1 files changed, 135 insertions, 0 deletions
diff --git a/src/cmd/factotum/ssh.c b/src/cmd/factotum/ssh.c
new file mode 100644
index 00000000..4c88bfe6
--- /dev/null
+++ b/src/cmd/factotum/ssh.c
@@ -0,0 +1,135 @@
+#include "dat.h"
+#include <mp.h>
+#include <libsec.h>
+
+typedef struct Sshrsastate Sshrsastate;
+
+enum {
+	CReadpub,
+	CWritechal,
+	CReadresp,
+};
+struct State
+{
+	RSApriv *priv;
+	Key *k;
+	mpint *resp;
+	int phase;
+};
+
+static RSApriv*
+readrsapriv(char *s)
+{
+	RSApriv *priv;
+
+	priv = rsaprivalloc();
+
+	strtoul(s, &s, 10);
+	if((priv->pub.ek=strtomp(s, &s, 16, nil)) == nil)
+		goto Error;
+	if((priv->dk=strtomp(s, &s, 16, nil)) == nil)
+		goto Error;
+	if((priv->pub.n=strtomp(s, &s, 16, nil)) == nil)
+		goto Error;
+	if((priv->p=strtomp(s, &s, 16, nil)) == nil)
+		goto Error;
+	if((priv->q=strtomp(s, &s, 16, nil)) == nil)
+		goto Error;
+	if((priv->kp=strtomp(s, &s, 16, nil)) == nil)
+		goto Error;
+	if((priv->kq=strtomp(s, &s, 16, nil)) == nil)
+		goto Error;
+	if((priv->c2=strtomp(s, &s, 16, nil)) == nil)
+		goto Error;
+
+	return priv;
+
+Error:
+	rsaprivfree(priv);
+	return nil;
+}
+
+int
+sshinit(Fsstate *fss, 
+sshrsaopen(Key *k, char*, int client)
+{
+	Sshrsastate *s;
+
+	fmtinstall('B', mpconv);
+	assert(client);
+	s = emalloc(sizeof *s);
+	s->priv = readrsapriv(s_to_c(k->data));
+	s->k = k;
+	if(s->priv == nil){
+		agentlog("error parsing ssh key %s", k->file);
+		free(s);
+		return nil;
+	}
+	return s;
+}
+
+int
+sshrsaread(void *va, void *buf, int n)
+{
+	Sshrsastate *s;
+
+	s = va;
+	switch(s->phase){
+	case Readpub:
+		s->phase = Done;
+		return snprint(buf, n, "%B", s->priv->pub.n);
+	case Readresp:
+		s->phase = Done;
+		return snprint(buf, n, "%B", s->resp);
+	default:
+		return 0;
+	}
+}
+
+int
+sshrsawrite(void *va, void *vbuf, int n)
+{
+	mpint *m;
+	char *buf;
+	Sshrsastate *s;
+
+	s = va;
+	if((s->k->flags&Fconfirmuse) && confirm("ssh use") < 0)
+		return -1;
+
+	buf = emalloc(n+1);
+	memmove(buf, vbuf, n);
+	buf[n] = '\0';
+	m = strtomp(buf, nil, 16, nil);
+	free(buf);
+	if(m == nil){
+		werrstr("bad bignum");
+		return -1;
+	}
+
+	agentlog("ssh use");
+	m = rsadecrypt(s->priv, m, m);
+	s->resp = m;
+	s->phase = Readresp;
+	return n;
+}
+
+void
+sshrsaclose(void *v)
+{
+	Sshrsastate *s;
+
+	s = v;
+	rsaprivfree(s->priv);
+	mpfree(s->resp);
+	free(s);
+}
+
+Proto sshrsa = {
+.name=	"ssh-rsa",
+.perm=	0666,
+.open=	sshrsaopen,
+.read=	sshrsaread,
+.write=	sshrsawrite,
+.close=	sshrsaclose,
+};