static krb5_error_code ads_secrets_verify_ticket(krb5_context context,
krb5_auth_context auth_context,
krb5_principal host_princ,
const DATA_BLOB *ticket,
krb5_ticket **pp_tkt,
krb5_keyblock **keyblock,
krb5_error_code *perr)
{
krb5_error_code ret = 0;
bool auth_ok = False;
char *password_s = NULL;
krb5_data password;
krb5_enctype enctypes[] = {
#if defined(ENCTYPE_ARCFOUR_HMAC)
ENCTYPE_ARCFOUR_HMAC,
#endif
ENCTYPE_DES_CBC_CRC,
ENCTYPE_DES_CBC_MD5,
ENCTYPE_NULL
};
krb5_data packet;
int i;
*pp_tkt = NULL;
*keyblock = NULL;
*perr = 0;
if (!secrets_init()) {
DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
*perr = KRB5_CONFIG_CANTOPEN;
return False;
}
password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
if (!password_s) {
DEBUG(1,("ads_secrets_verify_ticket: failed to fetch machine password\n"));
*perr = KRB5_LIBOS_CANTREADPWD;
return False;
}
password.data = password_s;
password.length = strlen(password_s);
/* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
packet.length = ticket->length;
packet.data = (char *)ticket->data;
/* We need to setup a auth context with each possible encoding type in turn. */
for (i=0;enctypes[i];i++) {
krb5_keyblock *key = NULL;
if (!(key = SMB_MALLOC_P(krb5_keyblock))) {
ret = ENOMEM;
goto out;
}
if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i], false)) {
SAFE_FREE(key);
continue;
}
krb5_auth_con_setuseruserkey(context, auth_context, key);
if (!(ret = krb5_rd_req(context, &auth_context, &packet,
NULL,
NULL, NULL, pp_tkt))) {
DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
(unsigned int)enctypes[i] ));
auth_ok = True;
krb5_copy_keyblock(context, key, keyblock);
krb5_free_keyblock(context, key);
break;
}
DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
(unsigned int)enctypes[i], error_message(ret)));
/* successfully decrypted but ticket is just not valid at the moment */
if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
ret == KRB5KRB_AP_ERR_SKEW) {
krb5_free_keyblock(context, key);
break;
}
krb5_free_keyblock(context, key);
}
out:
SAFE_FREE(password_s);
*perr = ret;
return auth_ok;
}
/*
* Serialize krb5_auth_context.
*/
static krb5_error_code
ser_acontext_test(krb5_context kcontext, int verbose)
{
krb5_error_code kret;
krb5_auth_context actx;
krb5_address local_address;
krb5_address remote_address;
krb5_octet laddr_bytes[16];
krb5_octet raddr_bytes[16];
krb5_keyblock ukeyblock;
krb5_octet keydata[8];
krb5_authenticator aent;
char clname[128];
krb5_authdata *adatalist[3];
krb5_authdata adataent;
actx = (krb5_auth_context) NULL;
if (!(kret = krb5_auth_con_init(kcontext, &actx)) &&
!(kret = ser_data(verbose, "> Vanilla auth context",
(krb5_pointer) actx,
KV5M_AUTH_CONTEXT))) {
memset(&local_address, 0, sizeof(local_address));
memset(&remote_address, 0, sizeof(remote_address));
memset(laddr_bytes, 0, sizeof(laddr_bytes));
memset(raddr_bytes, 0, sizeof(raddr_bytes));
local_address.addrtype = ADDRTYPE_INET;
local_address.length = sizeof(laddr_bytes);
local_address.contents = laddr_bytes;
laddr_bytes[0] = 6;
laddr_bytes[1] = 2;
laddr_bytes[2] = 69;
laddr_bytes[3] = 16;
laddr_bytes[4] = 1;
laddr_bytes[5] = 0;
laddr_bytes[6] = 0;
laddr_bytes[7] = 127;
remote_address.addrtype = ADDRTYPE_INET;
remote_address.length = sizeof(raddr_bytes);
remote_address.contents = raddr_bytes;
raddr_bytes[0] = 6;
raddr_bytes[1] = 2;
raddr_bytes[2] = 70;
raddr_bytes[3] = 16;
raddr_bytes[4] = 1;
raddr_bytes[5] = 0;
raddr_bytes[6] = 0;
raddr_bytes[7] = 127;
if (!(kret = krb5_auth_con_setaddrs(kcontext, actx,
&local_address,
&remote_address)) &&
!(kret = krb5_auth_con_setports(kcontext, actx,
&local_address,
&remote_address)) &&
!(kret = ser_data(verbose, "> Auth context with addrs/ports",
(krb5_pointer) actx,
KV5M_AUTH_CONTEXT))) {
memset(&ukeyblock, 0, sizeof(ukeyblock));
memset(keydata, 0, sizeof(keydata));
ukeyblock.enctype = ENCTYPE_DES_CBC_MD5;
ukeyblock.length = sizeof(keydata);
ukeyblock.contents = keydata;
keydata[0] = 0xde;
keydata[1] = 0xad;
keydata[2] = 0xbe;
keydata[3] = 0xef;
keydata[4] = 0xfe;
keydata[5] = 0xed;
keydata[6] = 0xf0;
keydata[7] = 0xd;
if (!(kret = krb5_auth_con_setuseruserkey(kcontext, actx,
&ukeyblock)) &&
!(kret = ser_data(verbose, "> Auth context with user key",
(krb5_pointer) actx,
KV5M_AUTH_CONTEXT)) &&
!(kret = krb5_auth_con_initivector(kcontext, actx)) &&
!(kret = ser_data(verbose, "> Auth context with new vector",
(krb5_pointer) actx,
KV5M_AUTH_CONTEXT)) &&
(krb5_xfree(actx->i_vector), actx->i_vector) &&
!(kret = krb5_auth_con_setivector(kcontext, actx,
(krb5_pointer) print_erep)
) &&
!(kret = ser_data(verbose, "> Auth context with set vector",
(krb5_pointer) actx,
KV5M_AUTH_CONTEXT))) {
/*
* Finally, add an authenticator.
*/
memset(&aent, 0, sizeof(aent));
aent.magic = KV5M_AUTHENTICATOR;
snprintf(clname, sizeof(clname),
"help/me/%[email protected]", (int) getpid());
actx->authentp = &aent;
if (!(kret = krb5_parse_name(kcontext, clname,
&aent.client)) &&
!(kret = ser_data(verbose,
"> Auth context with authenticator",
(krb5_pointer) actx,
KV5M_AUTH_CONTEXT))) {
adataent.magic = KV5M_AUTHDATA;
adataent.ad_type = 123;
adataent.length = 128;
adataent.contents = (krb5_octet *) stuff;
adatalist[0] = &adataent;
adatalist[1] = &adataent;
adatalist[2] = (krb5_authdata *) NULL;
aent.authorization_data = adatalist;
if (!(kret = ser_data(verbose,
"> Auth context with full auth",
(krb5_pointer) actx,
KV5M_AUTH_CONTEXT))) {
if (verbose)
printf("* krb5_auth_context test succeeded\n");
}
krb5_free_principal(kcontext, aent.client);
}
actx->authentp = (krb5_authenticator *) NULL;
}
}
}
if (actx)
krb5_auth_con_free(kcontext, actx);
if (kret)
printf("* krb5_auth_context test failed\n");
return(kret);
}
DWORD
LwKrb5InitializeUserLoginCredentials(
IN PCSTR pszUserPrincipalName,
IN PCSTR pszPassword,
IN uid_t uid,
IN gid_t gid,
IN LW_KRB5_LOGIN_FLAGS Flags,
IN PCSTR pszServicePrincipal,
IN PCSTR pszServiceRealm,
IN PCSTR pszServicePassword,
OUT PVOID* ppNdrPacInfo,
OUT size_t* pNdrPacInfoSize,
OUT PDWORD pdwGoodUntilTime
)
{
DWORD dwError = 0;
krb5_error_code ret = 0;
krb5_context ctx = NULL;
krb5_ccache cc = NULL;
// Free with krb5_free_cred_contents
krb5_creds credsRequest = {0};
krb5_creds *pTgsCreds = NULL;
krb5_ticket *pTgsTicket = NULL;
krb5_ticket *pDecryptedTgs = NULL;
krb5_auth_context authContext = NULL;
krb5_data apReqPacket = {0};
krb5_keyblock serviceKey = {0};
krb5_data salt = {0};
// Do not free
krb5_data machinePassword = {0};
krb5_flags flags = 0;
krb5_int32 authcon_flags = 0;
BOOLEAN bInLock = FALSE;
PCSTR pszTempCacheName = NULL;
PSTR pszTempCachePath = NULL;
PVOID pNdrPacInfo = NULL;
size_t ndrPacInfoSize = 0;
DWORD dwGoodUntilTime = 0;
ret = krb5_init_context(&ctx);
BAIL_ON_KRB_ERROR(ctx, ret);
/* Generates a new filed based credentials cache in /tmp. The file will
* be owned by root and only accessible by root.
*/
ret = krb5_cc_new_unique(
ctx,
"FILE",
"hint",
&cc);
BAIL_ON_KRB_ERROR(ctx, ret);
if (Flags & LW_KRB5_LOGIN_FLAG_SMART_CARD)
{
dwError = LwKrb5GetTgtWithSmartCard(
pszUserPrincipalName,
pszPassword,
krb5_cc_get_name(ctx, cc),
&dwGoodUntilTime);
}
else
{
dwError = LwKrb5GetTgt(
pszUserPrincipalName,
pszPassword,
krb5_cc_get_name(ctx, cc),
&dwGoodUntilTime);
}
BAIL_ON_LW_ERROR(dwError);
ret = krb5_parse_name(ctx, pszServicePrincipal, &credsRequest.server);
BAIL_ON_KRB_ERROR(ctx, ret);
ret = krb5_cc_get_principal(ctx, cc, &credsRequest.client);
BAIL_ON_KRB_ERROR(ctx, ret);
/* Get a TGS for our service using the tgt in the cache */
ret = krb5_get_credentials(
ctx,
0, /*no options (not user to user encryption,
and not only cached) */
cc,
&credsRequest,
&pTgsCreds);
// Don't trust pTgsCreds on an unsuccessful return
// This may be non-zero due to the krb5 libs following referrals
// but has been freed in the krb5 libs themselves and any useful
// tickets have already been cached.
if (ret != 0) {
pTgsCreds = NULL;
}
BAIL_ON_KRB_ERROR(ctx, ret);
//No need to store the tgs in the cc. Kerberos does that automatically
/* Generate an ap_req message, but don't send it anywhere. Just decode it
* immediately. This is the only way to get kerberos to decrypt the tgs
* using public APIs */
ret = krb5_mk_req_extended(
ctx,
&authContext,
0, /* no options necessary */
NULL, /* since this isn't a real ap_req, we don't have any
supplemental data to send with it. */
pTgsCreds,
&apReqPacket);
BAIL_ON_KRB_ERROR(ctx, ret);
/* Decode (but not decrypt) the tgs ticket so that we can figure out
* which encryption type was used in it. */
ret = krb5_decode_ticket(&pTgsCreds->ticket, &pTgsTicket);
/* The TGS ticket is encrypted with the machine password and salted with
* the service principal. pszServicePrincipal could probably be used
* directly, but it's safer to unparse pTgsCreds->server, because the KDC
* sent that to us.
*/
salt.magic = KV5M_DATA;
ret = krb5_unparse_name(
ctx,
pTgsCreds->server,
&salt.data);
BAIL_ON_KRB_ERROR(ctx, ret);
salt.length = strlen(salt.data);
machinePassword.magic = KV5M_DATA;
machinePassword.data = (PSTR)pszServicePassword,
machinePassword.length = strlen(pszServicePassword),
/* Generate a key to decrypt the TGS */
ret = krb5_c_string_to_key(
ctx,
pTgsTicket->enc_part.enctype,
&machinePassword,
&salt,
&serviceKey);
BAIL_ON_KRB_ERROR(ctx, ret);
/* Typically krb5_rd_req would decode the AP_REQ using the keytab, but
* we don't want to depend on the keytab. As a side effect of kerberos'
* user to user authentication support, if a key is explictly set on the
* auth context, that key will be used to decrypt the TGS instead of the
* keytab.
*
* By manually generating the key and setting it, we don't require
* a keytab.
*/
if (authContext != NULL)
{
ret = krb5_auth_con_free(ctx, authContext);
BAIL_ON_KRB_ERROR(ctx, ret);
}
ret = krb5_auth_con_init(ctx, &authContext);
BAIL_ON_KRB_ERROR(ctx, ret);
ret = krb5_auth_con_setuseruserkey(
ctx,
authContext,
&serviceKey);
BAIL_ON_KRB_ERROR(ctx, ret);
/* Disable replay detection which is unnecessary and
* can fail when authenticating large numbers of users.
*/
krb5_auth_con_getflags(ctx,
authContext,
&authcon_flags);
krb5_auth_con_setflags(ctx,
authContext,
authcon_flags & ~KRB5_AUTH_CONTEXT_DO_TIME);
if (pszServiceRealm)
{
ret = krb5_set_default_realm(ctx, pszServiceRealm);
BAIL_ON_KRB_ERROR(ctx, ret);
}
/* This decrypts the TGS. As a side effect it ensures that the KDC that
* the user's TGT came from is in the same realm that the machine was
* joined to (this prevents users from spoofing the KDC).
*/
ret = krb5_rd_req(
ctx,
&authContext,
&apReqPacket,
pTgsCreds->server,
NULL, /* we're not using the keytab */
&flags,
&pDecryptedTgs);
BAIL_ON_KRB_ERROR(ctx, ret);
dwError = LwKrb5FindPac(
ctx,
pDecryptedTgs,
&serviceKey,
&pNdrPacInfo,
&ndrPacInfoSize);
BAIL_ON_LW_ERROR(dwError);
if (Flags & LW_KRB5_LOGIN_FLAG_UPDATE_CACHE)
{
/* 1. Copy old credentials from the existing user creds cache to
* the temporary cache.
* 2. Delete the existing creds cache.
* 3. Move the temporary cache file into the final path.
*/
dwError = pthread_mutex_lock(&gLwKrb5State.UserCacheMutex);
BAIL_ON_LW_ERROR(dwError);
bInLock = TRUE;
dwError = LwKrb5CopyFromUserCache(
ctx,
cc,
uid
);
BAIL_ON_LW_ERROR(dwError);
pszTempCacheName = krb5_cc_get_name(ctx, cc);
if (!strncasecmp(pszTempCacheName, "FILE:", sizeof("FILE:")-1)) {
pszTempCacheName += sizeof("FILE:") - 1;
}
dwError = LwAllocateString(pszTempCacheName, &pszTempCachePath);
BAIL_ON_LW_ERROR(dwError);
krb5_cc_close(ctx, cc);
// Just to make sure no one accesses this now invalid pointer
cc = NULL;
dwError = LwKrb5MoveCCacheToUserPath(
ctx,
pszTempCachePath,
uid,
gid);
if (dwError != LW_ERROR_SUCCESS)
{
/* Let the user login, even if we couldn't create the ccache for
* them. Possible causes are:
* 1. /tmp is readonly
* 2. Another user maliciously setup a weird file (such as a
* directory) where the ccache would go.
* 3. Someone created a ccache in the small window after we delete
* the old one and before we move in the new one.
*/
LW_LOG_WARNING("Unable to set up credentials cache with tgt for uid %ld", (long)uid);
dwError = LwRemoveFile(pszTempCachePath);
BAIL_ON_LW_ERROR(dwError);
}
}
error:
if (dwError)
{
LW_SAFE_FREE_MEMORY(pNdrPacInfo);
ndrPacInfoSize = 0;
dwGoodUntilTime = 0;
}
if (ctx)
{
// This function skips fields which are NULL
krb5_free_cred_contents(ctx, &credsRequest);
if (pTgsCreds != NULL)
{
krb5_free_creds(ctx, pTgsCreds);
}
if (pTgsTicket != NULL)
{
krb5_free_ticket(ctx, pTgsTicket);
}
if (pDecryptedTgs != NULL)
{
krb5_free_ticket(ctx, pDecryptedTgs);
}
if (authContext != NULL)
{
krb5_auth_con_free(ctx, authContext);
}
krb5_free_data_contents(ctx, &apReqPacket);
krb5_free_data_contents(ctx, &salt);
krb5_free_keyblock_contents(ctx, &serviceKey);
if (cc != NULL)
{
krb5_cc_destroy(ctx, cc);
}
krb5_free_context(ctx);
}
if (bInLock)
{
pthread_mutex_unlock(&gLwKrb5State.UserCacheMutex);
}
LW_SAFE_FREE_STRING(pszTempCachePath);
*ppNdrPacInfo = pNdrPacInfo;
*pNdrPacInfoSize = ndrPacInfoSize;
*pdwGoodUntilTime = dwGoodUntilTime;
return dwError;
}
static krb5_error_code ads_secrets_verify_ticket(krb5_context context,
krb5_auth_context auth_context,
krb5_principal host_princ,
const DATA_BLOB *ticket,
krb5_ticket **pp_tkt,
krb5_keyblock **keyblock,
krb5_error_code *perr)
{
krb5_error_code ret = 0;
bool auth_ok = False;
bool cont = true;
char *password_s = NULL;
/* Let's make some room for 2 password (old and new)*/
krb5_data passwords[2];
krb5_enctype enctypes[] = {
#ifdef HAVE_ENCTYPE_AES256_CTS_HMAC_SHA1_96
ENCTYPE_AES256_CTS_HMAC_SHA1_96,
#endif
#ifdef HAVE_ENCTYPE_AES128_CTS_HMAC_SHA1_96
ENCTYPE_AES128_CTS_HMAC_SHA1_96,
#endif
ENCTYPE_ARCFOUR_HMAC,
ENCTYPE_DES_CBC_CRC,
ENCTYPE_DES_CBC_MD5,
ENCTYPE_NULL
};
krb5_data packet;
int i, j;
*pp_tkt = NULL;
*keyblock = NULL;
*perr = 0;
ZERO_STRUCT(passwords);
if (!secrets_init()) {
DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
*perr = KRB5_CONFIG_CANTOPEN;
return False;
}
password_s = secrets_fetch_machine_password(lp_workgroup(),
NULL, NULL);
if (!password_s) {
DEBUG(1,(__location__ ": failed to fetch machine password\n"));
*perr = KRB5_LIBOS_CANTREADPWD;
return False;
}
passwords[0].data = password_s;
passwords[0].length = strlen(password_s);
password_s = secrets_fetch_prev_machine_password(lp_workgroup());
if (password_s) {
DEBUG(10, (__location__ ": found previous password\n"));
passwords[1].data = password_s;
passwords[1].length = strlen(password_s);
}
/* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
packet.length = ticket->length;
packet.data = (char *)ticket->data;
/* We need to setup a auth context with each possible encoding type
* in turn. */
for (j=0; j<2 && passwords[j].length; j++) {
for (i=0;enctypes[i];i++) {
krb5_keyblock *key = NULL;
if (!(key = SMB_MALLOC_P(krb5_keyblock))) {
ret = ENOMEM;
goto out;
}
if (create_kerberos_key_from_string(context,
host_princ, &passwords[j],
key, enctypes[i], false)) {
SAFE_FREE(key);
continue;
}
krb5_auth_con_setuseruserkey(context,
auth_context, key);
if (!(ret = krb5_rd_req(context, &auth_context,
&packet, NULL, NULL,
NULL, pp_tkt))) {
DEBUG(10, (__location__ ": enc type [%u] "
"decrypted message !\n",
(unsigned int)enctypes[i]));
auth_ok = True;
cont = false;
krb5_copy_keyblock(context, key, keyblock);
krb5_free_keyblock(context, key);
break;
}
DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
(__location__ ": enc type [%u] failed to "
"decrypt with error %s\n",
(unsigned int)enctypes[i],
error_message(ret)));
/* successfully decrypted but ticket is just not
* valid at the moment */
if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
ret == KRB5KRB_AP_ERR_SKEW) {
krb5_free_keyblock(context, key);
cont = false;
break;
}
krb5_free_keyblock(context, key);
}
if (!cont) {
/* If we found a valid pass then no need to try
* the next one or we have invalid ticket so no need
* to try next password*/
break;
}
}
out:
SAFE_FREE(passwords[0].data);
SAFE_FREE(passwords[1].data);
*perr = ret;
return auth_ok;
}
