#include <u.h>#include <libc.h>#include <authsrv.h> extern int form1B2M(char *ap, int n, uchar key[32]); intconvA2M(Authenticator *f, char *ap, int n, Ticket *t){	uchar *p; 	if(n < 1+CHALLEN)		return 0; 	p = (uchar*)ap;	*p++ = f->num;	memmove(p, f->chal, CHALLEN), p += CHALLEN;	switch(t->form){	case 0:		if(n < 1+CHALLEN+4)			return 0; 		memset(p, 0, 4), p += 4;	/* unused id field */		n = p - (uchar*)ap;		encrypt(t->key, ap, n);		return n;	case 1:		if(n < 12+CHALLEN+NONCELEN+16)			return 0; 		memmove(p, f->rand, NONCELEN), p += NONCELEN;		return form1B2M(ap, (char*)p - ap, t->key);	} 	return 0;}