postgresql/contrib/pgcrypto/internal.c
Neil Conway 1abf76e82c "Annual" pgcrypto update from Marko Kreen:
Few cleanups and couple of new things:

 - add SHA2 algorithm to older OpenSSL
 - add BIGNUM math to have public-key cryptography work on non-OpenSSL
   build.
 - gen_random_bytes() function

The status of SHA2 algoritms and public-key encryption can now be
changed to 'always available.'

That makes pgcrypto functionally complete and unless there will be new
editions of AES, SHA2 or OpenPGP standards, there is no major changes
planned.
2006-07-13 04:15:25 +00:00

687 lines
12 KiB
C

/*
* internal.c
* Wrapper for builtin functions
*
* Copyright (c) 2001 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.
*
* $PostgreSQL: pgsql/contrib/pgcrypto/internal.c,v 1.24 2006/07/13 04:15:24 neilc Exp $
*/
#include "postgres.h"
#include <time.h>
#include "px.h"
#include "md5.h"
#include "sha1.h"
#include "sha2.h"
#include "blf.h"
#include "rijndael.h"
#include "fortuna.h"
/*
* System reseeds should be separated at least this much.
*/
#define SYSTEM_RESEED_MIN (20*60) /* 20 min */
/*
* How often to roll dice.
*/
#define SYSTEM_RESEED_CHECK_TIME (10*60) /* 10 min */
/*
* The chance is x/256 that the reseed happens.
*/
#define SYSTEM_RESEED_CHANCE (4) /* 256/4 * 10min ~ 10h */
/*
* If this much time has passed, force reseed.
*/
#define SYSTEM_RESEED_MAX (12*60*60) /* 12h */
#ifndef MD5_DIGEST_LENGTH
#define MD5_DIGEST_LENGTH 16
#endif
#ifndef SHA1_DIGEST_LENGTH
#ifdef SHA1_RESULTLEN
#define SHA1_DIGEST_LENGTH SHA1_RESULTLEN
#else
#define SHA1_DIGEST_LENGTH 20
#endif
#endif
#define SHA1_BLOCK_SIZE 64
#define MD5_BLOCK_SIZE 64
static void init_md5(PX_MD * h);
static void init_sha1(PX_MD * h);
void init_sha224(PX_MD * h);
void init_sha256(PX_MD * h);
void init_sha384(PX_MD * h);
void init_sha512(PX_MD * h);
struct int_digest
{
char *name;
void (*init) (PX_MD * h);
};
static const struct int_digest
int_digest_list[] = {
{"md5", init_md5},
{"sha1", init_sha1},
{"sha224", init_sha224},
{"sha256", init_sha256},
{"sha384", init_sha384},
{"sha512", init_sha512},
{NULL, NULL}
};
/* MD5 */
static unsigned
int_md5_len(PX_MD * h)
{
return MD5_DIGEST_LENGTH;
}
static unsigned
int_md5_block_len(PX_MD * h)
{
return MD5_BLOCK_SIZE;
}
static void
int_md5_update(PX_MD * h, const uint8 *data, unsigned dlen)
{
MD5_CTX *ctx = (MD5_CTX *) h->p.ptr;
MD5Update(ctx, data, dlen);
}
static void
int_md5_reset(PX_MD * h)
{
MD5_CTX *ctx = (MD5_CTX *) h->p.ptr;
MD5Init(ctx);
}
static void
int_md5_finish(PX_MD * h, uint8 *dst)
{
MD5_CTX *ctx = (MD5_CTX *) h->p.ptr;
MD5Final(dst, ctx);
}
static void
int_md5_free(PX_MD * h)
{
MD5_CTX *ctx = (MD5_CTX *) h->p.ptr;
memset(ctx, 0, sizeof(*ctx));
px_free(ctx);
px_free(h);
}
/* SHA1 */
static unsigned
int_sha1_len(PX_MD * h)
{
return SHA1_DIGEST_LENGTH;
}
static unsigned
int_sha1_block_len(PX_MD * h)
{
return SHA1_BLOCK_SIZE;
}
static void
int_sha1_update(PX_MD * h, const uint8 *data, unsigned dlen)
{
SHA1_CTX *ctx = (SHA1_CTX *) h->p.ptr;
SHA1Update(ctx, data, dlen);
}
static void
int_sha1_reset(PX_MD * h)
{
SHA1_CTX *ctx = (SHA1_CTX *) h->p.ptr;
SHA1Init(ctx);
}
static void
int_sha1_finish(PX_MD * h, uint8 *dst)
{
SHA1_CTX *ctx = (SHA1_CTX *) h->p.ptr;
SHA1Final(dst, ctx);
}
static void
int_sha1_free(PX_MD * h)
{
SHA1_CTX *ctx = (SHA1_CTX *) h->p.ptr;
memset(ctx, 0, sizeof(*ctx));
px_free(ctx);
px_free(h);
}
/* init functions */
static void
init_md5(PX_MD * md)
{
MD5_CTX *ctx;
ctx = px_alloc(sizeof(*ctx));
memset(ctx, 0, sizeof(*ctx));
md->p.ptr = ctx;
md->result_size = int_md5_len;
md->block_size = int_md5_block_len;
md->reset = int_md5_reset;
md->update = int_md5_update;
md->finish = int_md5_finish;
md->free = int_md5_free;
md->reset(md);
}
static void
init_sha1(PX_MD * md)
{
SHA1_CTX *ctx;
ctx = px_alloc(sizeof(*ctx));
memset(ctx, 0, sizeof(*ctx));
md->p.ptr = ctx;
md->result_size = int_sha1_len;
md->block_size = int_sha1_block_len;
md->reset = int_sha1_reset;
md->update = int_sha1_update;
md->finish = int_sha1_finish;
md->free = int_sha1_free;
md->reset(md);
}
/*
* ciphers generally
*/
#define INT_MAX_KEY (512/8)
#define INT_MAX_IV (128/8)
struct int_ctx
{
uint8 keybuf[INT_MAX_KEY];
uint8 iv[INT_MAX_IV];
union
{
blf_ctx bf;
rijndael_ctx rj;
} ctx;
unsigned keylen;
int is_init;
int mode;
};
static void
intctx_free(PX_Cipher * c)
{
struct int_ctx *cx = (struct int_ctx *) c->ptr;
if (cx)
{
memset(cx, 0, sizeof *cx);
px_free(cx);
}
px_free(c);
}
/*
* AES/rijndael
*/
#define MODE_ECB 0
#define MODE_CBC 1
static unsigned
rj_block_size(PX_Cipher * c)
{
return 128 / 8;
}
static unsigned
rj_key_size(PX_Cipher * c)
{
return 256 / 8;
}
static unsigned
rj_iv_size(PX_Cipher * c)
{
return 128 / 8;
}
static int
rj_init(PX_Cipher * c, const uint8 *key, unsigned klen, const uint8 *iv)
{
struct int_ctx *cx = (struct int_ctx *) c->ptr;
if (klen <= 128 / 8)
cx->keylen = 128 / 8;
else if (klen <= 192 / 8)
cx->keylen = 192 / 8;
else if (klen <= 256 / 8)
cx->keylen = 256 / 8;
else
return PXE_KEY_TOO_BIG;
memcpy(&cx->keybuf, key, klen);
if (iv)
memcpy(cx->iv, iv, 128 / 8);
return 0;
}
static int
rj_real_init(struct int_ctx * cx, int dir)
{
aes_set_key(&cx->ctx.rj, cx->keybuf, cx->keylen * 8, dir);
return 0;
}
static int
rj_encrypt(PX_Cipher * c, const uint8 *data, unsigned dlen, uint8 *res)
{
struct int_ctx *cx = (struct int_ctx *) c->ptr;
if (!cx->is_init)
{
if (rj_real_init(cx, 1))
return PXE_CIPHER_INIT;
}
if (dlen == 0)
return 0;
if (dlen & 15)
return PXE_NOTBLOCKSIZE;
memcpy(res, data, dlen);
if (cx->mode == MODE_CBC)
{
aes_cbc_encrypt(&cx->ctx.rj, cx->iv, res, dlen);
memcpy(cx->iv, res + dlen - 16, 16);
}
else
aes_ecb_encrypt(&cx->ctx.rj, res, dlen);
return 0;
}
static int
rj_decrypt(PX_Cipher * c, const uint8 *data, unsigned dlen, uint8 *res)
{
struct int_ctx *cx = (struct int_ctx *) c->ptr;
if (!cx->is_init)
if (rj_real_init(cx, 0))
return PXE_CIPHER_INIT;
if (dlen == 0)
return 0;
if (dlen & 15)
return PXE_NOTBLOCKSIZE;
memcpy(res, data, dlen);
if (cx->mode == MODE_CBC)
{
aes_cbc_decrypt(&cx->ctx.rj, cx->iv, res, dlen);
memcpy(cx->iv, data + dlen - 16, 16);
}
else
aes_ecb_decrypt(&cx->ctx.rj, res, dlen);
return 0;
}
/*
* initializers
*/
static PX_Cipher *
rj_load(int mode)
{
PX_Cipher *c;
struct int_ctx *cx;
c = px_alloc(sizeof *c);
memset(c, 0, sizeof *c);
c->block_size = rj_block_size;
c->key_size = rj_key_size;
c->iv_size = rj_iv_size;
c->init = rj_init;
c->encrypt = rj_encrypt;
c->decrypt = rj_decrypt;
c->free = intctx_free;
cx = px_alloc(sizeof *cx);
memset(cx, 0, sizeof *cx);
cx->mode = mode;
c->ptr = cx;
return c;
}
/*
* blowfish
*/
static unsigned
bf_block_size(PX_Cipher * c)
{
return 8;
}
static unsigned
bf_key_size(PX_Cipher * c)
{
return BLF_MAXKEYLEN;
}
static unsigned
bf_iv_size(PX_Cipher * c)
{
return 8;
}
static int
bf_init(PX_Cipher * c, const uint8 *key, unsigned klen, const uint8 *iv)
{
struct int_ctx *cx = (struct int_ctx *) c->ptr;
blf_key(&cx->ctx.bf, key, klen);
if (iv)
memcpy(cx->iv, iv, 8);
return 0;
}
static int
bf_encrypt(PX_Cipher * c, const uint8 *data, unsigned dlen, uint8 *res)
{
struct int_ctx *cx = (struct int_ctx *) c->ptr;
if (dlen == 0)
return 0;
if (dlen & 7)
return PXE_NOTBLOCKSIZE;
memcpy(res, data, dlen);
switch (cx->mode)
{
case MODE_ECB:
blf_ecb_encrypt(&cx->ctx.bf, res, dlen);
break;
case MODE_CBC:
blf_cbc_encrypt(&cx->ctx.bf, cx->iv, res, dlen);
memcpy(cx->iv, res + dlen - 8, 8);
}
return 0;
}
static int
bf_decrypt(PX_Cipher * c, const uint8 *data, unsigned dlen, uint8 *res)
{
struct int_ctx *cx = (struct int_ctx *) c->ptr;
if (dlen == 0)
return 0;
if (dlen & 7)
return PXE_NOTBLOCKSIZE;
memcpy(res, data, dlen);
switch (cx->mode)
{
case MODE_ECB:
blf_ecb_decrypt(&cx->ctx.bf, res, dlen);
break;
case MODE_CBC:
blf_cbc_decrypt(&cx->ctx.bf, cx->iv, res, dlen);
memcpy(cx->iv, data + dlen - 8, 8);
}
return 0;
}
static PX_Cipher *
bf_load(int mode)
{
PX_Cipher *c;
struct int_ctx *cx;
c = px_alloc(sizeof *c);
memset(c, 0, sizeof *c);
c->block_size = bf_block_size;
c->key_size = bf_key_size;
c->iv_size = bf_iv_size;
c->init = bf_init;
c->encrypt = bf_encrypt;
c->decrypt = bf_decrypt;
c->free = intctx_free;
cx = px_alloc(sizeof *cx);
memset(cx, 0, sizeof *cx);
cx->mode = mode;
c->ptr = cx;
return c;
}
/* ciphers */
static PX_Cipher *
rj_128_ecb(void)
{
return rj_load(MODE_ECB);
}
static PX_Cipher *
rj_128_cbc(void)
{
return rj_load(MODE_CBC);
}
static PX_Cipher *
bf_ecb_load(void)
{
return bf_load(MODE_ECB);
}
static PX_Cipher *
bf_cbc_load(void)
{
return bf_load(MODE_CBC);
}
struct int_cipher
{
char *name;
PX_Cipher *(*load) (void);
};
static const struct int_cipher
int_ciphers[] = {
{"bf-cbc", bf_cbc_load},
{"bf-ecb", bf_ecb_load},
{"aes-128-cbc", rj_128_cbc},
{"aes-128-ecb", rj_128_ecb},
{NULL, NULL}
};
static const PX_Alias int_aliases[] = {
{"bf", "bf-cbc"},
{"blowfish", "bf-cbc"},
{"aes", "aes-128-cbc"},
{"aes-ecb", "aes-128-ecb"},
{"aes-cbc", "aes-128-cbc"},
{"aes-128", "aes-128-cbc"},
{"rijndael", "aes-128-cbc"},
{"rijndael-128", "aes-128-cbc"},
{NULL, NULL}
};
/* PUBLIC FUNCTIONS */
int
px_find_digest(const char *name, PX_MD ** res)
{
const struct int_digest *p;
PX_MD *h;
for (p = int_digest_list; p->name; p++)
if (pg_strcasecmp(p->name, name) == 0)
{
h = px_alloc(sizeof(*h));
p->init(h);
*res = h;
return 0;
}
return PXE_NO_HASH;
}
int
px_find_cipher(const char *name, PX_Cipher ** res)
{
int i;
PX_Cipher *c = NULL;
name = px_resolve_alias(int_aliases, name);
for (i = 0; int_ciphers[i].name; i++)
if (!strcmp(int_ciphers[i].name, name))
{
c = int_ciphers[i].load();
break;
}
if (c == NULL)
return PXE_NO_CIPHER;
*res = c;
return 0;
}
/*
* Randomness provider
*/
/*
* Use always strong randomness.
*/
int
px_get_pseudo_random_bytes(uint8 *dst, unsigned count)
{
return px_get_random_bytes(dst, count);
}
static time_t seed_time = 0;
static time_t check_time = 0;
static void
system_reseed(void)
{
uint8 buf[1024];
int n;
time_t t;
int skip = 1;
t = time(NULL);
if (seed_time == 0)
skip = 0;
else if ((t - seed_time) < SYSTEM_RESEED_MIN)
skip = 1;
else if ((t - seed_time) > SYSTEM_RESEED_MAX)
skip = 0;
else if (!check_time || (t - check_time) > SYSTEM_RESEED_CHECK_TIME)
{
check_time = t;
/* roll dice */
px_get_random_bytes(buf, 1);
skip = buf[0] >= SYSTEM_RESEED_CHANCE;
}
/* clear 1 byte */
memset(buf, 0, sizeof(buf));
if (skip)
return;
n = px_acquire_system_randomness(buf);
if (n > 0)
fortuna_add_entropy(buf, n);
seed_time = t;
memset(buf, 0, sizeof(buf));
}
int
px_get_random_bytes(uint8 *dst, unsigned count)
{
system_reseed();
fortuna_get_bytes(count, dst);
return 0;
}
int
px_add_entropy(const uint8 *data, unsigned count)
{
system_reseed();
fortuna_add_entropy(data, count);
return 0;
}