int
do_krb5_login (int infd, struct auth_data *ap, const char **err_msg)
{
krb5_auth_context auth_ctx = NULL;
krb5_error_code status;
krb5_data inbuf;
krb5_data version;
krb5_authenticator *authenticator;
krb5_rcache rcache;
krb5_keyblock *key;
krb5_ticket *ticket;
struct sockaddr_in laddr;
int len;
struct passwd *pwd;
char *name;
if (status = krb5_init_context (&ap->context))
{
syslog (LOG_ERR, "Error initializing krb5: %s", error_message (status));
return status;
}
if ((status = krb5_auth_con_init (ap->context, &auth_ctx))
|| (status = krb5_auth_con_genaddrs (ap->context, auth_ctx, infd,
KRB5_AUTH_CONTEXT_GENERATE_REMOTE_FULL_ADDR))
|| (status = krb5_auth_con_getrcache (ap->context, auth_ctx, &rcache)))
return status;
if (!rcache)
{
krb5_principal server;
status = krb5_sname_to_principal (ap->context, 0, 0, KRB5_NT_SRV_HST,
&server);
if (status)
return status;
status = krb5_get_server_rcache (ap->context,
krb5_princ_component (ap->context,
server, 0),
&rcache);
krb5_free_principal (ap->context, server);
if (status)
return status;
status = krb5_auth_con_setrcache (ap->context, auth_ctx, rcache);
if (status)
return status;
}
len = sizeof (laddr);
if (getsockname (infd, (struct sockaddr *) &laddr, &len))
return errno;
status = krb5_recvauth (ap->context, &auth_ctx, &infd, NULL, 0,
0, ap->keytab, &ticket);
if (status)
return status;
if ((status = krb5_auth_con_getauthenticator (ap->context, auth_ctx,
&authenticator)))
return status;
getstr (infd, &ap->lusername, NULL);
getstr (infd, &ap->term, "TERM=");
pwd = getpwnam (ap->lusername);
if (pwd == NULL)
{
*err_msg = "getpwnam failed";
syslog (LOG_ERR, "getpwnam failed: %m");
return 1;
}
getstr (infd, &ap->rusername, NULL);
if ((status = krb5_copy_principal (ap->context,
ticket->enc_part2->client, &ap->client)))
return status;
/*OK:: */
if (ap->client && !krb5_kuserok (ap->context, ap->client, ap->lusername))
return 1;
krb5_unparse_name (ap->context, ap->client, &name);
syslog (LOG_INFO | LOG_AUTH,
"%sKerberos V login from %s on %s\n",
(pwd->pw_uid == 0) ? "ROOT " : "", name, ap->hostname);
free (name);
return 0;
}
/* XXX - check for cleanup */
krb5_error_code
setup_auth_context(krb5_context context,
krb5_auth_context auth_context,
struct sockaddr_in *localaddr,
struct sockaddr_in *remoteaddr,
char *uniq)
{
krb5_address laddr, raddr, *portlocal_addr;
krb5_rcache rcache;
krb5_data rcache_name;
char *outaddr;
krb5_error_code retval;
#ifndef HEIMDAL
/* Setting ports isn't compatible with Heimdal, if this code
is enabled, it's not possible to have an interoperable setup */
#if 0
laddr.addrtype = ADDRTYPE_IPPORT;
laddr.length = sizeof(localaddr->sin_port);
laddr.contents = (krb5_octet *)&(localaddr->sin_port);
raddr.addrtype = ADDRTYPE_IPPORT;
raddr.length = sizeof(remoteaddr->sin_port);
raddr.contents = (krb5_octet *)&(remoteaddr->sin_port);
if (retval = krb5_auth_con_setports(context, auth_context,
&laddr, &raddr)) {
sprintf(auth_con_error, "%s while setting auth_con ports\n",
error_message(retval));
return retval;
}
#endif
#endif
#ifdef HEIMDAL
laddr.addr_type = KRB5_ADDRESS_INET;
laddr.address.length = sizeof(localaddr->sin_addr);
laddr.address.data = (void *)&(localaddr->sin_addr);
raddr.addr_type = KRB5_ADDRESS_INET;
raddr.address.length = sizeof(remoteaddr->sin_addr);
raddr.address.data = (void *)&(remoteaddr->sin_addr);
#else
laddr.addrtype = ADDRTYPE_INET;
laddr.length = sizeof(localaddr->sin_addr);
laddr.contents = (krb5_octet *)&(localaddr->sin_addr);
raddr.addrtype = ADDRTYPE_INET;
raddr.length = sizeof(remoteaddr->sin_addr);
raddr.contents = (krb5_octet *)&(remoteaddr->sin_addr);
#endif
if (retval = krb5_auth_con_setaddrs(context, auth_context,
&laddr, &raddr)) {
sprintf(auth_con_error, "%s while setting auth_con addresses\n",
error_message(retval));
return retval;
}
#ifdef HEIMDAL
#else
/* Set up replay cache */
if ((retval = krb5_gen_portaddr(context,
&laddr,
(krb5_pointer) &(localaddr->sin_port),
&portlocal_addr))) {
sprintf(auth_con_error, "%s while generating port address",
error_message(retval));
return retval;
}
if ((retval = krb5_gen_replay_name(context, portlocal_addr,
uniq, &outaddr))) {
sprintf(auth_con_error, "%s while generating replay cache name",
error_message(retval));
return retval;
}
rcache_name.length = strlen(outaddr);
rcache_name.data = outaddr;
if ((retval = krb5_get_server_rcache(context, &rcache_name, &rcache))) {
sprintf(auth_con_error, "%s while getting server rcache",
error_message(retval));
return retval;
}
if (retval = krb5_auth_con_setrcache(context, auth_context, rcache)) {
sprintf(auth_con_error, "%s setting rcache",
error_message(retval));
return retval;
}
#endif
return retval;
}
int do_krb5_comm(krb5_context context, krb5_keytab keytab, krb5_principal server, char *cmddir) {
struct sockaddr_in c_saddr, s_saddr;
socklen_t namelen;
int sock = 0;
int len;
char buff[BUFFSIZE];
char *cname = NULL;
krb5_error_code retval;
krb5_data kdata, message;
krb5_auth_context auth_context = NULL;
krb5_ticket *ticket;
krb5_address ckaddr, skaddr;
krb5_rcache rcache;
krb5_data rcache_name;
long srand, rrand;
int fd[2];
char rcname_piece[RC_PIECE_MAXLEN];
namelen = sizeof(c_saddr);
if (getpeername(sock, (struct sockaddr *)&c_saddr, &namelen) < 0) {
syslog(LOG_ERR, "getpeername: %m");
return 1;
}
namelen = sizeof(s_saddr);
if (getsockname(sock, (struct sockaddr *)&s_saddr, &namelen) < 0) {
syslog(LOG_ERR, "getsockname: %m");
return 1;
}
/* INIT MSG = random number */
srand = random();
/* Send it */
if (send(sock, &srand, sizeof(srand), 0) < 0) {
syslog(LOG_ERR, "%m while sending init message");
return 1;
}
if (recv(sock, &rrand, sizeof(rrand), 0) < 0) {
syslog(LOG_ERR, "%m while receiving init reply");
return 1;
}
/* Reply should contain the same message (number) */
if (srand != rrand) {
syslog(LOG_ERR, "Bad init reply");
return 1;
}
/* Do authentication */
if (retval = krb5_recvauth(context, &auth_context, (krb5_pointer)&sock, AFSADM_VERSION, server, 0, keytab, &ticket)) {
syslog(LOG_ERR, "recvauth failed: %s", error_message(retval));
exit(1);
}
/* Get client name */
if (retval = krb5_unparse_name(context, ticket->enc_part2->client, &cname)) {
syslog(LOG_ERR, "unparse failed: %s", error_message(retval));
return 1;
}
if (ticket)
krb5_free_ticket(context, ticket);
if (debug)
syslog(LOG_DEBUG, "Principal %s", cname);
/*******************************************************************/
ckaddr.addrtype = ADDRTYPE_IPPORT;
ckaddr.length = sizeof(c_saddr.sin_port);
ckaddr.contents = (krb5_octet *)&c_saddr.sin_port;
skaddr.addrtype = ADDRTYPE_IPPORT;
skaddr.length = sizeof(s_saddr.sin_port);
skaddr.contents = (krb5_octet *)&s_saddr.sin_port;
if ((retval = krb5_auth_con_setports(context, auth_context, &skaddr, &ckaddr))) {
syslog(LOG_ERR, "%s while setting ports", error_message(retval));
return 1;
}
/* Set foreign_addr for rd_priv() */
ckaddr.addrtype = ADDRTYPE_INET;
ckaddr.length = sizeof(c_saddr.sin_addr);
ckaddr.contents = (krb5_octet *)&c_saddr.sin_addr;
/* Set local_addr */
skaddr.addrtype = ADDRTYPE_INET;
skaddr.length = sizeof(s_saddr.sin_addr);
skaddr.contents = (krb5_octet *)&s_saddr.sin_addr;
if ((retval = krb5_auth_con_setaddrs(context, auth_context, &skaddr, &ckaddr))) {
syslog(LOG_ERR, "%s while setting addrs", error_message(retval));
return 1;
}
/* Receive a request */
if ((len = recv(sock, (char *)buff, sizeof(buff), 0)) < 0) {
syslog(LOG_ERR, "%m while receiving datagram");
return 1;
}
kdata.length = len;
kdata.data = buff;
if (debug)
syslog(LOG_DEBUG, "Received %d bytes", len);
/* Decrypt it */
if ((retval = krb5_rd_priv(context, auth_context, &kdata, &message, NULL))) {
syslog(LOG_ERR, "%s while verifying PRIV message", error_message(retval));
return 1;
}
if (message.length > 0) {
#ifdef __osf__
sprintf(rcname_piece, "afsadmd_%d", getpid());
#else
snprintf(rcname_piece, RC_PIECE_MAXLEN, "afsadmd_%d", getpid());
#endif
rcache_name.data = rcname_piece;
rcache_name.length = strlen(rcache_name.data);
if ((retval = krb5_get_server_rcache(context, &rcache_name, &rcache))) {
syslog(LOG_ERR, "%s while getting server rcache", error_message(retval));
return 1;
}
/* set auth_context rcache */
if (retval = krb5_auth_con_setrcache(context, auth_context, rcache)) {
syslog(LOG_ERR, "%s while setting rcache", error_message(retval));
return 1;
}
/*********************************************************************
* Call the desired command, read stdout/stderr, send it
*********************************************************************/
/* create fork */
if (pipe(fd) == -1)
printf("Failed create fork with pipe().\n");
if (fork() == 0) {
close(fd[0]);
close(1);
close(2);
dup2(fd[1], 1);
dup2(fd[1], 2);
/* Call required command */
do_command(context, keytab, server, cname, message.data, cmddir );
krb5_xfree(message.data);
exit(0);
} else {
/* Read stdout/stderr from pipe, store it to the buffer, encrypt it a send to the client */
krb5_data message, kdata;
char buff[PIPEBUFF];
int n = 0;
int len = 0;
int sent = 0;
int counter = 0;
int end = 0;
short netlen;
time_t starttime, oldtime, newtime;
FILE *pipedes;
close(fd[1]);
pipedes = fdopen(fd[0], "r");
starttime = oldtime = time(NULL);
for (n = 0; end == 0; ) {
/* Read line from pipe */
if (fgets(buff + n, PIPEBUFF - n, pipedes) == NULL)
end++;
else
n = strlen(buff);
/* Get time */
newtime = time(NULL);
/* Send buffer when
* a) buffer is full
* b) buffer contains data and
* 1) end-of-file encountered (end flag)
* 2) buffer sent before 1s
*/
if ((n == PIPEBUFF) || (((newtime > oldtime) || end ) && (n != 0))) {
/* Prepare data for sending */
message.data = buff;
message.length = n;
kdata.data = NULL;
/* Make the encrypted message */
if ((retval = krb5_mk_priv(context, auth_context, &message, &kdata, NULL))) {
syslog(LOG_ERR, "%s while making KRB_PRIV message", error_message(retval));
return 1;
}
/* Convert byte order */
netlen = htons((short)kdata.length);
/* Send len of encrypted data */
if ((len = send(sock, (char *)&netlen, sizeof(netlen), 0)) != sizeof(netlen)) {
krb5_xfree(kdata.data);
syslog(LOG_ERR, "%m while sending len of PRIV message");
return 1;
}
/* Send it */
if ((len = send(sock, (char *)kdata.data, kdata.length, 0)) != kdata.length) {
syslog(LOG_ERR, "%m while sending PRIV message");
krb5_xfree(kdata.data);
return 1;
}
/* Statistics */
sent += len;
counter++;
/* Timestanmp */
oldtime = newtime;
n = 0;
krb5_xfree(kdata.data);
}
}
newtime = time(NULL);
if (debug)
syslog(LOG_DEBUG, "Sent %d bytes in %ds [%d fragment(s)]", sent, (int)(newtime - starttime), counter);
}
}
//FIXME: There is no way to close or destroy rcache declared in krb5 headers
//krb5_rc_destroy(context, rcache);
/* set auth_context rcache */
if (retval = krb5_auth_con_setrcache(context, auth_context, rcache)) {
syslog(LOG_ERR, "%s while setting rcache to NULL", error_message(retval));
return 1;
}
free(cname);
krb5_auth_con_free(context, auth_context);
return 0;
}
NTSTATUS ads_verify_ticket(TALLOC_CTX *mem_ctx,
const char *realm,
time_t time_offset,
const DATA_BLOB *ticket,
char **principal,
struct PAC_DATA **pac_data,
DATA_BLOB *ap_rep,
DATA_BLOB *session_key,
bool use_replay_cache)
{
NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
NTSTATUS pac_ret;
DATA_BLOB auth_data;
krb5_context context = NULL;
krb5_auth_context auth_context = NULL;
krb5_data packet;
krb5_ticket *tkt = NULL;
krb5_rcache rcache = NULL;
krb5_keyblock *keyblock = NULL;
time_t authtime;
krb5_error_code ret = 0;
int flags = 0;
krb5_principal host_princ = NULL;
krb5_const_principal client_principal = NULL;
char *host_princ_s = NULL;
bool auth_ok = False;
bool got_auth_data = False;
struct named_mutex *mutex = NULL;
ZERO_STRUCT(packet);
ZERO_STRUCT(auth_data);
*principal = NULL;
*pac_data = NULL;
*ap_rep = data_blob_null;
*session_key = data_blob_null;
initialize_krb5_error_table();
ret = krb5_init_context(&context);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret)));
return NT_STATUS_LOGON_FAILURE;
}
if (time_offset != 0) {
krb5_set_real_time(context, time(NULL) + time_offset, 0);
}
ret = krb5_set_default_realm(context, realm);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret)));
goto out;
}
/* This whole process is far more complex than I would
like. We have to go through all this to allow us to store
the secret internally, instead of using /etc/krb5.keytab */
ret = krb5_auth_con_init(context, &auth_context);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret)));
goto out;
}
krb5_auth_con_getflags( context, auth_context, &flags );
if ( !use_replay_cache ) {
/* Disable default use of a replay cache */
flags &= ~KRB5_AUTH_CONTEXT_DO_TIME;
krb5_auth_con_setflags( context, auth_context, flags );
}
if (asprintf(&host_princ_s, "%s$", global_myname()) == -1) {
goto out;
}
strlower_m(host_princ_s);
ret = smb_krb5_parse_name(context, host_princ_s, &host_princ);
if (ret) {
DEBUG(1,("ads_verify_ticket: smb_krb5_parse_name(%s) failed (%s)\n",
host_princ_s, error_message(ret)));
goto out;
}
if ( use_replay_cache ) {
/* Lock a mutex surrounding the replay as there is no
locking in the MIT krb5 code surrounding the replay
cache... */
mutex = grab_named_mutex(talloc_tos(), "replay cache mutex",
10);
if (mutex == NULL) {
DEBUG(1,("ads_verify_ticket: unable to protect "
"replay cache with mutex.\n"));
ret = KRB5_CC_IO;
goto out;
}
/* JRA. We must set the rcache here. This will prevent
replay attacks. */
ret = krb5_get_server_rcache(context,
krb5_princ_component(context, host_princ, 0),
&rcache);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache "
"failed (%s)\n", error_message(ret)));
goto out;
}
ret = krb5_auth_con_setrcache(context, auth_context, rcache);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache "
"failed (%s)\n", error_message(ret)));
goto out;
}
}
/* Try secrets.tdb first and fallback to the krb5.keytab if
necessary */
auth_ok = ads_secrets_verify_ticket(context, auth_context, host_princ,
ticket, &tkt, &keyblock, &ret);
if (!auth_ok &&
(ret == KRB5KRB_AP_ERR_TKT_NYV ||
ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
ret == KRB5KRB_AP_ERR_SKEW)) {
goto auth_failed;
}
if (!auth_ok && lp_use_kerberos_keytab()) {
auth_ok = ads_keytab_verify_ticket(context, auth_context,
ticket, &tkt, &keyblock, &ret);
}
if ( use_replay_cache ) {
TALLOC_FREE(mutex);
#if 0
/* Heimdal leaks here, if we fix the leak, MIT crashes */
if (rcache) {
krb5_rc_close(context, rcache);
}
#endif
}
auth_failed:
if (!auth_ok) {
DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n",
error_message(ret)));
/* Try map the error return in case it's something like
* a clock skew error.
*/
sret = krb5_to_nt_status(ret);
if (NT_STATUS_IS_OK(sret) || NT_STATUS_EQUAL(sret,NT_STATUS_UNSUCCESSFUL)) {
sret = NT_STATUS_LOGON_FAILURE;
}
DEBUG(10,("ads_verify_ticket: returning error %s\n",
nt_errstr(sret) ));
goto out;
}
authtime = get_authtime_from_tkt(tkt);
client_principal = get_principal_from_tkt(tkt);
ret = krb5_mk_rep(context, auth_context, &packet);
if (ret) {
DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
error_message(ret)));
goto out;
}
*ap_rep = data_blob(packet.data, packet.length);
if (packet.data) {
kerberos_free_data_contents(context, &packet);
ZERO_STRUCT(packet);
}
get_krb5_smb_session_key(context, auth_context, session_key, True);
dump_data_pw("SMB session key (from ticket)\n", session_key->data, session_key->length);
#if 0
file_save("/tmp/ticket.dat", ticket->data, ticket->length);
#endif
/* continue when no PAC is retrieved or we couldn't decode the PAC
(like accounts that have the UF_NO_AUTH_DATA_REQUIRED flag set, or
Kerberos tickets encrypted using a DES key) - Guenther */
got_auth_data = get_auth_data_from_tkt(mem_ctx, &auth_data, tkt);
if (!got_auth_data) {
DEBUG(3,("ads_verify_ticket: did not retrieve auth data. continuing without PAC\n"));
}
if (got_auth_data) {
pac_ret = decode_pac_data(mem_ctx, &auth_data, context, keyblock, client_principal, authtime, pac_data);
if (!NT_STATUS_IS_OK(pac_ret)) {
DEBUG(3,("ads_verify_ticket: failed to decode PAC_DATA: %s\n", nt_errstr(pac_ret)));
*pac_data = NULL;
}
data_blob_free(&auth_data);
}
#if 0
#if defined(HAVE_KRB5_TKT_ENC_PART2)
/* MIT */
if (tkt->enc_part2) {
file_save("/tmp/authdata.dat",
tkt->enc_part2->authorization_data[0]->contents,
tkt->enc_part2->authorization_data[0]->length);
}
#else
/* Heimdal */
if (tkt->ticket.authorization_data) {
file_save("/tmp/authdata.dat",
tkt->ticket.authorization_data->val->ad_data.data,
tkt->ticket.authorization_data->val->ad_data.length);
}
#endif
#endif
if ((ret = smb_krb5_unparse_name(context, client_principal, principal))) {
DEBUG(3,("ads_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
error_message(ret)));
sret = NT_STATUS_LOGON_FAILURE;
goto out;
}
sret = NT_STATUS_OK;
out:
TALLOC_FREE(mutex);
if (!NT_STATUS_IS_OK(sret)) {
data_blob_free(&auth_data);
}
if (!NT_STATUS_IS_OK(sret)) {
data_blob_free(ap_rep);
}
if (host_princ) {
krb5_free_principal(context, host_princ);
}
if (keyblock) {
krb5_free_keyblock(context, keyblock);
}
if (tkt != NULL) {
krb5_free_ticket(context, tkt);
}
SAFE_FREE(host_princ_s);
if (auth_context) {
krb5_auth_con_free(context, auth_context);
}
if (context) {
krb5_free_context(context);
}
return sret;
}
static krb5_error_code
recvauth(int f,
krb5_context krb_context,
unsigned int *valid_checksum,
krb5_ticket **ticket,
int *auth_type,
krb5_principal *client,
int encr_flag,
krb5_keytab keytab)
{
krb5_error_code status = 0;
krb5_auth_context auth_context = NULL;
krb5_rcache rcache;
krb5_authenticator *authenticator;
krb5_data inbuf;
krb5_data auth_version;
*valid_checksum = 0;
if ((status = krb5_auth_con_init(krb_context, &auth_context)))
return (status);
/* Only need remote address for rd_cred() to verify client */
if ((status = krb5_auth_con_genaddrs(krb_context, auth_context, f,
KRB5_AUTH_CONTEXT_GENERATE_REMOTE_FULL_ADDR)))
return (status);
status = krb5_auth_con_getrcache(krb_context, auth_context, &rcache);
if (status)
return (status);
if (!rcache) {
krb5_principal server;
status = krb5_sname_to_principal(krb_context, 0, 0,
KRB5_NT_SRV_HST, &server);
if (status)
return (status);
status = krb5_get_server_rcache(krb_context,
krb5_princ_component(krb_context, server, 0),
&rcache);
krb5_free_principal(krb_context, server);
if (status)
return (status);
status = krb5_auth_con_setrcache(krb_context, auth_context,
rcache);
if (status)
return (status);
}
if ((status = krb5_compat_recvauth(krb_context,
&auth_context,
&f,
NULL, /* Specify daemon principal */
0, /* no flags */
keytab, /* NULL to use v5srvtab */
ticket, /* return ticket */
auth_type, /* authentication system */
&auth_version))) {
if (*auth_type == KRB5_RECVAUTH_V5) {
/*
* clean up before exiting
*/
getstr(f, rusername, sizeof (rusername), "remuser");
getstr(f, lusername, sizeof (lusername), "locuser");
getstr(f, term, sizeof (term), "Terminal type");
}
return (status);
}
getstr(f, lusername, sizeof (lusername), "locuser");
getstr(f, term, sizeof (term), "Terminal type");
kcmd_protocol = KCMD_UNKNOWN_PROTOCOL;
if (auth_version.length != 9 || auth_version.data == NULL) {
syslog(LOG_ERR, "Bad application protocol version length in "
"KRB5 exchange, exiting");
fatal(f, "Bad application version length, exiting.");
}
/*
* Determine which Kerberos CMD protocol was used.
*/
if (strncmp(auth_version.data, "KCMDV0.1", 9) == 0) {
kcmd_protocol = KCMD_OLD_PROTOCOL;
} else if (strncmp(auth_version.data, "KCMDV0.2", 9) == 0) {
kcmd_protocol = KCMD_NEW_PROTOCOL;
} else {
syslog(LOG_ERR, "Unrecognized KCMD protocol (%s), exiting",
(char *)auth_version.data);
fatal(f, "Unrecognized KCMD protocol, exiting");
}
if ((*auth_type == KRB5_RECVAUTH_V5) && chksum_flag &&
kcmd_protocol == KCMD_OLD_PROTOCOL) {
if ((status = krb5_auth_con_getauthenticator(krb_context,
auth_context,
&authenticator)))
return (status);
if (authenticator->checksum) {
struct sockaddr_storage adr;
int adr_length = sizeof (adr);
int buflen;
krb5_data input;
krb5_keyblock key;
char *chksumbuf;
/*
* Define the lenght of the chksum buffer.
* chksum string = "[portnum]:termstr:username"
* The extra 32 is to hold a integer string for
* the portnumber.
*/
buflen = strlen(term) + strlen(lusername) + 32;
chksumbuf = (char *)malloc(buflen);
if (chksumbuf == 0) {
krb5_free_authenticator(krb_context,
authenticator);
fatal(f, "Out of memory error");
}
if (getsockname(f, (struct sockaddr *)&adr,
&adr_length) != 0) {
krb5_free_authenticator(krb_context,
authenticator);
fatal(f, "getsockname error");
}
(void) snprintf(chksumbuf, buflen,
"%u:%s%s",
ntohs(SOCK_PORT(adr)),
term, lusername);
input.data = chksumbuf;
input.length = strlen(chksumbuf);
key.contents = (*ticket)->enc_part2->session->contents;
key.length = (*ticket)->enc_part2->session->length;
status = krb5_c_verify_checksum(krb_context,
&key, 0,
&input,
authenticator->checksum,
valid_checksum);
if (status == 0 && *valid_checksum == 0)
status = KRB5KRB_AP_ERR_BAD_INTEGRITY;
if (chksumbuf)
krb5_xfree(chksumbuf);
if (status) {
krb5_free_authenticator(krb_context,
authenticator);
return (status);
}
}
krb5_free_authenticator(krb_context, authenticator);
}
if ((status = krb5_copy_principal(krb_context,
(*ticket)->enc_part2->client,
client)))
return (status);
/* Get the Unix username of the remote user */
getstr(f, rusername, sizeof (rusername), "remuser");
/* Get the Kerberos principal name string of the remote user */
if ((status = krb5_unparse_name(krb_context, *client, &krusername)))
return (status);
#ifdef DEBUG
syslog(LOG_DEBUG | LOG_AUTH, "rlogind: got krb5 credentials for %s",
(krusername != NULL ? krusername : "******"));
#endif
if (encr_flag) {
status = krb5_auth_con_getremotesubkey(krb_context,
auth_context,
&session_key);
if (status) {
syslog(LOG_ERR, "Error getting KRB5 session "
"subkey, exiting");
fatal(f, "Error getting KRB5 session subkey, exiting");
}
/*
* The "new" protocol requires that a subkey be sent.
*/
if (session_key == NULL &&
kcmd_protocol == KCMD_NEW_PROTOCOL) {
syslog(LOG_ERR, "No KRB5 session subkey sent, exiting");
fatal(f, "No KRB5 session subkey sent, exiting");
}
/*
* The "old" protocol does not permit an authenticator subkey.
* The key is taken from the ticket instead (see below).
*/
if (session_key != NULL &&
kcmd_protocol == KCMD_OLD_PROTOCOL) {
syslog(LOG_ERR, "KRB5 session subkey not permitted "
"with old KCMD protocol, exiting");
fatal(f, "KRB5 session subkey not permitted "
"with old KCMD protocol, exiting");
}
/*
* If no key at this point, use the session key from
* the ticket.
*/
if (session_key == NULL) {
/*
* Save the session key so we can configure the crypto
* module later.
*/
status = krb5_copy_keyblock(krb_context,
(*ticket)->enc_part2->session,
&session_key);
if (status) {
syslog(LOG_ERR, "krb5_copy_keyblock failed");
fatal(f, "krb5_copy_keyblock failed");
}
}
/*
* If session key still cannot be found, we must
* exit because encryption is required here
* when encr_flag (-x) is set.
*/
if (session_key == NULL) {
syslog(LOG_ERR, "Could not find an encryption key,"
"exiting");
fatal(f, "Encryption required but key not found, "
"exiting");
}
}
/*
* Use krb5_read_message to read the principal stuff.
*/
if ((status = krb5_read_message(krb_context, (krb5_pointer)&f,
&inbuf)))
fatal(f, "Error reading krb5 message");
if (inbuf.length) { /* Forwarding being done, read creds */
krb5_creds **creds = NULL;
if (status = krb5_rd_cred(krb_context, auth_context, &inbuf,
&creds, NULL)) {
if (rcache)
(void) krb5_rc_close(krb_context, rcache);
krb5_free_creds(krb_context, *creds);
fatal(f, "Can't get forwarded credentials");
}
/* Store the forwarded creds in the ccache */
if (status = store_forw_creds(krb_context,
creds, *ticket, lusername,
&ccache)) {
if (rcache)
(void) krb5_rc_close(krb_context, rcache);
krb5_free_creds(krb_context, *creds);
fatal(f, "Can't store forwarded credentials");
}
krb5_free_creds(krb_context, *creds);
}
if (rcache)
(void) krb5_rc_close(krb_context, rcache);
return (status);
}
/* Given krb5 service name in KSSL_CTX *kssl_ctx (typically "kssl"),
** and krb5 AP_REQ message & message length,
** Return Kerberos session key and client principle
** to SSL Server in KSSL_CTX *kssl_ctx.
**
** 19990702 VRS Started.
*/
krb5_error_code
kssl_sget_tkt(
/* UPDATE */ KSSL_CTX *kssl_ctx,
/* IN */ krb5_data *indata,
/* OUT */ krb5_ticket_times *ttimes,
/* OUT */ KSSL_ERR *kssl_err )
{
krb5_error_code krb5rc = KRB5KRB_ERR_GENERIC;
static krb5_context krb5context = NULL;
static krb5_auth_context krb5auth_context = NULL;
krb5_ticket *krb5ticket = NULL;
KRB5_TKTBODY *asn1ticket = NULL;
const unsigned char *p;
krb5_keytab krb5keytab = NULL;
krb5_keytab_entry kt_entry;
krb5_principal krb5server;
krb5_rcache rcache = NULL;
kssl_err_set(kssl_err, 0, "");
if (!kssl_ctx) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
"No kssl_ctx defined.\n");
goto err;
}
#ifdef KSSL_DEBUG
printf("in kssl_sget_tkt(%s)\n", kstring(kssl_ctx->service_name));
#endif /* KSSL_DEBUG */
if (!krb5context && (krb5rc = krb5_init_context(&krb5context))) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
"krb5_init_context() fails.\n");
goto err;
}
if (krb5auth_context &&
(krb5rc = krb5_auth_con_free(krb5context, krb5auth_context))) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
"krb5_auth_con_free() fails.\n");
goto err;
} else
krb5auth_context = NULL;
if (!krb5auth_context &&
(krb5rc = krb5_auth_con_init(krb5context, &krb5auth_context))) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
"krb5_auth_con_init() fails.\n");
goto err;
}
if ((krb5rc = krb5_auth_con_getrcache(krb5context, krb5auth_context,
&rcache))) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
"krb5_auth_con_getrcache() fails.\n");
goto err;
}
if ((krb5rc = krb5_sname_to_principal(krb5context, NULL,
(kssl_ctx->service_name) ? kssl_ctx->service_name : KRB5SVC,
KRB5_NT_SRV_HST, &krb5server)) != 0) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
"krb5_sname_to_principal() fails.\n");
goto err;
}
if (rcache == NULL) {
if ((krb5rc = krb5_get_server_rcache(krb5context,
krb5_princ_component(krb5context, krb5server, 0),
&rcache))) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
"krb5_get_server_rcache() fails.\n");
goto err;
}
}
if ((krb5rc = krb5_auth_con_setrcache(krb5context, krb5auth_context,
rcache))) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
"krb5_auth_con_setrcache() fails.\n");
goto err;
}
/* kssl_ctx->keytab_file == NULL ==> use Kerberos default
*/
if (kssl_ctx->keytab_file) {
krb5rc = krb5_kt_resolve(krb5context, kssl_ctx->keytab_file,
&krb5keytab);
if (krb5rc) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
"krb5_kt_resolve() fails.\n");
goto err;
}
} else {
krb5rc = krb5_kt_default(krb5context, &krb5keytab);
if (krb5rc) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_INIT,
"krb5_kt_default() fails.\n");
goto err;
}
}
/* Actual Kerberos5 krb5_recvauth() has initial conversation here
** o check KRB5_SENDAUTH_BADAUTHVERS
** unless KRB5_RECVAUTH_SKIP_VERSION
** o check KRB5_SENDAUTH_BADAPPLVERS
** o send "0" msg if all OK
*/
/* 20010411 was using AP_REQ instead of true KerberosWrapper
**
** if ((krb5rc = krb5_rd_req(krb5context, &krb5auth_context,
** &krb5in_data, krb5server, krb5keytab,
** &ap_option, &krb5ticket)) != 0) { Error }
*/
p = (unsigned char *)indata->data;
if ((asn1ticket = (KRB5_TKTBODY *) d2i_KRB5_TICKET(NULL, &p,
(long)indata->length)) == NULL) {
(void) snprintf(kssl_err->text, KSSL_ERR_MAX,
"d2i_KRB5_TICKET() ASN.1 decode failure.\n");
kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
goto err;
}
/* Was: krb5rc = krb5_decode_ticket(krb5in_data,&krb5ticket)) != 0) */
if ((krb5rc = kssl_TKT2tkt(krb5context, asn1ticket, &krb5ticket,
kssl_err)) != 0) {
(void) snprintf(kssl_err->text, KSSL_ERR_MAX,
"Error converting ASN.1 ticket to krb5_ticket.\n");
kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
goto err;
}
if (!krb5_principal_compare(krb5context, krb5server,
krb5ticket->server)) {
krb5rc = KRB5_PRINC_NOMATCH;
(void) snprintf(kssl_err->text, KSSL_ERR_MAX,
"server principal != ticket principal\n");
kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
goto err;
}
if ((krb5rc = krb5_kt_get_entry(krb5context, krb5keytab,
krb5ticket->server, krb5ticket->enc_part.kvno,
krb5ticket->enc_part.enctype, &kt_entry)) != 0) {
(void) snprintf(kssl_err->text, KSSL_ERR_MAX,
"krb5_kt_get_entry() fails with %x.\n", krb5rc);
kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
goto err;
}
if ((krb5rc = krb5_decrypt_tkt_part(krb5context, &kt_entry.key,
krb5ticket)) != 0) {
(void) snprintf(kssl_err->text, KSSL_ERR_MAX,
"krb5_decrypt_tkt_part() failed.\n");
kssl_err->reason = SSL_R_KRB5_S_RD_REQ;
goto err;
} else {
krb5_kt_free_entry(krb5context, &kt_entry);
#ifdef KSSL_DEBUG
{
int i;
krb5_address **paddr = krb5ticket->enc_part2->caddrs;
printf("Decrypted ticket fields:\n");
printf("\tflags: %X, transit-type: %X",
krb5ticket->enc_part2->flags,
krb5ticket->enc_part2->transited.tr_type);
print_krb5_data("\ttransit-data: ",
&(krb5ticket->enc_part2->transited.tr_contents));
printf("\tcaddrs: %p, authdata: %p\n",
krb5ticket->enc_part2->caddrs,
krb5ticket->enc_part2->authorization_data);
if (paddr) {
printf("\tcaddrs:\n");
for (i = 0; paddr[i] != NULL; i++) {
krb5_data d;
d.length = paddr[i]->length;
d.data = paddr[i]->contents;
print_krb5_data("\t\tIP: ", &d);
}
}
printf("\tstart/auth/end times: %d / %d / %d\n",
krb5ticket->enc_part2->times.starttime,
krb5ticket->enc_part2->times.authtime,
krb5ticket->enc_part2->times.endtime);
}
#endif /* KSSL_DEBUG */
}
krb5rc = KRB5_NO_TKT_SUPPLIED;
if (!krb5ticket || !krb5ticket->enc_part2 ||
!krb5ticket->enc_part2->client ||
!krb5ticket->enc_part2->client->data ||
!krb5ticket->enc_part2->session) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_BAD_TICKET,
"bad ticket from krb5_rd_req.\n");
} else if (kssl_ctx_setprinc(kssl_ctx, KSSL_CLIENT,
&krb5ticket->enc_part2->client->realm,
krb5ticket->enc_part2->client->data,
krb5ticket->enc_part2->client->length)) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_BAD_TICKET,
"kssl_ctx_setprinc() fails.\n");
} else if (kssl_ctx_setkey(kssl_ctx, krb5ticket->enc_part2->session)) {
kssl_err_set(kssl_err, SSL_R_KRB5_S_BAD_TICKET,
"kssl_ctx_setkey() fails.\n");
} else if (krb5ticket->enc_part2->flags & TKT_FLG_INVALID) {
krb5rc = KRB5KRB_AP_ERR_TKT_INVALID;
kssl_err_set(kssl_err, SSL_R_KRB5_S_BAD_TICKET,
"invalid ticket from krb5_rd_req.\n");
} else
krb5rc = 0;
kssl_ctx->enctype = krb5ticket->enc_part.enctype;
ttimes->authtime = krb5ticket->enc_part2->times.authtime;
ttimes->starttime = krb5ticket->enc_part2->times.starttime;
ttimes->endtime = krb5ticket->enc_part2->times.endtime;
ttimes->renew_till = krb5ticket->enc_part2->times.renew_till;
err:
#ifdef KSSL_DEBUG
kssl_ctx_show(kssl_ctx);
#endif /* KSSL_DEBUG */
if (asn1ticket)
KRB5_TICKET_free((KRB5_TICKET *) asn1ticket);
if (krb5keytab)
krb5_kt_close(krb5context, krb5keytab);
if (krb5ticket)
krb5_free_ticket(krb5context, krb5ticket);
if (krb5server)
krb5_free_principal(krb5context, krb5server);
return (krb5rc);
}
int
kerberos5_is_auth (TN_Authenticator * ap, unsigned char *data, int cnt,
char *errbuf, int errbuflen)
{
int r = 0;
krb5_keytab keytabid = 0;
krb5_authenticator *authenticator;
char *name;
krb5_data outbuf;
krb5_keyblock *newkey = NULL;
krb5_principal server;
# ifdef ENCRYPTION
Session_Key skey;
# endif
auth.data = (char *) data;
auth.length = cnt;
if (!r && !auth_context)
r = krb5_auth_con_init (telnet_context, &auth_context);
if (!r)
{
krb5_rcache rcache;
r = krb5_auth_con_getrcache (telnet_context, auth_context, &rcache);
if (!r && !rcache)
{
r = krb5_sname_to_principal (telnet_context, 0, 0,
KRB5_NT_SRV_HST, &server);
if (!r)
{
r = krb5_get_server_rcache (telnet_context,
krb5_princ_component
(telnet_context, server, 0),
&rcache);
krb5_free_principal (telnet_context, server);
}
}
if (!r)
r = krb5_auth_con_setrcache (telnet_context, auth_context, rcache);
}
if (!r && telnet_srvtab)
r = krb5_kt_resolve (telnet_context, telnet_srvtab, &keytabid);
if (!r)
r = krb5_rd_req (telnet_context, &auth_context, &auth,
NULL, keytabid, NULL, &ticket);
if (r)
{
snprintf (errbuf, errbuflen, "krb5_rd_req failed: %s",
error_message (r));
return r;
}
/* 256 bytes should be much larger than any reasonable
first component of a service name especially since
the default is of length 4. */
if (krb5_princ_component (telnet_context, ticket->server, 0)->length < 256)
{
char princ[256];
strncpy (princ,
krb5_princ_component (telnet_context, ticket->server, 0)->data,
krb5_princ_component (telnet_context, ticket->server,
0)->length);
princ[krb5_princ_component (telnet_context, ticket->server, 0)->
length] = '\0';
if (strcmp ("host", princ))
{
snprintf (errbuf, errbuflen,
"incorrect service name: \"%s\" != \"host\"", princ);
return 1;
}
}
else
{
strncpy (errbuf, "service name too long", errbuflen);
return 1;
}
r = krb5_auth_con_getauthenticator (telnet_context,
auth_context, &authenticator);
if (r)
{
snprintf (errbuf, errbuflen,
"krb5_auth_con_getauthenticator failed: %s",
error_message (r));
return 1;
}
# ifdef AUTH_ENCRYPT_MASK
if ((ap->way & AUTH_ENCRYPT_MASK) == AUTH_ENCRYPT_ON
&& !authenticator->checksum)
{
snprintf (errbuf, errbuflen,
"authenticator is missing required checksum");
return 1;
}
# endif
if (authenticator->checksum)
{
char type_check[2];
krb5_checksum *cksum = authenticator->checksum;
krb5_keyblock *key;
type_check[0] = ap->type;
type_check[1] = ap->way;
r = krb5_auth_con_getkey (telnet_context, auth_context, &key);
if (r)
{
snprintf (errbuf, errbuflen,
"krb5_auth_con_getkey failed: %s", error_message (r));
return 1;
}
r = krb5_verify_checksum (telnet_context,
cksum->checksum_type, cksum,
&type_check, 2, key->contents, key->length);
if (r)
{
snprintf (errbuf, errbuflen,
"checksum verification failed: %s", error_message (r));
return 1;
}
krb5_free_keyblock (telnet_context, key);
}
krb5_free_authenticator (telnet_context, authenticator);
if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
{
if ((r = krb5_mk_rep (telnet_context, auth_context, &outbuf)))
{
snprintf (errbuf, errbuflen, "Make reply failed: %s",
error_message (r));
return 1;
}
Data (ap, KRB_RESPONSE, outbuf.data, outbuf.length);
}
if (krb5_unparse_name (telnet_context, ticket->enc_part2->client, &name))
name = 0;
Data (ap, KRB_ACCEPT, name, name ? -1 : 0);
DEBUG (("telnetd: Kerberos5 identifies him as ``%s''\r\n",
name ? name : ""));
auth_finished (ap, AUTH_USER);
free (name);
krb5_auth_con_getremotesubkey (telnet_context, auth_context, &newkey);
if (session_key)
{
krb5_free_keyblock (telnet_context, session_key);
session_key = 0;
}
if (newkey)
{
krb5_copy_keyblock (telnet_context, newkey, &session_key);
krb5_free_keyblock (telnet_context, newkey);
}
else
{
krb5_copy_keyblock (telnet_context, ticket->enc_part2->session,
&session_key);
}
telnet_encrypt_key (&skey);
return 0;
}
int
ksm_process_in_msg(struct snmp_secmod_incoming_params *parms)
{
long temp;
krb5_cksumtype cksumtype;
krb5_auth_context auth_context = NULL;
krb5_error_code retcode;
krb5_checksum checksum;
krb5_data ap_req, ivector;
krb5_flags flags;
krb5_keyblock *subkey = NULL;
#ifdef MIT_NEW_CRYPTO
krb5_data input, output;
krb5_boolean valid;
krb5_enc_data in_crypt;
#else /* MIT_NEW_CRYPTO */
krb5_encrypt_block eblock;
#endif /* MIT_NEW_CRYPTO */
krb5_ticket *ticket = NULL;
int retval = SNMPERR_SUCCESS, response = 0;
size_t length =
parms->wholeMsgLen - (u_int) (parms->secParams - parms->wholeMsg);
u_char *current = parms->secParams, type;
size_t cksumlength, blocksize;
long hint;
char *cname;
struct ksm_secStateRef *ksm_state;
struct ksm_cache_entry *entry;
DEBUGMSGTL(("ksm", "Processing has begun\n"));
checksum.contents = NULL;
ap_req.data = NULL;
ivector.length = 0;
ivector.data = NULL;
/*
* First, parse the security parameters (because we need the subkey inside
* of the ticket to do anything
*/
if ((current = asn_parse_sequence(current, &length, &type,
(ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR),
"ksm first octet")) == NULL) {
DEBUGMSGTL(("ksm", "Initial security paramter parsing failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
if ((current = asn_parse_sequence(current, &length, &type,
(ASN_SEQUENCE | ASN_CONSTRUCTOR),
"ksm sequence")) == NULL) {
DEBUGMSGTL(("ksm",
"Security parameter sequence parsing failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
if ((current = asn_parse_int(current, &length, &type, &temp,
sizeof(temp))) == NULL) {
DEBUGMSGTL(("ksm", "Security parameter checksum type parsing"
"failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
cksumtype = temp;
#ifdef MIT_NEW_CRYPTO
if (!krb5_c_valid_cksumtype(cksumtype)) {
DEBUGMSGTL(("ksm", "Invalid checksum type (%d)\n", cksumtype));
retval = SNMPERR_KRB5;
snmp_set_detail("Invalid checksum type");
goto error;
}
if (!krb5_c_is_keyed_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a keyed checksum\n",
cksumtype));
snmp_set_detail("Checksum is not a keyed checksum");
retval = SNMPERR_KRB5;
goto error;
}
if (!krb5_c_is_coll_proof_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a collision-proof "
"checksum\n", cksumtype));
snmp_set_detail("Checksum is not a collision-proof checksum");
retval = SNMPERR_KRB5;
goto error;
}
#else /* ! MIT_NEW_CRYPTO */
if (!valid_cksumtype(cksumtype)) {
DEBUGMSGTL(("ksm", "Invalid checksum type (%d)\n", cksumtype));
retval = SNMPERR_KRB5;
snmp_set_detail("Invalid checksum type");
goto error;
}
if (!is_keyed_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a keyed checksum\n",
cksumtype));
snmp_set_detail("Checksum is not a keyed checksum");
retval = SNMPERR_KRB5;
goto error;
}
if (!is_coll_proof_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a collision-proof "
"checksum\n", cksumtype));
snmp_set_detail("Checksum is not a collision-proof checksum");
retval = SNMPERR_KRB5;
goto error;
}
#endif /* MIT_NEW_CRYPTO */
checksum.checksum_type = cksumtype;
cksumlength = length;
if ((current = asn_parse_sequence(current, &cksumlength, &type,
(ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), "ksm checksum")) ==
NULL) {
DEBUGMSGTL(("ksm",
"Security parameter checksum parsing failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
checksum.contents = malloc(cksumlength);
if (!checksum.contents) {
DEBUGMSGTL(("ksm", "Unable to malloc %d bytes for checksum.\n",
cksumlength));
retval = SNMPERR_MALLOC;
goto error;
}
memcpy(checksum.contents, current, cksumlength);
checksum.length = cksumlength;
checksum.checksum_type = cksumtype;
/*
* Zero out the checksum so the validation works correctly
*/
memset(current, 0, cksumlength);
current += cksumlength;
length = parms->wholeMsgLen - (u_int) (current - parms->wholeMsg);
if ((current = asn_parse_sequence(current, &length, &type,
(ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), "ksm ap_req")) ==
NULL) {
DEBUGMSGTL(("ksm", "KSM security parameter AP_REQ/REP parsing "
"failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
ap_req.length = length;
ap_req.data = malloc(length);
if (!ap_req.data) {
DEBUGMSGTL(("ksm",
"KSM unable to malloc %d bytes for AP_REQ/REP.\n",
length));
retval = SNMPERR_MALLOC;
goto error;
}
memcpy(ap_req.data, current, length);
current += length;
length = parms->wholeMsgLen - (u_int) (current - parms->wholeMsg);
if ((current = asn_parse_int(current, &length, &type, &hint,
sizeof(hint))) == NULL) {
DEBUGMSGTL(("ksm",
"KSM security parameter hint parsing failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
/*
* Okay! We've got it all! Now try decoding the damn ticket.
*
* But of course there's a WRINKLE! We need to figure out if we're
* processing a AP_REQ or an AP_REP. How do we do that? We're going
* to cheat, and look at the first couple of bytes (which is what
* the Kerberos library routines do anyway).
*
* If there are ever new Kerberos message formats, we'll need to fix
* this here.
*
* If it's a _response_, then we need to get the auth_context
* from our cache.
*/
if (ap_req.length
&& (ap_req.data[0] == 0x6e || ap_req.data[0] == 0x4e)) {
/*
* We need to initalize the authorization context, and set the
* replay cache in it (and initialize the replay cache if we
* haven't already
*/
retcode = krb5_auth_con_init(kcontext, &auth_context);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_auth_con_init failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
if (!rcache) {
krb5_data server;
server.data = "host";
server.length = strlen(server.data);
retcode = krb5_get_server_rcache(kcontext, &server, &rcache);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_get_server_rcache failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
}
retcode = krb5_auth_con_setrcache(kcontext, auth_context, rcache);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_auth_con_setrcache failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
retcode = krb5_rd_req(kcontext, &auth_context, &ap_req, NULL,
keytab, &flags, &ticket);
krb5_auth_con_setrcache(kcontext, auth_context, NULL);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_rd_req() failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
retcode =
krb5_unparse_name(kcontext, ticket->enc_part2->client, &cname);
if (retcode == 0) {
DEBUGMSGTL(("ksm", "KSM authenticated principal name: %s\n",
cname));
free(cname);
}
/*
* Check to make sure AP_OPTS_MUTUAL_REQUIRED was set
*/
if (!(flags & AP_OPTS_MUTUAL_REQUIRED)) {
DEBUGMSGTL(("ksm",
"KSM MUTUAL_REQUIRED not set in request!\n"));
retval = SNMPERR_KRB5;
snmp_set_detail("MUTUAL_REQUIRED not set in message");
goto error;
}
retcode =
krb5_auth_con_getremotesubkey(kcontext, auth_context, &subkey);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM remote subkey retrieval failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
} else if (ap_req.length && (ap_req.data[0] == 0x6f ||
ap_req.data[0] == 0x4f)) {
/*
* Looks like a response; let's see if we've got that auth_context
* in our cache.
*/
krb5_ap_rep_enc_part *repl = NULL;
response = 1;
entry = ksm_get_cache(parms->pdu->msgid);
if (!entry) {
DEBUGMSGTL(("ksm",
"KSM: Unable to find auth_context for PDU with "
"message ID of %ld\n", parms->pdu->msgid));
retval = SNMPERR_KRB5;
goto error;
}
auth_context = entry->auth_context;
/*
* In that case, let's call the rd_rep function
*/
retcode = krb5_rd_rep(kcontext, auth_context, &ap_req, &repl);
if (repl)
krb5_free_ap_rep_enc_part(kcontext, repl);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM: krb5_rd_rep() failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: krb5_rd_rep() decoded successfully.\n"));
retcode =
krb5_auth_con_getlocalsubkey(kcontext, auth_context, &subkey);
if (retcode) {
DEBUGMSGTL(("ksm", "Unable to retrieve local subkey: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail("Unable to retrieve local subkey");
goto error;
}
} else {
DEBUGMSGTL(("ksm", "Unknown Kerberos message type (%02x)\n",
ap_req.data[0]));
retval = SNMPERR_KRB5;
snmp_set_detail("Unknown Kerberos message type");
goto error;
}
#ifdef MIT_NEW_CRYPTO
input.data = (char *) parms->wholeMsg;
input.length = parms->wholeMsgLen;
retcode =
krb5_c_verify_checksum(kcontext, subkey, KSM_KEY_USAGE_CHECKSUM,
&input, &checksum, &valid);
#else /* MIT_NEW_CRYPTO */
retcode = krb5_verify_checksum(kcontext, cksumtype, &checksum,
parms->wholeMsg, parms->wholeMsgLen,
(krb5_pointer) subkey->contents,
subkey->length);
#endif /* MIT_NEW_CRYPTO */
if (retcode) {
DEBUGMSGTL(("ksm", "KSM checksum verification failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
/*
* Don't ask me why they didn't simply return an error, but we have
* to check to see if "valid" is false.
*/
#ifdef MIT_NEW_CRYPTO
if (!valid) {
DEBUGMSGTL(("ksm", "Computed checksum did not match supplied "
"checksum!\n"));
retval = SNMPERR_KRB5;
snmp_set_detail
("Computed checksum did not match supplied checksum");
goto error;
}
#endif /* MIT_NEW_CRYPTO */
/*
* Handle an encrypted PDU. Note that it's an OCTET_STRING of the
* output of whatever Kerberos cryptosystem you're using (defined by
* the encryption type). Note that this is NOT the EncryptedData
* sequence - it's what goes in the "cipher" field of EncryptedData.
*/
if (parms->secLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
if ((current = asn_parse_sequence(current, &length, &type,
(ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), "ksm pdu")) ==
NULL) {
DEBUGMSGTL(("ksm", "KSM sPDU octet decoding failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
/*
* The PDU is now pointed at by "current", and the length is in
* "length".
*/
DEBUGMSGTL(("ksm", "KSM starting sPDU decode\n"));
/*
* We need to set up a blank initialization vector for the decryption.
* Use a block of all zero's (which is dependent on the block size
* of the encryption method).
*/
#ifdef MIT_NEW_CRYPTO
retcode = krb5_c_block_size(kcontext, subkey->enctype, &blocksize);
if (retcode) {
DEBUGMSGTL(("ksm",
"Unable to determine crypto block size: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
#else /* MIT_NEW_CRYPTO */
blocksize =
krb5_enctype_array[subkey->enctype]->system->block_length;
#endif /* MIT_NEW_CRYPTO */
ivector.data = malloc(blocksize);
if (!ivector.data) {
DEBUGMSGTL(("ksm", "Unable to allocate %d bytes for ivector\n",
blocksize));
retval = SNMPERR_MALLOC;
goto error;
}
ivector.length = blocksize;
memset(ivector.data, 0, blocksize);
#ifndef MIT_NEW_CRYPTO
krb5_use_enctype(kcontext, &eblock, subkey->enctype);
retcode = krb5_process_key(kcontext, &eblock, subkey);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM key post-processing failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
#endif /* !MIT_NEW_CRYPTO */
if (length > *parms->scopedPduLen) {
DEBUGMSGTL(("ksm", "KSM not enough room - have %d bytes to "
"decrypt but only %d bytes available\n", length,
*parms->scopedPduLen));
retval = SNMPERR_TOO_LONG;
#ifndef MIT_NEW_CRYPTO
krb5_finish_key(kcontext, &eblock);
#endif /* ! MIT_NEW_CRYPTO */
goto error;
}
#ifdef MIT_NEW_CRYPTO
in_crypt.ciphertext.data = (char *) current;
in_crypt.ciphertext.length = length;
in_crypt.enctype = subkey->enctype;
output.data = (char *) *parms->scopedPdu;
output.length = *parms->scopedPduLen;
retcode =
krb5_c_decrypt(kcontext, subkey, KSM_KEY_USAGE_ENCRYPTION,
&ivector, &in_crypt, &output);
#else /* MIT_NEW_CRYPTO */
retcode = krb5_decrypt(kcontext, (krb5_pointer) current,
*parms->scopedPdu, length, &eblock,
ivector.data);
krb5_finish_key(kcontext, &eblock);
#endif /* MIT_NEW_CRYPTO */
if (retcode) {
DEBUGMSGTL(("ksm", "Decryption failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
*parms->scopedPduLen = length;
} else {
/*
* Clear PDU
*/
*parms->scopedPdu = current;
*parms->scopedPduLen =
parms->wholeMsgLen - (current - parms->wholeMsg);
}
/*
* A HUGE GROSS HACK
*/
*parms->maxSizeResponse = parms->maxMsgSize - 200;
DEBUGMSGTL(("ksm", "KSM processing complete\n"));
/*
* Set the secName to the right value (a hack for now). But that's
* only used for when we're processing a request, not a response.
*/
if (!response) {
retcode = krb5_unparse_name(kcontext, ticket->enc_part2->client,
&cname);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM krb5_unparse_name failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
if (strlen(cname) > *parms->secNameLen + 1) {
DEBUGMSGTL(("ksm",
"KSM: Principal length (%d) is too long (%d)\n",
strlen(cname), parms->secNameLen));
retval = SNMPERR_TOO_LONG;
free(cname);
goto error;
}
strcpy(parms->secName, cname);
*parms->secNameLen = strlen(cname);
free(cname);
/*
* Also, if we're not a response, keep around our auth_context so we
* can encode the reply message correctly
*/
ksm_state = SNMP_MALLOC_STRUCT(ksm_secStateRef);
if (!ksm_state) {
DEBUGMSGTL(("ksm", "KSM unable to malloc memory for "
"ksm_secStateRef\n"));
retval = SNMPERR_MALLOC;
goto error;
}
ksm_state->auth_context = auth_context;
auth_context = NULL;
ksm_state->cksumtype = cksumtype;
*parms->secStateRef = ksm_state;
} else {
/*
* We _still_ have to set the secName in process_in_msg(). Do
* that now with what we were passed in before (we cached it,
* remember?)
*/
memcpy(parms->secName, entry->secName, entry->secNameLen);
*parms->secNameLen = entry->secNameLen;
}
/*
* Just in case
*/
parms->secEngineID = (u_char *) "";
*parms->secEngineIDLen = 0;
auth_context = NULL; /* So we don't try to free it on success */
error:
if (retval == SNMPERR_ASN_PARSE_ERR &&
snmp_increment_statistic(STAT_SNMPINASNPARSEERRS) == 0)
DEBUGMSGTL(("ksm", "Failed to increment statistics.\n"));
if (subkey)
krb5_free_keyblock(kcontext, subkey);
if (checksum.contents)
free(checksum.contents);
if (ivector.data)
free(ivector.data);
if (ticket)
krb5_free_ticket(kcontext, ticket);
if (!response && auth_context)
krb5_auth_con_free(kcontext, auth_context);
if (ap_req.data)
free(ap_req.data);
return retval;
}
