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/*
Unix SMB/CIFS implementation.
simple kerberos5/SPNEGO routines
Copyright (C) Andrew Tridgell 2001
Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2002
Copyright (C) Andrew Bartlett 2002-2003
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"
/*
this is a tiny msrpc packet generator. I am only using this to
avoid tying this code to a particular varient of our rpc code. This
generator is not general enough for all our rpc needs, its just
enough for the spnego/ntlmssp code
format specifiers are:
U = unicode string (input is unix string)
a = address (input is char *unix_string)
(1 byte type, 1 byte length, unicode/ASCII string, all inline)
A = ASCII string (input is unix string)
B = data blob (pointer + length)
b = data blob in header (pointer + length)
D
d = word (4 bytes)
C = constant ascii string
*/
BOOL msrpc_gen(TALLOC_CTX *mem_ctx, DATA_BLOB *blob,
const char *format, ...)
{
int i, n;
va_list ap;
char *s;
uint8_t *b;
int head_size=0, data_size=0;
int head_ofs, data_ofs;
/* first scan the format to work out the header and body size */
va_start(ap, format);
for (i=0; format[i]; i++) {
switch (format[i]) {
case 'U':
s = va_arg(ap, char *);
head_size += 8;
data_size += str_charnum(s) * 2;
break;
case 'A':
s = va_arg(ap, char *);
head_size += 8;
data_size += str_ascii_charnum(s);
break;
case 'a':
n = va_arg(ap, int);
s = va_arg(ap, char *);
data_size += (str_charnum(s) * 2) + 4;
break;
case 'B':
b = va_arg(ap, uint8_t *);
head_size += 8;
data_size += va_arg(ap, int);
break;
case 'b':
b = va_arg(ap, uint8_t *);
head_size += va_arg(ap, int);
break;
case 'd':
n = va_arg(ap, int);
head_size += 4;
break;
case 'C':
s = va_arg(ap, char *);
head_size += str_charnum(s) + 1;
break;
}
}
va_end(ap);
/* allocate the space, then scan the format again to fill in the values */
*blob = data_blob_talloc(mem_ctx, NULL, head_size + data_size);
head_ofs = 0;
data_ofs = head_size;
va_start(ap, format);
for (i=0; format[i]; i++) {
switch (format[i]) {
case 'U':
s = va_arg(ap, char *);
n = str_charnum(s);
SSVAL(blob->data, head_ofs, n*2); head_ofs += 2;
SSVAL(blob->data, head_ofs, n*2); head_ofs += 2;
SIVAL(blob->data, head_ofs, data_ofs); head_ofs += 4;
push_string(NULL, blob->data+data_ofs, s, n*2, STR_UNICODE|STR_NOALIGN);
data_ofs += n*2;
break;
case 'A':
s = va_arg(ap, char *);
n = str_ascii_charnum(s);
SSVAL(blob->data, head_ofs, n); head_ofs += 2;
SSVAL(blob->data, head_ofs, n); head_ofs += 2;
SIVAL(blob->data, head_ofs, data_ofs); head_ofs += 4;
push_string(NULL, blob->data+data_ofs, s, n, STR_ASCII|STR_NOALIGN);
data_ofs += n;
break;
case 'a':
n = va_arg(ap, int);
SSVAL(blob->data, data_ofs, n); data_ofs += 2;
s = va_arg(ap, char *);
n = str_charnum(s);
SSVAL(blob->data, data_ofs, n*2); data_ofs += 2;
if (0 < n) {
push_string(NULL, blob->data+data_ofs, s, n*2,
STR_UNICODE|STR_NOALIGN);
}
data_ofs += n*2;
break;
case 'B':
b = va_arg(ap, uint8_t *);
n = va_arg(ap, int);
SSVAL(blob->data, head_ofs, n); head_ofs += 2;
SSVAL(blob->data, head_ofs, n); head_ofs += 2;
SIVAL(blob->data, head_ofs, data_ofs); head_ofs += 4;
if (n && b) /* don't follow null pointers... */
memcpy(blob->data+data_ofs, b, n);
data_ofs += n;
break;
case 'd':
n = va_arg(ap, int);
SIVAL(blob->data, head_ofs, n); head_ofs += 4;
break;
case 'b':
b = va_arg(ap, uint8_t *);
n = va_arg(ap, int);
memcpy(blob->data + head_ofs, b, n);
head_ofs += n;
break;
case 'C':
s = va_arg(ap, char *);
head_ofs += push_string(NULL, blob->data+head_ofs, s, -1,
STR_ASCII|STR_TERMINATE);
break;
}
}
va_end(ap);
return True;
}
/* a helpful macro to avoid running over the end of our blob */
#define NEED_DATA(amount) \
if ((head_ofs + amount) > blob->length) { \
return False; \
}
/*
this is a tiny msrpc packet parser. This the the partner of msrpc_gen
format specifiers are:
U = unicode string (output is unix string)
A = ascii string
B = data blob
b = data blob in header
d = word (4 bytes)
C = constant ascii string
*/
BOOL msrpc_parse(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob,
const char *format, ...)
{
int i;
va_list ap;
const char **ps, *s;
DATA_BLOB *b;
size_t head_ofs = 0;
uint16_t len1, len2;
uint32_t ptr;
uint32_t *v;
pstring p;
va_start(ap, format);
for (i=0; format[i]; i++) {
switch (format[i]) {
case 'U':
NEED_DATA(8);
len1 = SVAL(blob->data, head_ofs); head_ofs += 2;
len2 = SVAL(blob->data, head_ofs); head_ofs += 2;
ptr = IVAL(blob->data, head_ofs); head_ofs += 4;
ps = va_arg(ap, char **);
if (len1 == 0 && len2 == 0) {
*ps = "";
} else {
/* make sure its in the right format - be strict */
if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
return False;
}
if (len1 & 1) {
/* if odd length and unicode */
return False;
}
if (blob->data + ptr < (uint8_t *)ptr || blob->data + ptr < blob->data)
return False;
if (0 < len1) {
pull_string(NULL, p, blob->data + ptr, sizeof(p),
len1,
STR_UNICODE|STR_NOALIGN);
(*ps) = talloc_strdup(mem_ctx, p);
if (!(*ps)) {
return False;
}
} else {
(*ps) = "";
}
}
break;
case 'A':
NEED_DATA(8);
len1 = SVAL(blob->data, head_ofs); head_ofs += 2;
len2 = SVAL(blob->data, head_ofs); head_ofs += 2;
ptr = IVAL(blob->data, head_ofs); head_ofs += 4;
ps = va_arg(ap, char **);
/* make sure its in the right format - be strict */
if (len1 == 0 && len2 == 0) {
*ps = "";
} else {
if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
return False;
}
if (blob->data + ptr < (uint8_t *)ptr || blob->data + ptr < blob->data)
return False;
if (0 < len1) {
pull_string(NULL, p, blob->data + ptr, sizeof(p),
len1,
STR_ASCII|STR_NOALIGN);
(*ps) = talloc_strdup(mem_ctx, p);
if (!(*ps)) {
return False;
}
} else {
(*ps) = "";
}
}
break;
case 'B':
NEED_DATA(8);
len1 = SVAL(blob->data, head_ofs); head_ofs += 2;
len2 = SVAL(blob->data, head_ofs); head_ofs += 2;
ptr = IVAL(blob->data, head_ofs); head_ofs += 4;
b = (DATA_BLOB *)va_arg(ap, void *);
if (len1 == 0 && len2 == 0) {
*b = data_blob_talloc(mem_ctx, NULL, 0);
} else {
/* make sure its in the right format - be strict */
if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
return False;
}
if (blob->data + ptr < (uint8_t *)ptr || blob->data + ptr < blob->data)
return False;
*b = data_blob_talloc(mem_ctx, blob->data + ptr, len1);
}
break;
case 'b':
b = (DATA_BLOB *)va_arg(ap, void *);
len1 = va_arg(ap, uint_t);
/* make sure its in the right format - be strict */
NEED_DATA(len1);
if (blob->data + head_ofs < (uint8_t *)head_ofs || blob->data + head_ofs < blob->data)
return False;
*b = data_blob_talloc(mem_ctx, blob->data + head_ofs, len1);
head_ofs += len1;
break;
case 'd':
v = va_arg(ap, uint32_t *);
NEED_DATA(4);
*v = IVAL(blob->data, head_ofs); head_ofs += 4;
break;
case 'C':
s = va_arg(ap, char *);
if (blob->data + head_ofs < (uint8_t *)head_ofs || blob->data + head_ofs < blob->data)
return False;
head_ofs += pull_string(NULL, p, blob->data+head_ofs, sizeof(p),
blob->length - head_ofs,
STR_ASCII|STR_TERMINATE);
if (strcmp(s, p) != 0) {
return False;
}
break;
}
}
va_end(ap);
return True;
}
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