#include <u.h>#include <libc.h>#include <auth.h>#include <mp.h>#include <libsec.h> #define GET4(p)	(u32int)(p)[3] | (u32int)(p)[2]<<8 | (u32int)(p)[1]<<16 | (u32int)(p)[0]<<24 static char *magic = "openssh-key-v1"; static uchar *pubkey;static uchar *pubend; static uchar *privkey;static uchar *privend; static void*emalloc(ulong size, int clr){	void *p;	if((p = mallocz(size, clr)) == nil)		sysfatal("emalloc: %r");	return p;} static longereadn(int fd, void *buf, long nbytes){	long n;	if((n = readn(fd, buf, nbytes)) != nbytes)		sysfatal("ereadn: %r");	return n;} static uchar*slurp(int fd, int alloc, u32int *np){	u32int n;	uchar buf[4], trash[1024];	uchar *p; 	ereadn(fd, buf, sizeof buf);	n = GET4(buf);	if(alloc){		*np = n;		p = emalloc(n, 0);		ereadn(fd, p, n);		return p;	}	if(n >= sizeof trash)		sysfatal("key component too large");	ereadn(fd, trash, n);	return nil;} static u32intdecode(int fd){	uchar buf[4];	u32int ret, n; 	/* ciphername */	slurp(fd, 0, nil);	/* kdfname */	slurp(fd, 0, nil);	/* kdfoptions */	slurp(fd, 0, nil); 	ereadn(fd, buf, 4);	ret = GET4(buf); 	pubkey = slurp(fd, 1, &n);	pubend = pubkey + n; 	privkey = slurp(fd, 1, &n);	privend = privkey + n; 	return ret;} static u32intscan(uchar **p, uchar *e){	u32int n; 	if(*p + 4 > e)		sysfatal("unexpected end of key");	n = GET4(*p); *p += 4;	if(*p + n > e)		sysfatal("unexpected end of key");	return n;} static mpint*scanmp(uchar **p, uchar *e){	mpint *m;	u32int n; 	n = scan(p, e);	if(n == 0)		sysfatal("required key component has zero length");	m = betomp(*p, n, nil);	if(m == nil)		sysfatal("betomp: %r");	*p += n;	return m;} static RSApriv*fill(void){	char *rsa = "ssh-rsa";	u32int n, a, b;	uchar *p, *e;	mpint *ek, *mod, *dk, *p0, *q0; 	p = pubkey;	e = pubend;	if(scan(&p, e) != 7 || memcmp(rsa, p, 7) != 0)		sysfatal("not a RSA key");	p += 7; 	ek = scanmp(&p, e);	mod = scanmp(&p, e); 	p = privkey;	e = privend;	if(p + 8 >= e)		sysfatal("unexpected end of key");	a = GET4(p); p += 4;	b = GET4(p); p += 4;	if(a != b)		sysfatal("private key seems encrypted"); 	if(scan(&p, e) != 7 || memcmp(rsa, p, 7) != 0)		sysfatal("not a RSA key");	p += 7; 	/* public components are repeated */	n = scan(&p, e); p += n;	n = scan(&p, e); p += n;	dk = scanmp(&p, e);	/* iq */	n = scan(&p, e); p += n;	p0 = scanmp(&p, e);	q0 = scanmp(&p, e); 	return rsafill(mod, ek, dk, p0, q0);} voidusage(void){	fprint(2, "usage: auth/ssh2rsa [file]\n");	exits("usage");} voidmain(int argc, char **argv){	int fd;	RSApriv *p;	char *s;	uchar buf[64]; 	fd = 0;	fmtinstall('B', mpfmt);	ARGBEGIN{	default:		usage();	}ARGEND	switch(argc){	default:		usage();	case 1:		fd = open(argv[0], OREAD);		if(fd < 0)			sysfatal("open: %r");	case 0:		break;	} 	ereadn(fd, buf, strlen(magic)+1);	if(memcmp(buf, magic, strlen(magic)+1) != 0)		sysfatal("bad magic"); 	if(decode(fd) != 1)		sysfatal("invalid key");	if((p = fill()) == nil)		sysfatal("fill: %r"); 	s = smprint("%s size=%d ek=%B !dk=%B n=%B !p=%B !q=%B !kp=%B !kq=%B !c2=%B\n",		"key service=ssh proto=rsa",		mpsignif(p->pub.n), p->pub.ek,		p->dk, p->pub.n, p->p, p->q,		p->kp, p->kq, p->c2);	if(s == nil)		sysfatal("smprint: %r");	if(write(1, s, strlen(s)) != strlen(s))		sysfatal("write: %r"); 	exits(nil);}