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-rw-r--r--src/srptool.c688
1 files changed, 688 insertions, 0 deletions
diff --git a/src/srptool.c b/src/srptool.c
new file mode 100644
index 0000000..a050de0
--- /dev/null
+++ b/src/srptool.c
@@ -0,0 +1,688 @@
+/*
+ * Copyright (C) 2001-2012 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>
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <gnutls/gnutls.h>
+#include <gnutls/crypto.h> /* for random */
+
+#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 <getpass.h>
+#include <minmax.h>
+
+#include "srptool-options.h"
+
+/* This may need some rewrite. A lot of stuff which should be here
+ * are in the library, which is not good.
+ */
+
+int crypt_int(const char *username, const char *passwd, int salt,
+ const char *tpasswd_conf, const char *tpasswd, int uindex);
+static int read_conf_values(gnutls_datum_t * g, gnutls_datum_t * n,
+ char *str);
+static int _verify_passwd_int(const char *username, const char *passwd,
+ char *verifier, const char *salt,
+ const gnutls_datum_t * g,
+ const gnutls_datum_t * n);
+
+static void print_num(const char *msg, const gnutls_datum_t * num)
+{
+ unsigned int i;
+
+ printf("%s:\t", msg);
+
+ for (i = 0; i < num->size; i++) {
+ if (i != 0 && i % 12 == 0)
+ printf("\n\t");
+ else if (i != 0 && i != num->size)
+ printf(":");
+ printf("%.2x", num->data[i]);
+ }
+ printf("\n\n");
+
+}
+
+static int generate_create_conf(const char *tpasswd_conf)
+{
+ FILE *fp;
+ char line[5 * 1024];
+ int index = 1, srp_idx;
+ gnutls_datum_t g, n;
+ gnutls_datum_t str_g, str_n;
+
+ fp = fopen(tpasswd_conf, "w");
+ if (fp == NULL) {
+ fprintf(stderr, "Cannot open file '%s'\n", tpasswd_conf);
+ return -1;
+ }
+
+ for (index = 1; index <= 5; index++) {
+
+ if (index == 1) {
+ srp_idx = 2;
+ n = gnutls_srp_1536_group_prime;
+ g = gnutls_srp_1536_group_generator;
+ } else if (index == 2) {
+ srp_idx = 3;
+ n = gnutls_srp_2048_group_prime;
+ g = gnutls_srp_2048_group_generator;
+ } else if (index == 3) {
+ srp_idx = 4;
+ n = gnutls_srp_3072_group_prime;
+ g = gnutls_srp_3072_group_generator;
+ } else if (index == 4) {
+ srp_idx = 5;
+ n = gnutls_srp_4096_group_prime;
+ g = gnutls_srp_4096_group_generator;
+ } else if (index == 5) {
+ srp_idx = 7;
+ n = gnutls_srp_8192_group_prime;
+ g = gnutls_srp_8192_group_generator;
+ } else {
+ fprintf(stderr, "Unknown index: %d\n", index);
+ fclose(fp);
+ return -1;
+ }
+
+ printf("\nGroup %d, of %d bits:\n", srp_idx, n.size * 8);
+ print_num("Generator", &g);
+ print_num("Prime", &n);
+
+ if (gnutls_srp_base64_encode_alloc(&n, &str_n) < 0) {
+ fprintf(stderr, "Could not encode\n");
+ fclose(fp);
+ return -1;
+ }
+
+ if (gnutls_srp_base64_encode_alloc(&g, &str_g) < 0) {
+ fprintf(stderr, "Could not encode\n");
+ fclose(fp);
+ return -1;
+ }
+
+ sprintf(line, "%d:%s:%s\n", srp_idx, str_n.data, str_g.data);
+
+ gnutls_free(str_n.data);
+ gnutls_free(str_g.data);
+
+ fwrite(line, 1, strlen(line), fp);
+
+ }
+
+ fclose(fp);
+
+ return 0;
+
+}
+
+/* The format of a tpasswd file is:
+ * username:verifier:salt:index
+ *
+ * index is the index of the prime-generator pair in tpasswd.conf
+ */
+static int
+_verify_passwd_int(const char *username, const char *passwd,
+ char *verifier, const char *salt,
+ const gnutls_datum_t * g, const gnutls_datum_t * n)
+{
+ char _salt[1024];
+ gnutls_datum_t tmp, raw_salt, new_verifier;
+ size_t salt_size;
+ char *pos;
+
+ if (salt == NULL || verifier == NULL)
+ return -1;
+
+ if (strlen(salt) >= sizeof(_salt)) {
+ fprintf(stderr, "Too long salt.\n");
+ return -1;
+ }
+
+ /* copy salt, and null terminate after the ':' */
+ strcpy(_salt, salt);
+ pos = strchr(_salt, ':');
+ if (pos != NULL)
+ *pos = 0;
+
+ /* convert salt to binary. */
+ tmp.data = (void *) _salt;
+ tmp.size = strlen(_salt);
+
+ if (gnutls_srp_base64_decode_alloc(&tmp, &raw_salt) < 0) {
+ fprintf(stderr, "Could not decode salt.\n");
+ return -1;
+ }
+
+ if (gnutls_srp_verifier
+ (username, passwd, &raw_salt, g, n, &new_verifier) < 0) {
+ fprintf(stderr, "Could not make the verifier\n");
+ return -1;
+ }
+
+ free(raw_salt.data);
+
+ /* encode the verifier into _salt */
+ salt_size = sizeof(_salt);
+ memset(_salt, 0, salt_size);
+ if (gnutls_srp_base64_encode(&new_verifier, _salt, &salt_size) < 0) {
+ fprintf(stderr, "Encoding error\n");
+ return -1;
+ }
+
+ free(new_verifier.data);
+
+ if (strncmp(verifier, _salt, strlen(_salt)) == 0) {
+ fprintf(stderr, "Password verified\n");
+ return 0;
+ } else {
+ fprintf(stderr, "Password does NOT match\n");
+ }
+ return -1;
+}
+
+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;
+}
+
+/* accepts password file */
+static int find_strchr(const char *username, const char *file)
+{
+ FILE *fp;
+ char *pos;
+ char line[5 * 1024];
+ unsigned int i;
+
+ fp = fopen(file, "r");
+ if (fp == NULL) {
+ fprintf(stderr, "Cannot open file '%s'\n", file);
+ return -1;
+ }
+
+ while (fgets(line, sizeof(line), fp) != NULL) {
+ /* move to first ':' */
+ i = 0;
+ while ((line[i] != ':') && (line[i] != '\0')
+ && (i < sizeof(line))) {
+ i++;
+ }
+ if (strncmp(username, line, MAX(i, strlen(username))) == 0) {
+ /* find the index */
+ pos = strrchr(line, ':');
+ pos++;
+ fclose(fp);
+ return atoi(pos);
+ }
+ }
+
+ fclose(fp);
+ return -1;
+}
+
+/* Parses the tpasswd files, in order to verify the given
+ * username/password pair.
+ */
+static int
+verify_passwd(const char *conffile, const char *tpasswd,
+ const char *username, const char *passwd)
+{
+ FILE *fp;
+ char line[5 * 1024];
+ unsigned int i;
+ gnutls_datum_t g, n;
+ int iindex;
+ char *p, *pos;
+
+ iindex = find_strchr(username, tpasswd);
+ if (iindex == -1) {
+ fprintf(stderr, "Cannot find '%s' in %s\n", username,
+ tpasswd);
+ return -1;
+ }
+
+ fp = fopen(conffile, "r");
+ if (fp == NULL) {
+ fprintf(stderr, "Cannot find %s\n", conffile);
+ return -1;
+ }
+
+ do {
+ p = fgets(line, sizeof(line) - 1, fp);
+ }
+ while (p != NULL && atoi(p) != iindex);
+
+ fclose(fp);
+
+ if (p == NULL) {
+ fprintf(stderr, "Cannot find entry in %s\n", conffile);
+ return -1;
+ }
+ line[sizeof(line) - 1] = 0;
+
+ if (read_conf_values(&g, &n, line) < 0) {
+ fprintf(stderr, "Cannot parse conf file '%s'\n", conffile);
+ return -1;
+ }
+
+ fp = fopen(tpasswd, "r");
+ if (fp == NULL) {
+ fprintf(stderr, "Cannot open file '%s'\n", tpasswd);
+ return -1;
+ }
+
+ while (fgets(line, sizeof(line), fp) != NULL) {
+ /* move to first ':'
+ * This is the actual verifier.
+ */
+ i = 0;
+ while ((line[i] != ':') && (line[i] != '\0')
+ && (i < sizeof(line))) {
+ i++;
+ }
+ if (strncmp(username, line, MAX(i, strlen(username))) == 0) {
+ char *verifier_pos, *salt_pos;
+
+ pos = strchr(line, ':');
+ fclose(fp);
+ if (pos == NULL) {
+ fprintf(stderr,
+ "Cannot parse conf file '%s'\n",
+ conffile);
+ return -1;
+ }
+ pos++;
+ verifier_pos = pos;
+
+ /* Move to the salt */
+ pos = strchr(pos, ':');
+ if (pos == NULL) {
+ fprintf(stderr,
+ "Cannot parse conf file '%s'\n",
+ conffile);
+ return -1;
+ }
+ pos++;
+ salt_pos = pos;
+
+ return _verify_passwd_int(username, passwd,
+ verifier_pos, salt_pos,
+ &g, &n);
+ }
+ }
+
+ fclose(fp);
+ return -1;
+
+}
+
+#define KPASSWD "/etc/tpasswd"
+#define KPASSWD_CONF "/etc/tpasswd.conf"
+
+static void tls_log_func(int level, const char *str)
+{
+ fprintf(stderr, "|<%d>| %s", level, str);
+}
+
+int main(int argc, char **argv)
+{
+ const char *passwd;
+ int salt_size, ret;
+ const char *fpasswd, *fpasswd_conf;
+ const char *username;
+#ifndef _WIN32
+ struct passwd *pwd;
+#endif
+
+ if ((ret = gnutls_global_init()) < 0) {
+ fprintf(stderr, "global_init: %s\n", gnutls_strerror(ret));
+ exit(1);
+ }
+
+ umask(066);
+
+ optionProcess(&srptoolOptions, argc, argv);
+
+ gnutls_global_set_log_function(tls_log_func);
+ gnutls_global_set_log_level(OPT_VALUE_DEBUG);
+
+ if (HAVE_OPT(CREATE_CONF)) {
+ return generate_create_conf(OPT_ARG(CREATE_CONF));
+ }
+
+ if (HAVE_OPT(PASSWD))
+ fpasswd = OPT_ARG(PASSWD);
+ else
+ fpasswd = (char *) KPASSWD;
+
+ if (HAVE_OPT(PASSWD_CONF))
+ fpasswd_conf = OPT_ARG(PASSWD_CONF);
+ else
+ fpasswd_conf = (char *) KPASSWD_CONF;
+
+ if (HAVE_OPT(USERNAME))
+ username = OPT_ARG(USERNAME);
+ else {
+#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
+ }
+
+ salt_size = 16;
+
+ passwd = getpass("Enter password: ");
+ if (passwd == NULL) {
+ fprintf(stderr, "Please specify a password\n");
+ return -1;
+ }
+
+/* not ready yet */
+ if (HAVE_OPT(VERIFY)) {
+ return verify_passwd(fpasswd_conf, fpasswd,
+ username, passwd);
+ }
+
+
+ return crypt_int(username, passwd, salt_size,
+ fpasswd_conf, fpasswd, OPT_VALUE_INDEX);
+
+}
+
+static char *_srp_crypt(const char *username, const char *passwd,
+ int salt_size, const gnutls_datum_t * g,
+ const gnutls_datum_t * n)
+{
+ unsigned char salt[128];
+ static char result[1024];
+ gnutls_datum_t dat_salt, txt_salt;
+ gnutls_datum_t verifier, txt_verifier;
+
+ if ((unsigned) salt_size > sizeof(salt))
+ return NULL;
+
+ /* generate the salt
+ */
+ if (gnutls_rnd(GNUTLS_RND_NONCE, salt, salt_size) < 0) {
+ fprintf(stderr, "Could not create nonce\n");
+ return NULL;
+ }
+
+ dat_salt.data = salt;
+ dat_salt.size = salt_size;
+
+ if (gnutls_srp_verifier
+ (username, passwd, &dat_salt, g, n, &verifier) < 0) {
+ fprintf(stderr, "Error getting verifier\n");
+ return NULL;
+ }
+
+ /* base64 encode the verifier */
+ if (gnutls_srp_base64_encode_alloc(&verifier, &txt_verifier) < 0) {
+ fprintf(stderr, "Error encoding\n");
+ free(verifier.data);
+ return NULL;
+ }
+
+ free(verifier.data);
+
+ if (gnutls_srp_base64_encode_alloc(&dat_salt, &txt_salt) < 0) {
+ fprintf(stderr, "Error encoding\n");
+ return NULL;
+ }
+
+ sprintf(result, "%s:%s", txt_verifier.data, txt_salt.data);
+ free(txt_salt.data);
+ free(txt_verifier.data);
+
+ return result;
+
+}
+
+
+int
+crypt_int(const char *username, const char *passwd, int salt_size,
+ const char *tpasswd_conf, const char *tpasswd, int uindex)
+{
+ FILE *fp;
+ char *cr;
+ gnutls_datum_t g, n;
+ char line[5 * 1024];
+ char *p, *pp;
+ int iindex;
+ char tmpname[1024];
+
+ fp = fopen(tpasswd_conf, "r");
+ if (fp == NULL) {
+ fprintf(stderr, "Cannot find %s\n", tpasswd_conf);
+ return -1;
+ }
+
+ do { /* find the specified uindex in file */
+ p = fgets(line, sizeof(line) - 1, fp);
+ }
+ while (p != NULL && atoi(p) != uindex);
+ fclose(fp);
+
+ if (p == NULL) {
+ fprintf(stderr, "Cannot find entry in %s\n", tpasswd_conf);
+ return -1;
+ }
+ line[sizeof(line) - 1] = 0;
+
+ if ((iindex = read_conf_values(&g, &n, line)) < 0) {
+ fprintf(stderr, "Cannot parse conf file '%s'\n",
+ tpasswd_conf);
+ return -1;
+ }
+
+ cr = _srp_crypt(username, passwd, salt_size, &g, &n);
+ if (cr == NULL) {
+ fprintf(stderr, "Cannot _srp_crypt()...\n");
+ return -1;
+ } else {
+ /* delete previous entry */
+ struct stat st;
+ FILE *fp2;
+ int put;
+
+ if (strlen(tpasswd) + 5 > sizeof(tmpname)) {
+ fprintf(stderr, "file '%s' is tooooo long\n",
+ tpasswd);
+ return -1;
+ }
+
+ snprintf(tmpname, sizeof(tmpname), "%s.tmp", tpasswd);
+
+ if (stat(tmpname, &st) != -1) {
+ fprintf(stderr, "file '%s' is locked\n", tpasswd);
+ return -1;
+ }
+
+ if (filecopy(tpasswd, tmpname) != 0) {
+ fprintf(stderr, "Cannot copy '%s' to '%s'\n",
+ tpasswd, tmpname);
+ return -1;
+ }
+
+ fp = fopen(tpasswd, "w");
+ if (fp == NULL) {
+ fprintf(stderr, "Cannot open '%s' for write\n",
+ tpasswd);
+ (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;
+ }
+
+ put = 0;
+ do {
+ p = fgets(line, sizeof(line) - 1, fp2);
+ if (p == NULL)
+ break;
+
+ pp = strchr(line, ':');
+ if (pp == NULL)
+ continue;
+
+ if (strncmp(p, username,
+ MAX(strlen(username),
+ (unsigned int) (pp - p))) == 0) {
+ put = 1;
+ fprintf(fp, "%s:%s:%u\n", username, cr,
+ iindex);
+ } else {
+ fputs(line, fp);
+ }
+ }
+ while (1);
+
+ if (put == 0) {
+ fprintf(fp, "%s:%s:%u\n", username, cr, iindex);
+ }
+
+ fclose(fp);
+ fclose(fp2);
+
+ (void)remove(tmpname);
+
+ }
+
+
+ return 0;
+}
+
+
+
+/* this function parses tpasswd.conf file. Format is:
+ * int(index):base64(n):base64(g)
+ */
+static int
+read_conf_values(gnutls_datum_t * g, gnutls_datum_t * n, char *str)
+{
+ char *p;
+ int len;
+ int index, ret;
+ gnutls_datum_t dat;
+
+ index = atoi(str);
+
+ p = strrchr(str, ':'); /* we have g */
+ if (p == NULL) {
+ return -1;
+ }
+
+ *p = '\0';
+ p++;
+
+ /* read the generator */
+ len = strlen(p);
+ if (p[len - 1] == '\n')
+ len--;
+
+ dat.data = (void *) p;
+ dat.size = len;
+ ret = gnutls_srp_base64_decode_alloc(&dat, g);
+
+ if (ret < 0) {
+ fprintf(stderr, "Decoding error\n");
+ return -1;
+ }
+
+ /* now go for n - modulo */
+ p = strrchr(str, ':'); /* we have n */
+ if (p == NULL) {
+ return -1;
+ }
+
+ *p = '\0';
+ p++;
+
+ dat.data = (void *) p;
+ dat.size = strlen(p);
+
+ ret = gnutls_srp_base64_decode_alloc(&dat, n);
+
+ if (ret < 0) {
+ fprintf(stderr, "Decoding error\n");
+ free(g->data);
+ return -1;
+ }
+
+ return index;
+}
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