postgresql/contrib/pgcrypto/pgp-encrypt.c
Michael Paquier ca7f8e2b86 Remove custom memory allocation layer in pgcrypto
PX_OWN_ALLOC was intended as a way to disable the use of palloc(), and
over the time new palloc() or equivalent calls have been added like in
32984d8, making this extra layer losing its original purpose.  This
simplifies on the way some code paths to use palloc0() rather than
palloc() followed by memset(0).

Author: Daniel Gustafsson
Discussion: https://postgr.es/m/A5BFAA1A-B2E8-4CBC-895E-7B1B9475A527@yesql.se
2020-09-25 10:25:55 +09:00

705 lines
12 KiB
C

/*
* pgp-encrypt.c
* OpenPGP encrypt.
*
* 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-encrypt.c
*/
#include "postgres.h"
#include <time.h>
#include "mbuf.h"
#include "pgp.h"
#include "px.h"
#define MDC_DIGEST_LEN 20
#define STREAM_ID 0xE0
#define STREAM_BLOCK_SHIFT 14
static uint8 *
render_newlen(uint8 *h, int len)
{
if (len <= 191)
{
*h++ = len & 255;
}
else if (len > 191 && len <= 8383)
{
*h++ = ((len - 192) >> 8) + 192;
*h++ = (len - 192) & 255;
}
else
{
*h++ = 255;
*h++ = (len >> 24) & 255;
*h++ = (len >> 16) & 255;
*h++ = (len >> 8) & 255;
*h++ = len & 255;
}
return h;
}
static int
write_tag_only(PushFilter *dst, int tag)
{
uint8 hdr = 0xC0 | tag;
return pushf_write(dst, &hdr, 1);
}
static int
write_normal_header(PushFilter *dst, int tag, int len)
{
uint8 hdr[8];
uint8 *h = hdr;
*h++ = 0xC0 | tag;
h = render_newlen(h, len);
return pushf_write(dst, hdr, h - hdr);
}
/*
* MAC writer
*/
static int
mdc_init(PushFilter *dst, void *init_arg, void **priv_p)
{
int res;
PX_MD *md;
res = pgp_load_digest(PGP_DIGEST_SHA1, &md);
if (res < 0)
return res;
*priv_p = md;
return 0;
}
static int
mdc_write(PushFilter *dst, void *priv, const uint8 *data, int len)
{
PX_MD *md = priv;
px_md_update(md, data, len);
return pushf_write(dst, data, len);
}
static int
mdc_flush(PushFilter *dst, void *priv)
{
int res;
uint8 pkt[2 + MDC_DIGEST_LEN];
PX_MD *md = priv;
/*
* create mdc pkt
*/
pkt[0] = 0xD3;
pkt[1] = 0x14; /* MDC_DIGEST_LEN */
px_md_update(md, pkt, 2);
px_md_finish(md, pkt + 2);
res = pushf_write(dst, pkt, 2 + MDC_DIGEST_LEN);
px_memset(pkt, 0, 2 + MDC_DIGEST_LEN);
return res;
}
static void
mdc_free(void *priv)
{
PX_MD *md = priv;
px_md_free(md);
}
static const PushFilterOps mdc_filter = {
mdc_init, mdc_write, mdc_flush, mdc_free
};
/*
* Encrypted pkt writer
*/
#define ENCBUF 8192
struct EncStat
{
PGP_CFB *ciph;
uint8 buf[ENCBUF];
};
static int
encrypt_init(PushFilter *next, void *init_arg, void **priv_p)
{
struct EncStat *st;
PGP_Context *ctx = init_arg;
PGP_CFB *ciph;
int resync = 1;
int res;
/* should we use newer packet format? */
if (ctx->disable_mdc == 0)
{
uint8 ver = 1;
resync = 0;
res = pushf_write(next, &ver, 1);
if (res < 0)
return res;
}
res = pgp_cfb_create(&ciph, ctx->cipher_algo,
ctx->sess_key, ctx->sess_key_len, resync, NULL);
if (res < 0)
return res;
st = palloc0(sizeof(*st));
st->ciph = ciph;
*priv_p = st;
return ENCBUF;
}
static int
encrypt_process(PushFilter *next, void *priv, const uint8 *data, int len)
{
int res;
struct EncStat *st = priv;
int avail = len;
while (avail > 0)
{
int tmplen = avail > ENCBUF ? ENCBUF : avail;
res = pgp_cfb_encrypt(st->ciph, data, tmplen, st->buf);
if (res < 0)
return res;
res = pushf_write(next, st->buf, tmplen);
if (res < 0)
return res;
data += tmplen;
avail -= tmplen;
}
return 0;
}
static void
encrypt_free(void *priv)
{
struct EncStat *st = priv;
if (st->ciph)
pgp_cfb_free(st->ciph);
px_memset(st, 0, sizeof(*st));
pfree(st);
}
static const PushFilterOps encrypt_filter = {
encrypt_init, encrypt_process, NULL, encrypt_free
};
/*
* Write Streamable pkts
*/
struct PktStreamStat
{
int final_done;
int pkt_block;
};
static int
pkt_stream_init(PushFilter *next, void *init_arg, void **priv_p)
{
struct PktStreamStat *st;
st = palloc(sizeof(*st));
st->final_done = 0;
st->pkt_block = 1 << STREAM_BLOCK_SHIFT;
*priv_p = st;
return st->pkt_block;
}
static int
pkt_stream_process(PushFilter *next, void *priv, const uint8 *data, int len)
{
int res;
uint8 hdr[8];
uint8 *h = hdr;
struct PktStreamStat *st = priv;
if (st->final_done)
return PXE_BUG;
if (len == st->pkt_block)
*h++ = STREAM_ID | STREAM_BLOCK_SHIFT;
else
{
h = render_newlen(h, len);
st->final_done = 1;
}
res = pushf_write(next, hdr, h - hdr);
if (res < 0)
return res;
return pushf_write(next, data, len);
}
static int
pkt_stream_flush(PushFilter *next, void *priv)
{
int res;
uint8 hdr[8];
uint8 *h = hdr;
struct PktStreamStat *st = priv;
/* stream MUST end with normal packet. */
if (!st->final_done)
{
h = render_newlen(h, 0);
res = pushf_write(next, hdr, h - hdr);
if (res < 0)
return res;
st->final_done = 1;
}
return 0;
}
static void
pkt_stream_free(void *priv)
{
struct PktStreamStat *st = priv;
px_memset(st, 0, sizeof(*st));
pfree(st);
}
static const PushFilterOps pkt_stream_filter = {
pkt_stream_init, pkt_stream_process, pkt_stream_flush, pkt_stream_free
};
int
pgp_create_pkt_writer(PushFilter *dst, int tag, PushFilter **res_p)
{
int res;
res = write_tag_only(dst, tag);
if (res < 0)
return res;
return pushf_create(res_p, &pkt_stream_filter, NULL, dst);
}
/*
* Text conversion filter
*/
static int
crlf_process(PushFilter *dst, void *priv, const uint8 *data, int len)
{
const uint8 *data_end = data + len;
const uint8 *p2,
*p1 = data;
int line_len;
static const uint8 crlf[] = {'\r', '\n'};
int res = 0;
while (p1 < data_end)
{
p2 = memchr(p1, '\n', data_end - p1);
if (p2 == NULL)
p2 = data_end;
line_len = p2 - p1;
/* write data */
res = 0;
if (line_len > 0)
{
res = pushf_write(dst, p1, line_len);
if (res < 0)
break;
p1 += line_len;
}
/* write crlf */
while (p1 < data_end && *p1 == '\n')
{
res = pushf_write(dst, crlf, 2);
if (res < 0)
break;
p1++;
}
}
return res;
}
static const PushFilterOps crlf_filter = {
NULL, crlf_process, NULL, NULL
};
/*
* Initialize literal data packet
*/
static int
init_litdata_packet(PushFilter **pf_res, PGP_Context *ctx, PushFilter *dst)
{
int res;
int hdrlen;
uint8 hdr[6];
uint32 t;
PushFilter *pkt;
int type;
/*
* Create header
*/
if (ctx->text_mode)
type = ctx->unicode_mode ? 'u' : 't';
else
type = 'b';
/*
* Store the creation time into packet. The goal is to have as few known
* bytes as possible.
*/
t = (uint32) time(NULL);
hdr[0] = type;
hdr[1] = 0;
hdr[2] = (t >> 24) & 255;
hdr[3] = (t >> 16) & 255;
hdr[4] = (t >> 8) & 255;
hdr[5] = t & 255;
hdrlen = 6;
res = write_tag_only(dst, PGP_PKT_LITERAL_DATA);
if (res < 0)
return res;
res = pushf_create(&pkt, &pkt_stream_filter, ctx, dst);
if (res < 0)
return res;
res = pushf_write(pkt, hdr, hdrlen);
if (res < 0)
{
pushf_free(pkt);
return res;
}
*pf_res = pkt;
return 0;
}
/*
* Initialize compression filter
*/
static int
init_compress(PushFilter **pf_res, PGP_Context *ctx, PushFilter *dst)
{
int res;
uint8 type = ctx->compress_algo;
PushFilter *pkt;
res = write_tag_only(dst, PGP_PKT_COMPRESSED_DATA);
if (res < 0)
return res;
res = pushf_create(&pkt, &pkt_stream_filter, ctx, dst);
if (res < 0)
return res;
res = pushf_write(pkt, &type, 1);
if (res >= 0)
res = pgp_compress_filter(pf_res, ctx, pkt);
if (res < 0)
pushf_free(pkt);
return res;
}
/*
* Initialize encdata packet
*/
static int
init_encdata_packet(PushFilter **pf_res, PGP_Context *ctx, PushFilter *dst)
{
int res;
int tag;
if (ctx->disable_mdc)
tag = PGP_PKT_SYMENCRYPTED_DATA;
else
tag = PGP_PKT_SYMENCRYPTED_DATA_MDC;
res = write_tag_only(dst, tag);
if (res < 0)
return res;
return pushf_create(pf_res, &pkt_stream_filter, ctx, dst);
}
/*
* write prefix
*/
static int
write_prefix(PGP_Context *ctx, PushFilter *dst)
{
uint8 prefix[PGP_MAX_BLOCK + 2];
int res,
bs;
bs = pgp_get_cipher_block_size(ctx->cipher_algo);
if (!pg_strong_random(prefix, bs))
return PXE_NO_RANDOM;
prefix[bs + 0] = prefix[bs - 2];
prefix[bs + 1] = prefix[bs - 1];
res = pushf_write(dst, prefix, bs + 2);
px_memset(prefix, 0, bs + 2);
return res < 0 ? res : 0;
}
/*
* write symmetrically encrypted session key packet
*/
static int
symencrypt_sesskey(PGP_Context *ctx, uint8 *dst)
{
int res;
PGP_CFB *cfb;
uint8 algo = ctx->cipher_algo;
res = pgp_cfb_create(&cfb, ctx->s2k_cipher_algo,
ctx->s2k.key, ctx->s2k.key_len, 0, NULL);
if (res < 0)
return res;
pgp_cfb_encrypt(cfb, &algo, 1, dst);
pgp_cfb_encrypt(cfb, ctx->sess_key, ctx->sess_key_len, dst + 1);
pgp_cfb_free(cfb);
return ctx->sess_key_len + 1;
}
/* 5.3: Symmetric-Key Encrypted Session-Key */
static int
write_symenc_sesskey(PGP_Context *ctx, PushFilter *dst)
{
uint8 pkt[256];
int pktlen;
int res;
uint8 *p = pkt;
*p++ = 4; /* 5.3 - version number */
*p++ = ctx->s2k_cipher_algo;
*p++ = ctx->s2k.mode;
*p++ = ctx->s2k.digest_algo;
if (ctx->s2k.mode > 0)
{
memcpy(p, ctx->s2k.salt, 8);
p += 8;
}
if (ctx->s2k.mode == 3)
*p++ = ctx->s2k.iter;
if (ctx->use_sess_key)
{
res = symencrypt_sesskey(ctx, p);
if (res < 0)
return res;
p += res;
}
pktlen = p - pkt;
res = write_normal_header(dst, PGP_PKT_SYMENCRYPTED_SESSKEY, pktlen);
if (res >= 0)
res = pushf_write(dst, pkt, pktlen);
px_memset(pkt, 0, pktlen);
return res;
}
/*
* key setup
*/
static int
init_s2k_key(PGP_Context *ctx)
{
int res;
if (ctx->s2k_cipher_algo < 0)
ctx->s2k_cipher_algo = ctx->cipher_algo;
res = pgp_s2k_fill(&ctx->s2k, ctx->s2k_mode, ctx->s2k_digest_algo, ctx->s2k_count);
if (res < 0)
return res;
return pgp_s2k_process(&ctx->s2k, ctx->s2k_cipher_algo,
ctx->sym_key, ctx->sym_key_len);
}
static int
init_sess_key(PGP_Context *ctx)
{
if (ctx->use_sess_key || ctx->pub_key)
{
ctx->sess_key_len = pgp_get_cipher_key_size(ctx->cipher_algo);
if (!pg_strong_random(ctx->sess_key, ctx->sess_key_len))
return PXE_NO_RANDOM;
}
else
{
ctx->sess_key_len = ctx->s2k.key_len;
memcpy(ctx->sess_key, ctx->s2k.key, ctx->s2k.key_len);
}
return 0;
}
/*
* combine
*/
int
pgp_encrypt(PGP_Context *ctx, MBuf *src, MBuf *dst)
{
int res;
int len;
uint8 *buf;
PushFilter *pf,
*pf_tmp;
/*
* do we have any key
*/
if (!ctx->sym_key && !ctx->pub_key)
return PXE_ARGUMENT_ERROR;
/* MBuf writer */
res = pushf_create_mbuf_writer(&pf, dst);
if (res < 0)
goto out;
/*
* initialize sym_key
*/
if (ctx->sym_key)
{
res = init_s2k_key(ctx);
if (res < 0)
goto out;
}
res = init_sess_key(ctx);
if (res < 0)
goto out;
/*
* write keypkt
*/
if (ctx->pub_key)
res = pgp_write_pubenc_sesskey(ctx, pf);
else
res = write_symenc_sesskey(ctx, pf);
if (res < 0)
goto out;
/* encrypted data pkt */
res = init_encdata_packet(&pf_tmp, ctx, pf);
if (res < 0)
goto out;
pf = pf_tmp;
/* encrypter */
res = pushf_create(&pf_tmp, &encrypt_filter, ctx, pf);
if (res < 0)
goto out;
pf = pf_tmp;
/* hasher */
if (ctx->disable_mdc == 0)
{
res = pushf_create(&pf_tmp, &mdc_filter, ctx, pf);
if (res < 0)
goto out;
pf = pf_tmp;
}
/* prefix */
res = write_prefix(ctx, pf);
if (res < 0)
goto out;
/* compressor */
if (ctx->compress_algo > 0 && ctx->compress_level > 0)
{
res = init_compress(&pf_tmp, ctx, pf);
if (res < 0)
goto out;
pf = pf_tmp;
}
/* data streamer */
res = init_litdata_packet(&pf_tmp, ctx, pf);
if (res < 0)
goto out;
pf = pf_tmp;
/* text conversion? */
if (ctx->text_mode && ctx->convert_crlf)
{
res = pushf_create(&pf_tmp, &crlf_filter, ctx, pf);
if (res < 0)
goto out;
pf = pf_tmp;
}
/*
* chain complete
*/
len = mbuf_grab(src, mbuf_avail(src), &buf);
res = pushf_write(pf, buf, len);
if (res >= 0)
res = pushf_flush(pf);
out:
pushf_free_all(pf);
return res;
}