--- /dev/null
+PBKDF2 for OpenLDAP
+=======================
+
+pw-pbkdf2.c provides support for PBKDF2 key derivation functions in
+OpenLDAP.
+
+# Requirements
+
+ * OpenSSL 1.0.0 or later
+
+# Installations
+
+ $ cd <OPENLDAP_BUILD_DIR>/contrib/slapd-modules/passwd/
+ $ git clone https://github.com/hamano/openldap-pbkdf2.git
+ $ cd openldap-pbkdf2/
+ $ make
+ # make install
+
+# Configuration
+
+In slapd.conf:
+
+ moduleload pw-pbkdf2.so
+
+You can also tell OpenLDAP to use the schemes when processing LDAP
+Password Modify Extended Operations, thanks to the password-hash
+option in slapd.conf. For example:
+
+ password-hash {PBKDF2}
+
+# Testing
+
+You can get hash to use slappasswd.
+
+ $ slappasswd -o module-load=pw-pbkdf2.la -h {PBKDF2} -s secret
+ {PBKDF2}60000$Y6ZHtTTbeUgpIbIW0QDmDA$j/aU7jFKUSbH4UobNQDm9OEIwuw
+
+A quick way to test whether it's working is to customize the rootdn and
+rootpw in slapd.conf, eg:
+
+ rootdn "cn=Manager,dc=example,dc=com"
+ rootpw {PBKDF2}60000$Y6ZHtTTbeUgpIbIW0QDmDA$j/aU7jFKUSbH4UobNQDm9OEIwuw
+
+Then to test, run something like:
+
+ $ ldapsearch -x -b "dc=example,dc=com" -D "cn=Manager,dc=example,dc=com" -w secret
+
+# Debugging
+You can specify -DSLAPD_PBKDF2_DEBUG flag for debugging.
+
+# Message Format
+
+ {PBKDF2}<Iteration>$<Adapted Base64 Salt>$<Adapted Base64 DK>
+
+# References
+
+* [RFC 2898 Password-Based Cryptography][^1]
+[^1]: http://tools.ietf.org/html/rfc2898
+
+* [PKCS #5 PBKDF2 Test Vectors][^2]
+[^2]: http://tools.ietf.org/html/draft-josefsson-pbkdf2-test-vectors-06
+
+* [RFC 2307 Using LDAP as a Network Information Service][^3]
+[^3]: http://tools.ietf.org/html/rfc2307
+
+* [Python Passlib][^4]
+[^4]: http://pythonhosted.org/passlib/
+
+* [Adapted Base64 Encoding][^5]
+[^5]: http://pythonhosted.org/passlib/lib/passlib.utils.html#passlib.utils.ab64_encode
+
+# License
+This work is part of OpenLDAP Software <http://www.openldap.org/>.
+
+Copyright 2009-2013 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>
--- /dev/null
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2009-2013 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 "portable.h"
+#include <ac/string.h>
+#include "lber_pvt.h"
+#include "lutil.h"
+
+#include <openssl/evp.h>
+
+#define PBKDF2_SALT_SIZE 16
+#define PBKDF2_DK_SIZE 20
+#define PBKDF2_ITERATION 60000
+
+const struct berval pbkdf2scheme = BER_BVC("{PBKDF2}");
+
+/*
+ * 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;
+ while(*p++){
+ if(*p == '+'){
+ *p = '.';
+ }
+ if(*p == '='){
+ *p = '\0';
+ break;
+ }
+ }
+ 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] != '$'; i++){
+ if(i >= dstsize){
+ dst[0] = '\0';
+ return -1;
+ }
+ if(p[i] == '.'){
+ dst[i] = '+';
+ }else{
+ dst[i] = p[i];
+ }
+ }
+ for(;i%4;i++){
+ if(i >= dstsize){
+ dst[0] = '\0';
+ return -1;
+ }
+ dst[i] = '=';
+ }
+ dst[i] = '\0';
+ return 0;
+}
+
+static int pbkdf2_format(
+ const struct berval *sc,
+ int iteration,
+ const struct berval *salt,
+ const struct berval *dk,
+ struct berval *msg)
+{
+
+ int rc;
+ char salt_b64[LUTIL_BASE64_ENCODE_LEN(PBKDF2_SALT_SIZE) + 1];
+ char dk_b64[LUTIL_BASE64_ENCODE_LEN(PBKDF2_DK_SIZE) + 1];
+
+ rc = lutil_b64_ntop((unsigned char *)salt->bv_val, salt->bv_len,
+ salt_b64, sizeof(salt_b64));
+ if(rc < 0){
+ return LUTIL_PASSWD_ERR;
+ }
+ b64_to_ab64(salt_b64);
+ rc = lutil_b64_ntop((unsigned char *)dk->bv_val, dk->bv_len,
+ dk_b64, sizeof(dk_b64));
+ if(rc < 0){
+ return LUTIL_PASSWD_ERR;
+ }
+ b64_to_ab64(dk_b64);
+ msg->bv_len = asprintf(&msg->bv_val, "%s%d$%s$%s",
+ sc->bv_val, iteration,
+ salt_b64, dk_b64);
+ if(msg->bv_len < 0){
+ return LUTIL_PASSWD_ERR;
+ }
+
+#ifdef SLAPD_PBKDF2_DEBUG
+ printf(" Output:\t%s\n", msg->bv_val);
+#endif
+ 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_DK_SIZE];
+ struct berval dk;
+ int iteration = PBKDF2_ITERATION;
+
+ dk.bv_val = (char *)dk_value;
+ dk.bv_len = PBKDF2_DK_SIZE;
+ salt.bv_val = (char *)salt_value;
+ salt.bv_len = sizeof(salt_value);
+
+ if(lutil_entropy((unsigned char *)salt.bv_val, salt.bv_len) < 0){
+ return LUTIL_PASSWD_ERR;
+ }
+
+ if(!PKCS5_PBKDF2_HMAC_SHA1(passwd->bv_val, passwd->bv_len,
+ (unsigned char *)salt.bv_val, salt.bv_len,
+ iteration, PBKDF2_DK_SIZE, dk_value)){
+ return LUTIL_PASSWD_ERR;
+ }
+
+#ifdef SLAPD_PBKDF2_DEBUG
+ printf("DEBUG pbkdf2_encrypt()\n");
+ 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<PBKDF2_DK_SIZE; i++){
+ printf("%02x", dk_value[i]);
+ }
+ printf("\n");
+#endif
+
+ return pbkdf2_format(scheme, iteration, &salt, &dk, msg);
+}
+
+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_DK_SIZE + 1 in lutil_b64_pton. */
+ unsigned char dk_value[PBKDF2_DK_SIZE + 1];
+ char dk_b64[LUTIL_BASE64_ENCODE_LEN(PBKDF2_DK_SIZE) + 1];
+ unsigned char input_dk_value[PBKDF2_DK_SIZE];
+
+#ifdef SLAPD_PBKDF2_DEBUG
+ printf("DEBUG pbkdf2_check()\n");
+ printf(" Stored Value:\t%s\n", passwd->bv_val);
+ printf(" Input Cred:\t%s\n", cred->bv_val);
+#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_DK_SIZE + 1 in lutil_b64_pton. */
+ rc = lutil_b64_pton(dk_b64, dk_value, PBKDF2_DK_SIZE + 1);
+ if(rc < 0){
+ return LUTIL_PASSWD_ERR;
+ }
+
+ /* consistency check */
+ if(rc != PBKDF2_DK_SIZE){
+ return LUTIL_PASSWD_ERR;
+ }
+
+ if(!PKCS5_PBKDF2_HMAC_SHA1(cred->bv_val, cred->bv_len,
+ salt_value, PBKDF2_SALT_SIZE,
+ iteration, PBKDF2_DK_SIZE, input_dk_value)){
+ return LUTIL_PASSWD_ERR;
+ }
+
+ rc = memcmp(dk_value, input_dk_value, PBKDF2_DK_SIZE);
+#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<PBKDF2_DK_SIZE; i++){
+ printf("%02x", dk_value[i]);
+ }
+ printf("\n");
+
+ printf(" Input DK:\t");
+ for(i=0; i<PBKDF2_DK_SIZE; 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 *)&pbkdf2scheme,
+ pbkdf2_check, pbkdf2_encrypt);
+ if(!rc) return rc;
+
+ /* TODO: add {PBKDF2-SHA256} and {PBKDF2-SHA512} schemes. */
+ return rc;
+}
+
+/*
+ * Local variables:
+ * indent-tabs-mode: t
+ * tab-width: 4
+ * c-basic-offset: 4
+ * End:
+ */