int
_gsasl_kerberos_v5_client_init (Gsasl_ctx * ctx)
{
if (!shishi_check_version (SHISHI_VERSION))
return GSASL_UNKNOWN_MECHANISM;
return GSASL_OK;
}
int
main (int argc, char *argv[])
{
Shishi *h;
Shishi_ap *ap;
char *sname;
int rc;
printf ("sample-client (shishi " SHISHI_VERSION ")\n");
if (!shishi_check_version (SHISHI_VERSION))
{
printf ("shishi_check_version() failed:\n"
"Header file incompatible with shared library.\n");
return 1;
}
rc = shishi_init (&h);
if (rc != SHISHI_OK)
{
printf ("error initializing shishi: %s\n", shishi_strerror (rc));
return 1;
}
if (argc > 1)
sname = argv[1];
else
sname = shishi_server_for_local_service (h, SERVICE);
ap = auth (h, 1, shishi_principal_default (h), sname);
if (ap)
rc = doit (h, ap, 1);
else
rc = 1;
shishi_done (h);
return rc;
}
int
main (int argc, char **argv)
{
char *user = NULL;
char *luser = NULL;
char *host = NULL;
char *port = "shell";
char *p;
char lport[5];
struct passwd *pw;
int af = AF_UNSPEC;
struct addrinfo hint, *ai, *aip, *lai;
struct sockaddr raddr;
int raddrlen;
int err, sock = -1, lsock = -1, esock = -1, i;
int opt;
bool verbose = false;
char hostaddr[NI_MAXHOST];
char portnr[NI_MAXSERV];
char buf[3][BUFLEN], *bufp[3];
int len[3], wlen;
fd_set infd, outfd, infdset, outfdset, errfd;
int maxfd;
int flags;
#ifdef SHISHI
Shishi *h;
Shishi_key *enckey = NULL, *deckey = NULL;
int rc;
char *sname = NULL;
int shishi = 0;
int encryption = 0;
int auth2 = 0;
char *cmd, *tcmd;
int hostlen, cmdlen;
struct hostent *hostdata;
char *iv = NULL;
char *iv2 = NULL;
char *iv3 = NULL;
int ivlen;
int ivlen2;
int ivlen3;
#endif
argv0 = argv[0];
/* Lookup local username */
if (!(pw = getpwuid (getuid ())))
{
fprintf (stderr, "%s: Could not lookup username: %s\n", argv0,
strerror (errno));
return 1;
}
/* Process options */
#ifdef SHISHI
while ((opt = getopt (argc, argv, "+l:p:46vsx")) != -1)
#else
while ((opt = getopt (argc, argv, "+l:p:46v")) != -1)
#endif
{
switch (opt)
{
case 'l':
user = optarg;
break;
case 'p':
port = optarg;
break;
case '4':
af = AF_INET;
break;
case '6':
af = AF_INET6;
break;
case 'v':
verbose = true;
break;
#ifdef SHISHI
case 's':
shishi = 1;
port = "544";
break;
case 'x':
shishi = 1;
encryption = 1;
port = "544";
break;
#endif
default:
fprintf (stderr, "%s: Unknown option!\n", argv0);
usage ();
return 1;
}
}
if (optind == argc)
{
fprintf (stderr, "%s: No host specified!\n", argv0);
usage ();
return 1;
}
#ifdef SHISHI
if (!shishi)
{
luser = pw->pw_name;
if (!user)
user = luser;
}
#endif
host = argv[optind++];
if ((p = strchr (host, '@')))
{
user = host;
*p = '\0';
host = p + 1;
}
/* Resolve hostname and try to make a connection */
memset (&hint, '\0', sizeof (hint));
hint.ai_family = af;
hint.ai_socktype = SOCK_STREAM;
err = getaddrinfo (host, port, &hint, &ai);
if (err)
{
fprintf (stderr, "%s: Error looking up host: %s\n", argv0,
gai_strerror (err));
return 1;
}
hint.ai_flags = AI_PASSIVE;
for (aip = ai; aip; aip = aip->ai_next)
{
if (getnameinfo
(aip->ai_addr, aip->ai_addrlen, hostaddr, sizeof (hostaddr), portnr,
sizeof (portnr), NI_NUMERICHOST | NI_NUMERICSERV))
{
fprintf (stderr, "%s: Error resolving address: %s\n", argv0,
strerror (errno));
return 1;
}
if (verbose)
fprintf (stderr, "Trying %s port %s...", hostaddr, portnr);
if ((sock =
socket (aip->ai_family, aip->ai_socktype, aip->ai_protocol)) == -1)
{
if (verbose)
fprintf (stderr, " Could not open socket: %s\n",
strerror (errno));
continue;
}
hint.ai_family = aip->ai_family;
/* Bind to a privileged port */
for (i = 1023; i >= 512; i--)
{
snprintf (lport, sizeof (lport), "%d", i);
err = getaddrinfo (NULL, lport, &hint, &lai);
if (err)
{
fprintf (stderr, " Error looking up localhost: %s\n",
gai_strerror (err));
return 1;
}
err = bind (sock, lai->ai_addr, lai->ai_addrlen);
freeaddrinfo (lai);
if (err)
continue;
else
break;
}
if (err)
{
if (verbose)
fprintf (stderr, " Could not bind to privileged port: %s\n",
strerror (errno));
continue;
}
if (connect (sock, aip->ai_addr, aip->ai_addrlen) == -1)
{
if (verbose)
fprintf (stderr, " Connection failed: %s\n", strerror (errno));
continue;
}
if (verbose)
fprintf (stderr, " Connected.\n");
break;
}
if (!aip)
{
fprintf (stderr, "%s: Could not make a connection.\n", argv0);
return 1;
}
/* Create a socket for the incoming connection for stderr output */
if ((lsock =
socket (aip->ai_family, aip->ai_socktype, aip->ai_protocol)) == -1)
{
fprintf (stderr, "%s: Could not open socket: %s\n", argv0,
strerror (errno));
return 1;
}
hint.ai_family = aip->ai_family;
freeaddrinfo (ai);
for (i--; i >= 512; i--)
{
snprintf (lport, sizeof (lport), "%d", i);
err = getaddrinfo (NULL, lport, &hint, &lai);
if (err)
{
fprintf (stderr, "%s: Error looking up localhost: %s\n", argv0,
gai_strerror (err));
return 1;
}
err = bind (lsock, lai->ai_addr, lai->ai_addrlen);
freeaddrinfo (lai);
if (err)
continue;
else
break;
}
if (err)
{
fprintf (stderr, "%s: Could not bind to privileged port: %s\n", argv0,
strerror (errno));
return 1;
}
if (listen (lsock, 1))
{
fprintf (stderr, "%s: Could not listen: %s\n", argv0, strerror (errno));
return 1;
}
/* Drop privileges */
if (setuid (getuid ()))
{
fprintf (stderr, "%s: Unable to drop privileges: %s\n", argv0,
strerror (errno));
return 1;
}
/* Send required information to the server */
bufp[0] = buf[0];
len[0] = sizeof (buf[0]);
#ifdef SHISHI
if (shishi)
{
if (!shishi_check_version (SHISHI_VERSION))
{
printf ("shishi_check_version() failed:\n"
"Header file incompatible with shared library.\n");
return 1;
}
rc = shishi_init (&h);
if (rc != SHISHI_OK)
{
printf ("error initializing shishi: %s\n", shishi_strerror (rc));
return 1;
}
hostdata = gethostbyname (host);
hostlen = strlen (hostdata->h_name) + strlen (SERVICE) + 2;
sname = malloc (hostlen);
snprintf (sname, hostlen, "%s/%s", SERVICE, hostdata->h_name);
rc = optind;
cmdlen = BUFLEN;
cmd = malloc (cmdlen);
tcmd = cmd;
if (encryption)
safecpy (&tcmd, &cmdlen, "-x ", 0);
for (; optind < argc; optind++)
{
safecpy (&tcmd, &cmdlen, argv[optind], 0);
if (optind < argc - 1)
safecpy (&tcmd, &cmdlen, " ", 0);
}
safecpy (&tcmd, &cmdlen, "", 1);
optind = rc;
if (!user)
user = (char *) shishi_principal_default (h);
safewrite (sock, lport, strlen (lport) + 1);
/* Wait for incoming connection from server */
if ((esock = accept (lsock, &raddr, &raddrlen)) == -1)
{
fprintf (stderr, "%s: Could not accept stderr connection: %s\n",
argv0, strerror (errno));
return 1;
}
close (lsock);
if (auth (h, 0, user, sname, sock, cmd, port, &enckey, deckey) !=
AUTH_OK)
return 1;
free (cmd);
}
else
{
safecpy (&bufp[0], &len[0], lport, 1);
safecpy (&bufp[0], &len[0], luser, 1);
}
#else
safecpy (&bufp[0], &len[0], lport, 1);
safecpy (&bufp[0], &len[0], luser, 1);
#endif
safecpy (&bufp[0], &len[0], user, 1);
#ifdef SHISHI
if (encryption)
safecpy (&bufp[0], &len[0], "-x ", 0);
#endif
for (; optind < argc; optind++)
{
safecpy (&bufp[0], &len[0], argv[optind], 0);
if (optind < argc - 1)
safecpy (&bufp[0], &len[0], " ", 0);
}
#ifdef SHISHI
if (shishi)
{
safecpy (&bufp[0], &len[0], "", 1);
safecpy (&bufp[0], &len[0], user, 1);
}
else
#endif
safecpy (&bufp[0], &len[0], "", 1);
if (!len[0])
{
fprintf (stderr, "%s: Arguments too long!\n", argv0);
return 1;
}
if (safewrite (sock, buf[0], bufp[0] - buf[0]) == -1)
{
fprintf (stderr, "%s: Unable to send required information: %s\n", argv0,
strerror (errno));
return 1;
}
#ifdef SHISHI
if (shishi)
{
safewrite (sock, &auth2, sizeof (int));
}
#endif
/* Wait for acknowledgement from server */
errno = 0;
if (read (sock, buf[0], 1) != 1 || *buf[0])
{
fprintf (stderr, "%s: Didn't receive NULL byte from server: %s\n",
argv0, strerror (errno));
return 1;
}
#ifdef SHISHI
if (encryption)
{
ivlen = ivlen2 = ivlen3 = shishi_key_length (enckey);
iv = malloc (ivlen);
memset (iv, 1, ivlen);
iv2 = malloc (ivlen2);
memset (iv2, 3, ivlen2);
iv3 = malloc (ivlen3);
memset (iv3, 0, ivlen3);
}
if (!shishi)
{
/* Wait for incoming connection from server */
if ((esock = accept (lsock, &raddr, &raddrlen)) == -1)
{
fprintf (stderr, "%s: Could not accept stderr connection: %s\n",
argv0, strerror (errno));
return 1;
}
close (lsock);
}
#else
/* Wait for incoming connection from server */
if ((esock = accept (lsock, &raddr, &raddrlen)) == -1)
{
fprintf (stderr, "%s: Could not accept stderr connection: %s\n", argv0,
strerror (errno));
return 1;
}
close (lsock);
#endif
/* Process input/output */
flags = fcntl (sock, F_GETFL);
fcntl (sock, F_SETFL, flags | O_NONBLOCK);
flags = fcntl (esock, F_GETFL);
fcntl (esock, F_SETFL, flags | O_NONBLOCK);
bufp[0] = buf[0];
bufp[1] = buf[1];
bufp[2] = buf[2];
FD_ZERO (&infdset);
FD_ZERO (&outfdset);
FD_SET (0, &infdset);
FD_SET (sock, &infdset);
FD_SET (esock, &infdset);
maxfd = (sock > esock ? sock : esock) + 1;
for (;;)
{
errno = 0;
infd = infdset;
outfd = outfdset;
errfd = infdset;
if (select (maxfd, &infd, &outfd, &errfd, NULL) <= 0)
{
if (errno == EINTR)
continue;
else
break;
}
if (FD_ISSET (esock, &infd))
{
#ifdef SHISHI
if (encryption)
{
rc = readenc (h, esock, buf[2], &len[2], iv2, &ivlen2, enckey);
if (rc != SHISHI_OK)
break;
}
else
#endif
len[2] = read (esock, buf[2], BUFLEN);
if (len[2] <= 0)
{
if (errno != EINTR)
{
if (FD_ISSET (sock, &infdset) || FD_ISSET (1, &outfdset))
FD_CLR (esock, &infdset);
else
break;
}
}
else
{
FD_SET (2, &outfdset);
FD_CLR (esock, &infdset);
}
}
if (FD_ISSET (2, &outfd))
{
wlen = write (2, bufp[2], len[2]);
if (wlen <= 0)
{
if (errno != EINTR)
{
if (FD_ISSET (sock, &infdset) || FD_ISSET (1, &outfdset))
FD_CLR (esock, &infdset);
else
break;
}
}
else
{
len[2] -= wlen;
bufp[2] += wlen;
if (!len[2])
{
FD_CLR (2, &outfdset);
FD_SET (esock, &infdset);
bufp[2] = buf[2];
}
}
}
if (FD_ISSET (sock, &infd))
{
#ifdef SHISHI
if (encryption)
{
rc = readenc (h, sock, buf[1], &len[1], iv, &ivlen, enckey);
if (rc != SHISHI_OK)
break;
}
else
#endif
len[1] = read (sock, buf[1], BUFLEN);
if (len[1] <= 0)
{
if (errno != EINTR)
{
if (FD_ISSET (esock, &infdset) || FD_ISSET (2, &outfdset))
FD_CLR (sock, &infdset);
else
break;
}
}
else
{
FD_SET (1, &outfdset);
FD_CLR (sock, &infdset);
}
}
if (FD_ISSET (1, &outfd))
{
wlen = write (1, bufp[1], len[1]);
if (wlen <= 0)
{
if (errno != EINTR)
{
if (FD_ISSET (esock, &infdset) || FD_ISSET (2, &outfdset))
FD_CLR (sock, &infdset);
else
break;
}
}
else
{
len[1] -= wlen;
bufp[1] += wlen;
if (!len[1])
{
FD_CLR (1, &outfdset);
FD_SET (sock, &infdset);
bufp[1] = buf[1];
}
}
}
if (FD_ISSET (0, &infd))
{
len[0] = read (0, buf[0], BUFLEN);
if (len[0] <= 0)
{
if (errno != EINTR)
{
FD_CLR (0, &infdset);
shutdown (sock, SHUT_WR);
}
}
else
{
FD_SET (sock, &outfdset);
FD_CLR (0, &infdset);
}
}
if (FD_ISSET (sock, &outfd))
{
#ifdef SHISHI
if (encryption)
{
rc =
writeenc (h, sock, bufp[0], len[0], &wlen, iv3, &ivlen3,
enckey);
if (rc != SHISHI_OK)
break;
}
else
#endif
wlen = write (sock, bufp[0], len[0]);
if (wlen <= 0)
{
if (errno != EINTR)
break;
}
else
{
len[0] -= wlen;
bufp[0] += wlen;
if (!len[0])
{
FD_CLR (sock, &outfdset);
FD_SET (0, &infdset);
bufp[0] = buf[0];
}
}
}
}
if (errno)
{
fprintf (stderr, "%s: %s\n", argv0, strerror (errno));
return 1;
}
close (sock);
close (esock);
#ifdef SHISHI
if (shishi)
{
shishi_done (h);
if (encryption)
{
free (iv);
free (iv2);
free (iv3);
}
}
#endif
return 0;
}
/* authentication, server side */
int
get_auth (int infd, krb5_context *ctx, krb5_auth_context *actx,
krb5_keyblock **key, const char **err_msg,
int *protoversion, int *cksumtype,
char **cksum, size_t *cksumlen, char *srvname)
{
char *out;
size_t outlen;
char *buf;
int buflen;
int len;
int rc;
int error;
/* KERBEROS 5 SENDAUTH MESSAGE */
char krb5sendauth[] = "KRB5_SENDAUTH_V1.0";
/* PROTOCOL VERSION */
char krb5kcmd1[] = "KCMDV0.1";
char krb5kcmd2[] = "KCMDV0.2";
char *servername, *server = NULL, *realm = NULL;
*err_msg = NULL;
/* Get key for the server. */
# if 0
/*
* XXX: Taken straight from the version for libshishi.
* XXX: No adaptions yet.
*/
rc = shishi_init_server (handle);
if (rc != SHISHI_OK)
return rc;
if (srvname && *srvname)
{
rc = shishi_parse_name (*handle, srvname, &server, &realm);
if (rc != SHISHI_OK)
{
*err_msg = shishi_strerror (rc);
return rc;
}
}
if (server && *server)
{
char *p;
servername = malloc (sizeof (SERVICE) + strlen (server) + 2);
if (!servername)
{
*err_msg = "Not enough memory";
return SHISHI_TOO_SMALL_BUFFER;
}
p = strchr (server, '/');
if (p && (p != server))
sprintf (servername, "%s", server); /* Non-empty prefix. */
else
sprintf (servername, "%s/%s", SERVICE,
server + (p ? 1 : 0)); /* Remove initial slash. */
}
else
servername = shishi_server_for_local_service (*handle, SERVICE);
if (realm && *realm)
shishi_realm_default_set (*handle, realm);
free (server);
free (realm);
/* Enable use of `~/.k5login'. */
if (shishi_check_version ("1.0.2")) /* Faulty in version 1.0.1. */
{
rc = shishi_cfg_authorizationtype_set (*handle, "k5login basic");
if (rc != SHISHI_OK)
{
*err_msg = shishi_error (*handle);
return rc;
}
}
key = shishi_hostkeys_for_serverrealm (*handle, servername,
shishi_realm_default (*handle));
free (servername);
if (!key)
{
*err_msg = shishi_error (*handle);
return SHISHI_INVALID_KEY;
}
/* Read Kerberos 5 sendauth message */
rc = read (infd, &len, sizeof (int));
if (rc != sizeof (int))
{
*err_msg = "Error reading message size";
return SHISHI_IO_ERROR;
}
buflen = ntohl (len);
buf = malloc (buflen);
if (!buf)
{
*err_msg = "Not enough memory";
return SHISHI_TOO_SMALL_BUFFER;
}
rc = read (infd, buf, buflen);
if (rc != buflen)
{
*err_msg = "Error reading authentication message";
return SHISHI_IO_ERROR;
}
len = strlen (krb5sendauth);
rc = strncmp (buf, krb5sendauth, buflen >= len ? len : buflen);
if (rc)
{
*err_msg = "Invalid authentication type";
/* Authentication type is wrong. */
write (infd, "\001", 1);
return SHISHI_VERIFY_FAILED;
}
free (buf);
/* Read protocol version */
rc = read (infd, &len, sizeof (int));
if (rc != sizeof (int))
{
*err_msg = "Error reading protocol message size";
return SHISHI_IO_ERROR;
}
buflen = ntohl (len);
buf = malloc (buflen);
if (!buf)
{
*err_msg = "Not enough memory";
return SHISHI_TOO_SMALL_BUFFER;
}
rc = read (infd, buf, buflen);
if (rc != buflen)
{
*err_msg = "Error reading protocol message";
return SHISHI_IO_ERROR;
}
len = strlen (krb5kcmd1);
rc = strncmp (buf, krb5kcmd1, buflen >= len ? len : buflen);
if (rc)
{
len = strlen (krb5kcmd2);
rc = strncmp (buf, krb5kcmd2, buflen >= len ? len : buflen);
if (rc)
{
*err_msg = "Protocol version not supported";
/* Protocol version is wrong. */
write (infd, "\002", 1);
return SHISHI_VERIFY_FAILED;
}
*protoversion = 2;
}
else
*protoversion = 1;
free (buf);
/* Authentication type is ok */
write (infd, "\0", 1);
/* Read Authentication request from client */
rc = read (infd, &len, sizeof (int));
if (rc != sizeof (int))
{
*err_msg = "Error reading authentication request size";
return SHISHI_IO_ERROR;
}
buflen = ntohl (len);
buf = malloc (buflen);
if (!buf)
{
*err_msg = "Not enough memory";
return SHISHI_TOO_SMALL_BUFFER;
}
rc = read (infd, buf, buflen);
if (rc != buflen)
{
*err_msg = "Error reading authentication request";
return SHISHI_IO_ERROR;
}
/* Create Authentication context */
rc = shishi_ap_nosubkey (*handle, ap);
if (rc != SHISHI_OK)
return rc;
/* Store request in context */
rc = shishi_ap_req_der_set (*ap, buf, buflen);
if (rc != SHISHI_OK)
return rc;
free (buf);
/* Process authentication request */
rc = shishi_ap_req_process (*ap, key);
if (rc != SHISHI_OK)
return rc;
# ifdef ENCRYPTION
/* extract subkey if present from ap exchange for secure connection */
if (*protoversion == 2)
{
*enckey = NULL;
shishi_authenticator_get_subkey (*handle,
shishi_ap_authenticator (*ap), enckey);
}
# endif
/* Get authenticator checksum */
rc = shishi_authenticator_cksum (*handle,
shishi_ap_authenticator (*ap),
cksumtype, cksum, cksumlen);
if (rc != SHISHI_OK)
return rc;
/* User is authenticated. */
error = 0;
write (infd, &error, sizeof (int));
/* Authenticate ourself to client, if requested. */
if (shishi_apreq_mutual_required_p (*handle, shishi_ap_req (*ap)))
{
int len;
rc = shishi_ap_rep_der (*ap, &out, &outlen);
if (rc != SHISHI_OK)
return rc;
len = outlen;
len = htonl (len);
rc = write (infd, &len, sizeof (len));
if (rc != sizeof (int))
{
*err_msg = "Error sending AP-REP";
free (out);
return SHISHI_IO_ERROR;
}
rc = write (infd, out, ntohl (len));
if (rc != (int) ntohl (len))
{
*err_msg = "Error sending AP-REP";
free (out);
return SHISHI_IO_ERROR;
}
free (out);
/* We are authenticated to client */
}
# ifdef ENCRYPTION
if (*protoversion == 1)
{
Shishi_tkt *tkt;
tkt = shishi_ap_tkt (*ap);
if (tkt == NULL)
{
*err_msg = "Could not get tkt from AP-REQ";
return SHISHI_INVALID_TICKET;
}
rc = shishi_encticketpart_get_key (*handle,
shishi_tkt_encticketpart (tkt),
enckey);
if (rc != SHISHI_OK)
return rc;
}
# endif /* ENCRYPTION */
return 0;
# else
return -1;
# endif
}
static Shishi *
init_handle (int outputtype)
{
Shishi *handle;
int rc;
handle = xcalloc (1, sizeof (*handle));
shishi_error_set_outputtype (handle, outputtype);
if (!shishi_check_version (SHISHI_VERSION))
{
shishi_warn (handle, "Library and header version missmatch (%s vs %s).",
shishi_check_version (NULL), SHISHI_VERSION);
free (handle);
return NULL;
}
rc = gl_sockets_startup (SOCKETS_2_1);
if (rc)
{
shishi_warn (handle, "Failed to initialized Windows sockets (%d)", rc);
free (handle);
return NULL;
}
rc = _shishi_crypto_init (handle);
if (rc != SHISHI_OK)
{
shishi_warn (handle, "Cannot initialize crypto library");
free (handle);
return NULL;
}
#ifdef USE_STARTTLS
rc = _shishi_tls_init (handle);
if (rc != SHISHI_OK)
{
shishi_warn (handle, "Cannot initialize TLS library");
free (handle);
return NULL;
}
#endif
rc = _shishi_asn1_init (handle);
if (rc != SHISHI_OK)
{
shishi_warn (handle, "%s", shishi_strerror (SHISHI_ASN1_ERROR));
free (handle);
return NULL;
}
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
handle->kdctimeout = 5;
handle->kdcretries = 3;
handle->ticketlife = TICKETLIFE;
handle->renewlife = RENEWLIFE;
handle->nclientkdcetypes = 1;
handle->clientkdcetypes = xmalloc (sizeof (*handle->clientkdcetypes) *
handle->nclientkdcetypes);
handle->clientkdcetypes[0] = SHISHI_AES256_CTS_HMAC_SHA1_96;
handle->nauthorizationtypes = 1;
handle->authorizationtypes = xmalloc (sizeof (*handle->authorizationtypes) *
handle->nauthorizationtypes);
handle->authorizationtypes[0] = SHISHI_AUTHORIZATION_BASIC;
return handle;
}
/* shishi authentication */
int
shishi_auth (Shishi ** handle, int verbose, char **cname,
const char *sname, int sock,
char *cmd, int port, Shishi_key ** enckey, char *realm)
{
Shishi_ap *ap;
Shishi_tkt *tkt;
Shishi_tkts_hint hint;
Shishi *h;
int rc;
char *out;
int outlen;
int krb5len, msglen;
char *tmpserver;
char auth;
/* KERBEROS 5 SENDAUTH MESSAGE */
char krb5sendauth[] = "KRB5_SENDAUTH_V1.0";
/* PROTOCOL VERSION */
char krb5sendclient[] = "KCMDV0.2";
/* to store error msg sent by server */
char errormsg[101];
char cksumdata[101];
if (!shishi_check_version (SHISHI_VERSION))
{
fprintf (stderr, "shishi_check_version() failed:\n"
"Header file incompatible with shared library.\n");
return 1;
}
if (realm)
shishi_realm_default_set (*handle, realm);
rc = shishi_init (handle);
if (rc != SHISHI_OK)
{
fprintf (stderr,
"error initializing shishi: %s\n", shishi_strerror (rc));
return 1;
}
h = *handle;
if (!*cname)
*cname = (char *) shishi_principal_default (h);
/* size of KRB5 auth message */
krb5len = strlen (krb5sendauth) + 1;
msglen = htonl (krb5len);
write (sock, &msglen, sizeof (int));
/* KRB5 authentication message */
write (sock, krb5sendauth, krb5len);
/* size of client message */
krb5len = strlen (krb5sendclient) + 1;
msglen = htonl (krb5len);
write (sock, &msglen, sizeof (int));
/* KRB5 client message */
write (sock, krb5sendclient, krb5len);
/* get answer from server 0 = ok, 1 = error with message */
read (sock, &auth, 1);
if (auth)
{
read (sock, errormsg, 100);
errormsg[100] = '\0';
fprintf (stderr, "Error during server authentication : %s\n", errormsg);
return 1;
}
if (verbose)
{
printf ("Client: %s\n", *cname);
printf ("Server: %s\n", sname);
}
/* Get a ticket for the server. */
memset (&hint, 0, sizeof (hint));
tmpserver = malloc (strlen (SERVICE) + strlen (sname) + 2);
if (!tmpserver)
{
perror ("shishi_auth()");
return 1;
}
strcpy (tmpserver, SERVICE);
strcat (tmpserver, "/");
strcat (tmpserver, sname);
hint.client = (char *) *cname;
hint.server = (char *) tmpserver;
tkt = shishi_tkts_get (shishi_tkts_default (h), &hint);
if (!tkt)
{
free (tmpserver);
fprintf (stderr, "cannot find ticket for \"%s\"\n", sname);
return 1;
}
free (tmpserver);
if (verbose)
shishi_tkt_pretty_print (tkt, stderr);
/* Create Authentication context */
rc = shishi_ap_tktoptions (h, &ap, tkt, SHISHI_APOPTIONS_MUTUAL_REQUIRED);
if (rc != SHISHI_OK)
{
fprintf (stderr, "cannot create authentication context\n");
return 1;
}
/* checksum = port: terminal name */
snprintf (cksumdata, 100, "%u:%s%s", ntohs (port), cmd, *cname);
/* add checksum to authenticator */
shishi_ap_authenticator_cksumdata_set (ap, cksumdata, strlen (cksumdata));
/* To be compatible with MIT rlogind */
shishi_ap_authenticator_cksumtype_set (ap, SHISHI_RSA_MD5);
/* create der encoded AP-REQ */
rc = shishi_ap_req_der (ap, &out, &outlen);
if (rc != SHISHI_OK)
{
fprintf (stderr, "cannot build authentication request: %s\n",
shishi_strerror (rc));
return 1;
}
if (verbose)
shishi_authenticator_print (h, stderr, shishi_ap_authenticator (ap));
/* extract subkey if present from ap exchange for secure connection */
if (enckey)
shishi_authenticator_get_subkey (h, shishi_ap_authenticator (ap), enckey);
/* send size of AP-REQ to the server */
msglen = htonl (outlen);
write (sock, (char *) &msglen, sizeof (int));
/* send AP-REQ to the server */
write (sock, out, outlen);
/* read a respond from server - what ? */
read (sock, &auth, sizeof (int));
/* For mutual authentication, wait for server reply. */
if (shishi_apreq_mutual_required_p (h, shishi_ap_req (ap)))
{
if (verbose)
printf ("Waiting for server to authenticate itself...\n");
/* read size of the AP-REP */
read (sock, (char *) &outlen, sizeof (int));
/* read AP-REP */
outlen = ntohl (outlen);
outlen = read (sock, out, outlen);
rc = shishi_ap_rep_verify_der (ap, out, outlen);
if (rc == SHISHI_OK)
{
if (verbose)
printf ("AP-REP verification OK...\n");
}
else
{
if (rc == SHISHI_APREP_VERIFY_FAILED)
fprintf (stderr, "AP-REP verification failed...\n");
else
fprintf (stderr, "AP-REP verification error: %s\n",
shishi_strerror (rc));
return 1;
}
/* The server is authenticated. */
if (verbose)
printf ("Server authenticated.\n");
}
/* We are now authenticated. */
if (verbose)
printf ("User authenticated.\n");
return 0;
}
int
get_auth (int infd, Shishi ** handle, Shishi_ap ** ap,
Shishi_key ** enckey, const char **err_msg, int *protoversion,
int *cksumtype, char **cksum, int *cksumlen)
{
Shishi_key *key;
char *out;
int outlen;
char *buf;
int buflen;
int len;
int rc;
int i;
int error;
/* KERBEROS 5 SENDAUTH MESSAGE */
char krb5sendauth[] = "KRB5_SENDAUTH_V1.0";
/* PROTOCOL VERSION */
char krb5kcmd1[] = "KCMDV0.1";
char krb5kcmd2[] = "KCMDV0.2";
int auth_correct = 0;
char *servername;
*err_msg = NULL;
/* Get key for the server. */
if (!shishi_check_version (SHISHI_VERSION))
{
*err_msg =
"shishi_check_version() failed: header file incompatible with shared library.";
return 1;
}
rc = shishi_init_server (handle);
if (rc != SHISHI_OK)
return rc;
servername = shishi_server_for_local_service (*handle, SERVICE);
key = shishi_hostkeys_for_server (*handle, servername);
if (!key)
{
*err_msg = shishi_error (*handle);
return 1;
}
/* Read Kerberos 5 sendauth message */
rc = read (infd, &len, sizeof (int));
if (rc != sizeof (int))
{
*err_msg = "Error reading message size";
return 1;
}
buflen = ntohl (len);
buf = malloc (buflen);
if (!buf)
{
*err_msg = "Not enough memory";
return 1;
}
rc = read (infd, buf, buflen);
if (rc != buflen)
{
*err_msg = "Error reading authentication message";
return 1;
}
len = strlen (krb5sendauth);
rc = strncmp (buf, krb5sendauth, buflen >= len ? len : buflen);
if (rc)
{
*err_msg = "Invalid authentication type";
return 1;
}
free (buf);
/* Read protocol version */
rc = read (infd, &len, sizeof (int));
if (rc != sizeof (int))
{
*err_msg = "Error reading protocol message size";
return 1;
}
buflen = ntohl (len);
buf = malloc (buflen);
if (!buf)
{
*err_msg = "Not enough memory";
return 1;
}
rc = read (infd, buf, buflen);
if (rc != buflen)
{
*err_msg = "Error reading protocol message";
return 1;
}
len = strlen (krb5kcmd1);
rc = strncmp (buf, krb5kcmd1, buflen >= len ? len : buflen);
if (rc)
{
len = strlen (krb5kcmd2);
rc = strncmp (buf, krb5kcmd2, buflen >= len ? len : buflen);
if (rc)
{
*err_msg = "Protocol version not supported";
return 1;
}
*protoversion = 2;
}
else
*protoversion = 1;
free (buf);
/* Authentication type is ok */
write (infd, "\0", 1);
/* Read Authentication request from client */
rc = read (infd, &len, sizeof (int));
if (rc != sizeof (int))
{
*err_msg = "Error reading authentication request size";
return 1;
}
buflen = ntohl (len);
buf = malloc (buflen);
if (!buf)
{
*err_msg = "Not enough memory";
return 1;
}
rc = read (infd, buf, buflen);
if (rc != buflen)
{
*err_msg = "Error reading authentication request";
return 1;
}
/* Create Authentication context */
rc = shishi_ap_nosubkey (*handle, ap);
if (rc != SHISHI_OK)
return rc;
/* Store request in context */
shishi_ap_req_der_set (*ap, buf, buflen);
if (rc != SHISHI_OK)
return rc;
free (buf);
/* Process authentication request */
rc = shishi_ap_req_process (*ap, key);
if (rc != SHISHI_OK)
return rc;
# ifdef ENCRYPTION
/* extract subkey if present from ap exchange for secure connection */
if (*protoversion == 2)
{
*enckey = NULL;
shishi_authenticator_get_subkey (*handle,
shishi_ap_authenticator (*ap), enckey);
}
# endif
/* Get authenticator checksum */
rc = shishi_authenticator_cksum (*handle,
shishi_ap_authenticator (*ap),
cksumtype, cksum, cksumlen);
if (rc != SHISHI_OK)
return rc;
/* User is authenticated. */
error = 0;
write (infd, &error, sizeof (int));
/* Authenticate ourself to client, if request */
if (shishi_apreq_mutual_required_p (*handle, shishi_ap_req (*ap)))
{
rc = shishi_ap_rep_der (*ap, &out, &outlen);
if (rc != SHISHI_OK)
return rc;
outlen = htonl (outlen);
rc = write (infd, &outlen, sizeof (int));
if (rc != sizeof (int))
{
*err_msg = "Error sending AP-REP";
free (out);
return 1;
}
rc = write (infd, out, ntohl (outlen));
if (rc != ntohl (outlen))
{
*err_msg = "Error sending AP-REP";
free (out);
return 1;
}
free (out);
/* We are authenticated to client */
}
# ifdef ENCRYPTION
if (*protoversion == 1)
{
Shishi_tkt *tkt;
tkt = shishi_ap_tkt (*ap);
if (tkt == NULL)
{
*err_msg = "Could not get tkt from AP-REQ";
return 1;
}
rc = shishi_encticketpart_get_key (*handle,
shishi_tkt_encticketpart (tkt),
enckey);
if (rc != SHISHI_OK)
return rc;
}
# endif
return SHISHI_OK;
}
