1 files changed, 309 insertions, 0 deletions
diff --git a/src/psk.c b/src/psk.c
new file mode 100644
index 0000000..17cc076
--- /dev/null
+++ b/src/psk.c
@@ -0,0 +1,309 @@
+/*
+ * Copyright (C) 2005-2012 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuTLS.
+ *
+ * GnuTLS is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuTLS is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+
+/* Gnulib portability files. */
+
+#ifndef ENABLE_PSK
+
+#include <stdio.h>
+
+int main(int argc, char **argv)
+{
+	printf("\nPSK not supported. This program is a dummy.\n\n");
+	return 1;
+};
+
+#else
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <gnutls/gnutls.h>
+#include "psktool-options.h"
+
+#include <gnutls/crypto.h>	/* for random */
+
+#include <stdbool.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#ifndef _WIN32
+#include <pwd.h>
+#include <unistd.h>
+#else
+#include <windows.h>
+#endif
+
+/* Gnulib portability files. */
+#include <minmax.h>
+#include "close-stream.h"
+#include "getpass.h"
+#include "xsize.h"
+
+static int write_key(const char *username,
+		     const unsigned char *key, size_t key_size,
+		     const char *passwd_file);
+
+#define MAX_KEY_SIZE 512
+int main(int argc, char **argv)
+{
+	int ret;
+#ifndef _WIN32
+	struct passwd *pwd;
+#endif
+	unsigned char key[MAX_KEY_SIZE];
+	size_t key_size;
+	const char *passwd, *username;
+
+	if ((ret = gnutls_global_init()) < 0) {
+		fprintf(stderr, "global_init: %s\n", gnutls_strerror(ret));
+		exit(1);
+	}
+
+	umask(066);
+
+	optionProcess(&psktoolOptions, argc, argv);
+
+	if (!HAVE_OPT(PSKFILE)) {
+		fprintf(stderr, "You need to specify a PSK key file\n");
+		exit(1);
+	} else
+		passwd = OPT_ARG(PSKFILE);
+
+	if (!HAVE_OPT(USERNAME)) {
+#ifndef _WIN32
+		pwd = getpwuid(getuid());
+
+		if (pwd == NULL) {
+			fprintf(stderr, "No such user\n");
+			return -1;
+		}
+
+		username = pwd->pw_name;
+#else
+		fprintf(stderr, "Please specify a user\n");
+		return -1;
+#endif
+	} else
+		username = OPT_ARG(USERNAME);
+
+	if (HAVE_OPT(KEYSIZE) && OPT_VALUE_KEYSIZE > MAX_KEY_SIZE) {
+		fprintf(stderr, "Key size is too long\n");
+		exit(1);
+	}
+
+	if (!HAVE_OPT(KEYSIZE) || OPT_VALUE_KEYSIZE < 1)
+		key_size = 32;
+	else
+		key_size = OPT_VALUE_KEYSIZE;
+
+	printf("Generating a random key for user '%s'\n", username);
+
+	ret = gnutls_rnd(GNUTLS_RND_RANDOM, (char *) key, key_size);
+	if (ret < 0) {
+		fprintf(stderr, "Not enough randomness\n");
+		exit(1);
+	}
+
+	ret = write_key(username, key, key_size, passwd);
+	if (ret == 0)
+		printf("Key stored to %s\n", passwd);
+
+	return ret;
+}
+
+static int filecopy(const char *src, const char *dst)
+{
+	FILE *fp, *fp2;
+	char line[5 * 1024];
+	char *p;
+
+	fp = fopen(dst, "w");
+	if (fp == NULL) {
+		fprintf(stderr, "Cannot open '%s' for write\n", dst);
+		return -1;
+	}
+
+	fp2 = fopen(src, "r");
+	if (fp2 == NULL) {
+		/* empty file */
+		fclose(fp);
+		return 0;
+	}
+
+	line[sizeof(line) - 1] = 0;
+	do {
+		p = fgets(line, sizeof(line) - 1, fp2);
+		if (p == NULL)
+			break;
+
+		fputs(line, fp);
+	}
+	while (1);
+
+	fclose(fp);
+	fclose(fp2);
+
+	return 0;
+}
+
+static int
+write_key(const char *username, const unsigned char *key, size_t key_size,
+	  const char *passwd_file)
+{
+	FILE *fp;
+	char line[5 * 1024];
+	char *p, *pp;
+	char tmpname[1024];
+	gnutls_datum_t tmp, _username = { NULL, 0 }, _key = { NULL, 0 };
+	struct stat st;
+	FILE *fp2;
+	bool put;
+	int ret = 0;
+
+	if (strlen(passwd_file) + 5 > sizeof(tmpname)) {
+		fprintf(stderr, "file '%s' is tooooo long\n", passwd_file);
+		return -1;
+	}
+
+	snprintf(tmpname, sizeof(tmpname), "%s.tmp", passwd_file);
+
+	if (stat(tmpname, &st) != -1) {
+		fprintf(stderr, "file '%s' is locked\n", tmpname);
+		return -1;
+	}
+
+	if (filecopy(passwd_file, tmpname) != 0) {
+		fprintf(stderr, "Cannot copy '%s' to '%s'\n", passwd_file,
+			tmpname);
+		return -1;
+	}
+
+	fp = fopen(passwd_file, "w");
+	if (fp == NULL) {
+		fprintf(stderr, "Cannot open '%s' for write\n",
+			passwd_file);
+		(void)remove(tmpname);
+		return -1;
+	}
+
+	fp2 = fopen(tmpname, "r");
+	if (fp2 == NULL) {
+		fprintf(stderr, "Cannot open '%s' for read\n", tmpname);
+		(void)remove(tmpname);
+		fclose(fp);
+		return -1;
+	}
+
+	/* encode username if it contains special characters */
+	if (strcspn(username, ":\n") != strlen(username)) {
+		char *new_data;
+		size_t new_size;
+
+		tmp.data = (void *)username;
+		tmp.size = strlen(username);
+
+		ret = gnutls_hex_encode2(&tmp, &_username);
+		if (ret < 0) {
+			fprintf(stderr, "HEX encoding error\n");
+			ret = -1;
+			goto out;
+		}
+
+		/* prepend '#' */
+		new_size = xsum(_username.size, 2);
+		if (size_overflow_p(new_size)) {
+			ret = -1;
+			goto out;
+		}
+		new_data = gnutls_realloc(_username.data, new_size);
+		if (!new_data) {
+			ret = -1;
+			goto out;
+		}
+		memmove(new_data + 1, new_data, _username.size);
+		new_data[0] = '#';
+		new_data[_username.size + 1] = '\0';
+		_username.data = (void *)new_data;
+		_username.size = new_size - 1;
+	} else {
+		_username.data = (void *)gnutls_strdup(username);
+		if (!_username.data) {
+			ret = -1;
+			goto out;
+		}
+		_username.size = strlen(username);
+	}
+
+	/* encode key */
+	tmp.data = (void *)key;
+	tmp.size = key_size;
+
+	ret = gnutls_hex_encode2(&tmp, &_key);
+	if (ret < 0) {
+		fprintf(stderr, "HEX encoding error\n");
+		ret = -1;
+		goto out;
+	}
+
+	put = false;
+	while (true) {
+		p = fgets(line, sizeof(line) - 1, fp2);
+		if (p == NULL)
+			break;
+
+		pp = strchr(line, ':');
+		if (pp == NULL)
+			continue;
+
+		if (strncmp(p, (const char *) _username.data,
+			    MAX(_username.size,
+				(unsigned int) (pp - p))) == 0) {
+			put = true;
+			fprintf(fp, "%s:%s\n", _username.data, _key.data);
+		} else {
+			fputs(line, fp);
+		}
+	}
+
+	if (!put) {
+		fprintf(fp, "%s:%s\n", _username.data, _key.data);
+	}
+
+ out:
+	if (close_stream(fp) == EOF) {
+		fprintf(stderr, "Error writing %s: %s\n",
+			passwd_file, strerror(errno));
+		ret = -1;
+	}
+
+	fclose(fp2);
+
+	(void)remove(tmpname);
+	gnutls_free(_username.data);
+	gnutls_free(_key.data);
+
+	return ret;
+}
+
+#endif				/* ENABLE_PSK */