Lean and mean initial commit

Not much functionality yet

1 files changed, 139 insertions, 0 deletions

diff --git a/fmt_asn1generic.c b/fmt_asn1generic.c
new file mode 100644
index 0000000..c97ee96
--- /dev/null
+++ b/fmt_asn1generic.c
@@ -0,0 +1,139 @@
+#include <stdarg.h>
+#include <string.h>
+#include "asn1.h"
+
+size_t fmt_asn1generic(char* dest,const char* fmt,...) {
+  size_t containerstack[100];
+  size_t curinstack=0;
+  va_list args;
+  va_start(args,fmt);
+  unsigned long* application=0;
+  struct string* s;
+  struct oid* o;
+  struct string S;
+  size_t curlen=0;
+  size_t cursor=0;
+  size_t seqlen;
+  unsigned long desttag=0;
+  unsigned long appstore;
+  int stringtype;
+  while (*fmt) {
+    char* realdest=dest?dest+cursor:NULL;
+    switch (*fmt) {
+    case '*':	// make next tag use APPLICATION with this tag
+      appstore=va_arg(args,unsigned long);
+      application=&appstore;
+      break;
+    case '0':	// UNIVERSAL PRIMITIVE NULL length 0
+      if (application)
+	curlen=fmt_asn1tag(realdest,APPLICATION,PRIMITIVE,_NULL);
+      else
+	curlen=fmt_asn1tag(realdest,UNIVERSAL,PRIMITIVE,_NULL);
+      application=NULL;
+      curlen+=fmt_asn1length(realdest?realdest+curlen:NULL,0);
+      break;
+    case 'i':	// send integer
+      {
+	unsigned long i=va_arg(args,unsigned long);
+	if (application)
+	  curlen=fmt_asn1int(realdest,APPLICATION,PRIMITIVE,*application,i);
+	else
+	  curlen=fmt_asn1int(realdest,UNIVERSAL,PRIMITIVE,INTEGER,i);
+	application=NULL;
+	break;
+      }
+    case 'b':	// send BIT_STRING, using struct string* as arg (expect l to be in bits, not bytes)
+      s=va_arg(args,struct string*);
+      if (application)
+	curlen=fmt_asn1bitstring(realdest,APPLICATION,PRIMITIVE,*application,s->s,s->l);
+      else
+	curlen=fmt_asn1bitstring(realdest,UNIVERSAL,PRIMITIVE,BIT_STRING,s->s,s->l);
+      application=NULL;
+      break;
+    case 'B':
+      stringtype=BIT_STRING;
+      goto stringcopy;
+    case 'A':
+      stringtype=IA5String;
+      goto stringcopy;
+    case 'P':
+      stringtype=PrintableString;
+      goto stringcopy;
+    case 'S':	// send OCTET_STRING, using struct string* as arg
+      stringtype=OCTET_STRING;
+stringcopy:
+      s=va_arg(args,struct string*);
+copystring:
+      if (application)
+	curlen=fmt_asn1string(realdest,APPLICATION,PRIMITIVE,*application,s->s,s->l);
+      else
+	curlen=fmt_asn1string(realdest,UNIVERSAL,PRIMITIVE,stringtype,s->s,s->l);
+      application=NULL;
+      break;
+    case 't':
+      stringtype=UTCTIME;
+      goto stringcopy_alt;
+    case 'a':
+      stringtype=IA5String;
+      goto stringcopy_alt;
+    case 'p':
+      stringtype=PrintableString;
+      goto stringcopy_alt;
+    case 's':	// send OCTET_STRING, using const char* with strlen() as arg
+      stringtype=OCTET_STRING;
+stringcopy_alt:
+      S.s=va_arg(args,const char*);
+      S.l=strlen(S.s);
+      s=&S;
+      goto copystring;
+    case 'o':	// send OBJECT_IDENTIFIER, using struct oid* as arg
+      o=va_arg(args,struct oid*);
+      if (application)
+	curlen=fmt_asn1OID(realdest,APPLICATION,PRIMITIVE,*application,o->a,o->l);
+      else
+	curlen=fmt_asn1OID(realdest,UNIVERSAL,PRIMITIVE,OBJECT_IDENTIFIER,o->a,o->l);
+      application=NULL;
+      break;
+
+    case 'C':	// copy raw ASN.1 DER data, take struct string*
+      s=va_arg(args,struct string*);
+      if (realdest) memcpy(realdest,s->s,s->l);
+      curlen=s->l;
+      break;
+
+    case 'c':	// start context specific section
+      desttag=va_arg(args,unsigned long);
+      // fall through
+    case '[':	// start SET
+    case '{':	// start SEQUENCE
+      if (application)
+	curlen=fmt_asn1tag(realdest,APPLICATION,CONSTRUCTED,*application);
+      else if (*fmt=='c')
+	curlen=fmt_asn1tag(realdest,PRIVATE,CONSTRUCTED,desttag);
+      else
+	curlen=fmt_asn1tag(realdest,UNIVERSAL,CONSTRUCTED,*fmt=='{'?SEQUENCE_OF:SET_OF);
+      containerstack[curinstack++]=cursor+curlen;
+      application=NULL;
+      break;
+    case ']':	// end of SET
+    case '}':	// end of SEQUENCE
+      /* we just wrote the tag and the sequence.  Now that we wrote the
+       * sequence, we know the length it took, and we need to move the
+       * sequence data backwards to make room to write the ASN.1 length */
+      {
+	char* anfang;
+	if (!curinstack) return 0;
+	anfang=dest+containerstack[--curinstack];
+	seqlen=dest+cursor-anfang;
+	curlen=fmt_asn1length(NULL,seqlen);
+	if (!dest) break;
+	memmove(anfang+curlen,anfang,seqlen);
+	fmt_asn1length(anfang,seqlen);
+	break;
+      }
+    }
+    cursor+=curlen;
+    ++fmt;
+  }
+  return cursor;
+}