ref: 2e714ffe7c3dd2d0a449622189df4efc69a9adba
parent: bef681b892d4aac23279f30013bc28041ef25bd0
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Thu Apr 20 18:28:21 EDT 2017
ssh: implement password and keyboard-interactive authentication methods
--- a/sys/src/cmd/ssh.c
+++ b/sys/src/cmd/ssh.c
@@ -3,6 +3,7 @@
#include <mp.h>
#include <libsec.h>
#include <auth.h>
+#include <authsrv.h>
enum {MSG_DISCONNECT = 1,
@@ -24,6 +25,8 @@
MSG_USERAUTH_BANNER,
MSG_USERAUTH_PK_OK = 60,
+ MSG_USERAUTH_INFO_REQUEST = 60,
+ MSG_USERAUTH_INFO_RESPONSE = 61,
MSG_GLOBAL_REQUEST = 80,
MSG_REQUEST_SUCCESS,
@@ -59,9 +62,10 @@
int nsid;
uchar sid[256];
+char thumb[2*SHA2_256dlen+1];
int fd, intr, raw, debug;
-char *user, *status, *host, *cmd;
+char *user, *service, *status, *host, *cmd;
Oneway recv, send;
void dispatch(void);
@@ -302,7 +306,8 @@
if(n < 0 && wasintr()){n = 0;
continue;
- }
+ } else if(n == 0)
+ werrstr("eof");break;
}
}
@@ -481,7 +486,7 @@
uchar cookie[16], x[32], yc[32], z[32], k[32+1], h[SHA2_256dlen], *ys, *ks, *sig;
uchar k12[2*ChachaKeylen];
- int nk, nys, nks, nsig;
+ int i, nk, nys, nks, nsig;
DigestState *ds;
mpint *S, *K;
RSApub *pub;
@@ -558,6 +563,14 @@
ds = hashstr(yc, 32, ds);
ds = hashstr(ys, 32, ds);
+ sha2_256(ks, nks, h, nil);
+ i = snprint(thumb, sizeof(thumb), "%.*[", sizeof(h), h);
+ while(i > 0 && thumb[i-1] == '=')
+ thumb[--i] = '\0';
+
+if(debug)
+ fprint(2, "host fingerprint: %s\n", thumb);
+
if((pub = ssh2rsapub(ks, nks)) == nil)
sysfatal("bad server public key");if((S = ssh2rsasig(sig, nsig)) == nil)
@@ -605,10 +618,9 @@
}
int
-auth(char *username, char *servicename)
+pubkeyauth(void)
{- static char sshuserauth[] = "ssh-userauth";
- static char publickey[] = "publickey";
+ static char authmeth[] = "publickey";
uchar pk[4096], sig[4096];
int npk, nsig;
@@ -619,14 +631,8 @@
AuthRpc *rpc;
RSApub *pub;
- sendpkt("bs", MSG_SERVICE_REQUEST, sshuserauth, sizeof(sshuserauth)-1);-Next0: switch(recvpkt()){- default:
- dispatch();
- goto Next0;
- case MSG_SERVICE_ACCEPT:
- break;
- }
+if(debug)
+ fprint(2, "%s...\n", authmeth);
if((afd = open("/mnt/factotum/rpc", ORDWR)) < 0)return -1;
@@ -657,9 +663,9 @@
npk = rsapub2ssh(pub, pk, sizeof(pk));
sendpkt("bsssbss", MSG_USERAUTH_REQUEST,- username, strlen(username),
- servicename, strlen(servicename),
- publickey, sizeof(publickey)-1,
+ user, strlen(user),
+ service, strlen(service),
+ authmeth, sizeof(authmeth)-1,
0,
sshrsa, sizeof(sshrsa)-1,
pk, npk);
@@ -678,9 +684,9 @@
n = pack(send.b, sizeof(send.b), "sbsssbss",
sid, nsid,
MSG_USERAUTH_REQUEST,
- username, strlen(username),
- servicename, strlen(servicename),
- publickey, sizeof(publickey)-1,
+ user, strlen(user),
+ service, strlen(service),
+ authmeth, sizeof(authmeth)-1,
1,
sshrsa, sizeof(sshrsa)-1,
pk, npk);
@@ -699,9 +705,9 @@
/* send final userauth request with the signature */
sendpkt("bsssbsss", MSG_USERAUTH_REQUEST,- username, strlen(username),
- servicename, strlen(servicename),
- publickey, sizeof(publickey)-1,
+ user, strlen(user),
+ service, strlen(service),
+ authmeth, sizeof(authmeth)-1,
1,
sshrsa, sizeof(sshrsa)-1,
pk, npk,
@@ -726,6 +732,132 @@
return -1;
}
+int
+passauth(void)
+{+ static char authmeth[] = "password";
+ UserPasswd *up;
+
+if(debug)
+ fprint(2, "%s...\n", authmeth);
+
+ up = auth_getuserpasswd(auth_getkey, "proto=pass servive=ssh user=%q server=%q thumb=%q",
+ user, host, thumb);
+ if(up == nil)
+ return -1;
+
+ sendpkt("bsssbs", MSG_USERAUTH_REQUEST,+ user, strlen(user),
+ service, strlen(service),
+ authmeth, sizeof(authmeth)-1,
+ 0,
+ up->passwd, strlen(up->passwd));
+
+ memset(up->passwd, 0, strlen(up->passwd));
+ free(up);
+
+Next0: switch(recvpkt()){+ default:
+ dispatch();
+ goto Next0;
+ case MSG_USERAUTH_FAILURE:
+ werrstr("%s authentication failed", authmeth);+ return -1;
+ case MSG_USERAUTH_SUCCESS:
+ return 0;
+ }
+}
+
+int
+kbintauth(void)
+{+ static char authmeth[] = "keyboard-interactive";
+
+ char *name, *inst, *s, *a;
+ int fd, i, n, m;
+ int nquest, echo;
+ uchar *ans, *answ;
+
+if(debug)
+ fprint(2, "%s...\n", authmeth);
+
+ sendpkt("bsssss", MSG_USERAUTH_REQUEST,+ user, strlen(user),
+ service, strlen(service),
+ authmeth, sizeof(authmeth)-1,
+ "", 0,
+ "", 0);
+
+Next0: switch(recvpkt()){+ default:
+ dispatch();
+ goto Next0;
+ case MSG_USERAUTH_FAILURE:
+ werrstr("%s authentication failed", authmeth);+ return -1;
+ case MSG_USERAUTH_SUCCESS:
+ return 0;
+ case MSG_USERAUTH_INFO_REQUEST:
+ break;
+ }
+
+ if((fd = open("/dev/cons", OWRITE)) < 0)+ return -1;
+
+ if(unpack(recv.r, recv.w-recv.r, "_ss.", &name, &n, &inst, &m, &recv.r) < 0)
+ sysfatal("bad info request: name, inst");+
+ while(n > 0 && strchr("\r\n\t ", name[n-1]) != nil)+ n--;
+ while(m > 0 && strchr("\r\n\t ", inst[m-1]) != nil)+ m--;
+
+ if(n > 0)
+ fprint(fd, "%.*s\n", n, name);
+ if(m > 0)
+ fprint(fd, "%.*s\n", m, inst);
+
+ /* lang, nprompt */
+ if(unpack(recv.r, recv.w-recv.r, "su.", &s, &n, &nquest, &recv.r) < 0)
+ sysfatal("bad info request: lang, #quest");+
+ ans = answ = nil;
+ for(i = 0; i < nquest; i++){+ if(unpack(recv.r, recv.w-recv.r, "sb.", &s, &n, &echo, &recv.r) < 0)
+ sysfatal("bad info request: question [%d]", i);+
+ while(n > 0 && strchr("\r\n\t :", s[n-1]) != nil)+ n--;
+ s[n] = '\0';
+
+ if((a = readcons(s, nil, !echo)) == nil)
+ sysfatal("readcons: %r");+
+ n = answ - ans;
+ m = strlen(a)+4;
+ if((s = realloc(ans, n + m)) == nil)
+ sysfatal("realloc: %r");+ ans = (uchar*)s;
+ answ = ans+n;
+ answ += pack(answ, m, "s", a, m-4);
+ }
+
+ sendpkt("bu[", MSG_USERAUTH_INFO_RESPONSE, i, ans, answ - ans);+ free(ans);
+ close(fd);
+
+Next1: switch(recvpkt()){+ default:
+ dispatch();
+ goto Next1;
+ case MSG_USERAUTH_FAILURE:
+ werrstr("%s authentication failed", authmeth);+ return -1;
+ case MSG_USERAUTH_SUCCESS:
+ return 0;
+ }
+}
+
void
dispatch(void)
{@@ -886,6 +1018,7 @@
quotefmtinstall();
fmtinstall('B', mpfmt); fmtinstall('H', encodefmt);+ fmtinstall('[', encodefmt); s = getenv("TERM");raw = s != nil && strcmp(s, "dumb") != 0;
@@ -940,9 +1073,21 @@
recv.v = strdup(recv.v);
kex(0);
+
if(user == nil)
user = getuser();
- if(auth(user, "ssh-connection") < 0)
+ service = "ssh-connection";
+
+ sendpkt("bs", MSG_SERVICE_REQUEST, "ssh-userauth", 12);+Next0: switch(recvpkt()){+ default:
+ dispatch();
+ goto Next0;
+ case MSG_SERVICE_ACCEPT:
+ break;
+ }
+
+ if(pubkeyauth() < 0 && passauth() < 0 && kbintauth() < 0)
sysfatal("auth: %r");/* open hailing frequencies */
@@ -952,10 +1097,10 @@
sizeof(buf),
sizeof(buf));
-Next0: switch(recvpkt()){+Next1: switch(recvpkt()){default:
dispatch();
- goto Next0;
+ goto Next1;
case MSG_CHANNEL_OPEN_FAILURE:
if(unpack(recv.r, recv.w-recv.r, "_uus", &c, &b, &s, &n) < 0)
n = strlen(s = "???");