postgresql/contrib/pgcrypto/openssl.c
Michael Paquier aecaa04418 Add error code for encryption failure in pgcrypto
PXE_DECRYPT_FAILED exists already for decryption errors, and an
equivalent for encryption did not exist.  There is one code path that
deals with such failures for OpenSSL but it used PXE_ERR_GENERIC, which
was inconsistent.  This switches this code path to use the new error
PXE_ENCRYPT_FAILED instead of PXE_ERR_GENERIC, making the code used for
encryption more consistent with the decryption.

Author: Daniel Gustafsson
Discussion: https://postgr.es/m/03049139-CB7A-436E-B71B-42696D3E2EF7@yesql.se
2020-11-01 19:22:59 +09:00

807 lines
17 KiB
C

/*
* openssl.c
* Wrapper for OpenSSL library.
*
* 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/openssl.c
*/
#include "postgres.h"
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include "px.h"
#include "utils/memutils.h"
#include "utils/resowner.h"
/*
* Max lengths we might want to handle.
*/
#define MAX_KEY (512/8)
#define MAX_IV (128/8)
/*
* Hashes
*/
/*
* To make sure we don't leak OpenSSL handles on abort, we keep OSSLDigest
* objects in a linked list, allocated in TopMemoryContext. We use the
* ResourceOwner mechanism to free them on abort.
*/
typedef struct OSSLDigest
{
const EVP_MD *algo;
EVP_MD_CTX *ctx;
ResourceOwner owner;
struct OSSLDigest *next;
struct OSSLDigest *prev;
} OSSLDigest;
static OSSLDigest *open_digests = NULL;
static bool digest_resowner_callback_registered = false;
static void
free_openssl_digest(OSSLDigest *digest)
{
EVP_MD_CTX_destroy(digest->ctx);
if (digest->prev)
digest->prev->next = digest->next;
else
open_digests = digest->next;
if (digest->next)
digest->next->prev = digest->prev;
pfree(digest);
}
/*
* Close any open OpenSSL handles on abort.
*/
static void
digest_free_callback(ResourceReleasePhase phase,
bool isCommit,
bool isTopLevel,
void *arg)
{
OSSLDigest *curr;
OSSLDigest *next;
if (phase != RESOURCE_RELEASE_AFTER_LOCKS)
return;
next = open_digests;
while (next)
{
curr = next;
next = curr->next;
if (curr->owner == CurrentResourceOwner)
{
if (isCommit)
elog(WARNING, "pgcrypto digest reference leak: digest %p still referenced", curr);
free_openssl_digest(curr);
}
}
}
static unsigned
digest_result_size(PX_MD *h)
{
OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
return EVP_MD_CTX_size(digest->ctx);
}
static unsigned
digest_block_size(PX_MD *h)
{
OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
return EVP_MD_CTX_block_size(digest->ctx);
}
static void
digest_reset(PX_MD *h)
{
OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
EVP_DigestInit_ex(digest->ctx, digest->algo, NULL);
}
static void
digest_update(PX_MD *h, const uint8 *data, unsigned dlen)
{
OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
EVP_DigestUpdate(digest->ctx, data, dlen);
}
static void
digest_finish(PX_MD *h, uint8 *dst)
{
OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
EVP_DigestFinal_ex(digest->ctx, dst, NULL);
}
static void
digest_free(PX_MD *h)
{
OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
free_openssl_digest(digest);
pfree(h);
}
static int px_openssl_initialized = 0;
/* PUBLIC functions */
int
px_find_digest(const char *name, PX_MD **res)
{
const EVP_MD *md;
EVP_MD_CTX *ctx;
PX_MD *h;
OSSLDigest *digest;
if (!px_openssl_initialized)
{
px_openssl_initialized = 1;
OpenSSL_add_all_algorithms();
}
if (!digest_resowner_callback_registered)
{
RegisterResourceReleaseCallback(digest_free_callback, NULL);
digest_resowner_callback_registered = true;
}
md = EVP_get_digestbyname(name);
if (md == NULL)
return PXE_NO_HASH;
/*
* Create an OSSLDigest object, an OpenSSL MD object, and a PX_MD object.
* The order is crucial, to make sure we don't leak anything on
* out-of-memory or other error.
*/
digest = MemoryContextAlloc(TopMemoryContext, sizeof(*digest));
ctx = EVP_MD_CTX_create();
if (!ctx)
{
pfree(digest);
return -1;
}
if (EVP_DigestInit_ex(ctx, md, NULL) == 0)
{
EVP_MD_CTX_destroy(ctx);
pfree(digest);
return -1;
}
digest->algo = md;
digest->ctx = ctx;
digest->owner = CurrentResourceOwner;
digest->next = open_digests;
digest->prev = NULL;
open_digests = digest;
/* The PX_MD object is allocated in the current memory context. */
h = palloc(sizeof(*h));
h->result_size = digest_result_size;
h->block_size = digest_block_size;
h->reset = digest_reset;
h->update = digest_update;
h->finish = digest_finish;
h->free = digest_free;
h->p.ptr = (void *) digest;
*res = h;
return 0;
}
/*
* Ciphers
*
* We use OpenSSL's EVP* family of functions for these.
*/
/*
* prototype for the EVP functions that return an algorithm, e.g.
* EVP_aes_128_cbc().
*/
typedef const EVP_CIPHER *(*ossl_EVP_cipher_func) (void);
/*
* ossl_cipher contains the static information about each cipher.
*/
struct ossl_cipher
{
int (*init) (PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv);
ossl_EVP_cipher_func cipher_func;
int block_size;
int max_key_size;
};
/*
* OSSLCipher contains the state for using a cipher. A separate OSSLCipher
* object is allocated in each px_find_cipher() call.
*
* To make sure we don't leak OpenSSL handles on abort, we keep OSSLCipher
* objects in a linked list, allocated in TopMemoryContext. We use the
* ResourceOwner mechanism to free them on abort.
*/
typedef struct OSSLCipher
{
EVP_CIPHER_CTX *evp_ctx;
const EVP_CIPHER *evp_ciph;
uint8 key[MAX_KEY];
uint8 iv[MAX_IV];
unsigned klen;
unsigned init;
const struct ossl_cipher *ciph;
ResourceOwner owner;
struct OSSLCipher *next;
struct OSSLCipher *prev;
} OSSLCipher;
static OSSLCipher *open_ciphers = NULL;
static bool cipher_resowner_callback_registered = false;
static void
free_openssl_cipher(OSSLCipher *od)
{
EVP_CIPHER_CTX_free(od->evp_ctx);
if (od->prev)
od->prev->next = od->next;
else
open_ciphers = od->next;
if (od->next)
od->next->prev = od->prev;
pfree(od);
}
/*
* Close any open OpenSSL cipher handles on abort.
*/
static void
cipher_free_callback(ResourceReleasePhase phase,
bool isCommit,
bool isTopLevel,
void *arg)
{
OSSLCipher *curr;
OSSLCipher *next;
if (phase != RESOURCE_RELEASE_AFTER_LOCKS)
return;
next = open_ciphers;
while (next)
{
curr = next;
next = curr->next;
if (curr->owner == CurrentResourceOwner)
{
if (isCommit)
elog(WARNING, "pgcrypto cipher reference leak: cipher %p still referenced", curr);
free_openssl_cipher(curr);
}
}
}
/* Common routines for all algorithms */
static unsigned
gen_ossl_block_size(PX_Cipher *c)
{
OSSLCipher *od = (OSSLCipher *) c->ptr;
return od->ciph->block_size;
}
static unsigned
gen_ossl_key_size(PX_Cipher *c)
{
OSSLCipher *od = (OSSLCipher *) c->ptr;
return od->ciph->max_key_size;
}
static unsigned
gen_ossl_iv_size(PX_Cipher *c)
{
unsigned ivlen;
OSSLCipher *od = (OSSLCipher *) c->ptr;
ivlen = od->ciph->block_size;
return ivlen;
}
static void
gen_ossl_free(PX_Cipher *c)
{
OSSLCipher *od = (OSSLCipher *) c->ptr;
free_openssl_cipher(od);
pfree(c);
}
static int
gen_ossl_decrypt(PX_Cipher *c, const uint8 *data, unsigned dlen,
uint8 *res)
{
OSSLCipher *od = c->ptr;
int outlen;
if (!od->init)
{
if (!EVP_DecryptInit_ex(od->evp_ctx, od->evp_ciph, NULL, NULL, NULL))
return PXE_CIPHER_INIT;
if (!EVP_CIPHER_CTX_set_key_length(od->evp_ctx, od->klen))
return PXE_CIPHER_INIT;
if (!EVP_DecryptInit_ex(od->evp_ctx, NULL, NULL, od->key, od->iv))
return PXE_CIPHER_INIT;
od->init = true;
}
if (!EVP_DecryptUpdate(od->evp_ctx, res, &outlen, data, dlen))
return PXE_DECRYPT_FAILED;
return 0;
}
static int
gen_ossl_encrypt(PX_Cipher *c, const uint8 *data, unsigned dlen,
uint8 *res)
{
OSSLCipher *od = c->ptr;
int outlen;
if (!od->init)
{
if (!EVP_EncryptInit_ex(od->evp_ctx, od->evp_ciph, NULL, NULL, NULL))
return PXE_CIPHER_INIT;
if (!EVP_CIPHER_CTX_set_key_length(od->evp_ctx, od->klen))
return PXE_CIPHER_INIT;
if (!EVP_EncryptInit_ex(od->evp_ctx, NULL, NULL, od->key, od->iv))
return PXE_CIPHER_INIT;
od->init = true;
}
if (!EVP_EncryptUpdate(od->evp_ctx, res, &outlen, data, dlen))
return PXE_ENCRYPT_FAILED;
return 0;
}
/* Blowfish */
/*
* Check if strong crypto is supported. Some OpenSSL installations
* support only short keys and unfortunately BF_set_key does not return any
* error value. This function tests if is possible to use strong key.
*/
static int
bf_check_supported_key_len(void)
{
static const uint8 key[56] = {
0xf0, 0xe1, 0xd2, 0xc3, 0xb4, 0xa5, 0x96, 0x87, 0x78, 0x69,
0x5a, 0x4b, 0x3c, 0x2d, 0x1e, 0x0f, 0x00, 0x11, 0x22, 0x33,
0x44, 0x55, 0x66, 0x77, 0x04, 0x68, 0x91, 0x04, 0xc2, 0xfd,
0x3b, 0x2f, 0x58, 0x40, 0x23, 0x64, 0x1a, 0xba, 0x61, 0x76,
0x1f, 0x1f, 0x1f, 0x1f, 0x0e, 0x0e, 0x0e, 0x0e, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff
};
static const uint8 data[8] = {0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10};
static const uint8 res[8] = {0xc0, 0x45, 0x04, 0x01, 0x2e, 0x4e, 0x1f, 0x53};
uint8 out[8];
EVP_CIPHER_CTX *evp_ctx;
int outlen;
int status = 0;
/* encrypt with 448bits key and verify output */
evp_ctx = EVP_CIPHER_CTX_new();
if (!evp_ctx)
return 0;
if (!EVP_EncryptInit_ex(evp_ctx, EVP_bf_ecb(), NULL, NULL, NULL))
goto leave;
if (!EVP_CIPHER_CTX_set_key_length(evp_ctx, 56))
goto leave;
if (!EVP_EncryptInit_ex(evp_ctx, NULL, NULL, key, NULL))
goto leave;
if (!EVP_EncryptUpdate(evp_ctx, out, &outlen, data, 8))
goto leave;
if (memcmp(out, res, 8) != 0)
goto leave; /* Output does not match -> strong cipher is
* not supported */
status = 1;
leave:
EVP_CIPHER_CTX_free(evp_ctx);
return status;
}
static int
bf_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
{
OSSLCipher *od = c->ptr;
unsigned bs = gen_ossl_block_size(c);
static int bf_is_strong = -1;
/*
* Test if key len is supported. BF_set_key silently cut large keys and it
* could be a problem when user transfer crypted data from one server to
* another.
*/
if (bf_is_strong == -1)
bf_is_strong = bf_check_supported_key_len();
if (!bf_is_strong && klen > 16)
return PXE_KEY_TOO_BIG;
/* Key len is supported. We can use it. */
od->klen = klen;
memcpy(od->key, key, klen);
if (iv)
memcpy(od->iv, iv, bs);
else
memset(od->iv, 0, bs);
return 0;
}
/* DES */
static int
ossl_des_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
{
OSSLCipher *od = c->ptr;
unsigned bs = gen_ossl_block_size(c);
od->klen = 8;
memset(od->key, 0, 8);
memcpy(od->key, key, klen > 8 ? 8 : klen);
if (iv)
memcpy(od->iv, iv, bs);
else
memset(od->iv, 0, bs);
return 0;
}
/* DES3 */
static int
ossl_des3_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
{
OSSLCipher *od = c->ptr;
unsigned bs = gen_ossl_block_size(c);
od->klen = 24;
memset(od->key, 0, 24);
memcpy(od->key, key, klen > 24 ? 24 : klen);
if (iv)
memcpy(od->iv, iv, bs);
else
memset(od->iv, 0, bs);
return 0;
}
/* CAST5 */
static int
ossl_cast_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
{
OSSLCipher *od = c->ptr;
unsigned bs = gen_ossl_block_size(c);
od->klen = klen;
memcpy(od->key, key, klen);
if (iv)
memcpy(od->iv, iv, bs);
else
memset(od->iv, 0, bs);
return 0;
}
/* AES */
static int
ossl_aes_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
{
OSSLCipher *od = c->ptr;
unsigned bs = gen_ossl_block_size(c);
if (klen <= 128 / 8)
od->klen = 128 / 8;
else if (klen <= 192 / 8)
od->klen = 192 / 8;
else if (klen <= 256 / 8)
od->klen = 256 / 8;
else
return PXE_KEY_TOO_BIG;
memcpy(od->key, key, klen);
if (iv)
memcpy(od->iv, iv, bs);
else
memset(od->iv, 0, bs);
return 0;
}
static int
ossl_aes_ecb_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
{
OSSLCipher *od = c->ptr;
int err;
err = ossl_aes_init(c, key, klen, iv);
if (err)
return err;
switch (od->klen)
{
case 128 / 8:
od->evp_ciph = EVP_aes_128_ecb();
break;
case 192 / 8:
od->evp_ciph = EVP_aes_192_ecb();
break;
case 256 / 8:
od->evp_ciph = EVP_aes_256_ecb();
break;
default:
/* shouldn't happen */
err = PXE_CIPHER_INIT;
break;
}
return err;
}
static int
ossl_aes_cbc_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
{
OSSLCipher *od = c->ptr;
int err;
err = ossl_aes_init(c, key, klen, iv);
if (err)
return err;
switch (od->klen)
{
case 128 / 8:
od->evp_ciph = EVP_aes_128_cbc();
break;
case 192 / 8:
od->evp_ciph = EVP_aes_192_cbc();
break;
case 256 / 8:
od->evp_ciph = EVP_aes_256_cbc();
break;
default:
/* shouldn't happen */
err = PXE_CIPHER_INIT;
break;
}
return err;
}
/*
* aliases
*/
static PX_Alias ossl_aliases[] = {
{"bf", "bf-cbc"},
{"blowfish", "bf-cbc"},
{"blowfish-cbc", "bf-cbc"},
{"blowfish-ecb", "bf-ecb"},
{"blowfish-cfb", "bf-cfb"},
{"des", "des-cbc"},
{"3des", "des3-cbc"},
{"3des-ecb", "des3-ecb"},
{"3des-cbc", "des3-cbc"},
{"cast5", "cast5-cbc"},
{"aes", "aes-cbc"},
{"rijndael", "aes-cbc"},
{"rijndael-cbc", "aes-cbc"},
{"rijndael-ecb", "aes-ecb"},
{NULL}
};
static const struct ossl_cipher ossl_bf_cbc = {
bf_init,
EVP_bf_cbc,
64 / 8, 448 / 8
};
static const struct ossl_cipher ossl_bf_ecb = {
bf_init,
EVP_bf_ecb,
64 / 8, 448 / 8
};
static const struct ossl_cipher ossl_bf_cfb = {
bf_init,
EVP_bf_cfb,
64 / 8, 448 / 8
};
static const struct ossl_cipher ossl_des_ecb = {
ossl_des_init,
EVP_des_ecb,
64 / 8, 64 / 8
};
static const struct ossl_cipher ossl_des_cbc = {
ossl_des_init,
EVP_des_cbc,
64 / 8, 64 / 8
};
static const struct ossl_cipher ossl_des3_ecb = {
ossl_des3_init,
EVP_des_ede3_ecb,
64 / 8, 192 / 8
};
static const struct ossl_cipher ossl_des3_cbc = {
ossl_des3_init,
EVP_des_ede3_cbc,
64 / 8, 192 / 8
};
static const struct ossl_cipher ossl_cast_ecb = {
ossl_cast_init,
EVP_cast5_ecb,
64 / 8, 128 / 8
};
static const struct ossl_cipher ossl_cast_cbc = {
ossl_cast_init,
EVP_cast5_cbc,
64 / 8, 128 / 8
};
static const struct ossl_cipher ossl_aes_ecb = {
ossl_aes_ecb_init,
NULL, /* EVP_aes_XXX_ecb(), determined in init
* function */
128 / 8, 256 / 8
};
static const struct ossl_cipher ossl_aes_cbc = {
ossl_aes_cbc_init,
NULL, /* EVP_aes_XXX_cbc(), determined in init
* function */
128 / 8, 256 / 8
};
/*
* Special handlers
*/
struct ossl_cipher_lookup
{
const char *name;
const struct ossl_cipher *ciph;
};
static const struct ossl_cipher_lookup ossl_cipher_types[] = {
{"bf-cbc", &ossl_bf_cbc},
{"bf-ecb", &ossl_bf_ecb},
{"bf-cfb", &ossl_bf_cfb},
{"des-ecb", &ossl_des_ecb},
{"des-cbc", &ossl_des_cbc},
{"des3-ecb", &ossl_des3_ecb},
{"des3-cbc", &ossl_des3_cbc},
{"cast5-ecb", &ossl_cast_ecb},
{"cast5-cbc", &ossl_cast_cbc},
{"aes-ecb", &ossl_aes_ecb},
{"aes-cbc", &ossl_aes_cbc},
{NULL}
};
/* PUBLIC functions */
int
px_find_cipher(const char *name, PX_Cipher **res)
{
const struct ossl_cipher_lookup *i;
PX_Cipher *c = NULL;
EVP_CIPHER_CTX *ctx;
OSSLCipher *od;
name = px_resolve_alias(ossl_aliases, name);
for (i = ossl_cipher_types; i->name; i++)
if (strcmp(i->name, name) == 0)
break;
if (i->name == NULL)
return PXE_NO_CIPHER;
if (!cipher_resowner_callback_registered)
{
RegisterResourceReleaseCallback(cipher_free_callback, NULL);
cipher_resowner_callback_registered = true;
}
/*
* Create an OSSLCipher object, an EVP_CIPHER_CTX object and a PX_Cipher.
* The order is crucial, to make sure we don't leak anything on
* out-of-memory or other error.
*/
od = MemoryContextAllocZero(TopMemoryContext, sizeof(*od));
od->ciph = i->ciph;
/* Allocate an EVP_CIPHER_CTX object. */
ctx = EVP_CIPHER_CTX_new();
if (!ctx)
{
pfree(od);
return PXE_CIPHER_INIT;
}
od->evp_ctx = ctx;
od->owner = CurrentResourceOwner;
od->next = open_ciphers;
od->prev = NULL;
open_ciphers = od;
if (i->ciph->cipher_func)
od->evp_ciph = i->ciph->cipher_func();
/* The PX_Cipher is allocated in current memory context */
c = palloc(sizeof(*c));
c->block_size = gen_ossl_block_size;
c->key_size = gen_ossl_key_size;
c->iv_size = gen_ossl_iv_size;
c->free = gen_ossl_free;
c->init = od->ciph->init;
c->encrypt = gen_ossl_encrypt;
c->decrypt = gen_ossl_decrypt;
c->ptr = od;
*res = c;
return 0;
}