all: import netsniff-ng 0.5.8-rc0 source

We decided to get rid of the old Git history and start a new one for
several reasons:

 *) Allow / enforce only high-quality commits (which was not the case
    for many commits in the history), have a policy that is more close
    to the one from the Linux kernel. With high quality commits, we
    mean code that is logically split into commits and commit messages
    that are signed-off and have a proper subject and message body.
    We do not allow automatic Github merges anymore, since they are
    total bullshit. However, we will either cherry-pick your patches
    or pull them manually.

 *) The old archive was about ~27MB for no particular good reason.
    This basically derived from the bad decision that also some PDF
    files where stored there. From this moment onwards, no binary
    objects are allowed to be stored in this repository anymore.

The old archive is not wiped away from the Internet. You will still
be able to find it, e.g. on git.cryptoism.org etc.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 772 insertions, 0 deletions

diff --git a/ct_usermgmt.c b/ct_usermgmt.c
new file mode 100644
index 0000000..0c80dc7
--- /dev/null
+++ b/ct_usermgmt.c
@@ -0,0 +1,772 @@
+/*
+ * netsniff-ng - the packet sniffing beast
+ * Copyright 2011 Daniel Borkmann.
+ * Subject to the GPL, version 2.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <syslog.h>
+#include <limits.h>
+#include <arpa/inet.h>
+
+#include "die.h"
+#include "ct_usermgmt.h"
+#include "locking.h"
+#include "xmalloc.h"
+#include "xio.h"
+#include "curvetun.h"
+#include "xutils.h"
+#include "curve.h"
+#include "hash.h"
+#include "crypto_verify_32.h"
+#include "crypto_hash_sha512.h"
+#include "crypto_box_curve25519xsalsa20poly1305.h"
+#include "crypto_auth_hmacsha512256.h"
+
+#define crypto_box_pub_key_size crypto_box_curve25519xsalsa20poly1305_PUBLICKEYBYTES
+
+/* Config line format: username;pubkey\n */
+
+struct user_store {
+	char username[256];
+	unsigned char publickey[crypto_box_pub_key_size];
+	struct curve25519_proto proto_inf;
+	struct user_store *next;
+};
+
+struct sock_map_entry {
+	int fd;
+	struct curve25519_proto *proto;
+	struct sock_map_entry *next;
+};
+
+struct sockaddr_map_entry {
+	struct sockaddr_storage *sa;
+	size_t sa_len;
+	struct curve25519_proto *proto;
+	struct sockaddr_map_entry *next;
+};
+
+static struct user_store *store = NULL;
+static struct rwlock store_lock;
+
+static struct hash_table sock_mapper;
+static struct rwlock sock_map_lock;
+
+static struct hash_table sockaddr_mapper;
+static struct rwlock sockaddr_map_lock;
+
+static unsigned char token[crypto_auth_hmacsha512256_KEYBYTES];
+
+static void init_sock_mapper(void)
+{
+	rwlock_init(&sock_map_lock);
+
+	rwlock_wr_lock(&sock_map_lock);
+
+	memset(&sock_mapper, 0, sizeof(sock_mapper));
+	init_hash(&sock_mapper);
+
+	rwlock_unlock(&sock_map_lock);
+}
+
+static void init_sockaddr_mapper(void)
+{
+	rwlock_init(&sockaddr_map_lock);
+	rwlock_wr_lock(&sockaddr_map_lock);
+
+	memset(&sockaddr_mapper, 0, sizeof(sockaddr_mapper));
+	init_hash(&sockaddr_mapper);
+
+	rwlock_unlock(&sockaddr_map_lock);
+}
+
+static int cleanup_batch_sock_mapper(void *ptr)
+{
+	struct sock_map_entry *next;
+	struct sock_map_entry *e = ptr;
+
+	if (!e)
+		return 0;
+
+	while ((next = e->next)) {
+		e->next = NULL;
+		xfree(e);
+		e = next;
+	}
+
+	xfree(e);
+
+	return 0;
+}
+
+static void destroy_sock_mapper(void)
+{
+	rwlock_wr_lock(&sock_map_lock);
+	for_each_hash(&sock_mapper, cleanup_batch_sock_mapper);
+	free_hash(&sock_mapper);
+	rwlock_unlock(&sock_map_lock);
+
+	rwlock_destroy(&sock_map_lock);
+}
+
+static int cleanup_batch_sockaddr_mapper(void *ptr)
+{
+	struct sockaddr_map_entry *next;
+	struct sockaddr_map_entry *e = ptr;
+
+	if (!e)
+		return 0;
+
+	while ((next = e->next)) {
+		e->next = NULL;
+		xfree(e);
+		e = next;
+	}
+
+	xfree(e);
+	return 0;
+}
+
+static void destroy_sockaddr_mapper(void)
+{
+	rwlock_wr_lock(&sockaddr_map_lock);
+	for_each_hash(&sockaddr_mapper, cleanup_batch_sockaddr_mapper);
+	free_hash(&sockaddr_mapper);
+	rwlock_unlock(&sockaddr_map_lock);
+
+	rwlock_destroy(&sockaddr_map_lock);
+}
+
+static struct user_store *user_store_alloc(void)
+{
+	return xzmalloc(sizeof(struct user_store));
+}
+
+static void user_store_free(struct user_store *us)
+{
+	if (!us)
+		return;
+	memset(us, 0, sizeof(struct user_store));
+	xfree(us);
+}
+
+/* already in lock */
+static int __check_duplicate_username(char *username, size_t len)
+{
+	int duplicate = 0;
+	struct user_store *elem = store;
+
+	while (elem) {
+		if (!memcmp(elem->username, username,
+			    strlen(elem->username) + 1)) {
+			duplicate = 1;
+			break;
+		}
+		elem = elem->next;
+	}
+
+	return duplicate;
+}
+
+/* already in lock */
+static int __check_duplicate_pubkey(unsigned char *pubkey, size_t len)
+{
+	int duplicate = 0;
+	struct user_store *elem = store;
+
+	while (elem) {
+		if (!memcmp(elem->publickey, pubkey,
+			    sizeof(elem->publickey))) {
+			duplicate = 1;
+			break;
+		}
+		elem = elem->next;
+	}
+
+	return duplicate;
+}
+
+enum parse_states {
+	PARSE_USERNAME,
+	PARSE_PUBKEY,
+	PARSE_DONE,
+};
+
+static int parse_line(char *line, char *homedir)
+{
+	int ret;
+	char *str;
+	enum parse_states s = PARSE_USERNAME;
+	struct user_store *elem;
+	unsigned char pkey[crypto_box_pub_key_size];
+
+	elem = user_store_alloc();
+	elem->next = store;
+
+	str = strtok(line, ";");
+	for (; str != NULL;) {
+		switch (s) {
+		case PARSE_USERNAME:
+			if (__check_duplicate_username(str, strlen(str) + 1))
+				return -EINVAL;
+			strlcpy(elem->username, str, sizeof(elem->username));
+			s = PARSE_PUBKEY;
+			break;
+		case PARSE_PUBKEY:
+			if (!curve25519_pubkey_hexparse_32(pkey, sizeof(pkey),
+							   str, strlen(str)))
+				return -EINVAL;
+			if (__check_duplicate_pubkey(pkey, sizeof(pkey)))
+				return -EINVAL;
+			memcpy(elem->publickey, pkey, sizeof(elem->publickey));
+			ret = curve25519_proto_init(&elem->proto_inf,
+					 	    elem->publickey,
+						    sizeof(elem->publickey),
+						    homedir, 1);
+			if (ret)
+				return -EIO;
+			s = PARSE_DONE;
+			break;
+		case PARSE_DONE:
+			break;
+		default:
+			return -EIO;
+		}
+
+		str = strtok(NULL, ";");
+	}
+
+	store = elem;
+	return s == PARSE_DONE ? 0 : -EIO;
+}
+
+void parse_userfile_and_generate_user_store_or_die(char *homedir)
+{
+	FILE *fp;
+	char path[PATH_MAX], buff[512];
+	int line = 1, ret, fd;
+
+	memset(path, 0, sizeof(path));
+	slprintf(path, sizeof(path), "%s/%s", homedir, FILE_CLIENTS);
+
+	rwlock_init(&store_lock);
+	rwlock_wr_lock(&store_lock);
+
+	fp = fopen(path, "r");
+	if (!fp)
+		panic("Cannot open client file!\n");
+
+	memset(buff, 0, sizeof(buff));
+	while (fgets(buff, sizeof(buff), fp) != NULL) {
+		buff[sizeof(buff) - 1] = 0;
+		/* A comment. Skip this line */
+		if (buff[0] == '#' || buff[0] == '\n') {
+			memset(buff, 0, sizeof(buff));
+			line++;
+			continue;
+		}
+
+		ret = parse_line(buff, homedir);
+		if (ret < 0)
+			panic("Cannot parse line %d from clients!\n", line);
+		line++;
+		memset(buff, 0, sizeof(buff));
+	}
+
+	fclose(fp);
+
+	if (store == NULL)
+		panic("No registered clients found!\n");
+
+	rwlock_unlock(&store_lock);
+
+	init_sock_mapper();
+	init_sockaddr_mapper();
+
+	/*
+	 * Pubkey is also used as a hmac of the initial packet to check
+	 * the integrity of the packet, so that we know if it's just random
+	 * garbage or a 'valid' packet. Again, just for the integrity!
+	 */
+
+	memset(path, 0, sizeof(path));
+	slprintf(path, sizeof(path), "%s/%s", homedir, FILE_PUBKEY);
+
+	fd = open_or_die(path, O_RDONLY);
+	ret = read(fd, token, sizeof(token));
+	if (ret != crypto_auth_hmacsha512256_KEYBYTES)
+		panic("Cannot read public key!\n");
+	close(fd);
+}
+
+void dump_user_store(void)
+{
+	int i;
+	struct user_store *elem;
+
+	rwlock_rd_lock(&store_lock);
+
+	elem = store;
+	while (elem) {
+		printf("%s -> ", elem->username);
+		for (i = 0; i < sizeof(elem->publickey); ++i)
+			if (i == (sizeof(elem->publickey) - 1))
+				printf("%02x\n", (unsigned char)
+				       elem->publickey[i]);
+			else
+				printf("%02x:", (unsigned char)
+				       elem->publickey[i]);
+		elem = elem->next;
+	}
+
+	rwlock_unlock(&store_lock);
+}
+
+void destroy_user_store(void)
+{
+	struct user_store *elem, *nelem = NULL;
+
+	rwlock_wr_lock(&store_lock);
+
+	elem = store;
+	while (elem) {
+		nelem = elem->next;
+		elem->next = NULL;
+		user_store_free(elem);
+		elem = nelem;
+	}
+	rwlock_unlock(&store_lock);
+
+	rwlock_destroy(&store_lock);
+
+	destroy_sock_mapper();
+	destroy_sockaddr_mapper();
+}
+
+int username_msg(char *username, size_t len, char *dst, size_t dlen)
+{
+	int fd;
+	ssize_t ret;
+	uint32_t salt;
+	unsigned char h[crypto_hash_sha512_BYTES];
+	struct username_struct *us = (struct username_struct *) dst;
+	char *uname;
+	size_t uname_len;
+
+	if (dlen < sizeof(struct username_struct))
+		return -ENOMEM;
+
+	uname_len = 512;
+	uname = xzmalloc(uname_len);
+
+	fd = open_or_die("/dev/random", O_RDONLY);
+	ret = read_exact(fd, &salt, sizeof(salt), 0);
+	if (ret != sizeof(salt))
+		panic("Cannot read from /dev/random!\n");
+	close(fd);
+
+	slprintf(uname, uname_len, "%s%u", username, salt);
+	crypto_hash_sha512(h, (unsigned char *) uname, strlen(uname));
+
+	us->salt = htonl(salt);
+	memcpy(us->hash, h, sizeof(us->hash));
+
+	xfree(uname);
+	return 0;
+}
+
+enum is_user_enum username_msg_is_user(char *src, size_t slen, char *username,
+				       size_t len)
+{
+	char *uname;
+	size_t uname_len;
+	uint32_t salt;
+	struct username_struct *us = (struct username_struct *) src;
+	unsigned char h[crypto_hash_sha512_BYTES];
+
+	if (slen < sizeof(struct username_struct)) {
+		errno = ENOMEM;
+		return USERNAMES_ERR;
+	}
+
+	uname_len = 512;
+	uname = xzmalloc(uname_len);
+
+	salt = ntohl(us->salt);
+
+	slprintf(uname, uname_len, "%s%u", username, salt);
+	crypto_hash_sha512(h, (unsigned char *) uname, strlen(uname));
+	xfree(uname);
+
+	if (!crypto_verify_32(&h[0], &us->hash[0]) &&
+	    !crypto_verify_32(&h[32], &us->hash[32]))
+		return USERNAMES_OK;
+	else
+		return USERNAMES_NE;
+}
+
+static int register_user_by_socket(int fd, struct curve25519_proto *proto)
+{
+	void **pos;
+	struct sock_map_entry *entry;
+
+	rwlock_wr_lock(&sock_map_lock);
+
+	entry = xzmalloc(sizeof(*entry));
+	entry->fd = fd;
+	entry->proto = proto;
+
+	pos = insert_hash(entry->fd, entry, &sock_mapper);
+	if (pos) {
+		entry->next = (*pos);
+		(*pos) = entry;
+	}
+
+	rwlock_unlock(&sock_map_lock);
+
+	return 0;
+}
+
+static int register_user_by_sockaddr(struct sockaddr_storage *sa,
+				     size_t sa_len,
+				     struct curve25519_proto *proto)
+{
+	void **pos;
+	struct sockaddr_map_entry *entry;
+	unsigned int hash = hash_name((char *) sa, sa_len);
+
+	rwlock_wr_lock(&sockaddr_map_lock);
+
+	entry = xzmalloc(sizeof(*entry));
+	entry->sa = xmemdupz(sa, sa_len);
+	entry->sa_len = sa_len;
+	entry->proto = proto;
+
+	pos = insert_hash(hash, entry, &sockaddr_mapper);
+	if (pos) {
+		entry->next = (*pos);
+		(*pos) = entry;
+	}
+
+	rwlock_unlock(&sockaddr_map_lock);
+
+	return 0;
+}
+
+int try_register_user_by_socket(struct curve25519_struct *c,
+				char *src, size_t slen, int sock, int log)
+{
+	int ret = -1;
+	char *cbuff = NULL;
+	size_t real_len = 132;
+	ssize_t clen;
+	struct user_store *elem;
+	enum is_user_enum err;
+	unsigned char auth[crypto_auth_hmacsha512256_BYTES];
+	struct taia arrival_taia;
+
+	/* assert(132 == clen + sizeof(auth)); */
+	/*
+	 * Check hmac first, if malicious, drop immediately before we
+	 * investigate more efforts.
+	 */
+	if (slen < real_len)
+		return -1;
+
+	taia_now(&arrival_taia);
+
+	memcpy(auth, src, sizeof(auth));
+
+	src += sizeof(auth);
+	real_len -= sizeof(auth);
+
+	if (crypto_auth_hmacsha512256_verify(auth, (unsigned char *) src,
+					     real_len, token)) {
+		syslog(LOG_ERR, "Bad packet hmac for id %d! Dropping!\n", sock);
+		return -1;
+	} else {
+		if (log)
+			syslog(LOG_INFO, "Good packet hmac for id %d!\n", sock);
+	}
+
+	rwlock_rd_lock(&store_lock);
+
+	elem = store;
+	while (elem) {
+		clen = curve25519_decode(c, &elem->proto_inf,
+					 (unsigned char *) src, real_len,
+					 (unsigned char **) &cbuff,
+					 &arrival_taia);
+		if (clen <= 0) {
+			elem = elem->next;
+			continue;
+		}
+
+		cbuff += crypto_box_zerobytes;
+		clen -= crypto_box_zerobytes;
+
+		if (log)
+			syslog(LOG_INFO, "Packet decoded sucessfully for id %d!\n", sock);
+
+		err = username_msg_is_user(cbuff, clen, elem->username,
+					   strlen(elem->username) + 1);
+		if (err == USERNAMES_OK) {
+			if (log)
+				syslog(LOG_INFO, "Found user %s for id %d! Registering ...\n",
+				       elem->username, sock);
+			ret = register_user_by_socket(sock, &elem->proto_inf);
+			break;
+		}
+
+		elem = elem->next;
+	}
+
+	rwlock_unlock(&store_lock);
+
+	if (ret == -1)
+		syslog(LOG_ERR, "User not found! Dropping connection!\n");
+
+	return ret;
+}
+
+int try_register_user_by_sockaddr(struct curve25519_struct *c,
+				  char *src, size_t slen,
+				  struct sockaddr_storage *sa,
+				  size_t sa_len, int log)
+{
+	int ret = -1;
+	char *cbuff = NULL;
+	struct user_store *elem;
+	ssize_t clen;
+	size_t real_len = 132;
+	enum is_user_enum err;
+	unsigned char auth[crypto_auth_hmacsha512256_BYTES];
+	struct taia arrival_taia;
+
+	/* assert(132 == clen + sizeof(auth)); */
+	/*
+	 * Check hmac first, if malicious, drop immediately before we
+	 * investigate more efforts.
+	 */
+	if (slen < real_len)
+		return -1;
+
+	taia_now(&arrival_taia);
+
+	memcpy(auth, src, sizeof(auth));
+
+	src += sizeof(auth);
+	real_len -= sizeof(auth);
+
+	if (crypto_auth_hmacsha512256_verify(auth, (unsigned char *) src,
+					     real_len, token)) {
+		syslog(LOG_ERR, "Got bad packet hmac! Dropping!\n");
+		return -1;
+	} else {
+		if (log)
+			syslog(LOG_INFO, "Got good packet hmac!\n");
+	}
+
+	rwlock_rd_lock(&store_lock);
+
+	elem = store;
+	while (elem) {
+		clen = curve25519_decode(c, &elem->proto_inf,
+					 (unsigned char *) src, real_len,
+					 (unsigned char **) &cbuff,
+					 &arrival_taia);
+		if (clen <= 0) {
+			elem = elem->next;
+			continue;
+		}
+
+		cbuff += crypto_box_zerobytes;
+		clen -= crypto_box_zerobytes;
+
+		if (log)
+			syslog(LOG_INFO, "Packet decoded sucessfully!\n");
+
+		err = username_msg_is_user(cbuff, clen, elem->username,
+					   strlen(elem->username) + 1);
+		if (err == USERNAMES_OK) {
+			if (log)
+				syslog(LOG_INFO, "Found user %s! Registering ...\n",
+				       elem->username);
+			ret = register_user_by_sockaddr(sa, sa_len,
+							&elem->proto_inf);
+			break;
+		}
+
+		elem = elem->next;
+	}
+
+	rwlock_unlock(&store_lock);
+
+	if (ret == -1)
+		syslog(LOG_ERR, "User not found! Dropping connection!\n");
+
+	return ret;
+}
+
+int get_user_by_socket(int fd, struct curve25519_proto **proto)
+{
+	int ret = -1;
+	struct sock_map_entry *entry;
+
+	errno = 0;
+
+	rwlock_rd_lock(&sock_map_lock);
+
+	entry = lookup_hash(fd, &sock_mapper);
+	while (entry && fd != entry->fd)
+		entry = entry->next;
+	if (entry && fd == entry->fd) {
+		(*proto) = entry->proto;
+		ret = 0;
+	} else {
+		(*proto) = NULL;
+		errno = ENOENT;
+	}
+
+	rwlock_unlock(&sock_map_lock);
+
+	return ret;
+}
+
+int get_user_by_sockaddr(struct sockaddr_storage *sa, size_t sa_len,
+			 struct curve25519_proto **proto)
+{
+	int ret = -1;
+	struct sockaddr_map_entry *entry;
+	unsigned int hash = hash_name((char *) sa, sa_len);
+
+	errno = 0;
+
+	rwlock_rd_lock(&sockaddr_map_lock);
+
+	entry = lookup_hash(hash, &sockaddr_mapper);
+	while (entry && entry->sa_len == sa_len &&
+	       memcmp(sa, entry->sa, entry->sa_len))
+		entry = entry->next;
+	if (entry && entry->sa_len == sa_len &&
+	    !memcmp(sa, entry->sa, entry->sa_len)) {
+		(*proto) = entry->proto;
+		ret = 0;
+	} else {
+		(*proto) = NULL;
+		errno = ENOENT;
+	}
+
+	rwlock_unlock(&sockaddr_map_lock);
+
+	return ret;
+}
+
+static struct sock_map_entry *socket_to_sock_map_entry(int fd)
+{
+	struct sock_map_entry *entry, *ret = NULL;
+
+	errno = 0;
+
+	rwlock_rd_lock(&sock_map_lock);
+
+	entry = lookup_hash(fd, &sock_mapper);
+	while (entry && fd != entry->fd)
+		entry = entry->next;
+	if (entry && fd == entry->fd)
+		ret = entry;
+	else
+		errno = ENOENT;
+
+	rwlock_unlock(&sock_map_lock);
+
+	return ret;
+}
+
+void remove_user_by_socket(int fd)
+{
+	struct sock_map_entry *pos;
+	struct sock_map_entry *entry = socket_to_sock_map_entry(fd);
+
+	if (!entry)
+		return;
+
+	rwlock_wr_lock(&sock_map_lock);
+
+	pos = remove_hash(entry->fd, entry, entry->next, &sock_mapper);
+	while (pos && pos->next && pos->next != entry)
+		pos = pos->next;
+	if (pos && pos->next && pos->next == entry)
+		pos->next = entry->next;
+
+	memset(entry->proto->enonce, 0, sizeof(entry->proto->enonce));
+	memset(entry->proto->dnonce, 0, sizeof(entry->proto->dnonce));
+
+	entry->proto = NULL;
+	entry->next = NULL;
+
+	xfree(entry);
+
+	rwlock_unlock(&sock_map_lock);
+}
+
+static struct sockaddr_map_entry *
+sockaddr_to_sockaddr_map_entry(struct sockaddr_storage *sa, size_t sa_len)
+{
+	struct sockaddr_map_entry *entry, *ret = NULL;
+	unsigned int hash = hash_name((char *) sa, sa_len);
+
+	errno = 0;
+
+	rwlock_rd_lock(&sockaddr_map_lock);
+
+	entry = lookup_hash(hash, &sockaddr_mapper);
+	while (entry && entry->sa_len == sa_len &&
+	       memcmp(sa, entry->sa, entry->sa_len))
+		entry = entry->next;
+	if (entry && entry->sa_len == sa_len &&
+	    !memcmp(sa, entry->sa, entry->sa_len))
+		ret = entry;
+	else
+		errno = ENOENT;
+
+	rwlock_unlock(&sockaddr_map_lock);
+
+	return ret;
+}
+
+void remove_user_by_sockaddr(struct sockaddr_storage *sa, size_t sa_len)
+{
+	struct sockaddr_map_entry *pos;
+	struct sockaddr_map_entry *entry;
+	unsigned int hash = hash_name((char *) sa, sa_len);
+
+	entry = sockaddr_to_sockaddr_map_entry(sa, sa_len);
+	if (!entry)
+		return;
+
+	rwlock_wr_lock(&sockaddr_map_lock);
+
+	pos = remove_hash(hash, entry, entry->next, &sockaddr_mapper);
+	while (pos && pos->next && pos->next != entry)
+		pos = pos->next;
+	if (pos && pos->next && pos->next == entry)
+		pos->next = entry->next;
+
+	memset(entry->proto->enonce, 0, sizeof(entry->proto->enonce));
+	memset(entry->proto->dnonce, 0, sizeof(entry->proto->dnonce));
+
+	entry->proto = NULL;
+	entry->next = NULL;
+
+	xfree(entry->sa);
+	xfree(entry);
+
+	rwlock_unlock(&sockaddr_map_lock);
+}