/*

* 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 "px.h"

#include <openssl/evp.h>

#include <openssl/err.h>

#include <openssl/rand.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

} 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);

px_free(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)

{

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 = px_alloc(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

};

/*

* 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

} 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);

px_free(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_ERR_GENERIC;

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

};

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 = px_alloc(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;

}