gecko/security/nss/lib/util/dersubr.c
2008-06-06 08:40:11 -04:00

267 lines
6.1 KiB
C

/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Netscape security libraries.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1994-2000
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "secder.h"
#include <limits.h>
#include "secerr.h"
int
DER_LengthLength(PRUint32 len)
{
if (len > 127) {
if (len > 255) {
if (len > 65535L) {
if (len > 16777215L) {
return 5;
} else {
return 4;
}
} else {
return 3;
}
} else {
return 2;
}
} else {
return 1;
}
}
unsigned char *
DER_StoreHeader(unsigned char *buf, unsigned int code, PRUint32 len)
{
unsigned char b[4];
b[0] = (unsigned char)(len >> 24);
b[1] = (unsigned char)(len >> 16);
b[2] = (unsigned char)(len >> 8);
b[3] = (unsigned char)len;
if ((code & DER_TAGNUM_MASK) == DER_SET
|| (code & DER_TAGNUM_MASK) == DER_SEQUENCE)
code |= DER_CONSTRUCTED;
*buf++ = code;
if (len > 127) {
if (len > 255) {
if (len > 65535) {
if (len > 16777215) {
*buf++ = 0x84;
*buf++ = b[0];
*buf++ = b[1];
*buf++ = b[2];
*buf++ = b[3];
} else {
*buf++ = 0x83;
*buf++ = b[1];
*buf++ = b[2];
*buf++ = b[3];
}
} else {
*buf++ = 0x82;
*buf++ = b[2];
*buf++ = b[3];
}
} else {
*buf++ = 0x81;
*buf++ = b[3];
}
} else {
*buf++ = b[3];
}
return buf;
}
/*
* XXX This should be rewritten, generalized, to take a long instead
* of a PRInt32.
*/
SECStatus
DER_SetInteger(PRArenaPool *arena, SECItem *it, PRInt32 i)
{
unsigned char bb[4];
unsigned len;
bb[0] = (unsigned char) (i >> 24);
bb[1] = (unsigned char) (i >> 16);
bb[2] = (unsigned char) (i >> 8);
bb[3] = (unsigned char) (i);
/*
** Small integers are encoded in a single byte. Larger integers
** require progressively more space.
*/
if (i < -128) {
if (i < -32768L) {
if (i < -8388608L) {
len = 4;
} else {
len = 3;
}
} else {
len = 2;
}
} else if (i > 127) {
if (i > 32767L) {
if (i > 8388607L) {
len = 4;
} else {
len = 3;
}
} else {
len = 2;
}
} else {
len = 1;
}
it->data = (unsigned char*) PORT_ArenaAlloc(arena, len);
if (!it->data) {
return SECFailure;
}
it->len = len;
PORT_Memcpy(it->data, bb + (4 - len), len);
return SECSuccess;
}
/*
* XXX This should be rewritten, generalized, to take an unsigned long instead
* of a PRUint32.
*/
SECStatus
DER_SetUInteger(PRArenaPool *arena, SECItem *it, PRUint32 ui)
{
unsigned char bb[5];
int len;
bb[0] = 0;
bb[1] = (unsigned char) (ui >> 24);
bb[2] = (unsigned char) (ui >> 16);
bb[3] = (unsigned char) (ui >> 8);
bb[4] = (unsigned char) (ui);
/*
** Small integers are encoded in a single byte. Larger integers
** require progressively more space.
*/
if (ui > 0x7f) {
if (ui > 0x7fff) {
if (ui > 0x7fffffL) {
if (ui >= 0x80000000L) {
len = 5;
} else {
len = 4;
}
} else {
len = 3;
}
} else {
len = 2;
}
} else {
len = 1;
}
it->data = (unsigned char *)PORT_ArenaAlloc(arena, len);
if (it->data == NULL) {
return SECFailure;
}
it->len = len;
PORT_Memcpy(it->data, bb + (sizeof(bb) - len), len);
return SECSuccess;
}
/*
** Convert a der encoded *signed* integer into a machine integral value.
** If an underflow/overflow occurs, sets error code and returns min/max.
*/
long
DER_GetInteger(SECItem *it)
{
long ival = 0;
unsigned len = it->len;
unsigned char *cp = it->data;
unsigned long overflow = 0x1ffUL << (((sizeof(ival) - 1) * 8) - 1);
unsigned long ofloinit;
if (*cp & 0x80)
ival = -1L;
ofloinit = ival & overflow;
while (len) {
if ((ival & overflow) != ofloinit) {
PORT_SetError(SEC_ERROR_BAD_DER);
if (ival < 0) {
return LONG_MIN;
}
return LONG_MAX;
}
ival = ival << 8;
ival |= *cp++;
--len;
}
return ival;
}
/*
** Convert a der encoded *unsigned* integer into a machine integral value.
** If an underflow/overflow occurs, sets error code and returns min/max.
*/
unsigned long
DER_GetUInteger(SECItem *it)
{
unsigned long ival = 0;
unsigned len = it->len;
unsigned char *cp = it->data;
unsigned long overflow = 0xffUL << ((sizeof(ival) - 1) * 8);
/* Cannot put a negative value into an unsigned container. */
if (*cp & 0x80) {
PORT_SetError(SEC_ERROR_BAD_DER);
return 0;
}
while (len) {
if (ival & overflow) {
PORT_SetError(SEC_ERROR_BAD_DER);
return ULONG_MAX;
}
ival = ival << 8;
ival |= *cp++;
--len;
}
return ival;
}