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/* secstore - network login client */
#include <u.h>
#include <libc.h>
#include <mp.h>
#include <libsec.h>
#include <authsrv.h>
#include "SConn.h"
#include "secstore.h"
enum{ CHK = 16, MAXFILES = 100 };
typedef struct AuthConn{
SConn *conn;
char pass[64];
int passlen;
} AuthConn;
int verbose;
Nvrsafe nvr;
void
usage(void)
{
fprint(2, "usage: secstore [-cinv] [-[gG] getfile] [-p putfile] "
"[-r rmfile] [-s tcp!server!5356] [-u user]\n");
exits("usage");
}
static int
getfile(SConn *conn, char *gf, uchar **buf, ulong *buflen, uchar *key, int nkey)
{
int fd = -1, i, n, nr, nw, len;
char s[Maxmsg+1];
uchar skey[SHA1dlen], ib[Maxmsg+CHK], *ibr, *ibw, *bufw, *bufe;
AESstate aes;
DigestState *sha;
memset(&aes, 0, sizeof aes);
snprint(s, Maxmsg, "GET %s", gf);
conn->write(conn, (uchar*)s, strlen(s));
/* get file size */
s[0] = '\0';
bufw = bufe = nil;
if(readstr(conn, s) < 0){
fprint(2, "secstore: remote: %s\n", s);
return -1;
}
len = atoi(s);
if(len == -1){
fprint(2, "secstore: remote file %s does not exist\n", gf);
return -1;
}else if(len == -3){
fprint(2, "secstore: implausible filesize for %s\n", gf);
return -1;
}else if(len < 0){
fprint(2, "secstore: GET refused for %s\n", gf);
return -1;
}
if(buf != nil){
*buflen = len - AESbsize - CHK;
*buf = bufw = emalloc(len);
bufe = bufw + len;
}
/* directory listing */
if(strcmp(gf,".")==0){
if(buf != nil)
*buflen = len;
for(i=0; i < len; i += n){
if((n = conn->read(conn, (uchar*)s, Maxmsg)) <= 0){
fprint(2, "secstore: empty file chunk\n");
return -1;
}
if(buf == nil)
write(1, s, n);
else
memmove(*buf + i, s, n);
}
return 0;
}
/*
* conn is already encrypted against wiretappers, but gf is also
* encrypted against server breakin.
*/
if(buf == nil && (fd = create(gf, OWRITE, 0600)) < 0){
fprint(2, "secstore: can't open %s: %r\n", gf);
return -1;
}
ibr = ibw = ib;
for(nr=0; nr < len;){
if((n = conn->read(conn, ibw, Maxmsg)) <= 0){
fprint(2, "secstore: empty file chunk n=%d nr=%d len=%d: %r\n",
n, nr, len);
return -1;
}
nr += n;
ibw += n;
if(!aes.setup){ /* first time, read 16 byte IV */
if(n < AESbsize){
fprint(2, "secstore: no IV in file\n");
return -1;
}
sha = sha1((uchar*)"aescbc file", 11, nil, nil);
sha1(key, nkey, skey, sha);
setupAESstate(&aes, skey, AESbsize, ibr);
memset(skey, 0, sizeof skey);
ibr += AESbsize;
n -= AESbsize;
}
aesCBCdecrypt(ibw-n, n, &aes);
n = ibw - ibr - CHK;
if(n > 0){
if(buf == nil){
nw = write(fd, ibr, n);
if(nw != n){
fprint(2, "secstore: write error on %s", gf);
return -1;
}
}else{
assert(bufw + n <= bufe);
memmove(bufw, ibr, n);
bufw += n;
}
ibr += n;
}
memmove(ib, ibr, ibw-ibr);
ibw = ib + (ibw-ibr);
ibr = ib;
}
if(buf == nil)
close(fd);
n = ibw-ibr;
if(n != CHK || memcmp(ib, "XXXXXXXXXXXXXXXX", CHK) != 0){
fprint(2, "secstore: decrypted file failed to authenticate!\n");
return -1;
}
return 0;
}
/*
* This sends a file to the secstore disk that can, in an emergency, be
* decrypted by the program aescbc.c.
*/
static int
putfile(SConn *conn, char *pf, uchar *buf, ulong len, uchar *key, int nkey)
{
int i, n, fd, ivo, bufi, done;
char s[Maxmsg];
uchar skey[SHA1dlen], b[CHK+Maxmsg], IV[AESbsize];
AESstate aes;
DigestState *sha;
/* create initialization vector */
srand(time(0)); /* doesn't need to be unpredictable */
for(i=0; i<AESbsize; i++)
IV[i] = 0xff & rand();
sha = sha1((uchar*)"aescbc file", 11, nil, nil);
sha1(key, nkey, skey, sha);
setupAESstate(&aes, skey, AESbsize, IV);
memset(skey, 0, sizeof skey);
snprint(s, Maxmsg, "PUT %s", pf);
conn->write(conn, (uchar*)s, strlen(s));
if(buf == nil){
/* get file size */
if((fd = open(pf, OREAD)) < 0){
fprint(2, "secstore: can't open %s: %r\n", pf);
return -1;
}
len = seek(fd, 0, 2);
seek(fd, 0, 0);
} else
fd = -1;
if(len > MAXFILESIZE){
fprint(2, "secstore: implausible filesize %ld for %s\n",
len, pf);
return -1;
}
/* send file size */
snprint(s, Maxmsg, "%ld", len + AESbsize + CHK);
conn->write(conn, (uchar*)s, strlen(s));
/* send IV and file+XXXXX in Maxmsg chunks */
ivo = AESbsize;
bufi = 0;
memcpy(b, IV, ivo);
for(done = 0; !done; ){
if(buf == nil){
n = read(fd, b+ivo, Maxmsg-ivo);
if(n < 0){
fprint(2, "secstore: read error on %s: %r\n",
pf);
return -1;
}
}else{
if((n = len - bufi) > Maxmsg-ivo)
n = Maxmsg-ivo;
memcpy(b+ivo, buf+bufi, n);
bufi += n;
}
n += ivo;
ivo = 0;
if(n < Maxmsg){ /* EOF on input; append XX... */
memset(b+n, 'X', CHK);
n += CHK; /* might push n>Maxmsg */
done = 1;
}
aesCBCencrypt(b, n, &aes);
if(n > Maxmsg){
assert(done==1);
conn->write(conn, b, Maxmsg);
n -= Maxmsg;
memmove(b, b+Maxmsg, n);
}
conn->write(conn, b, n);
}
if(buf == nil)
close(fd);
fprint(2, "secstore: saved %ld bytes\n", len);
return 0;
}
static int
removefile(SConn *conn, char *rf)
{
char buf[Maxmsg];
if(strchr(rf, '/') != nil){
fprint(2, "secstore: simple filenames, not paths like %s\n", rf);
return -1;
}
snprint(buf, Maxmsg, "RM %s", rf);
conn->write(conn, (uchar*)buf, strlen(buf));
return 0;
}
static int
cmd(AuthConn *c, char **gf, int *Gflag, char **pf, char **rf)
{
ulong len;
int rv = -1;
uchar *memfile, *memcur, *memnext;
while(*gf != nil){
if(verbose)
fprint(2, "get %s\n", *gf);
if(getfile(c->conn, *gf, *Gflag? &memfile: nil, &len,
(uchar*)c->pass, c->passlen) < 0)
goto Out;
if(*Gflag){
/* write 1 line at a time, as required by /mnt/factotum/ctl */
memcur = memfile;
while(len>0){
memnext = (uchar*)strchr((char*)memcur, '\n');
if(memnext){
write(1, memcur, memnext-memcur+1);
len -= memnext-memcur+1;
memcur = memnext+1;
}else{
write(1, memcur, len);
break;
}
}
free(memfile);
}
gf++;
Gflag++;
}
while(*pf != nil){
if(verbose)
fprint(2, "put %s\n", *pf);
if(putfile(c->conn, *pf, nil, 0, (uchar*)c->pass, c->passlen) < 0)
goto Out;
pf++;
}
while(*rf != nil){
if(verbose)
fprint(2, "rm %s\n", *rf);
if(removefile(c->conn, *rf) < 0)
goto Out;
rf++;
}
c->conn->write(c->conn, (uchar*)"BYE", 3);
rv = 0;
Out:
c->conn->free(c->conn);
return rv;
}
static int
chpasswd(AuthConn *c, char *id)
{
int rv = -1, newpasslen = 0;
ulong len;
uchar *memfile;
char *newpass, *passck, *list, *cur, *next, *hexHi;
char *f[8], prompt[128];
mpint *H, *Hi;
H = mpnew(0);
Hi = mpnew(0);
/* changing our password is vulnerable to connection failure */
for(;;){
snprint(prompt, sizeof(prompt), "new password for %s: ", id);
newpass = getpassm(prompt);
if(newpass == nil)
goto Out;
if(strlen(newpass) >= 7)
break;
else if(strlen(newpass) == 0){
fprint(2, "!password change aborted\n");
goto Out;
}
print("!password must be at least 7 characters\n");
}
newpasslen = strlen(newpass);
snprint(prompt, sizeof(prompt), "retype password: ");
passck = getpassm(prompt);
if(passck == nil){
fprint(2, "secstore: getpassm failed\n");
goto Out;
}
if(strcmp(passck, newpass) != 0){
fprint(2, "secstore: passwords didn't match\n");
goto Out;
}
c->conn->write(c->conn, (uchar*)"CHPASS", strlen("CHPASS"));
hexHi = PAK_Hi(id, newpass, H, Hi);
c->conn->write(c->conn, (uchar*)hexHi, strlen(hexHi));
free(hexHi);
mpfree(H);
mpfree(Hi);
if(getfile(c->conn, ".", (uchar **) &list, &len, nil, 0) < 0){
fprint(2, "secstore: directory listing failed.\n");
goto Out;
}
/* Loop over files and reencrypt them; try to keep going after error */
for(cur=list; (next=strchr(cur, '\n')) != nil; cur=next+1){
*next = '\0';
if(tokenize(cur, f, nelem(f))< 1)
break;
fprint(2, "secstore: reencrypting '%s'\n", f[0]);
if(getfile(c->conn, f[0], &memfile, &len, (uchar*)c->pass,
c->passlen) < 0){
fprint(2, "secstore: getfile of '%s' failed\n", f[0]);
continue;
}
if(putfile(c->conn, f[0], memfile, len, (uchar*)newpass,
newpasslen) < 0)
fprint(2, "secstore: putfile of '%s' failed\n", f[0]);
free(memfile);
}
free(list);
c->conn->write(c->conn, (uchar*)"BYE", 3);
rv = 0;
Out:
if(newpass != nil){
memset(newpass, 0, newpasslen);
free(newpass);
}
c->conn->free(c->conn);
return rv;
}
static AuthConn*
login(char *id, char *dest, int pass_stdin, int pass_nvram)
{
int fd, n, ntry = 0;
char *S, *PINSTA = nil, *nl, s[Maxmsg+1], *pass;
AuthConn *c;
if(dest == nil)
sysfatal("tried to login with nil dest");
c = emalloc(sizeof(*c));
if(pass_nvram){
if(readnvram(&nvr, 0) < 0)
exits("readnvram: %r");
strecpy(c->pass, c->pass+sizeof c->pass, nvr.config);
}
if(pass_stdin){
n = readn(0, s, Maxmsg-2); /* so len(PINSTA)<Maxmsg-3 */
if(n < 1)
exits("no password on standard input");
s[n] = 0;
nl = strchr(s, '\n');
if(nl){
*nl++ = 0;
PINSTA = estrdup(nl);
nl = strchr(PINSTA, '\n');
if(nl)
*nl = 0;
}
strecpy(c->pass, c->pass+sizeof c->pass, s);
}
for(;;){
if(verbose)
fprint(2, "dialing %s\n", dest);
if((fd = dial(dest, nil, nil, nil)) < 0){
fprint(2, "secstore: can't dial %s\n", dest);
free(c);
return nil;
}
if((c->conn = newSConn(fd)) == nil){
free(c);
return nil;
}
ntry++;
if(!pass_stdin && !pass_nvram){
pass = getpassm("secstore password: ");
if(strlen(pass) >= sizeof c->pass){
fprint(2, "secstore: password too long, skipping secstore login\n");
exits("password too long");
}
strcpy(c->pass, pass);
memset(pass, 0, strlen(pass));
free(pass);
}
if(c->pass[0]==0){
fprint(2, "secstore: null password, skipping secstore login\n");
exits("no password");
}
if(PAKclient(c->conn, id, c->pass, &S) >= 0)
break;
c->conn->free(c->conn);
if(pass_stdin)
exits("invalid password on standard input");
if(pass_nvram)
exits("invalid password in nvram");
/* and let user try retyping the password */
if(ntry==3)
fprint(2, "Enter an empty password to quit.\n");
}
c->passlen = strlen(c->pass);
fprint(2, "%s\n", S);
free(S);
if(readstr(c->conn, s) < 0){
c->conn->free(c->conn);
free(c);
return nil;
}
if(strcmp(s, "STA") == 0){
long sn;
if(pass_stdin){
if(PINSTA)
strncpy(s+3, PINSTA, sizeof s - 3);
else
exits("missing PIN+SecureID on standard input");
free(PINSTA);
}else{
pass = getpassm("STA PIN+SecureID: ");
strncpy(s+3, pass, sizeof s - 4);
memset(pass, 0, strlen(pass));
free(pass);
}
sn = strlen(s+3);
if(verbose)
fprint(2, "%ld\n", sn);
c->conn->write(c->conn, (uchar*)s, sn+3);
readstr(c->conn, s); /* TODO: check for error? */
}
if(strcmp(s, "OK") != 0){
fprint(2, "%s: %s\n", argv0, s);
c->conn->free(c->conn);
free(c);
return nil;
}
return c;
}
void
main(int argc, char **argv)
{
int chpass = 0, pass_stdin = 0, pass_nvram = 0, rc;
int ngfile = 0, npfile = 0, nrfile = 0, Gflag[MAXFILES+1];
char *serve, *tcpserve, *user;
char *gfile[MAXFILES], *pfile[MAXFILES], *rfile[MAXFILES];
AuthConn *c;
serve = "$auth";
user = getuser();
memset(Gflag, 0, sizeof Gflag);
ARGBEGIN{
case 'c':
chpass = 1;
break;
case 'G':
Gflag[ngfile]++;
/* fall through */
case 'g':
if(ngfile >= MAXFILES)
exits("too many gfiles");
gfile[ngfile++] = EARGF(usage());
break;
case 'i':
pass_stdin = 1;
break;
case 'n':
pass_nvram = 1;
break;
case 'p':
if(npfile >= MAXFILES)
exits("too many pfiles");
pfile[npfile++] = EARGF(usage());
break;
case 'r':
if(nrfile >= MAXFILES)
exits("too many rfiles");
rfile[nrfile++] = EARGF(usage());
break;
case 's':
serve = EARGF(usage());
break;
case 'u':
user = EARGF(usage());
break;
case 'v':
verbose++;
break;
default:
usage();
break;
}ARGEND;
gfile[ngfile] = nil;
pfile[npfile] = nil;
rfile[nrfile] = nil;
if(argc!=0 || user==nil)
usage();
if(chpass && (ngfile || npfile || nrfile)){
fprint(2, "secstore: Get, put, and remove invalid with password change.\n");
exits("usage");
}
rc = strlen(serve) + sizeof "tcp!!99990";
tcpserve = emalloc(rc);
if(strchr(serve,'!'))
strcpy(tcpserve, serve);
else
snprint(tcpserve, rc, "tcp!%s!5356", serve);
c = login(user, tcpserve, pass_stdin, pass_nvram);
free(tcpserve);
if(c == nil)
sysfatal("secstore authentication failed");
if(chpass)
rc = chpasswd(c, user);
else
rc = cmd(c, gfile, Gflag, pfile, rfile);
if(rc < 0)
sysfatal("secstore cmd failed");
exits("");
}