Files
Cnomicon/src/libasn1/uper_get_ext.c
2021-01-22 10:16:20 -05:00

143 lines
3.9 KiB
C

/*****************************************************************************
* Copyright (C) 2004-2021
* ProbeStar Technical Systems, LLC
* All Rights Reserved. Proprietary and Confidential.
*============================================================================
*****************************************************************************/
/*****************************************************************************
* includes
*****************************************************************************/
#include "embtypes.h"
#include "asn1uper.h"
/*****************************************************************************
* defines
*****************************************************************************/
/*****************************************************************************
* macros
*****************************************************************************/
#define min(A,B) ((A)<(B)?(A):(B))
#define max(A,B) ((A)>(B)?(A):(B))
/*****************************************************************************
* structs & typedefs
*****************************************************************************/
/*****************************************************************************
* global constants
*****************************************************************************/
/*****************************************************************************
* global variables
*****************************************************************************/
/*****************************************************************************
* static constants
*****************************************************************************/
/*****************************************************************************
* static variables
*****************************************************************************/
/*****************************************************************************
* static prototypes
*****************************************************************************/
/*****************************************************************************
* C functions
*****************************************************************************/
// grab extension bits, check for extension defined by ellipses
uint uper_get_extension(UPER_Stream *uper, UPER_Extension *ext, uint noptions, uint ellipses)
{
if (!uper || !ext)
return 0;
uper_init_extension(ext);
ellipses &= 1;
if ((noptions+ellipses)==0) {
uper->error = 1;
return 0;
}
// check for extensions
if (ellipses) {
ext->ellipses = uper_get_bits_stream(uper, 1);
}
// check for options
if (noptions) {
ext->value = uper_get_bits_stream(uper, noptions);
ext->options = noptions;
}
if (ext->ellipses) {
uper_get_ext_length(uper, ext);
if (_asn1_debug_on_)
printf("\tEXT_LEN = %d\n", ext->length);
// otherwise no ...
}
return ellipses + noptions;
}
uint uper_get_ext_length(UPER_Stream *uper, UPER_Extension *ext)
{
if (!ext->ellipses)
return 0;
uint len = uper_get_bits_stream(uper, 8);
if (len & 0x80) {
len = (len & 0x7f) << 8;
len |= uper_get_bits_stream(uper, 8);
}
else
len &= 0x7f;
ext->length = len;
return len;
}
// if ellipses extension available
uint uper_get_ext_ellipses(UPER_Extension *ext)
{
if (ext)
return ext->ellipses;
return 0;
}
// from the front (high->low bits)
uint uper_get_ext_optional(UPER_Extension *ext, uint bit)
{
if (!ext || (bit>=ext->options))
return 0;
return (ext->value & 1<<(ext->options-bit));
}
uint uper_get_ext_skip(UPER_Stream *uper, UPER_Extension *ext)
{
if (!uper && !ext && !ext->length)
return 0;
int bits = ext->length;
// copy in
int sbit = uper->bit; // bit order in stream (not byte)
int ebit = (sbit+bits) % 8; // after last bit
// copy out
uper->ptr += (sbit + bits) / 8;
uper->bit = ebit;
uper->consumed += bits;
return bits;
}