1 #include "dat.h"
2 #include <mp.h>
3 #include <libsec.h>
4 
5 typedef struct Sshrsastate Sshrsastate;
6 
7 enum {
8 	CReadpub,
9 	CWritechal,
10 	CReadresp,
11 };
12 struct State
13 {
14 	RSApriv *priv;
15 	Key *k;
16 	mpint *resp;
17 	int phase;
18 };
19 
20 static RSApriv*
21 readrsapriv(char *s)
22 {
23 	RSApriv *priv;
24 
25 	priv = rsaprivalloc();
26 
27 	strtoul(s, &s, 10);
28 	if((priv->pub.ek=strtomp(s, &s, 16, nil)) == nil)
29 		goto Error;
30 	if((priv->dk=strtomp(s, &s, 16, nil)) == nil)
31 		goto Error;
32 	if((priv->pub.n=strtomp(s, &s, 16, nil)) == nil)
33 		goto Error;
34 	if((priv->p=strtomp(s, &s, 16, nil)) == nil)
35 		goto Error;
36 	if((priv->q=strtomp(s, &s, 16, nil)) == nil)
37 		goto Error;
38 	if((priv->kp=strtomp(s, &s, 16, nil)) == nil)
39 		goto Error;
40 	if((priv->kq=strtomp(s, &s, 16, nil)) == nil)
41 		goto Error;
42 	if((priv->c2=strtomp(s, &s, 16, nil)) == nil)
43 		goto Error;
44 
45 	return priv;
46 
47 Error:
48 	rsaprivfree(priv);
49 	return nil;
50 }
51 
52 int
53 sshinit(Fsstate *fss, 
54 sshrsaopen(Key *k, char*, int client)
55 {
56 	Sshrsastate *s;
57 
58 	fmtinstall('B', mpconv);
59 	assert(client);
60 	s = emalloc(sizeof *s);
61 	s->priv = readrsapriv(s_to_c(k->data));
62 	s->k = k;
63 	if(s->priv == nil){
64 		agentlog("error parsing ssh key %s", k->file);
65 		free(s);
66 		return nil;
67 	}
68 	return s;
69 }
70 
71 int
72 sshrsaread(void *va, void *buf, int n)
73 {
74 	Sshrsastate *s;
75 
76 	s = va;
77 	switch(s->phase){
78 	case Readpub:
79 		s->phase = Done;
80 		return snprint(buf, n, "%B", s->priv->pub.n);
81 	case Readresp:
82 		s->phase = Done;
83 		return snprint(buf, n, "%B", s->resp);
84 	default:
85 		return 0;
86 	}
87 }
88 
89 int
90 sshrsawrite(void *va, void *vbuf, int n)
91 {
92 	mpint *m;
93 	char *buf;
94 	Sshrsastate *s;
95 
96 	s = va;
97 	if((s->k->flags&Fconfirmuse) && confirm("ssh use") < 0)
98 		return -1;
99 
100 	buf = emalloc(n+1);
101 	memmove(buf, vbuf, n);
102 	buf[n] = '\0';
103 	m = strtomp(buf, nil, 16, nil);
104 	free(buf);
105 	if(m == nil){
106 		werrstr("bad bignum");
107 		return -1;
108 	}
109 
110 	agentlog("ssh use");
111 	m = rsadecrypt(s->priv, m, m);
112 	s->resp = m;
113 	s->phase = Readresp;
114 	return n;
115 }
116 
117 void
118 sshrsaclose(void *v)
119 {
120 	Sshrsastate *s;
121 
122 	s = v;
123 	rsaprivfree(s->priv);
124 	mpfree(s->resp);
125 	free(s);
126 }
127 
128 Proto sshrsa = {
129 .name=	"ssh-rsa",
130 .perm=	0666,
131 .open=	sshrsaopen,
132 .read=	sshrsaread,
133 .write=	sshrsawrite,
134 .close=	sshrsaclose,
135 };