/* 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
}
/* shishi authentication */
int
auth (Shishi * h, int verbose, const char *cname, const char *sname, int sock,
char *cmd, char *port, Shishi_key ** enckey, Shishi_key * deckey)
{
Shishi_ap *ap;
Shishi_tkt *tkt;
Shishi_tkts_hint hint;
int rc;
char *out;
int outlen;
int krb5len, msglen;
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];
/* size of KRB5 auth message */
krb5len = strlen (krb5sendauth) + 1;
msglen = htonl (krb5len);
safewrite (sock, &msglen, sizeof (int));
/* KRB5 authentication message */
safewrite (sock, krb5sendauth, krb5len);
/* size of client message */
krb5len = strlen (krb5sendclient) + 1;
msglen = htonl (krb5len);
safewrite (sock, &msglen, sizeof (int));
/* KRB5 client message */
safewrite (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';
printf ("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));
hint.client = (char *) cname;
hint.server = (char *) sname;
tkt = shishi_tkts_get (shishi_tkts_default (h), &hint);
if (!tkt)
{
printf ("cannot find ticket for \"%s\"\n", sname);
return 1;
}
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)
{
printf ("cannot create authentication context\n");
return 1;
}
/* checksum = port: terminal name */
snprintf (cksumdata, 100, "%s:%s%s", 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)
{
printf ("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 */
shishi_authenticator_get_subkey (h, shishi_ap_authenticator (ap), enckey);
/* send size of AP-REQ to the server */
msglen = htonl (outlen);
safewrite (sock, (char *) &msglen, sizeof (int));
/* send AP-REQ to the server */
safewrite (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)
printf ("AP-REP verification failed...\n");
else
printf ("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 AUTH_OK;
}
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;
}
