e04ca78ff8
fmt_asn1generic, see t10.c for example usage) add "generic" asn.1 dumper (in t10.c) fix some read off-by-one errors, minor cleanups add real OID support add bitstring support
26 lines
817 B
C
26 lines
817 B
C
#include <inttypes.h>
|
|
#include "asn1.h"
|
|
|
|
size_t scan_asn1length(const char* src,const char* max,size_t* length) {
|
|
const char* orig=src;
|
|
if (src>=max) return 0;
|
|
/* If the highest bit of the first byte is clear, the byte is the length.
|
|
* Otherwise the next n bytes are the length (n being the lower 7 bits) */
|
|
if (*src&0x80) {
|
|
int chars=*src&0x7f;
|
|
size_t l=0;
|
|
while (chars>0) {
|
|
if (++src>=max) return 0;
|
|
if (l>(((unsigned long)-1)>>8)) return 0; /* catch integer overflow */
|
|
l=l*256+(unsigned char)*src;
|
|
--chars;
|
|
}
|
|
*length=l;
|
|
} else
|
|
*length=*src&0x7f;
|
|
src++;
|
|
if (src+*length>max) return 0; /* catch integer overflow */
|
|
if ((uintptr_t)src+*length<(uintptr_t)src) return 0; /* gcc 4.1 removes this check without the cast to uintptr_t */
|
|
return src-orig;
|
|
}
|