+/*
+ Unix SMB/CIFS implementation.
+
+ code to encrypt/decrypt data using the user session key
+
+ Copyright (C) Andrew Tridgell 2004
+
+ 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; either version 2 of the License, or
+ (at your option) any later version.
+
+ 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+/*
+ encrypt or decrypt a blob of data using the user session key
+ as used in lsa_SetSecret
+
+ before calling, the out blob must be initialised to be the same size
+ as the in blob
+*/
+void sess_crypt_blob(DATA_BLOB *out, const DATA_BLOB *in, const uint8 session_key[16],
+ BOOL forward)
+{
+ int i, k;
+
+ for (i=0,k=0;
+ i<in->length;
+ i += 8, k += 7) {
+ uint8 bin[8], bout[8], key[7];
+
+ memset(bin, 0, 8);
+ memcpy(bin, &in->data[i], MIN(8, in->length-i));
+
+ if (k + 7 > 16) {
+ k = (16 - k);
+ }
+ memcpy(key, &session_key[k], 7);
+
+ smbhash(bout, bin, key, forward?1:0);
+
+ memcpy(&out->data[i], bout, MIN(8, in->length-i));
+ }
+}
+
+
+/*
+ a convenient wrapper around sess_crypt_blob() for strings, using the LSA convention
+
+ note that we round the length to a multiple of 8. This seems to be needed for
+ compatibility with windows
+
+ caller should free using data_blob_free()
+*/
+DATA_BLOB sess_encrypt_string(const char *str, const uint8 session_key[16])
+{
+ DATA_BLOB ret, src;
+ int slen = strlen(str);
+ int dlen = (slen+7) & ~7;
+
+ src = data_blob(NULL, 8+dlen);
+ if (!src.data) {
+ return data_blob(NULL, 0);
+ }
+
+ ret = data_blob(NULL, 8+dlen);
+ if (!ret.data) {
+ data_blob_free(&src);
+ return data_blob(NULL, 0);
+ }
+
+ SIVAL(src.data, 0, slen);
+ SIVAL(src.data, 4, 1);
+ memset(src.data+8, 0, dlen);
+ memcpy(src.data+8, str, slen);
+
+ sess_crypt_blob(&ret, &src, session_key, True);
+
+ data_blob_free(&src);
+
+ return ret;
+}
+
+/*
+ a convenient wrapper around sess_crypt_blob() for strings, using the LSA convention
+
+ caller should free the returned string
+*/
+char *sess_decrypt_string(DATA_BLOB *blob, const uint8 session_key[16])
+{
+ DATA_BLOB out;
+ int slen;
+ char *ret;
+
+ if (blob->length < 8) {
+ return NULL;
+ }
+
+ out = data_blob(NULL, blob->length);
+ if (!out.data) {
+ return NULL;
+ }
+
+ sess_crypt_blob(&out, blob, session_key, False);
+
+ slen = IVAL(out.data, 0);
+ if (slen > blob->length - 8) {
+ DEBUG(0,("Invalid crypt length %d\n", slen));
+ return NULL;
+ }
+
+ if (IVAL(out.data, 4) != 1) {
+ DEBUG(0,("Unexpected revision number %d in session crypted string\n",
+ IVAL(out.data, 4)));
+ return NULL;
+ }
+
+ ret = strndup(out.data+8, slen);
+
+ data_blob_free(&out);
+
+ return ret;
+}
git.samba.org / samba.git / commitdiff