && *p != '\n' && *p != '\r')
{
p = memchr(p, '\n', armor_end - p);
if (!p)
goto out;
/* step to start of next line */
p++;
}
base64_start = p;
/* find crc pos */
for (p = armor_end; p >= base64_start; p--)
if (*p == '=')
{
base64_end = p - 1;
break;
}
if (base64_end == NULL)
goto out;
/* decode crc */
if (pg_base64_decode(p + 1, 4, buf) != 3)
goto out;
crc = (((long) buf[0]) << 16) + (((long) buf[1]) << 8) + (long) buf[2];
/* decode data */
blen = (int) pg_base64_dec_len(len);
enlargeStringInfo(dst, blen);
res = pg_base64_decode(base64_start, base64_end - base64_start, (uint8 *) dst->data);
if (res > blen)
elog(FATAL, "overflow - decode estimate too small");
if (res >= 0)
{
if (crc24((uint8 *) dst->data, res) == crc)
dst->len += res;
else
res = PXE_PGP_CORRUPT_ARMOR;
}
out:
return res;
}
/*
* Extracts all armor headers from an ASCII-armored input.
*
* Returns 0 on success, or PXE_* error code on error. On success, the
* number of headers and their keys and values are returned in *nheaders,
* *nkeys and *nvalues.
*/
int
pgp_extract_armor_headers(const uint8 *src, unsigned len,
int *nheaders, char ***keys, char ***values)
{
const uint8 *data_end = src + len;
const uint8 *p;
const uint8 *base64_start;
const uint8 *armor_start;
const uint8 *armor_end;
Size armor_len;
char *line;
char *nextline;
char *eol,
*colon;
int hlen;
char *buf;
int hdrlines;
int n;
/* armor start */
hlen = find_header(src, data_end, &armor_start, 0);
if (hlen <= 0)
return PXE_PGP_CORRUPT_ARMOR;
armor_start += hlen;
/* armor end */
hlen = find_header(armor_start, data_end, &armor_end, 1);
if (hlen <= 0)
return PXE_PGP_CORRUPT_ARMOR;
/* Count the number of armor header lines. */
hdrlines = 0;
p = armor_start;
while (p < armor_end && *p != '\n' && *p != '\r')
{
p = memchr(p, '\n', armor_end - p);
if (!p)
return PXE_PGP_CORRUPT_ARMOR;
/* step to start of next line */
p++;
hdrlines++;
}
base64_start = p;
/*
* Make a modifiable copy of the part of the input that contains the
* headers. The returned key/value pointers will point inside the buffer.
*/
armor_len = base64_start - armor_start;
buf = palloc(armor_len + 1);
memcpy(buf, armor_start, armor_len);
buf[armor_len] = '\0';
/* Allocate return arrays */
*keys = (char **) palloc(hdrlines * sizeof(char *));
*values = (char **) palloc(hdrlines * sizeof(char *));
/*
* Split the header lines at newlines and ": " separators, and collect
* pointers to the keys and values in the return arrays.
*/
n = 0;
line = buf;
for (;;)
{
/* find end of line */
eol = strchr(line, '\n');
if (!eol)
break;
nextline = eol + 1;
/* if the line ends in CR + LF, strip the CR */
if (eol > line && *(eol - 1) == '\r')
eol--;
*eol = '\0';
/* find colon+space separating the key and value */
colon = strstr(line, ": ");
if (!colon)
return PXE_PGP_CORRUPT_ARMOR;
*colon = '\0';
/* shouldn't happen, we counted the number of lines beforehand */
if (n >= hdrlines)
elog(ERROR, "unexpected number of armor header lines");
(*keys)[n] = line;
(*values)[n] = colon + 2;
n++;
/* step to start of next line */
line = nextline;
}
if (n != hdrlines)
elog(ERROR, "unexpected number of armor header lines");
*nheaders = n;
return 0;
}
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