static krb5_error_code
process_chpw_request(krb5_context context, void *server_handle, char *realm,
krb5_keytab keytab, const krb5_fulladdr *local_faddr,
const krb5_fulladdr *remote_faddr, krb5_data *req,
krb5_data *rep)
{
krb5_error_code ret;
char *ptr;
unsigned int plen, vno;
krb5_data ap_req, ap_rep = empty_data();
krb5_data cipher = empty_data(), clear = empty_data();
krb5_auth_context auth_context = NULL;
krb5_principal changepw = NULL;
krb5_principal client, target = NULL;
krb5_ticket *ticket = NULL;
krb5_replay_data replay;
krb5_error krberror;
int numresult;
char strresult[1024];
char *clientstr = NULL, *targetstr = NULL;
const char *errmsg = NULL;
size_t clen;
char *cdots;
struct sockaddr_storage ss;
socklen_t salen;
char addrbuf[100];
krb5_address *addr = remote_faddr->address;
*rep = empty_data();
if (req->length < 4) {
/* either this, or the server is printing bad messages,
or the caller passed in garbage */
ret = KRB5KRB_AP_ERR_MODIFIED;
numresult = KRB5_KPASSWD_MALFORMED;
strlcpy(strresult, "Request was truncated", sizeof(strresult));
goto bailout;
}
ptr = req->data;
/* verify length */
plen = (*ptr++ & 0xff);
plen = (plen<<8) | (*ptr++ & 0xff);
if (plen != req->length) {
ret = KRB5KRB_AP_ERR_MODIFIED;
numresult = KRB5_KPASSWD_MALFORMED;
strlcpy(strresult, "Request length was inconsistent",
sizeof(strresult));
goto bailout;
}
/* verify version number */
vno = (*ptr++ & 0xff) ;
vno = (vno<<8) | (*ptr++ & 0xff);
if (vno != 1 && vno != RFC3244_VERSION) {
ret = KRB5KDC_ERR_BAD_PVNO;
numresult = KRB5_KPASSWD_BAD_VERSION;
snprintf(strresult, sizeof(strresult),
"Request contained unknown protocol version number %d", vno);
goto bailout;
}
/* read, check ap-req length */
ap_req.length = (*ptr++ & 0xff);
ap_req.length = (ap_req.length<<8) | (*ptr++ & 0xff);
if (ptr + ap_req.length >= req->data + req->length) {
ret = KRB5KRB_AP_ERR_MODIFIED;
numresult = KRB5_KPASSWD_MALFORMED;
strlcpy(strresult, "Request was truncated in AP-REQ",
sizeof(strresult));
goto bailout;
}
/* verify ap_req */
ap_req.data = ptr;
ptr += ap_req.length;
ret = krb5_auth_con_init(context, &auth_context);
if (ret) {
numresult = KRB5_KPASSWD_HARDERROR;
strlcpy(strresult, "Failed initializing auth context",
sizeof(strresult));
goto chpwfail;
}
ret = krb5_auth_con_setflags(context, auth_context,
KRB5_AUTH_CONTEXT_DO_SEQUENCE);
if (ret) {
numresult = KRB5_KPASSWD_HARDERROR;
strlcpy(strresult, "Failed initializing auth context",
sizeof(strresult));
goto chpwfail;
}
ret = krb5_build_principal(context, &changepw, strlen(realm), realm,
"kadmin", "changepw", NULL);
if (ret) {
numresult = KRB5_KPASSWD_HARDERROR;
strlcpy(strresult, "Failed building kadmin/changepw principal",
sizeof(strresult));
goto chpwfail;
}
ret = krb5_rd_req(context, &auth_context, &ap_req, changepw, keytab,
NULL, &ticket);
if (ret) {
numresult = KRB5_KPASSWD_AUTHERROR;
strlcpy(strresult, "Failed reading application request",
sizeof(strresult));
goto chpwfail;
}
/* construct the ap-rep */
ret = krb5_mk_rep(context, auth_context, &ap_rep);
if (ret) {
numresult = KRB5_KPASSWD_AUTHERROR;
strlcpy(strresult, "Failed replying to application request",
sizeof(strresult));
goto chpwfail;
}
/* decrypt the ChangePasswdData */
cipher.length = (req->data + req->length) - ptr;
cipher.data = ptr;
/*
* Don't set a remote address in auth_context before calling krb5_rd_priv,
* so that we can work against clients behind a NAT. Reflection attacks
* aren't a concern since we use sequence numbers and since our requests
* don't look anything like our responses. Also don't set a local address,
* since we don't know what interface the request was received on.
*/
ret = krb5_rd_priv(context, auth_context, &cipher, &clear, &replay);
if (ret) {
numresult = KRB5_KPASSWD_HARDERROR;
strlcpy(strresult, "Failed decrypting request", sizeof(strresult));
goto chpwfail;
}
client = ticket->enc_part2->client;
/* decode ChangePasswdData for setpw requests */
if (vno == RFC3244_VERSION) {
krb5_data *clear_data;
ret = decode_krb5_setpw_req(&clear, &clear_data, &target);
if (ret != 0) {
numresult = KRB5_KPASSWD_MALFORMED;
strlcpy(strresult, "Failed decoding ChangePasswdData",
sizeof(strresult));
goto chpwfail;
}
zapfree(clear.data, clear.length);
clear = *clear_data;
free(clear_data);
if (target != NULL) {
ret = krb5_unparse_name(context, target, &targetstr);
if (ret != 0) {
numresult = KRB5_KPASSWD_HARDERROR;
strlcpy(strresult, "Failed unparsing target name for log",
sizeof(strresult));
goto chpwfail;
}
}
}
ret = krb5_unparse_name(context, client, &clientstr);
if (ret) {
numresult = KRB5_KPASSWD_HARDERROR;
strlcpy(strresult, "Failed unparsing client name for log",
sizeof(strresult));
goto chpwfail;
}
/* for cpw, verify that this is an AS_REQ ticket */
if (vno == 1 &&
(ticket->enc_part2->flags & TKT_FLG_INITIAL) == 0) {
numresult = KRB5_KPASSWD_INITIAL_FLAG_NEEDED;
strlcpy(strresult, "Ticket must be derived from a password",
sizeof(strresult));
goto chpwfail;
}
/* change the password */
ptr = k5memdup0(clear.data, clear.length, &ret);
ret = schpw_util_wrapper(server_handle, client, target,
(ticket->enc_part2->flags & TKT_FLG_INITIAL) != 0,
ptr, NULL, strresult, sizeof(strresult));
if (ret)
errmsg = krb5_get_error_message(context, ret);
/* zap the password */
zapfree(clear.data, clear.length);
zapfree(ptr, clear.length);
clear = empty_data();
clen = strlen(clientstr);
trunc_name(&clen, &cdots);
switch (addr->addrtype) {
case ADDRTYPE_INET: {
struct sockaddr_in *sin = ss2sin(&ss);
sin->sin_family = AF_INET;
memcpy(&sin->sin_addr, addr->contents, addr->length);
sin->sin_port = htons(remote_faddr->port);
salen = sizeof(*sin);
break;
}
case ADDRTYPE_INET6: {
struct sockaddr_in6 *sin6 = ss2sin6(&ss);
sin6->sin6_family = AF_INET6;
memcpy(&sin6->sin6_addr, addr->contents, addr->length);
sin6->sin6_port = htons(remote_faddr->port);
salen = sizeof(*sin6);
break;
}
default: {
struct sockaddr *sa = ss2sa(&ss);
sa->sa_family = AF_UNSPEC;
salen = sizeof(*sa);
break;
}
}
if (getnameinfo(ss2sa(&ss), salen,
addrbuf, sizeof(addrbuf), NULL, 0,
NI_NUMERICHOST | NI_NUMERICSERV) != 0)
strlcpy(addrbuf, "<unprintable>", sizeof(addrbuf));
if (vno == RFC3244_VERSION) {
size_t tlen;
char *tdots;
const char *targetp;
if (target == NULL) {
tlen = clen;
tdots = cdots;
targetp = targetstr;
} else {
tlen = strlen(targetstr);
trunc_name(&tlen, &tdots);
targetp = clientstr;
}
krb5_klog_syslog(LOG_NOTICE, _("setpw request from %s by %.*s%s for "
"%.*s%s: %s"), addrbuf, (int) clen,
clientstr, cdots, (int) tlen, targetp, tdots,
errmsg ? errmsg : "success");
} else {
krb5_klog_syslog(LOG_NOTICE, _("chpw request from %s for %.*s%s: %s"),
addrbuf, (int) clen, clientstr, cdots,
errmsg ? errmsg : "success");
}
switch (ret) {
case KADM5_AUTH_CHANGEPW:
numresult = KRB5_KPASSWD_ACCESSDENIED;
break;
case KADM5_PASS_Q_TOOSHORT:
case KADM5_PASS_REUSE:
case KADM5_PASS_Q_CLASS:
case KADM5_PASS_Q_DICT:
case KADM5_PASS_Q_GENERIC:
case KADM5_PASS_TOOSOON:
numresult = KRB5_KPASSWD_SOFTERROR;
break;
case 0:
numresult = KRB5_KPASSWD_SUCCESS;
strlcpy(strresult, "", sizeof(strresult));
break;
default:
numresult = KRB5_KPASSWD_HARDERROR;
break;
}
chpwfail:
ret = alloc_data(&clear, 2 + strlen(strresult));
if (ret)
goto bailout;
ptr = clear.data;
*ptr++ = (numresult>>8) & 0xff;
*ptr++ = numresult & 0xff;
memcpy(ptr, strresult, strlen(strresult));
cipher = empty_data();
if (ap_rep.length) {
ret = krb5_auth_con_setaddrs(context, auth_context,
local_faddr->address, NULL);
if (ret) {
numresult = KRB5_KPASSWD_HARDERROR;
strlcpy(strresult,
"Failed storing client and server internet addresses",
sizeof(strresult));
} else {
ret = krb5_mk_priv(context, auth_context, &clear, &cipher,
&replay);
if (ret) {
numresult = KRB5_KPASSWD_HARDERROR;
strlcpy(strresult, "Failed encrypting reply",
sizeof(strresult));
}
}
}
/* if no KRB-PRIV was constructed, then we need a KRB-ERROR.
if this fails, just bail. there's nothing else we can do. */
if (cipher.length == 0) {
/* clear out ap_rep now, so that it won't be inserted in the
reply */
if (ap_rep.length) {
free(ap_rep.data);
ap_rep = empty_data();
}
krberror.ctime = 0;
krberror.cusec = 0;
krberror.susec = 0;
ret = krb5_timeofday(context, &krberror.stime);
if (ret)
goto bailout;
/* this is really icky. but it's what all the other callers
to mk_error do. */
krberror.error = ret;
krberror.error -= ERROR_TABLE_BASE_krb5;
if (krberror.error < 0 || krberror.error > KRB_ERR_MAX)
krberror.error = KRB_ERR_GENERIC;
krberror.client = NULL;
ret = krb5_build_principal(context, &krberror.server,
strlen(realm), realm,
"kadmin", "changepw", NULL);
if (ret)
goto bailout;
krberror.text.length = 0;
krberror.e_data = clear;
ret = krb5_mk_error(context, &krberror, &cipher);
krb5_free_principal(context, krberror.server);
if (ret)
goto bailout;
}
/* construct the reply */
ret = alloc_data(rep, 6 + ap_rep.length + cipher.length);
if (ret)
goto bailout;
ptr = rep->data;
/* length */
*ptr++ = (rep->length>>8) & 0xff;
*ptr++ = rep->length & 0xff;
/* version == 0x0001 big-endian */
*ptr++ = 0;
*ptr++ = 1;
/* ap_rep length, big-endian */
*ptr++ = (ap_rep.length>>8) & 0xff;
*ptr++ = ap_rep.length & 0xff;
/* ap-rep data */
if (ap_rep.length) {
memcpy(ptr, ap_rep.data, ap_rep.length);
ptr += ap_rep.length;
}
/* krb-priv or krb-error */
memcpy(ptr, cipher.data, cipher.length);
bailout:
krb5_auth_con_free(context, auth_context);
krb5_free_principal(context, changepw);
krb5_free_ticket(context, ticket);
free(ap_rep.data);
free(clear.data);
free(cipher.data);
krb5_free_principal(context, target);
krb5_free_unparsed_name(context, targetstr);
krb5_free_unparsed_name(context, clientstr);
krb5_free_error_message(context, errmsg);
return ret;
}
static krb5_error_code kpasswd_set_password(struct kdc_server *kdc,
TALLOC_CTX *mem_ctx,
struct auth_session_info *session_info,
DATA_BLOB *decoded_data,
DATA_BLOB *kpasswd_reply,
const char **error_string)
{
krb5_context context = kdc->smb_krb5_context->krb5_context;
krb5_data k_dec_data;
krb5_data *k_clear_data;
krb5_principal target_principal;
krb5_error_code code;
DATA_BLOB password;
char *target_realm = NULL;
char *target_name = NULL;
char *target_principal_string = NULL;
bool is_service_principal = false;
bool ok;
size_t num_components;
enum samPwdChangeReason reject_reason = SAM_PWD_CHANGE_NO_ERROR;
struct samr_DomInfo1 *dominfo = NULL;
NTSTATUS status;
k_dec_data.length = decoded_data->length;
k_dec_data.data = (char *)decoded_data->data;
code = decode_krb5_setpw_req(&k_dec_data,
&k_clear_data,
&target_principal);
if (code != 0) {
DBG_WARNING("decode_krb5_setpw_req failed: %s\n",
error_message(code));
ok = kpasswd_make_error_reply(mem_ctx,
KRB5_KPASSWD_MALFORMED,
"Failed to decode packet",
kpasswd_reply);
if (!ok) {
*error_string = "Failed to create reply";
return KRB5_KPASSWD_HARDERROR;
}
return 0;
}
ok = convert_string_talloc_handle(mem_ctx,
lpcfg_iconv_handle(kdc->task->lp_ctx),
CH_UTF8,
CH_UTF16,
(const char *)k_clear_data->data,
k_clear_data->length,
(void **)&password.data,
&password.length);
krb5_free_data(context, k_clear_data);
if (!ok) {
DBG_WARNING("String conversion failed\n");
*error_string = "String conversion failed";
return KRB5_KPASSWD_HARDERROR;
}
target_realm = smb_krb5_principal_get_realm(context, target_principal);
code = krb5_unparse_name_flags(context,
target_principal,
KRB5_PRINCIPAL_UNPARSE_NO_REALM,
&target_name);
if (code != 0) {
DBG_WARNING("Failed to parse principal\n");
*error_string = "String conversion failed";
return KRB5_KPASSWD_HARDERROR;
}
if ((target_name != NULL && target_realm == NULL) ||
(target_name == NULL && target_realm != NULL)) {
krb5_free_principal(context, target_principal);
SAFE_FREE(target_realm);
SAFE_FREE(target_name);
ok = kpasswd_make_error_reply(mem_ctx,
KRB5_KPASSWD_MALFORMED,
"Realm and principal must be "
"both present, or neither "
"present",
kpasswd_reply);
if (!ok) {
*error_string = "Failed to create reply";
return KRB5_KPASSWD_HARDERROR;
}
return 0;
}
if (target_name != NULL && target_realm != NULL) {
SAFE_FREE(target_realm);
SAFE_FREE(target_name);
} else {
krb5_free_principal(context, target_principal);
SAFE_FREE(target_realm);
SAFE_FREE(target_name);
return kpasswd_change_password(kdc,
mem_ctx,
session_info,
&password,
kpasswd_reply,
error_string);
}
num_components = krb5_princ_size(context, target_principal);
if (num_components >= 2) {
is_service_principal = true;
code = krb5_unparse_name_flags(context,
target_principal,
KRB5_PRINCIPAL_UNPARSE_SHORT,
&target_principal_string);
} else {
code = krb5_unparse_name(context,
target_principal,
&target_principal_string);
}
krb5_free_principal(context, target_principal);
if (code != 0) {
ok = kpasswd_make_error_reply(mem_ctx,
KRB5_KPASSWD_MALFORMED,
"Failed to parse principal",
kpasswd_reply);
if (!ok) {
*error_string = "Failed to create reply";
return KRB5_KPASSWD_HARDERROR;
}
}
status = kpasswd_samdb_set_password(mem_ctx,
kdc->task->event_ctx,
kdc->task->lp_ctx,
session_info,
is_service_principal,
target_principal_string,
&password,
&reject_reason,
&dominfo);
if (!NT_STATUS_IS_OK(status)) {
DBG_ERR("kpasswd_samdb_set_password failed - %s\n",
nt_errstr(status));
}
ok = kpasswd_make_pwchange_reply(mem_ctx,
status,
reject_reason,
dominfo,
kpasswd_reply);
if (!ok) {
*error_string = "Failed to create reply";
return KRB5_KPASSWD_HARDERROR;
}
return 0;
}
