#include <u.h>#include <libc.h>#include <mp.h>#include <ctype.h>#include <libsec.h>#include <fcall.h>#include <thread.h>#include <9p.h>#include "sshtun.h" static intparsepubkey(char *s, RSApub *key, char **sp, int base){	int n;	char *host, *p, *z; 	z = nil;	n = strtoul(s, &p, 10);	host = nil;	if(n < 256 || !isspace(*p)){	/* maybe this is a host name */		host = s;		s = strpbrk(s, " \t");		if(s == nil)			return -1;		z = s;		*s++ = '\0';		s += strspn(s, " \t"); 		n = strtoul(s, &p, 10);		if(n < 256 || !isspace(*p)){			if(z)				*z = ' ';			return -1;		}	} 	if((key->ek = strtomp(p, &p, base, nil)) == nil	|| (key->n = strtomp(p, &p, base, nil)) == nil	|| (*p != '\0' && !isspace(*p))	|| mpsignif(key->n) < 256){	/* 256 is just a sanity check */		mpfree(key->ek);		mpfree(key->n);		key->ek = nil;		key->n = nil;		if(z)			*z = ' ';		return -1;	}	if(host == nil){		if(*p != '\0'){			p += strspn(p, " \t");			if(*p != '\0'){				host = emalloc9p(strlen(p)+1);				strcpy(host, p);			}		}		free(s);	}	*sp = host;	return 0;} RSApub*readpublickey(Biobuf *b, char **sp){	char *s;	RSApub *key; 	key = emalloc9p(sizeof(RSApub));	if(key == nil)		return nil; 	for(;;){		if((s = Brdstr(b, '\n', 1)) == nil){			free(key);			return nil;		}		if(s[0]=='#'){			free(s);			continue;		}		if(parsepubkey(s, key, sp, 10)==0		|| parsepubkey(s, key, sp, 16)==0)			return key;		fprint(2, "warning: skipping line '%s'; cannot parse\n", s);		free(s);	}} static intmatch(char *pattern, char *aliases){	char *s, *snext;	char *a, *anext, *ae; 	for(s=pattern; s && *s; s=snext){		if((snext=strchr(s, ',')) != nil)			*snext++ = '\0';		for(a=aliases; a && *a; a=anext){			if((anext=strchr(a, ',')) != nil){				ae = anext;				anext++;			}else				ae = a+strlen(a);			if(ae-a == strlen(s) && memcmp(s, a, ae-a)==0)				return 0;		}	}	return 1;} intfindkey(char *keyfile, char *host, RSApub *key){	char *h;	Biobuf *b;	RSApub *k;	int res; 	if ((b = Bopen(keyfile, OREAD)) == nil)		return NoKeyFile; 	for (res = NoKey; res != KeyOk;) {		if ((k = readpublickey(b, &h)) == nil)			break;		if (match(h, host) == 0) {			if (mpcmp(k->n, key->n) == 0 && mpcmp(k->ek, key->ek) == 0)				res = KeyOk;			else				res = KeyWrong;		}		free(h);		free(k->ek);		free(k->n);		free(k);	}	Bterm(b);	return res;} intreplacekey(char *keyfile, char *host, RSApub *hostkey){	char *h, *nkey, *p;	Biobuf *br, *bw;	Dir *d, nd;	RSApub *k; 	nkey = smprint("%s.new", keyfile);	if(nkey == nil)		return -1; 	if((br = Bopen(keyfile, OREAD)) == nil){		free(nkey);		return -1;	}	if((bw = Bopen(nkey, OWRITE)) == nil){		Bterm(br);		free(nkey);		return -1;	} 	while((k = readpublickey(br, &h)) != nil){		if(match(h, host) != 0){			Bprint(bw, "%s %d %.10M %.10M\n",				h, mpsignif(k->n), k->ek, k->n);		}		free(h);		rsapubfree(k);	}	Bprint(bw, "%s %d %.10M %.10M\n", host, mpsignif(hostkey->n), hostkey->ek, hostkey->n);	Bterm(bw);	Bterm(br); 	d = dirstat(nkey);	if(d == nil){		fprint(2, "new key file disappeared?\n");		free(nkey);		return -1;	} 	p = strrchr(d->name, '.');	if(p==nil || strcmp(p, ".new")!=0){		fprint(2, "new key file changed names? %s to %s\n", nkey, d->name);		free(d);		free(nkey);		return -1;	} 	*p = '\0';	nulldir(&nd);	nd.name = d->name;	if(remove(keyfile) < 0){		fprint(2, "error removing %s: %r\n", keyfile);		free(d);		free(nkey);		return -1;	}	if(dirwstat(nkey, &nd) < 0){		fprint(2, "error renaming %s to %s: %r\n", nkey, d->name);		free(nkey);		free(d);		return -1;	}	free(d);	free(nkey);	return 0;} intappendkey(char *keyfile, char *host, RSApub *key){	int fd; 	if((fd = open(keyfile, OWRITE)) < 0){		fd = create(keyfile, OWRITE, 0666);		if(fd < 0){			fprint(2, "cannot open nor create %s: %r\n", keyfile);			return -1;		}	}	if(seek(fd, 0, 2) < 0	|| fprint(fd, "%s %d %.10M %.10M\n", host, mpsignif(key->n), key->ek, key->n) < 0){		close(fd);		return -1;	}	close(fd);	return 0;}