/* $NetBSD: pw-pbkdf2.c,v 1.1.1.2.6.1 2019/08/10 06:17:10 martin Exp $ */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 2009-2019 The OpenLDAP Foundation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in the file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
/* ACKNOWLEDGEMENT:
* This work was initially developed by HAMANO Tsukasa <hamano@osstech.co.jp>
*/
#define _GNU_SOURCE
#include <sys/cdefs.h>
__RCSID("$NetBSD: pw-pbkdf2.c,v 1.1.1.2.6.1 2019/08/10 06:17:10 martin Exp $");
#include "portable.h"
#include <ac/string.h>
#include "lber_pvt.h"
#include "lutil.h"
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_OPENSSL
#include <openssl/evp.h>
#elif HAVE_GNUTLS
#include <nettle/pbkdf2.h>
#include <nettle/hmac.h>
typedef void (*pbkdf2_hmac_update)(void *, unsigned, const uint8_t *);
typedef void (*pbkdf2_hmac_digest)(void *, unsigned, uint8_t *);
#else
#error Unsupported crypto backend.
#endif
#define PBKDF2_ITERATION 10000
#define PBKDF2_SALT_SIZE 16
#define PBKDF2_SHA1_DK_SIZE 20
#define PBKDF2_SHA256_DK_SIZE 32
#define PBKDF2_SHA512_DK_SIZE 64
#define PBKDF2_MAX_DK_SIZE 64
const struct berval pbkdf2_scheme = BER_BVC("{PBKDF2}");
const struct berval pbkdf2_sha1_scheme = BER_BVC("{PBKDF2-SHA1}");
const struct berval pbkdf2_sha256_scheme = BER_BVC("{PBKDF2-SHA256}");
const struct berval pbkdf2_sha512_scheme = BER_BVC("{PBKDF2-SHA512}");
/*
* Converting base64 string to adapted base64 string.
* Adapted base64 encode is identical to general base64 encode except
* that it uses '.' instead of '+', and omits trailing padding '=' and
* whitepsace.
* see http://pythonhosted.org/passlib/lib/passlib.utils.html
* This is destructive function.
*/
static int b64_to_ab64(char *str)
{
char *p = str;
do {
if(*p == '+'){
*p = '.';
}
if(*p == '='){
*p = '\0';
}
} while(*p++);
return 0;
}
/*
* Converting adapted base64 string to base64 string.
* dstsize will require src length + 2, due to output string have
* potential to append "=" or "==".
* return -1 if few output buffer.
*/
static int ab64_to_b64(char *src, char *dst, size_t dstsize){
int i;
char *p = src;
for(i=0; p[i] && p[i] != '$'; i++){
if(i >= dstsize){
dst[0] = '\0';
return -1;
}
if(p[i] == '.'){
dst[i] = '+';
}else{
dst[i] = p[i];
}
}
for(;i%4;i++){
if(i >= dstsize){
dst[0] = '\0';
return -1;
}
dst[i] = '=';
}
dst[i] = '\0';
return 0;
}
static int pbkdf2_format(
const struct berval *sc,
int iteration,
const struct berval *salt,
const struct berval *dk,
struct berval *msg)
{
int rc, msg_len;
char salt_b64[LUTIL_BASE64_ENCODE_LEN(PBKDF2_SALT_SIZE) + 1];
char dk_b64[LUTIL_BASE64_ENCODE_LEN(PBKDF2_MAX_DK_SIZE) + 1];
rc = lutil_b64_ntop((unsigned char *)salt->bv_val, salt->bv_len,
salt_b64, sizeof(salt_b64));
if(rc < 0){
return LUTIL_PASSWD_ERR;
}
b64_to_ab64(salt_b64);
rc = lutil_b64_ntop((unsigned char *)dk->bv_val, dk->bv_len,
dk_b64, sizeof(dk_b64));
if(rc < 0){
return LUTIL_PASSWD_ERR;
}
b64_to_ab64(dk_b64);
msg_len = asprintf(&msg->bv_val, "%s%d$%s$%s",
sc->bv_val, iteration,
salt_b64, dk_b64);
if(msg_len < 0){
msg->bv_len = 0;
return LUTIL_PASSWD_ERR;
}
msg->bv_len = msg_len;
return LUTIL_PASSWD_OK;
}
static int pbkdf2_encrypt(
const struct berval *scheme,
const struct berval *passwd,
struct berval *msg,
const char **text)
{
unsigned char salt_value[PBKDF2_SALT_SIZE];
struct berval salt;
unsigned char dk_value[PBKDF2_MAX_DK_SIZE];
struct berval dk;
int iteration = PBKDF2_ITERATION;
int rc;
#ifdef HAVE_OPENSSL
const EVP_MD *md;
#elif HAVE_GNUTLS
struct hmac_sha1_ctx sha1_ctx;
struct hmac_sha256_ctx sha256_ctx;
struct hmac_sha512_ctx sha512_ctx;
void * current_ctx = NULL;
pbkdf2_hmac_update current_hmac_update = NULL;
pbkdf2_hmac_digest current_hmac_digest = NULL;
#endif
salt.bv_val = (char *)salt_value;
salt.bv_len = sizeof(salt_value);
dk.bv_val = (char *)dk_value;
#ifdef HAVE_OPENSSL
if(!ber_bvcmp(scheme, &pbkdf2_scheme)){
dk.bv_len = PBKDF2_SHA1_DK_SIZE;
md = EVP_sha1();
}else if(!ber_bvcmp(scheme, &pbkdf2_sha1_scheme)){
dk.bv_len = PBKDF2_SHA1_DK_SIZE;
md = EVP_sha1();
}else if(!ber_bvcmp(scheme, &pbkdf2_sha256_scheme)){
dk.bv_len = PBKDF2_SHA256_DK_SIZE;
md = EVP_sha256();
}else if(!ber_bvcmp(scheme, &pbkdf2_sha512_scheme)){
dk.bv_len = PBKDF2_SHA512_DK_SIZE;
md = EVP_sha512();
}else{
return LUTIL_PASSWD_ERR;
}
#elif HAVE_GNUTLS
if(!ber_bvcmp(scheme, &pbkdf2_scheme)){
dk.bv_len = PBKDF2_SHA1_DK_SIZE;
current_ctx = &sha1_ctx;
current_hmac_update = (pbkdf2_hmac_update) &hmac_sha1_update;
current_hmac_digest = (pbkdf2_hmac_digest) &hmac_sha1_digest;
hmac_sha1_set_key(current_ctx, passwd->bv_len, (const uint8_t *) passwd->bv_val);
}else if(!ber_bvcmp(scheme, &pbkdf2_sha1_scheme)){
dk.bv_len = PBKDF2_SHA1_DK_SIZE;
current_ctx = &sha1_ctx;
current_hmac_update = (pbkdf2_hmac_update) &hmac_sha1_update;
current_hmac_digest = (pbkdf2_hmac_digest) &hmac_sha1_digest;
hmac_sha1_set_key(current_ctx, passwd->bv_len, (const uint8_t *) passwd->bv_val);
}else if(!ber_bvcmp(scheme, &pbkdf2_sha256_scheme)){
dk.bv_len = PBKDF2_SHA256_DK_SIZE;
current_ctx = &sha256_ctx;
current_hmac_update = (pbkdf2_hmac_update) &hmac_sha256_update;
current_hmac_digest = (pbkdf2_hmac_digest) &hmac_sha256_digest;
hmac_sha256_set_key(current_ctx, passwd->bv_len, (const uint8_t *) passwd->bv_val);
}else if(!ber_bvcmp(scheme, &pbkdf2_sha512_scheme)){
dk.bv_len = PBKDF2_SHA512_DK_SIZE;
current_ctx = &sha512_ctx;
current_hmac_update = (pbkdf2_hmac_update) &hmac_sha512_update;
current_hmac_digest = (pbkdf2_hmac_digest) &hmac_sha512_digest;
hmac_sha512_set_key(current_ctx, passwd->bv_len, (const uint8_t *) passwd->bv_val);
}else{
return LUTIL_PASSWD_ERR;
}
#endif
if(lutil_entropy((unsigned char *)salt.bv_val, salt.bv_len) < 0){
return LUTIL_PASSWD_ERR;
}
#ifdef HAVE_OPENSSL
if(!PKCS5_PBKDF2_HMAC(passwd->bv_val, passwd->bv_len,
(unsigned char *)salt.bv_val, salt.bv_len,
iteration, md, dk.bv_len, dk_value)){
return LUTIL_PASSWD_ERR;
}
#elif HAVE_GNUTLS
PBKDF2(current_ctx, current_hmac_update, current_hmac_digest,
dk.bv_len, iteration,
salt.bv_len, (const uint8_t *) salt.bv_val,
dk.bv_len, dk_value);
#endif
#ifdef SLAPD_PBKDF2_DEBUG
printf("Encrypt for %s\n", scheme->bv_val);
printf(" Password:\t%s\n", passwd->bv_val);
printf(" Salt:\t\t");
int i;
for(i=0; i<salt.bv_len; i++){
printf("%02x", salt_value[i]);
}
printf("\n");
printf(" Iteration:\t%d\n", iteration);
printf(" DK:\t\t");
for(i=0; i<dk.bv_len; i++){
printf("%02x", dk_value[i]);
}
printf("\n");
#endif
rc = pbkdf2_format(scheme, iteration, &salt, &dk, msg);
#ifdef SLAPD_PBKDF2_DEBUG
printf(" Output:\t%s\n", msg->bv_val);
#endif
return rc;
}
static int pbkdf2_check(
const struct berval *scheme,
const struct berval *passwd,
const struct berval *cred,
const char **text)
{
int rc;
int iteration;
/* salt_value require PBKDF2_SALT_SIZE + 1 in lutil_b64_pton. */
unsigned char salt_value[PBKDF2_SALT_SIZE + 1];
char salt_b64[LUTIL_BASE64_ENCODE_LEN(PBKDF2_SALT_SIZE) + 1];
/* dk_value require PBKDF2_MAX_DK_SIZE + 1 in lutil_b64_pton. */
unsigned char dk_value[PBKDF2_MAX_DK_SIZE + 1];
char dk_b64[LUTIL_BASE64_ENCODE_LEN(PBKDF2_MAX_DK_SIZE) + 1];
unsigned char input_dk_value[PBKDF2_MAX_DK_SIZE];
size_t dk_len;
#ifdef HAVE_OPENSSL
const EVP_MD *md;
#elif HAVE_GNUTLS
struct hmac_sha1_ctx sha1_ctx;
struct hmac_sha256_ctx sha256_ctx;
struct hmac_sha512_ctx sha512_ctx;
void * current_ctx = NULL;
pbkdf2_hmac_update current_hmac_update = NULL;
pbkdf2_hmac_digest current_hmac_digest = NULL;
#endif
#ifdef SLAPD_PBKDF2_DEBUG
printf("Checking for %s\n", scheme->bv_val);
printf(" Stored Value:\t%s\n", passwd->bv_val);
printf(" Input Cred:\t%s\n", cred->bv_val);
#endif
#ifdef HAVE_OPENSSL
if(!ber_bvcmp(scheme, &pbkdf2_scheme)){
dk_len = PBKDF2_SHA1_DK_SIZE;
md = EVP_sha1();
}else if(!ber_bvcmp(scheme, &pbkdf2_sha1_scheme)){
dk_len = PBKDF2_SHA1_DK_SIZE;
md = EVP_sha1();
}else if(!ber_bvcmp(scheme, &pbkdf2_sha256_scheme)){
dk_len = PBKDF2_SHA256_DK_SIZE;
md = EVP_sha256();
}else if(!ber_bvcmp(scheme, &pbkdf2_sha512_scheme)){
dk_len = PBKDF2_SHA512_DK_SIZE;
md = EVP_sha512();
}else{
return LUTIL_PASSWD_ERR;
}
#elif HAVE_GNUTLS
if(!ber_bvcmp(scheme, &pbkdf2_scheme)){
dk_len = PBKDF2_SHA1_DK_SIZE;
current_ctx = &sha1_ctx;
current_hmac_update = (pbkdf2_hmac_update) &hmac_sha1_update;
current_hmac_digest = (pbkdf2_hmac_digest) &hmac_sha1_digest;
hmac_sha1_set_key(current_ctx, cred->bv_len, (const uint8_t *) cred->bv_val);
}else if(!ber_bvcmp(scheme, &pbkdf2_sha1_scheme)){
dk_len = PBKDF2_SHA1_DK_SIZE;
current_ctx = &sha1_ctx;
current_hmac_update = (pbkdf2_hmac_update) &hmac_sha1_update;
current_hmac_digest = (pbkdf2_hmac_digest) &hmac_sha1_digest;
hmac_sha1_set_key(current_ctx, cred->bv_len, (const uint8_t *) cred->bv_val);
}else if(!ber_bvcmp(scheme, &pbkdf2_sha256_scheme)){
dk_len = PBKDF2_SHA256_DK_SIZE;
current_ctx = &sha256_ctx;
current_hmac_update = (pbkdf2_hmac_update) &hmac_sha256_update;
current_hmac_digest = (pbkdf2_hmac_digest) &hmac_sha256_digest;
hmac_sha256_set_key(current_ctx, cred->bv_len, (const uint8_t *) cred->bv_val);
}else if(!ber_bvcmp(scheme, &pbkdf2_sha512_scheme)){
dk_len = PBKDF2_SHA512_DK_SIZE;
current_ctx = &sha512_ctx;
current_hmac_update = (pbkdf2_hmac_update) &hmac_sha512_update;
current_hmac_digest = (pbkdf2_hmac_digest) &hmac_sha512_digest;
hmac_sha512_set_key(current_ctx, cred->bv_len, (const uint8_t *) cred->bv_val);
}else{
return LUTIL_PASSWD_ERR;
}
#endif
iteration = atoi(passwd->bv_val);
if(iteration < 1){
return LUTIL_PASSWD_ERR;
}
char *ptr;
ptr = strchr(passwd->bv_val, '$');
if(!ptr){
return LUTIL_PASSWD_ERR;
}
ptr++; /* skip '$' */
rc = ab64_to_b64(ptr, salt_b64, sizeof(salt_b64));
if(rc < 0){
return LUTIL_PASSWD_ERR;
}
ptr = strchr(ptr, '$');
if(!ptr){
return LUTIL_PASSWD_ERR;
}
ptr++; /* skip '$' */
rc = ab64_to_b64(ptr, dk_b64, sizeof(dk_b64));
if(rc < 0){
return LUTIL_PASSWD_ERR;
}
/* The targetsize require PBKDF2_SALT_SIZE + 1 in lutil_b64_pton. */
rc = lutil_b64_pton(salt_b64, salt_value, PBKDF2_SALT_SIZE + 1);
if(rc < 0){
return LUTIL_PASSWD_ERR;
}
/* consistency check */
if(rc != PBKDF2_SALT_SIZE){
return LUTIL_PASSWD_ERR;
}
/* The targetsize require PBKDF2_MAX_DK_SIZE + 1 in lutil_b64_pton. */
rc = lutil_b64_pton(dk_b64, dk_value, sizeof(dk_value));
if(rc < 0){
return LUTIL_PASSWD_ERR;
}
/* consistency check */
if(rc != dk_len){
return LUTIL_PASSWD_ERR;
}
#ifdef HAVE_OPENSSL
if(!PKCS5_PBKDF2_HMAC(cred->bv_val, cred->bv_len,
salt_value, PBKDF2_SALT_SIZE,
iteration, md, dk_len, input_dk_value)){
return LUTIL_PASSWD_ERR;
}
#elif HAVE_GNUTLS
PBKDF2(current_ctx, current_hmac_update, current_hmac_digest,
dk_len, iteration,
PBKDF2_SALT_SIZE, salt_value,
dk_len, input_dk_value);
#endif
rc = memcmp(dk_value, input_dk_value, dk_len);
#ifdef SLAPD_PBKDF2_DEBUG
printf(" Iteration:\t%d\n", iteration);
printf(" Base64 Salt:\t%s\n", salt_b64);
printf(" Base64 DK:\t%s\n", dk_b64);
int i;
printf(" Stored Salt:\t");
for(i=0; i<PBKDF2_SALT_SIZE; i++){
printf("%02x", salt_value[i]);
}
printf("\n");
printf(" Stored DK:\t");
for(i=0; i<dk_len; i++){
printf("%02x", dk_value[i]);
}
printf("\n");
printf(" Input DK:\t");
for(i=0; i<dk_len; i++){
printf("%02x", input_dk_value[i]);
}
printf("\n");
printf(" Result:\t%d\n", rc);
#endif
return rc?LUTIL_PASSWD_ERR:LUTIL_PASSWD_OK;
}
int init_module(int argc, char *argv[]) {
int rc;
rc = lutil_passwd_add((struct berval *)&pbkdf2_scheme,
pbkdf2_check, pbkdf2_encrypt);
if(rc) return rc;
rc = lutil_passwd_add((struct berval *)&pbkdf2_sha1_scheme,
pbkdf2_check, pbkdf2_encrypt);
if(rc) return rc;
rc = lutil_passwd_add((struct berval *)&pbkdf2_sha256_scheme,
pbkdf2_check, pbkdf2_encrypt);
if(rc) return rc;
rc = lutil_passwd_add((struct berval *)&pbkdf2_sha512_scheme,
pbkdf2_check, pbkdf2_encrypt);
return rc;
}
/*
* Local variables:
* indent-tabs-mode: t
* tab-width: 4
* c-basic-offset: 4
* End:
*/