1 files changed, 427 insertions, 0 deletions

diff --git a/accel-pppd/auth/auth_chap_md5.c b/accel-pppd/auth/auth_chap_md5.c
new file mode 100644
index 0000000..d19634a
--- /dev/null
+++ b/accel-pppd/auth/auth_chap_md5.c
@@ -0,0 +1,427 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <arpa/inet.h>
+
+#include <openssl/md5.h>
+
+#include "log.h"
+#include "ppp.h"
+#include "ppp_auth.h"
+#include "ppp_lcp.h"
+#include "pwdb.h"
+
+#include "memdebug.h"
+
+#define CHAP_CHALLENGE 1
+#define CHAP_RESPONSE  2
+#define CHAP_SUCCESS   3
+#define CHAP_FAILURE   4
+
+#define CHAP_MD5 5
+
+#define VALUE_SIZE 16
+
+#define MSG_FAILURE   "Authentication failed"
+#define MSG_SUCCESS   "Authentication successed"
+
+#define HDR_LEN (sizeof(struct chap_hdr_t)-2)
+
+static int conf_timeout = 5;
+static int conf_interval = 0;
+static int conf_max_failure = 3;
+static int conf_any_login = 0;
+
+static int urandom_fd;
+
+struct chap_hdr_t
+{
+	uint16_t proto;
+	uint8_t code;
+	uint8_t id;
+	uint16_t len;
+} __attribute__((packed));
+
+struct chap_challenge_t
+{
+	struct chap_hdr_t hdr;
+	uint8_t val_size;
+	uint8_t val[VALUE_SIZE];
+	char name[0];
+} __attribute__((packed));
+
+struct chap_failure_t
+{
+	struct chap_hdr_t hdr;
+	char message[sizeof(MSG_FAILURE)];
+} __attribute__((packed));
+
+struct chap_success_t
+{
+	struct chap_hdr_t hdr;
+	char message[sizeof(MSG_SUCCESS)];
+} __attribute__((packed));
+
+
+struct chap_auth_data_t
+{
+	struct auth_data_t auth;
+	struct ppp_handler_t h;
+	struct ppp_t *ppp;
+	int id;
+	uint8_t val[VALUE_SIZE];
+	struct triton_timer_t timeout;
+	struct triton_timer_t interval;
+	int failure;
+	int started:1;
+};
+
+static void chap_send_challenge(struct chap_auth_data_t *ad);
+static void chap_recv(struct ppp_handler_t *h);
+static void chap_timeout_timer(struct triton_timer_t *t);
+static void chap_restart_timer(struct triton_timer_t *t);
+
+static void print_buf(const uint8_t *buf, int size)
+{
+	int i;
+	for (i=0; i < size; i++)
+		log_ppp_info2("%x", buf[i]);
+}
+static void print_str(const char *buf, int size)
+{
+	int i;
+	for (i = 0; i < size; i++)
+		log_ppp_info2("%c", buf[i]);
+}
+
+static struct auth_data_t* auth_data_init(struct ppp_t *ppp)
+{
+	struct chap_auth_data_t *d = _malloc(sizeof(*d));
+
+	memset(d, 0, sizeof(*d));
+	d->auth.proto = PPP_CHAP;
+	d->ppp = ppp;
+
+	return &d->auth;
+}
+
+static void auth_data_free(struct ppp_t *ppp, struct auth_data_t *auth)
+{
+	struct chap_auth_data_t *d = container_of(auth, typeof(*d), auth);
+
+	if (d->timeout.tpd)
+		triton_timer_del(&d->timeout);
+
+	if (d->interval.tpd)
+		triton_timer_del(&d->interval);
+
+	_free(d);
+}
+
+static int chap_start(struct ppp_t *ppp, struct auth_data_t *auth)
+{
+	struct chap_auth_data_t *d = container_of(auth, typeof(*d), auth);
+
+	d->h.proto = PPP_CHAP;
+	d->h.recv = chap_recv;
+	d->timeout.expire = chap_timeout_timer;
+	d->timeout.period = conf_timeout * 1000;
+	d->interval.expire = chap_restart_timer;
+	d->interval.period = conf_interval * 1000;
+
+	ppp_register_chan_handler(ppp, &d->h);
+
+	chap_send_challenge(d);
+
+	return 0;
+}
+
+static int chap_finish(struct ppp_t *ppp, struct auth_data_t *auth)
+{
+	struct chap_auth_data_t *d = container_of(auth, typeof(*d), auth);
+
+	if (d->timeout.tpd)
+		triton_timer_del(&d->timeout);
+
+	if (d->interval.tpd)
+		triton_timer_del(&d->interval);
+
+	ppp_unregister_handler(ppp, &d->h);
+
+	return 0;
+}
+
+static void chap_timeout_timer(struct triton_timer_t *t)
+{
+	struct chap_auth_data_t *d = container_of(t, typeof(*d), timeout);
+
+	if (conf_ppp_verbose)
+		log_ppp_warn("chap-md5: timeout\n");
+
+	if (++d->failure == conf_max_failure) {
+		if (d->started)
+			ppp_terminate(d->ppp, TERM_USER_ERROR, 0);
+		else
+			ppp_auth_failed(d->ppp, NULL);
+	} else {
+		--d->id;
+		chap_send_challenge(d);
+	}
+}
+
+static void chap_restart_timer(struct triton_timer_t *t)
+{
+	struct chap_auth_data_t *d = container_of(t, typeof(*d), interval);
+	
+	chap_send_challenge(d);
+}
+
+static int lcp_send_conf_req(struct ppp_t *ppp, struct auth_data_t *d, uint8_t *ptr)
+{
+	*ptr = CHAP_MD5;
+	return 1;
+}
+
+static int lcp_recv_conf_req(struct ppp_t *ppp, struct auth_data_t *d, uint8_t *ptr)
+{
+	if (*ptr == CHAP_MD5)
+		return LCP_OPT_ACK;
+	return LCP_OPT_NAK;
+}
+
+static void chap_send_failure(struct chap_auth_data_t *ad)
+{
+	struct chap_failure_t msg = {
+		.hdr.proto = htons(PPP_CHAP),
+		.hdr.code = CHAP_FAILURE,
+		.hdr.id = ad->id,
+		.hdr.len = htons(sizeof(msg) - 1 - 2),
+		.message = MSG_FAILURE,
+	};
+	
+	if (conf_ppp_verbose)
+		log_ppp_info2("send [CHAP Failure id=%x \"%s\"]\n", msg.hdr.id, MSG_FAILURE);
+
+	ppp_chan_send(ad->ppp, &msg, ntohs(msg.hdr.len) + 2);
+}
+
+static void chap_send_success(struct chap_auth_data_t *ad)
+{
+	struct chap_success_t msg =	{
+		.hdr.proto = htons(PPP_CHAP),
+		.hdr.code = CHAP_SUCCESS,
+		.hdr.id = ad->id,
+		.hdr.len = htons(sizeof(msg)-1-2),
+		.message = MSG_SUCCESS,
+	};
+	
+	if (conf_ppp_verbose)
+		log_ppp_info2("send [CHAP Success id=%x \"%s\"]\n", msg.hdr.id, MSG_SUCCESS);
+
+	ppp_chan_send(ad->ppp, &msg, ntohs(msg.hdr.len) + 2);
+}
+
+static void chap_send_challenge(struct chap_auth_data_t *ad)
+{
+	struct chap_challenge_t msg =	{
+		.hdr.proto = htons(PPP_CHAP),
+		.hdr.code = CHAP_CHALLENGE,
+		.hdr.id = ++ad->id,
+		.hdr.len = htons(sizeof(msg) - 2),
+		.val_size = VALUE_SIZE,
+	};
+
+	read(urandom_fd, ad->val, VALUE_SIZE);
+	memcpy(msg.val, ad->val, VALUE_SIZE);
+
+	if (conf_ppp_verbose) {
+		log_ppp_info2("send [CHAP Challenge id=%x <", msg.hdr.id);
+		print_buf(msg.val, VALUE_SIZE);
+		log_ppp_info2(">]\n");
+	}
+
+	ppp_chan_send(ad->ppp, &msg, ntohs(msg.hdr.len) + 2);
+
+	if (conf_timeout && !ad->timeout.tpd)
+		triton_timer_add(ad->ppp->ctrl->ctx, &ad->timeout, 0);
+}
+
+static void chap_recv_response(struct chap_auth_data_t *ad, struct chap_hdr_t *hdr)
+{
+	MD5_CTX md5_ctx;
+	uint8_t md5[MD5_DIGEST_LENGTH];
+	char *passwd;
+	char *name;
+	int r;
+	struct chap_challenge_t *msg = (struct chap_challenge_t*)hdr;
+
+	if (ad->timeout.tpd)
+		triton_timer_del(&ad->timeout);
+
+	if (conf_ppp_verbose) {
+		log_ppp_info2("recv [CHAP Response id=%x <", msg->hdr.id);
+		print_buf(msg->val, msg->val_size);
+		log_ppp_info2(">, name=\"");
+		print_str(msg->name, ntohs(msg->hdr.len) - sizeof(*msg) + 2);
+		log_ppp_info2("\"]\n");
+	}
+
+	if (msg->hdr.id != ad->id) {
+		if (conf_ppp_verbose)
+			log_ppp_error("chap-md5: id mismatch\n");
+		chap_send_failure(ad);
+		ppp_terminate(ad->ppp, TERM_USER_ERROR, 0);
+	}
+
+	if (msg->val_size != VALUE_SIZE) {
+		log_ppp_error("chap-md5: incorrect value-size (%i)\n", msg->val_size);
+		chap_send_failure(ad);
+		ppp_terminate(ad->ppp, TERM_USER_ERROR, 0);
+	}
+
+	name = _strndup(msg->name,ntohs(msg->hdr.len) - sizeof(*msg) + 2);
+
+	if (conf_any_login) {
+		chap_send_success(ad);
+		ad->started = 1;
+		ppp_auth_successed(ad->ppp, name);
+		return;
+	}
+
+	r = pwdb_check(ad->ppp, name, PPP_CHAP, CHAP_MD5, ad->id, ad->val, VALUE_SIZE, msg->val);
+
+	if (r == PWDB_NO_IMPL) {
+		passwd = pwdb_get_passwd(ad->ppp,name);
+		if (!passwd)
+		{
+			_free(name);
+			if (conf_ppp_verbose)
+				log_ppp_warn("chap-md5: user not found\n");
+			chap_send_failure(ad);
+			return;
+		}
+
+		MD5_Init(&md5_ctx);
+		MD5_Update(&md5_ctx,&msg->hdr.id,1);
+		MD5_Update(&md5_ctx,passwd,strlen(passwd));
+		MD5_Update(&md5_ctx,ad->val,VALUE_SIZE);
+		MD5_Final(md5,&md5_ctx);
+		
+		if (memcmp(md5,msg->val,sizeof(md5)))
+		{
+			if (conf_ppp_verbose)
+				log_ppp_warn("chap-md5: challenge response mismatch\n");
+			chap_send_failure(ad);
+			if (ad->started)
+				ppp_terminate(ad->ppp, TERM_USER_ERROR, 0);
+			else
+				ppp_auth_failed(ad->ppp, name);
+			_free(name);
+		} else {
+			chap_send_success(ad);
+			if (!ad->started) {
+				ad->started = 1;
+				if (conf_interval)
+					triton_timer_add(ad->ppp->ctrl->ctx, &ad->interval, 0);
+				ppp_auth_successed(ad->ppp, name);
+			} else
+				_free(name);
+		}
+		_free(passwd);
+	} else if (r == PWDB_DENIED) {
+		chap_send_failure(ad);
+		if (ad->started)
+			ppp_terminate(ad->ppp, TERM_USER_ERROR, 0);
+		else
+			ppp_auth_failed(ad->ppp, name);
+		_free(name);
+	} else {
+		chap_send_success(ad);
+		if (!ad->started) {
+			ad->started = 1;
+			if (conf_interval)
+				triton_timer_add(ad->ppp->ctrl->ctx, &ad->interval, 0);
+			ppp_auth_successed(ad->ppp, name);
+		} else
+			_free(name);
+	}
+}
+
+static int chap_check(uint8_t *ptr)
+{
+	return *ptr == CHAP_MD5;
+}
+
+static int chap_restart(struct ppp_t *ppp, struct auth_data_t *auth)
+{
+	struct chap_auth_data_t *d = container_of(auth, typeof(*d), auth);
+	
+	chap_send_challenge(d);
+
+	return 0;
+}
+
+static struct ppp_auth_handler_t chap=
+{
+	.name          = "CHAP-md5",
+	.init          = auth_data_init,
+	.free          = auth_data_free,
+	.send_conf_req = lcp_send_conf_req,
+	.recv_conf_req = lcp_recv_conf_req,
+	.start         = chap_start,
+	.finish        = chap_finish,
+	.check         = chap_check,
+	.restart       = chap_restart,
+};
+
+static void chap_recv(struct ppp_handler_t *h)
+{
+	struct chap_auth_data_t *d = container_of(h, typeof(*d), h);
+	struct chap_hdr_t *hdr = (struct chap_hdr_t *)d->ppp->chan_buf;
+
+	if (d->ppp->chan_buf_size < sizeof(*hdr) || ntohs(hdr->len) < HDR_LEN || ntohs(hdr->len) < d->ppp->chan_buf_size - 2)	{
+		log_ppp_warn("chap-md5: short packet received\n");
+		return;
+	}
+
+	if (hdr->code == CHAP_RESPONSE)
+		chap_recv_response(d, hdr);
+	else
+		log_ppp_warn("chap-md5: unknown code received %x\n", hdr->code);
+}
+
+static void __init auth_chap_md5_init()
+{
+	char *opt;
+
+	opt = conf_get_opt("auth", "timeout");
+	if (opt && atoi(opt) > 0)
+		conf_timeout = atoi(opt);
+
+	opt = conf_get_opt("auth", "interval");
+	if (opt && atoi(opt) > 0)
+		conf_interval = atoi(opt);
+
+	opt = conf_get_opt("auth", "max-failure");
+	if (opt && atoi(opt) > 0)
+		conf_max_failure = atoi(opt);
+
+	opt = conf_get_opt("auth", "any-login");
+	if (opt && atoi(opt) > 0)
+		conf_any_login = 1;
+
+	urandom_fd=open("/dev/urandom", O_RDONLY);
+
+	if (urandom_fd < 0) {
+		log_emerg("chap-md5: failed to open /dev/urandom: %s\n", strerror(errno));
+		return;
+	}
+
+	if (ppp_auth_register_handler(&chap))
+		log_emerg("chap-md5: failed to register handler\n");
+}
+