postgresql/contrib/pgcrypto/internal.c
Peter Eisentraut 037a82704c Standardize treatment of strcmp() return value
Always compare the return value to 0, don't use cute tricks like
if (!strcmp(...)).
2011-12-27 21:19:09 +02:00

689 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.
*
* contrib/pgcrypto/internal.c
*/
#include "postgres.h"
#include <time.h>
#include "px.h"
#include "md5.h"
#include "sha1.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
{
BlowfishContext 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 448 / 8;
}
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;
blowfish_setkey(&cx->ctx.bf, key, klen);
if (iv)
blowfish_setiv(&cx->ctx.bf, iv);
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;
BlowfishContext *bfctx = &cx->ctx.bf;
if (dlen == 0)
return 0;
if (dlen & 7)
return PXE_NOTBLOCKSIZE;
memcpy(res, data, dlen);
switch (cx->mode)
{
case MODE_ECB:
blowfish_encrypt_ecb(res, dlen, bfctx);
break;
case MODE_CBC:
blowfish_encrypt_cbc(res, dlen, bfctx);
break;
}
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;
BlowfishContext *bfctx = &cx->ctx.bf;
if (dlen == 0)
return 0;
if (dlen & 7)
return PXE_NOTBLOCKSIZE;
memcpy(res, data, dlen);
switch (cx->mode)
{
case MODE_ECB:
blowfish_decrypt_ecb(res, dlen, bfctx);
break;
case MODE_CBC:
blowfish_decrypt_cbc(res, dlen, bfctx);
break;
}
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) == 0)
{
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 == 0 ||
(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;
}