From 3e808b831ce315b41c222a17de3ff7836a34d490 Mon Sep 17 00:00:00 2001
From: Jouni Malinen <j@w1.fi>
Date: Sat, 28 Mar 2015 09:43:33 +0200
Subject: [PATCH] EAP-pwd peer: Add support for hashed password

This extends EAP-pwd peer support to allow NtHash version of password
storage in addition to full plaintext password. In addition, this allows
the server to request hashed version even if the plaintext password is
available on the client. Furthermore, unsupported password preparation
requests are now rejected rather than allowing the authentication
attempt to continue.

Signed-off-by: Jouni Malinen <j@w1.fi>
---
 src/eap_peer/eap_pwd.c | 66 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 60 insertions(+), 6 deletions(-)

diff --git a/src/eap_peer/eap_pwd.c b/src/eap_peer/eap_pwd.c
index 059bbeecb..f2b092669 100644
--- a/src/eap_peer/eap_pwd.c
+++ b/src/eap_peer/eap_pwd.c
@@ -10,6 +10,7 @@
 
 #include "common.h"
 #include "crypto/sha256.h"
+#include "crypto/ms_funcs.h"
 #include "eap_peer/eap_i.h"
 #include "eap_common/eap_pwd_common.h"
 
@@ -25,6 +26,7 @@ struct eap_pwd_data {
 	size_t id_server_len;
 	u8 *password;
 	size_t password_len;
+	int password_hash;
 	u16 group_num;
 	EAP_PWD_group *grp;
 
@@ -86,8 +88,9 @@ static void * eap_pwd_init(struct eap_sm *sm)
 	const u8 *identity, *password;
 	size_t identity_len, password_len;
 	int fragment_size;
+	int pwhash;
 
-	password = eap_get_config_password(sm, &password_len);
+	password = eap_get_config_password2(sm, &password_len, &pwhash);
 	if (password == NULL) {
 		wpa_printf(MSG_INFO, "EAP-PWD: No password configured!");
 		return NULL;
@@ -129,6 +132,7 @@ static void * eap_pwd_init(struct eap_sm *sm)
 	}
 	os_memcpy(data->password, password, password_len);
 	data->password_len = password_len;
+	data->password_hash = pwhash;
 
 	data->out_frag_pos = data->in_frag_pos = 0;
 	data->inbuf = data->outbuf = NULL;
@@ -216,6 +220,10 @@ eap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
 			    const u8 *payload, size_t payload_len)
 {
 	struct eap_pwd_id *id;
+	const u8 *password;
+	size_t password_len;
+	u8 pwhashhash[16];
+	int res;
 
 	if (data->state != PWD_ID_Req) {
 		ret->ignore = TRUE;
@@ -231,6 +239,9 @@ eap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
 
 	id = (struct eap_pwd_id *) payload;
 	data->group_num = be_to_host16(id->group_num);
+	wpa_printf(MSG_DEBUG,
+		   "EAP-PWD: Server EAP-pwd-ID proposal: group=%u random=%u prf=%u prep=%u",
+		   data->group_num, id->random_function, id->prf, id->prep);
 	if ((id->random_function != EAP_PWD_DEFAULT_RAND_FUNC) ||
 	    (id->prf != EAP_PWD_DEFAULT_PRF)) {
 		ret->ignore = TRUE;
@@ -238,6 +249,22 @@ eap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
 		return;
 	}
 
+	if (id->prep != EAP_PWD_PREP_NONE &&
+	    id->prep != EAP_PWD_PREP_MS) {
+		wpa_printf(MSG_DEBUG,
+			   "EAP-PWD: Unsupported password pre-processing technique (Prep=%u)",
+			   id->prep);
+		eap_pwd_state(data, FAILURE);
+		return;
+	}
+
+	if (id->prep == EAP_PWD_PREP_NONE && data->password_hash) {
+		wpa_printf(MSG_DEBUG,
+			   "EAP-PWD: Unhashed password not available");
+		eap_pwd_state(data, FAILURE);
+		return;
+	}
+
 	wpa_printf(MSG_DEBUG, "EAP-PWD (peer): using group %d",
 		   data->group_num);
 
@@ -260,12 +287,39 @@ eap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
 		return;
 	}
 
+	if (id->prep == EAP_PWD_PREP_MS) {
+		if (data->password_hash) {
+			res = hash_nt_password_hash(data->password, pwhashhash);
+		} else {
+			u8 pwhash[16];
+
+			res = nt_password_hash(data->password,
+					       data->password_len, pwhash);
+			if (res == 0)
+				res = hash_nt_password_hash(pwhash, pwhashhash);
+			os_memset(pwhash, 0, sizeof(pwhash));
+		}
+
+		if (res) {
+			eap_pwd_state(data, FAILURE);
+			return;
+		}
+
+		password = pwhashhash;
+		password_len = sizeof(pwhashhash);
+	} else {
+		password = data->password;
+		password_len = data->password_len;
+	}
+
 	/* compute PWE */
-	if (compute_password_element(data->grp, data->group_num,
-				     data->password, data->password_len,
-				     data->id_server, data->id_server_len,
-				     data->id_peer, data->id_peer_len,
-				     id->token)) {
+	res = compute_password_element(data->grp, data->group_num,
+				       password, password_len,
+				       data->id_server, data->id_server_len,
+				       data->id_peer, data->id_peer_len,
+				       id->token);
+	os_memset(pwhashhash, 0, sizeof(pwhashhash));
+	if (res) {
 		wpa_printf(MSG_INFO, "EAP-PWD (peer): unable to compute PWE");
 		eap_pwd_state(data, FAILURE);
 		return;