Added a small utility for decoding password salt information

2 files changed, 91 insertions, 0 deletions

diff --git a/utils/CMakeLists.txt b/utils/CMakeLists.txt
index bcaed05..dcc8b00 100644
--- a/utils/CMakeLists.txt
+++ b/utils/CMakeLists.txt
@@ -26,4 +26,10 @@ IF(EUREPHIADM)
   INCLUDE_DIRECTORIES(../common ../database ../eurephiadm)
   ADD_EXECUTABLE(eurephia_init ${e_init_SRC})
   TARGET_LINK_LIBRARIES(eurephia_init dl crypto ${EXTRA_LIBS})
+
+  SET(saltdecode_SRC
+        saltdecode.c
+        ../eurephiadm/get_console_input.c
+  )
+  ADD_EXECUTABLE(saltdecode ${saltdecode_SRC})
 ENDIF(EUREPHIADM)
diff --git a/utils/saltdecode.c b/utils/saltdecode.c
new file mode 100644
index 0000000..ddaf4c7
--- /dev/null
+++ b/utils/saltdecode.c
@@ -0,0 +1,85 @@
+/* saltdecode.c  --  Decode a given password salt into a readable format
+ *
+ *  GPLv2 only - Copyright (C) 2009
+ *               David Sommerseth <dazo@users.sourceforge.net>
+ *
+ *  This program 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; version 2
+ *  of the License.
+ *
+ *  This program 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, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <sys/param.h>
+
+#include <eurephia_nullsafe.h>
+#include <get_console_input.h>
+
+#define ROUNDS_MIN 1000
+#define ROUNDS_MAX 999999999
+
+inline unsigned int get_salt_p2(const char *pwd) {
+        int n = 0;
+        long int saltinfo_p2 = 0, t = 0;
+
+        for( n = 0; n < strlen_nullsafe(pwd); n++ ) {
+                t += pwd[n];
+        }
+
+        for( n = 0; n < 4; n++ ) {
+                saltinfo_p2 <<= 8;
+                saltinfo_p2 += (strlen_nullsafe(pwd) ^ (t % 0xff));
+        }
+        return saltinfo_p2;
+}
+
+unsigned int unpack_saltinfo(const char *insalt, const char *pwd) {
+        unsigned int in_salt_prefix = 0;
+
+        assert(insalt != NULL && pwd != NULL);
+
+        if( sscanf(insalt, "%08x", &in_salt_prefix) > -1 ) {
+                long int regen_p2 = in_salt_prefix ^ get_salt_p2(pwd);
+                return regen_p2 ^ 0xAAAAAAAA;
+        } else {
+                return -1;
+        }
+}
+
+
+int main(int argc, char **argv) {
+        char key[258];
+        unsigned int saltinfo = 0;
+        size_t rounds = 0, salt_len = 0;
+
+        if( argc != 2 ) {
+                fprintf(stderr, "Usage: %s <password salt>\n", argv[0]);
+                return 1;
+        }
+
+        memset(&key, 0, 258);
+        printf("\nYou will need to give the correct password for this salt.\n");
+        printf("If you give the wrong password, the information will be decoded wrong.\n\n");
+        get_console_input(key, 256, "Password:", 1);
+        saltinfo = unpack_saltinfo(argv[1], key);
+        memset(&key, 0, 258);
+
+        salt_len = saltinfo & 0x000000ff;
+        rounds = MAX(ROUNDS_MIN, MIN(((saltinfo & 0xffffff00) >> 8), ROUNDS_MAX));
+
+        printf("\nSalt length: %ld\nHash rounds: %ld\n\n", salt_len, rounds);
+
+        return 0;
+}