2 * Present factotum in ssh agent clothing.
16 enum /* agent protocol packet types */
19 SSH_AGENTC_REQUEST_RSA_IDENTITIES,
20 SSH_AGENT_RSA_IDENTITIES_ANSWER,
21 SSH_AGENTC_RSA_CHALLENGE,
22 SSH_AGENT_RSA_RESPONSE,
25 SSH_AGENTC_ADD_RSA_IDENTITY,
26 SSH_AGENTC_REMOVE_RSA_IDENTITY,
27 SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES,
29 SSH2_AGENTC_REQUEST_IDENTITIES = 11,
30 SSH2_AGENT_IDENTITIES_ANSWER,
31 SSH2_AGENTC_SIGN_REQUEST,
32 SSH2_AGENT_SIGN_RESPONSE,
34 SSH2_AGENTC_ADD_IDENTITY = 17,
35 SSH2_AGENTC_REMOVE_IDENTITY,
36 SSH2_AGENTC_REMOVE_ALL_IDENTITIES,
37 SSH2_AGENTC_ADD_SMARTCARD_KEY,
38 SSH2_AGENTC_REMOVE_SMARTCARD_KEY,
42 SSH_AGENTC_ADD_RSA_ID_CONSTRAINED,
43 SSH2_AGENTC_ADD_ID_CONSTRAINED,
44 SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED,
46 SSH_AGENT_CONSTRAIN_LIFETIME = 1,
47 SSH_AGENT_CONSTRAIN_CONFIRM = 2,
49 SSH2_AGENT_FAILURE = 30,
51 SSH_COM_AGENT2_FAILURE = 102,
52 SSH_AGENT_OLD_SIGNATURE = 0x01
55 typedef struct Aconn Aconn;
65 typedef struct Msg Msg;
77 char *factotum = "factotum";
79 void agentproc(void *v);
81 void* erealloc(void *v, int n);
82 void listenproc(void *v);
84 void listkeystext(void);
89 fprint(2, "usage: 9 ssh-agent [-D] [factotum]\n");
90 threadexitsall("usage");
94 threadmain(int argc, char **argv)
96 int fd, pid, export, dotextlist;
98 char sock[200], addr[200];
104 fmtinstall('B', mpfmt);
105 fmtinstall('H', encodefmt);
106 fmtinstall('[', encodefmt);
134 snprint(sock, sizeof sock, "%s/ssh-agent.socket", ns);
136 x = ((uvlong)fastrand()<<32) | fastrand();
137 x ^= ((uvlong)fastrand()<<32) | fastrand();
138 snprint(dir, sizeof dir, "/tmp/ssh-%llux", x);
139 if((fd = create(dir, OREAD, DMDIR|0700)) < 0)
140 sysfatal("mkdir %s: %r", dir);
142 snprint(sock, sizeof sock, "%s/agent.%d", dir, pid);
144 snprint(addr, sizeof addr, "unix!%s", sock);
146 if((afd = announce(addr, adir)) < 0)
147 sysfatal("announce %s: %r", addr);
149 print("SSH_AUTH_SOCK=%s;\n", sock);
151 print("export SSH_AUTH_SOCK;\n");
152 print("SSH_AGENT_PID=%d;\n", pid);
154 print("export SSH_AGENT_PID;\n");
157 proccreate(listenproc, nil, STACK);
168 a = emalloc(sizeof *a);
169 a->ctl = listen(adir, a->dir);
171 sysfatal("listen: %r");
172 proccreate(agentproc, a, STACK);
183 a->fd = accept(a->ctl, a->dir);
187 a->data = erealloc(a->data, a->ndata+1024);
188 n = read(a->fd, a->data+a->ndata, 1024);
215 x = (m->p[0]<<8)|m->p[1];
226 x = (m->p[0]<<24)|(m->p[1]<<16)|(m->p[2]<<8)|m->p[3];
266 if((p=getn(m, n)) == nil)
268 return betomp(p, n, nil);
278 if((p = getn(m, n)) == nil)
280 return betomp(p, n, nil);
286 memset(m, 0, sizeof *m);
293 memset(m->bp, 0, m->ep-m->bp);
296 memset(m, 0, sizeof *m);
300 getm(Msg *m, Msg *mm)
306 if((p = getn(m, n)) == nil)
316 ensure(Msg *m, int n)
325 p = emalloc(m->ep - m->bp);
326 memmove(p, m->bp, m->ep - m->bp);
329 m->ep += m->bp - obp;
336 m->bp = erealloc(m->bp, len+n+1024);
338 m->ep += m->bp - obp;
378 putn(Msg *m, void *a, uint n)
387 putmp(Msg *m, mpint *b)
396 mptobe(b, p, n, nil);
400 putmp2(Msg *m, mpint *b)
405 if(mpcmp(b, mpzero) == 0){
417 mptobe(b, p, n, nil);
421 putstr(Msg *m, char *s)
431 putm(Msg *m, Msg *mm)
441 newreply(Msg *m, int type)
443 memset(m, 0, sizeof *m);
449 reply(Aconn *a, Msg *m)
454 n = (m->p - m->bp) - 4;
461 fprint(2, "respond %d t=%d: %.*H\n", n, p[4], n, m->bp+4);
462 write(a->fd, p, n+4);
466 typedef struct Key Key;
475 find(char **f, int nf, char *k)
480 for(i=1; i<nf; i++) /* i=1: f[0] is "key" */
481 if(strncmp(f[i], k, len) == 0 && f[i][len] == '=')
487 putrsa1(Msg *m, char **f, int nf)
492 p = find(f, nf, "n");
493 if(p == nil || (mod = strtomp(p, nil, 16, nil)) == nil)
495 p = find(f, nf, "ek");
496 if(p == nil || (ek = strtomp(p, nil, 16, nil)) == nil){
500 p = find(f, nf, "comment");
503 put4(m, mpsignif(mod));
513 printattr(char **f, int nf)
524 printrsa1(char **f, int nf)
529 p = find(f, nf, "n");
530 if(p == nil || (mod = strtomp(p, nil, 16, nil)) == nil)
532 p = find(f, nf, "ek");
533 if(p == nil || (ek = strtomp(p, nil, 16, nil)) == nil){
537 p = find(f, nf, "comment");
543 print("%d %.10B %.10B %s\n", mpsignif(mod), ek, mod, p);
549 putrsa(Msg *m, char **f, int nf)
554 p = find(f, nf, "n");
555 if(p == nil || (mod = strtomp(p, nil, 16, nil)) == nil)
557 p = find(f, nf, "ek");
558 if(p == nil || (ek = strtomp(p, nil, 16, nil)) == nil){
562 putstr(m, "ssh-rsa");
580 if(k->ek == nil || k->n == nil){
588 putdsa(Msg *m, char **f, int nf)
592 mpint *dp, *dq, *dalpha, *dkey;
595 dp = dq = dalpha = dkey = nil;
596 p = find(f, nf, "p");
597 if(p == nil || (dp = strtomp(p, nil, 16, nil)) == nil)
599 p = find(f, nf, "q");
600 if(p == nil || (dq = strtomp(p, nil, 16, nil)) == nil)
602 p = find(f, nf, "alpha");
603 if(p == nil || (dalpha = strtomp(p, nil, 16, nil)) == nil)
605 p = find(f, nf, "key");
606 if(p == nil || (dkey = strtomp(p, nil, 16, nil)) == nil)
608 putstr(m, "ssh-dss");
623 putkey2(Msg *m, int (*put)(Msg*,char**,int), char **f, int nf)
629 if(put(&mm, f, nf) < 0)
633 p = find(f, nf, "comment");
641 printkey(char *type, int (*put)(Msg*,char**,int), char **f, int nf)
647 if(put(&m, f, nf) < 0)
649 p = find(f, nf, "comment");
654 print("%s %.*[ %s\n", type, m.p-m.bp, m.bp, p);
669 k->alpha = getmp2(m);
671 if(!k->p || !k->q || !k->alpha || !k->key){
679 listkeys(Msg *m, int version)
681 char buf[8192+1], *line[100], *f[20], *p, *s;
683 int i, n, nl, nf, nk;
689 if((fid = nsopen(factotum, nil, "ctl", OREAD)) == nil){
690 fprint(2, "ssh-agent: open factotum: %r\n");
694 if((n = fsread(fid, buf, sizeof buf-1)) <= 0)
697 nl = getfields(buf, line, nelem(line), 1, "\n");
699 nf = tokenize(line[i], f, nelem(f));
700 if(nf == 0 || strcmp(f[0], "key") != 0)
702 p = find(f, nf, "proto");
705 s = find(f, nf, "service");
709 if(version == 1 && strcmp(p, "rsa") == 0 && strcmp(s, "ssh") == 0)
710 if(putrsa1(m, f, nf) >= 0)
712 if(version == 2 && strcmp(p, "rsa") == 0 && strcmp(s, "ssh-rsa") == 0)
713 if(putkey2(m, putrsa, f, nf) >= 0)
715 if(version == 2 && strcmp(p, "dsa") == 0 && strcmp(s, "ssh-dss") == 0)
716 if(putkey2(m, putdsa, f, nf) >= 0)
721 fprint(2, "sending %d keys\n", nk);
723 m->bp[pnk+0] = (nk>>24)&0xFF;
724 m->bp[pnk+1] = (nk>>16)&0xFF;
725 m->bp[pnk+2] = (nk>>8)&0xFF;
726 m->bp[pnk+3] = nk&0xFF;
733 char buf[8192+1], *line[100], *f[20], *p, *s;
737 if((fid = nsopen(factotum, nil, "ctl", OREAD)) == nil){
738 fprint(2, "ssh-agent: open factotum: %r\n");
742 if((n = fsread(fid, buf, sizeof buf-1)) <= 0)
745 nl = getfields(buf, line, nelem(line), 1, "\n");
747 nf = tokenize(line[i], f, nelem(f));
748 if(nf == 0 || strcmp(f[0], "key") != 0)
750 p = find(f, nf, "proto");
753 s = find(f, nf, "service");
757 if(strcmp(p, "rsa") == 0 && strcmp(s, "ssh") == 0)
759 if(strcmp(p, "rsa") == 0 && strcmp(s, "ssh-rsa") == 0)
760 printkey("ssh-rsa", putrsa, f, nf);
761 if(strcmp(p, "dsa") == 0 && strcmp(s, "ssh-dss") == 0)
762 printkey("ssh-dss", putdsa, f, nf);
775 n = (mpsignif(b)+7)/8;
777 werrstr("rsaunpad: too big");
780 mptobe(b, buf, n, nil);
782 /* the initial zero has been eaten by the betomp -> mptobe sequence */
784 werrstr("rsaunpad: expected leading 2");
790 return betomp(buf+i, n-i, nil);
794 mptoberjust(mpint *b, uchar *buf, int len)
798 n = mptobe(b, buf, len, nil);
802 memmove(buf+len, buf, n);
808 dorsa(Aconn *a, mpint *mod, mpint *exp, mpint *chal, uchar chalbuf[32])
815 if((rpc = auth_allocrpc()) == nil){
816 fprint(2, "ssh-agent: auth_allocrpc: %r\n");
819 snprint(buf, sizeof buf, "proto=rsa service=ssh role=decrypt n=%lB ek=%lB", mod, exp);
821 fprint(2, "ssh-agent: start %s\n", buf);
822 if(auth_rpc(rpc, "start", buf, strlen(buf)) != ARok){
823 fprint(2, "ssh-agent: auth 'start' failed: %r\n");
829 p = mptoa(chal, 16, nil, 0);
831 fprint(2, "ssh-agent: dorsa: mptoa: %r\n");
835 fprint(2, "ssh-agent: challenge %B => %s\n", chal, p);
836 if(auth_rpc(rpc, "writehex", p, strlen(p)) != ARok){
837 fprint(2, "ssh-agent: dorsa: auth 'write': %r\n");
842 if(auth_rpc(rpc, "readhex", nil, 0) != ARok){
843 fprint(2, "ssh-agent: dorsa: auth 'read': %r\n");
846 decr = strtomp(rpc->arg, nil, 16, nil);
848 fprint(2, "ssh-agent: response %s => %B\n", rpc->arg, decr);
850 fprint(2, "ssh-agent: dorsa: strtomp: %r\n");
853 unpad = rsaunpad(decr);
855 fprint(2, "ssh-agent: unpad %B => %B\n", decr, unpad);
857 fprint(2, "ssh-agent: dorsa: rsaunpad: %r\n");
862 mptoberjust(unpad, chalbuf, 32);
869 keysign(Msg *mkey, Msg *mdata, Msg *msig)
876 uchar digest[SHA1dlen];
879 if(strcmp(s, "ssh-rsa") == 0){
880 rsa = getrsapub(mkey);
883 snprint(buf, sizeof buf, "proto=rsa service=ssh-rsa role=sign n=%lB ek=%lB",
886 }else if(strcmp(s, "ssh-dss") == 0){
887 dsa = getdsapub(mkey);
890 snprint(buf, sizeof buf, "proto=dsa service=ssh-dss role=sign p=%lB q=%lB alpha=%lB key=%lB",
891 dsa->p, dsa->q, dsa->alpha, dsa->key);
894 fprint(2, "ssh-agent: cannot sign key type %s\n", s);
895 werrstr("unknown key type %s", s);
899 if((rpc = auth_allocrpc()) == nil){
900 fprint(2, "ssh-agent: auth_allocrpc: %r\n");
904 fprint(2, "ssh-agent: start %s\n", buf);
905 if(auth_rpc(rpc, "start", buf, strlen(buf)) != ARok){
906 fprint(2, "ssh-agent: auth 'start' failed: %r\n");
911 sha1(mdata->bp, mdata->ep-mdata->bp, digest, nil);
912 if(auth_rpc(rpc, "write", digest, SHA1dlen) != ARok){
913 fprint(2, "ssh-agent: auth 'write in sign failed: %r\n");
916 if(auth_rpc(rpc, "read", nil, 0) != ARok){
917 fprint(2, "ssh-agent: auth 'read' failed: %r\n");
922 put4(msig, rpc->narg);
923 putn(msig, rpc->arg, rpc->narg);
932 int n, nk, type, rt, vers;
933 mpint *ek, *mod, *chal;
934 uchar sessid[16], chalbuf[32], digest[MD5dlen];
937 Msg m, mkey, mdata, msig;
941 len = (a->data[0]<<24)|(a->data[1]<<16)|(a->data[2]<<8)|a->data[3];
948 fprint(2, "msg %d: %.*H\n", type, len, m.p);
952 newreply(&m, SSH_AGENT_FAILURE);
956 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
958 newreply(&m, SSH_AGENT_RSA_IDENTITIES_ANSWER);
960 case SSH2_AGENTC_REQUEST_IDENTITIES:
962 newreply(&m, SSH2_AGENT_IDENTITIES_ANSWER);
964 nk = listkeys(&m, vers);
970 fprint(2, "request identities\n", nk);
974 case SSH_AGENTC_RSA_CHALLENGE:
979 if((p = (char*)getn(&m, 16)) == nil){
986 memmove(sessid, p, 16);
988 if(rt != 1 || dorsa(a, mod, ek, chal, chalbuf) < 0)
990 s = md5(chalbuf, 32, nil, nil);
993 md5(sessid, 16, digest, s);
994 print("md5 %.*H %.*H => %.*H\n", 32, chalbuf, 16, sessid, MD5dlen, digest);
996 newreply(&m, SSH_AGENT_RSA_RESPONSE);
997 putn(&m, digest, 16);
1005 case SSH2_AGENTC_SIGN_REQUEST:
1006 if(getm(&m, &mkey) == nil
1007 || getm(&m, &mdata) == nil)
1010 if(flags & SSH_AGENT_OLD_SIGNATURE)
1012 if(keysign(&mkey, &mdata, &msig) < 0)
1015 fprint(2, "signature: %.*H\n",
1016 msig.p-msig.bp, msig.bp);
1017 newreply(&m, SSH2_AGENT_SIGN_RESPONSE);
1023 case SSH_AGENTC_ADD_RSA_IDENTITY:
1025 msg: n[4] mod[mp] pubexp[exp] privexp[mp]
1026 p^-1 mod q[mp] p[mp] q[mp] comment[str]
1030 case SSH_AGENTC_REMOVE_RSA_IDENTITY:
1032 msg: n[4] mod[mp] pubexp[mp]
1039 memmove(a->data, a->data+4+len, a->ndata);
1051 sysfatal("out of memory allocating %d", n);
1057 erealloc(void *v, int n)
1062 sysfatal("out of memory reallocating %d", n);