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
108 lines
2.6 KiB
C
108 lines
2.6 KiB
C
#include <stdarg.h>
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#include "asn1.h"
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size_t scan_asn1generic(const char* src,const char* max,const char* fmt,...) {
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size_t curlen,seqlen;
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const char* maxstack[100];
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size_t curmax=0;
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va_list args;
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int optional=0;
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unsigned long* application=NULL;
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unsigned long tag;
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enum asn1_tagclass tc;
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enum asn1_tagtype tt;
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const char* orig=src;
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va_start(args,fmt);
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maxstack[0]=max;
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while (*fmt) {
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switch (*fmt) {
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case '?': // ? = rest is optional (until end of sequence)
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optional=1;
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break;
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case 'i': // i = INTEGER
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{
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long* dest=va_arg(args,long*);
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*dest=0;
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curlen=scan_asn1int(src,maxstack[curmax],&tc,&tt,&tag,dest);
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if (application) {
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if (tc!=APPLICATION) return 0;
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*application=tag;
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} else {
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if (tc!=UNIVERSAL || tt!=PRIMITIVE || tag!=INTEGER)
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return 0;
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}
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if (!curlen) { if (optional) break; else return 0; }
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src+=curlen;
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application=0;
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break;
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}
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case 's': // s = STRING
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{
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struct string* dest=va_arg(args,struct string*);
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dest->l=0;
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dest->s=0;
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curlen=scan_asn1string(src,maxstack[curmax],&tc,&tt,&tag,&dest->s,&dest->l);
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if (!curlen) { if (optional) break; else return 0; }
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if (application) {
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if (tc!=APPLICATION) return 0;
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*application=tag;
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} else {
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if (tc!=UNIVERSAL || tt!=PRIMITIVE || tag!=OCTET_STRING)
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return 0;
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}
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src+=curlen;
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application=0;
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break;
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}
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case 'a': // next tag class is APPLICATION instead of UNIVERSAL; write tag to unsigned long*
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{
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application=va_arg(args,unsigned long*);
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break;
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}
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case '{': // { = SEQUENCE
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{
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curlen=scan_asn1tag(src,maxstack[curmax],&tc,&tt,&tag);
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if (!curlen) { if (optional) break; else return 0; }
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if (application) {
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if (tc!=APPLICATION) return 0;
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*application=tag;
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} else {
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if (tc!=UNIVERSAL || tt!=CONSTRUCTED || tag!=SEQUENCE_OF)
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return 0;
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}
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src+=curlen;
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curlen=scan_asn1length(src,maxstack[curmax],&seqlen);
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if (!curlen) return 0;
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if (curmax>99) return 0;
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maxstack[++curmax]=src+curlen+seqlen;
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src+=curlen;
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application=0;
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break;
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}
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case '!': // save current max-src into size_t
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// useful for ldap, where you have an application sequence
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// and the tag defines which encoding you have inside the
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// sequence, so you can't put it in the format string.
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// you still need to know the length so you can call this function
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// again on the rest of the data.
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{
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size_t* dest=va_arg(args,size_t*);
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*dest=maxstack[curmax]-src;
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break;
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}
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case '}': // } = end of SEQUENCE
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{
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optional=0;
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if (curmax==0) return 0;
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--curmax;
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break;
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}
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default:
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return 0;
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}
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++fmt;
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}
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va_end(args);
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return src-orig;
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}
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