krb5_error_code
krb5int_decode_tgs_rep(krb5_context context, krb5_data *enc_rep, const krb5_keyblock *key,
krb5_keyusage usage, krb5_kdc_rep **dec_rep)
{
krb5_error_code retval;
krb5_kdc_rep *local_dec_rep;
if (krb5_is_as_rep(enc_rep)) {
retval = decode_krb5_as_rep(enc_rep, &local_dec_rep);
} else if (krb5_is_tgs_rep(enc_rep)) {
retval = decode_krb5_tgs_rep(enc_rep, &local_dec_rep);
} else {
return KRB5KRB_AP_ERR_MSG_TYPE;
}
if (retval)
return retval;
if ((retval = krb5_kdc_rep_decrypt_proc(context, key, &usage,
local_dec_rep)))
krb5_free_kdc_rep(context, local_dec_rep);
else
*dec_rep = local_dec_rep;
return(retval);
}
static krb5_error_code
parse_tgs_rep(krb5_context context,
krb5_tkt_creds_context ctx,
krb5_data *in,
krb5_creds *outcred)
{
krb5_error_code ret;
krb5_kdc_rep rep;
size_t len;
memset(&rep, 0, sizeof(rep));
memset(outcred, 0, sizeof(*outcred));
if (ctx->ccache->ops->tgt_rep) {
return EINVAL;
}
if(decode_TGS_REP(in->data, in->length, &rep.kdc_rep, &len) == 0) {
unsigned eflags = 0;
ret = krb5_copy_principal(context,
ctx->next.client,
&outcred->client);
if(ret)
return ret;
ret = krb5_copy_principal(context,
ctx->next.server,
&outcred->server);
if(ret)
return ret;
/* this should go someplace else */
outcred->times.endtime = ctx->in_cred->times.endtime;
if (ctx->kdc_flags.b.constrained_delegation || ctx->impersonate_principal)
eflags |= EXTRACT_TICKET_ALLOW_CNAME_MISMATCH;
ret = _krb5_extract_ticket(context,
&rep,
outcred,
&ctx->tgt.session,
0,
&ctx->tgt.addresses,
ctx->nonce,
eflags,
NULL,
_krb5_decrypt_tkt_with_subkey,
ctx->subkey);
} else if(krb5_rd_error(context, in, &rep.error) == 0) {
ret = krb5_error_from_rd_error(context, &rep.error, ctx->in_cred);
} else {
ret = KRB5KRB_AP_ERR_MSG_TYPE;
krb5_clear_error_message(context);
}
krb5_free_kdc_rep(context, &rep);
return ret;
}
/* Modify an AS-REP reply, change the msg_type to KRB5_TGS_REP. */
static krb5_error_code
test_recv_modify_reply(krb5_context context, void *data, krb5_error_code code,
const krb5_data *realm, const krb5_data *message,
const krb5_data *reply, krb5_data **new_reply)
{
krb5_kdc_rep *as_rep;
assert(code == 0);
assert(krb5_is_as_rep(reply));
check(decode_krb5_as_rep(reply, &as_rep));
as_rep->msg_type = KRB5_TGS_REP;
check(encode_krb5_as_rep(as_rep, new_reply));
krb5_free_kdc_rep(context, as_rep);
return 0;
}
/* Verify that reply is an AS-REP with kvno 1 and a valid enctype. */
static krb5_error_code
test_recv_as_rep(krb5_context context, void *data, krb5_error_code code,
const krb5_data *realm, const krb5_data *message,
const krb5_data *reply, krb5_data **new_reply)
{
krb5_kdc_rep *as_rep;
assert(code == 0);
assert(krb5_is_as_rep(reply));
check(decode_krb5_as_rep(reply, &as_rep));
assert(as_rep->msg_type == KRB5_AS_REP);
assert(as_rep->ticket->enc_part.kvno == 1);
assert(krb5_c_valid_enctype(as_rep->ticket->enc_part.enctype));
krb5_free_kdc_rep(context, as_rep);
return 0;
}
static krb5_error_code
get_cred_kdc(krb5_context context,
krb5_ccache id,
krb5_kdc_flags flags,
krb5_addresses *addresses,
krb5_creds *in_creds,
krb5_creds *krbtgt,
krb5_principal impersonate_principal,
Ticket *second_ticket,
krb5_creds *out_creds)
{
TGS_REQ req;
krb5_data enc;
krb5_data resp;
krb5_kdc_rep rep;
KRB_ERROR error;
krb5_error_code ret;
unsigned nonce;
krb5_keyblock *subkey = NULL;
size_t len;
Ticket second_ticket_data;
METHOD_DATA padata;
krb5_data_zero(&resp);
krb5_data_zero(&enc);
padata.val = NULL;
padata.len = 0;
krb5_generate_random_block(&nonce, sizeof(nonce));
nonce &= 0xffffffff;
if(flags.b.enc_tkt_in_skey && second_ticket == NULL){
ret = decode_Ticket(in_creds->second_ticket.data,
in_creds->second_ticket.length,
&second_ticket_data, &len);
if(ret)
return ret;
second_ticket = &second_ticket_data;
}
if (impersonate_principal) {
krb5_crypto crypto;
PA_S4U2Self self;
krb5_data data;
void *buf;
size_t size;
self.name = impersonate_principal->name;
self.realm = impersonate_principal->realm;
self.auth = estrdup("Kerberos");
ret = _krb5_s4u2self_to_checksumdata(context, &self, &data);
if (ret) {
free(self.auth);
goto out;
}
ret = krb5_crypto_init(context, &krbtgt->session, 0, &crypto);
if (ret) {
free(self.auth);
krb5_data_free(&data);
goto out;
}
ret = krb5_create_checksum(context,
crypto,
KRB5_KU_OTHER_CKSUM,
0,
data.data,
data.length,
&self.cksum);
krb5_crypto_destroy(context, crypto);
krb5_data_free(&data);
if (ret) {
free(self.auth);
goto out;
}
ASN1_MALLOC_ENCODE(PA_S4U2Self, buf, len, &self, &size, ret);
free(self.auth);
free_Checksum(&self.cksum);
if (ret)
goto out;
if (len != size)
krb5_abortx(context, "internal asn1 error");
ret = krb5_padata_add(context, &padata, KRB5_PADATA_FOR_USER, buf, len);
if (ret)
goto out;
}
ret = init_tgs_req (context,
id,
addresses,
flags,
second_ticket,
in_creds,
krbtgt,
nonce,
&padata,
&subkey,
&req);
if (ret)
goto out;
ASN1_MALLOC_ENCODE(TGS_REQ, enc.data, enc.length, &req, &len, ret);
if (ret)
goto out;
if(enc.length != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
/* don't free addresses */
req.req_body.addresses = NULL;
free_TGS_REQ(&req);
/*
* Send and receive
*/
{
krb5_sendto_ctx stctx;
ret = krb5_sendto_ctx_alloc(context, &stctx);
if (ret)
return ret;
krb5_sendto_ctx_set_func(stctx, _krb5_kdc_retry, NULL);
ret = krb5_sendto_context (context, stctx, &enc,
krbtgt->server->name.name_string.val[1],
&resp);
krb5_sendto_ctx_free(context, stctx);
}
if(ret)
goto out;
memset(&rep, 0, sizeof(rep));
if(decode_TGS_REP(resp.data, resp.length, &rep.kdc_rep, &len) == 0) {
unsigned eflags = 0;
ret = krb5_copy_principal(context,
in_creds->client,
&out_creds->client);
if(ret)
goto out2;
ret = krb5_copy_principal(context,
in_creds->server,
&out_creds->server);
if(ret)
goto out2;
/* this should go someplace else */
out_creds->times.endtime = in_creds->times.endtime;
/* XXX should do better testing */
if (flags.b.constrained_delegation || impersonate_principal)
eflags |= EXTRACT_TICKET_ALLOW_CNAME_MISMATCH;
ret = _krb5_extract_ticket(context,
&rep,
out_creds,
&krbtgt->session,
NULL,
0,
&krbtgt->addresses,
nonce,
eflags,
decrypt_tkt_with_subkey,
subkey);
out2:
krb5_free_kdc_rep(context, &rep);
} else if(krb5_rd_error(context, &resp, &error) == 0) {
ret = krb5_error_from_rd_error(context, &error, in_creds);
krb5_free_error_contents(context, &error);
} else if(resp.length > 0 && ((char*)resp.data)[0] == 4) {
ret = KRB5KRB_AP_ERR_V4_REPLY;
krb5_clear_error_message(context);
} else {
ret = KRB5KRB_AP_ERR_MSG_TYPE;
krb5_clear_error_message(context);
}
out:
if (second_ticket == &second_ticket_data)
free_Ticket(&second_ticket_data);
free_METHOD_DATA(&padata);
krb5_data_free(&resp);
krb5_data_free(&enc);
if(subkey)
krb5_free_keyblock(context, subkey);
return ret;
}
static krb5_error_code
get_salt_and_kvno(krb5_context context,
kcm_ccache ccache,
krb5_enctype *etypes,
char *cpn,
char *newpw,
krb5_salt *salt,
unsigned *kvno)
{
krb5_error_code ret;
krb5_creds creds;
krb5_ccache_data ccdata;
krb5_flags options = 0;
krb5_kdc_rep reply;
struct kcm_keyseed_data s;
memset(&creds, 0, sizeof(creds));
memset(&reply, 0, sizeof(reply));
s.password = NULL;
s.salt.salttype = (int)ETYPE_NULL;
krb5_data_zero(&s.salt.saltvalue);
*kvno = 0;
kcm_internal_ccache(context, ccache, &ccdata);
s.password = newpw;
/* Do an AS-REQ to determine salt and key version number */
ret = krb5_copy_principal(context, ccache->client, &creds.client);
if (ret)
return ret;
/* Yes, get a ticket to ourselves */
ret = krb5_copy_principal(context, ccache->client, &creds.server);
if (ret) {
krb5_free_principal(context, creds.client);
return ret;
}
ret = krb5_get_in_tkt(context,
options,
NULL,
etypes,
NULL,
kcm_password_key_proc,
&s,
NULL,
NULL,
&creds,
&ccdata,
&reply);
if (ret) {
kcm_log(0, "Failed to get self ticket for principal %s: %s",
cpn, krb5_get_err_text(context, ret));
krb5_free_salt(context, s.salt);
} else {
*salt = s.salt; /* retrieve stashed salt */
if (reply.kdc_rep.enc_part.kvno != NULL)
*kvno = *(reply.kdc_rep.enc_part.kvno);
}
/* ccache may have been modified but it will get trashed anyway */
krb5_free_cred_contents(context, &creds);
krb5_free_kdc_rep(context, &reply);
return ret;
}
krb5_error_code KRB5_CALLCONV
krb5_get_init_creds_password(krb5_context context,
krb5_creds *creds,
krb5_principal client,
const char *password,
krb5_prompter_fct prompter,
void *data,
krb5_deltat start_time,
const char *in_tkt_service,
krb5_get_init_creds_opt *options)
{
krb5_error_code ret, ret2;
int use_master;
krb5_kdc_rep *as_reply;
int tries;
krb5_creds chpw_creds;
krb5_get_init_creds_opt *chpw_opts = NULL;
krb5_data pw0, pw1;
char banner[1024], pw0array[1024], pw1array[1024];
krb5_prompt prompt[2];
krb5_prompt_type prompt_types[sizeof(prompt)/sizeof(prompt[0])];
char *message;
use_master = 0;
as_reply = NULL;
memset(&chpw_creds, 0, sizeof(chpw_creds));
pw0.data = pw0array;
if (password && password[0]) {
if (strlcpy(pw0.data, password, sizeof(pw0array)) >= sizeof(pw0array)) {
ret = EINVAL;
goto cleanup;
}
pw0.length = strlen(password);
} else {
pw0.data[0] = '\0';
pw0.length = sizeof(pw0array);
}
pw1.data = pw1array;
pw1.data[0] = '\0';
pw1.length = sizeof(pw1array);
/* first try: get the requested tkt from any kdc */
ret = krb5int_get_init_creds(context, creds, client, prompter, data,
start_time, in_tkt_service, options,
krb5_get_as_key_password, (void *) &pw0,
&use_master, &as_reply);
/* check for success */
if (ret == 0)
goto cleanup;
/* If all the kdc's are unavailable, or if the error was due to a
user interrupt, fail */
if ((ret == KRB5_KDC_UNREACH) ||
(ret == KRB5_LIBOS_PWDINTR) ||
(ret == KRB5_REALM_CANT_RESOLVE))
goto cleanup;
/* if the reply did not come from the master kdc, try again with
the master kdc */
if (!use_master) {
TRACE_GIC_PWD_MASTER(context);
use_master = 1;
if (as_reply) {
krb5_free_kdc_rep( context, as_reply);
as_reply = NULL;
}
ret2 = krb5int_get_init_creds(context, creds, client, prompter, data,
start_time, in_tkt_service, options,
krb5_get_as_key_password, (void *) &pw0,
&use_master, &as_reply);
if (ret2 == 0) {
ret = 0;
goto cleanup;
}
/* if the master is unreachable, return the error from the
slave we were able to contact or reset the use_master flag */
if ((ret2 != KRB5_KDC_UNREACH) &&
(ret2 != KRB5_REALM_CANT_RESOLVE) &&
(ret2 != KRB5_REALM_UNKNOWN))
ret = ret2;
else
use_master = 0;
}
/* at this point, we have an error from the master. if the error
is not password expired, or if it is but there's no prompter,
return this error */
if ((ret != KRB5KDC_ERR_KEY_EXP) ||
(prompter == NULL))
goto cleanup;
/* historically the default has been to prompt for password change.
* if the change password prompt option has not been set, we continue
* to prompt. Prompting is only disabled if the option has been set
* and the value has been set to false.
*/
if (options && !(options->flags & KRB5_GET_INIT_CREDS_OPT_CHG_PWD_PRMPT))
goto cleanup;
TRACE_GIC_PWD_EXPIRED(context);
/* ok, we have an expired password. Give the user a few chances
to change it */
/* use a minimal set of options */
ret = krb5_get_init_creds_opt_alloc(context, &chpw_opts);
if (ret)
goto cleanup;
krb5_get_init_creds_opt_set_tkt_life(chpw_opts, 5*60);
krb5_get_init_creds_opt_set_renew_life(chpw_opts, 0);
krb5_get_init_creds_opt_set_forwardable(chpw_opts, 0);
krb5_get_init_creds_opt_set_proxiable(chpw_opts, 0);
if ((ret = krb5int_get_init_creds(context, &chpw_creds, client,
prompter, data,
start_time, "kadmin/changepw", chpw_opts,
krb5_get_as_key_password, (void *) &pw0,
&use_master, NULL)))
goto cleanup;
prompt[0].prompt = _("Enter new password");
prompt[0].hidden = 1;
prompt[0].reply = &pw0;
prompt_types[0] = KRB5_PROMPT_TYPE_NEW_PASSWORD;
prompt[1].prompt = _("Enter it again");
prompt[1].hidden = 1;
prompt[1].reply = &pw1;
prompt_types[1] = KRB5_PROMPT_TYPE_NEW_PASSWORD_AGAIN;
strlcpy(banner, _("Password expired. You must change it now."),
sizeof(banner));
for (tries = 3; tries; tries--) {
TRACE_GIC_PWD_CHANGEPW(context, tries);
pw0.length = sizeof(pw0array);
pw1.length = sizeof(pw1array);
/* PROMPTER_INVOCATION */
krb5int_set_prompt_types(context, prompt_types);
ret = (*prompter)(context, data, 0, banner,
sizeof(prompt)/sizeof(prompt[0]), prompt);
krb5int_set_prompt_types(context, 0);
if (ret)
goto cleanup;
if (strcmp(pw0.data, pw1.data) != 0) {
ret = KRB5_LIBOS_BADPWDMATCH;
snprintf(banner, sizeof(banner),
_("%s. Please try again."), error_message(ret));
} else if (pw0.length == 0) {
ret = KRB5_CHPW_PWDNULL;
snprintf(banner, sizeof(banner),
_("%s. Please try again."), error_message(ret));
} else {
int result_code;
krb5_data code_string;
krb5_data result_string;
if ((ret = krb5_change_password(context, &chpw_creds, pw0array,
&result_code, &code_string,
&result_string)))
goto cleanup;
/* the change succeeded. go on */
if (result_code == 0) {
free(result_string.data);
break;
}
/* set this in case the retry loop falls through */
ret = KRB5_CHPW_FAIL;
if (result_code != KRB5_KPASSWD_SOFTERROR) {
free(result_string.data);
goto cleanup;
}
/* the error was soft, so try again */
if (krb5_chpw_message(context, &result_string, &message) != 0)
message = NULL;
/* 100 is I happen to know that no code_string will be longer
than 100 chars */
if (message != NULL && strlen(message) > (sizeof(banner) - 100))
message[sizeof(banner) - 100] = '\0';
snprintf(banner, sizeof(banner),
_("%.*s%s%s. Please try again.\n"),
(int) code_string.length, code_string.data,
message ? ": " : "", message ? message : "");
free(message);
free(code_string.data);
free(result_string.data);
}
}
if (ret)
goto cleanup;
/* the password change was successful. Get an initial ticket
from the master. this is the last try. the return from this
is final. */
TRACE_GIC_PWD_CHANGED(context);
ret = krb5int_get_init_creds(context, creds, client, prompter, data,
start_time, in_tkt_service, options,
krb5_get_as_key_password, (void *) &pw0,
&use_master, &as_reply);
if (ret)
goto cleanup;
cleanup:
if (ret == 0)
warn_pw_expiry(context, options, prompter, data, in_tkt_service,
as_reply);
if (chpw_opts)
krb5_get_init_creds_opt_free(context, chpw_opts);
memset(pw0array, 0, sizeof(pw0array));
memset(pw1array, 0, sizeof(pw1array));
krb5_free_cred_contents(context, &chpw_creds);
if (as_reply)
krb5_free_kdc_rep(context, as_reply);
return(ret);
}
static krb5_error_code
get_cred_kdc_usage(krb5_context context,
krb5_ccache id,
krb5_kdc_flags flags,
krb5_addresses *addresses,
krb5_creds *in_creds,
krb5_creds *krbtgt,
krb5_creds *out_creds,
krb5_key_usage usage)
{
TGS_REQ req;
krb5_data enc;
krb5_data resp;
krb5_kdc_rep rep;
KRB_ERROR error;
krb5_error_code ret;
unsigned nonce;
krb5_keyblock *subkey = NULL;
size_t len;
Ticket second_ticket;
int send_to_kdc_flags = 0;
krb5_data_zero(&resp);
krb5_data_zero(&enc);
krb5_generate_random_block(&nonce, sizeof(nonce));
nonce &= 0xffffffff;
if(flags.b.enc_tkt_in_skey){
ret = decode_Ticket(in_creds->second_ticket.data,
in_creds->second_ticket.length,
&second_ticket, &len);
if(ret)
return ret;
}
ret = init_tgs_req (context,
id,
addresses,
flags,
flags.b.enc_tkt_in_skey ? &second_ticket : NULL,
in_creds,
krbtgt,
nonce,
&subkey,
&req,
usage);
if(flags.b.enc_tkt_in_skey)
free_Ticket(&second_ticket);
if (ret)
goto out;
ASN1_MALLOC_ENCODE(TGS_REQ, enc.data, enc.length, &req, &len, ret);
if (ret)
goto out;
if(enc.length != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
/* don't free addresses */
req.req_body.addresses = NULL;
free_TGS_REQ(&req);
/*
* Send and receive
*/
again:
ret = krb5_sendto_kdc_flags (context, &enc,
&krbtgt->server->name.name_string.val[1],
&resp,
send_to_kdc_flags);
if(ret)
goto out;
memset(&rep, 0, sizeof(rep));
if(decode_TGS_REP(resp.data, resp.length, &rep.kdc_rep, &len) == 0){
ret = krb5_copy_principal(context,
in_creds->client,
&out_creds->client);
if(ret)
goto out;
ret = krb5_copy_principal(context,
in_creds->server,
&out_creds->server);
if(ret)
goto out;
/* this should go someplace else */
out_creds->times.endtime = in_creds->times.endtime;
ret = _krb5_extract_ticket(context,
&rep,
out_creds,
&krbtgt->session,
NULL,
KRB5_KU_TGS_REP_ENC_PART_SESSION,
&krbtgt->addresses,
nonce,
TRUE,
flags.b.request_anonymous,
decrypt_tkt_with_subkey,
subkey);
krb5_free_kdc_rep(context, &rep);
} else if(krb5_rd_error(context, &resp, &error) == 0) {
ret = krb5_error_from_rd_error(context, &error, in_creds);
krb5_free_error_contents(context, &error);
if (ret == KRB5KRB_ERR_RESPONSE_TOO_BIG && !(send_to_kdc_flags & KRB5_KRBHST_FLAGS_LARGE_MSG)) {
send_to_kdc_flags |= KRB5_KRBHST_FLAGS_LARGE_MSG;
krb5_data_free(&resp);
goto again;
}
} else if(resp.data && ((char*)resp.data)[0] == 4) {
ret = KRB5KRB_AP_ERR_V4_REPLY;
krb5_clear_error_string(context);
} else {
ret = KRB5KRB_AP_ERR_MSG_TYPE;
krb5_clear_error_string(context);
}
out:
krb5_data_free(&resp);
krb5_data_free(&enc);
if(subkey){
krb5_free_keyblock_contents(context, subkey);
free(subkey);
}
return ret;
}
krb5_error_code
krb5int_process_tgs_reply(krb5_context context,
struct krb5int_fast_request_state *fast_state,
krb5_data *response_data,
krb5_creds *tkt,
krb5_flags kdcoptions,
krb5_address *const *address,
krb5_pa_data **in_padata,
krb5_creds *in_cred,
krb5_timestamp timestamp,
krb5_int32 nonce,
krb5_keyblock *subkey,
krb5_pa_data ***out_padata,
krb5_pa_data ***out_enc_padata,
krb5_creds **out_cred)
{
krb5_error_code retval;
krb5_kdc_rep *dec_rep = NULL;
krb5_error *err_reply = NULL;
krb5_boolean s4u2self;
s4u2self = krb5int_find_pa_data(context, in_padata,
KRB5_PADATA_S4U_X509_USER) ||
krb5int_find_pa_data(context, in_padata,
KRB5_PADATA_FOR_USER);
if (krb5_is_krb_error(response_data)) {
retval = decode_krb5_error(response_data, &err_reply);
if (retval != 0)
goto cleanup;
retval = krb5int_fast_process_error(context, fast_state,
&err_reply, NULL, NULL);
if (retval)
goto cleanup;
retval = (krb5_error_code) err_reply->error + ERROR_TABLE_BASE_krb5;
if (err_reply->text.length > 0) {
switch (err_reply->error) {
case KRB_ERR_GENERIC:
k5_setmsg(context, retval,
_("KDC returned error string: %.*s"),
err_reply->text.length, err_reply->text.data);
break;
case KDC_ERR_S_PRINCIPAL_UNKNOWN:
{
char *s_name;
if (err_reply->server &&
krb5_unparse_name(context, err_reply->server, &s_name) == 0) {
k5_setmsg(context, retval,
_("Server %s not found in Kerberos database"),
s_name);
krb5_free_unparsed_name(context, s_name);
} else
/* In case there's a stale S_PRINCIPAL_UNKNOWN
report already noted. */
krb5_clear_error_message(context);
}
break;
}
}
krb5_free_error(context, err_reply);
goto cleanup;
} else if (!krb5_is_tgs_rep(response_data)) {
retval = KRB5KRB_AP_ERR_MSG_TYPE;
goto cleanup;
}
/* Unfortunately, Heimdal at least up through 1.2 encrypts using
the session key not the subsession key. So we try both. */
retval = krb5int_decode_tgs_rep(context, fast_state, response_data, subkey,
KRB5_KEYUSAGE_TGS_REP_ENCPART_SUBKEY,
&dec_rep);
if (retval) {
TRACE_TGS_REPLY_DECODE_SESSION(context, &tkt->keyblock);
if ((krb5int_decode_tgs_rep(context, fast_state, response_data,
&tkt->keyblock,
KRB5_KEYUSAGE_TGS_REP_ENCPART_SESSKEY, &dec_rep)) == 0)
retval = 0;
else
goto cleanup;
}
if (dec_rep->msg_type != KRB5_TGS_REP) {
retval = KRB5KRB_AP_ERR_MSG_TYPE;
goto cleanup;
}
/*
* Don't trust the ok-as-delegate flag from foreign KDCs unless the
* cross-realm TGT also had the ok-as-delegate flag set.
*/
if (!tgt_is_local_realm(tkt)
&& !(tkt->ticket_flags & TKT_FLG_OK_AS_DELEGATE))
dec_rep->enc_part2->flags &= ~TKT_FLG_OK_AS_DELEGATE;
/* make sure the response hasn't been tampered with..... */
retval = 0;
if (s4u2self && !IS_TGS_PRINC(dec_rep->ticket->server)) {
/* Final hop, check whether KDC supports S4U2Self */
if (krb5_principal_compare(context, dec_rep->client, in_cred->server))
retval = KRB5KDC_ERR_PADATA_TYPE_NOSUPP;
} else if ((kdcoptions & KDC_OPT_CNAME_IN_ADDL_TKT) == 0) {
/* XXX for constrained delegation this check must be performed by caller
* as we don't have access to the key to decrypt the evidence ticket.
*/
if (!krb5_principal_compare(context, dec_rep->client, tkt->client))
retval = KRB5_KDCREP_MODIFIED;
}
if (retval == 0)
retval = check_reply_server(context, kdcoptions, in_cred, dec_rep);
if (dec_rep->enc_part2->nonce != nonce)
retval = KRB5_KDCREP_MODIFIED;
if ((kdcoptions & KDC_OPT_POSTDATED) &&
(in_cred->times.starttime != 0) &&
(in_cred->times.starttime != dec_rep->enc_part2->times.starttime))
retval = KRB5_KDCREP_MODIFIED;
if ((in_cred->times.endtime != 0) &&
(dec_rep->enc_part2->times.endtime > in_cred->times.endtime))
retval = KRB5_KDCREP_MODIFIED;
if ((kdcoptions & KDC_OPT_RENEWABLE) &&
(in_cred->times.renew_till != 0) &&
(dec_rep->enc_part2->times.renew_till > in_cred->times.renew_till))
retval = KRB5_KDCREP_MODIFIED;
if ((kdcoptions & KDC_OPT_RENEWABLE_OK) &&
(dec_rep->enc_part2->flags & KDC_OPT_RENEWABLE) &&
(in_cred->times.endtime != 0) &&
(dec_rep->enc_part2->times.renew_till > in_cred->times.endtime))
retval = KRB5_KDCREP_MODIFIED;
if (retval != 0)
goto cleanup;
if (!in_cred->times.starttime &&
!in_clock_skew(dec_rep->enc_part2->times.starttime,
timestamp)) {
retval = KRB5_KDCREP_SKEW;
goto cleanup;
}
if (out_padata != NULL) {
*out_padata = dec_rep->padata;
dec_rep->padata = NULL;
}
if (out_enc_padata != NULL) {
*out_enc_padata = dec_rep->enc_part2->enc_padata;
dec_rep->enc_part2->enc_padata = NULL;
}
retval = kdcrep2creds(context, dec_rep, address,
&in_cred->second_ticket, out_cred);
if (retval != 0)
goto cleanup;
cleanup:
if (dec_rep != NULL) {
memset(dec_rep->enc_part2->session->contents, 0,
dec_rep->enc_part2->session->length);
krb5_free_kdc_rep(context, dec_rep);
}
return retval;
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_get_in_cred(krb5_context context,
krb5_flags options,
const krb5_addresses *addrs,
const krb5_enctype *etypes,
const krb5_preauthtype *ptypes,
const krb5_preauthdata *preauth,
krb5_key_proc key_proc,
krb5_const_pointer keyseed,
krb5_decrypt_proc decrypt_proc,
krb5_const_pointer decryptarg,
krb5_creds *creds,
krb5_kdc_rep *ret_as_reply)
{
krb5_error_code ret;
AS_REQ a;
krb5_kdc_rep rep;
krb5_data req, resp;
size_t len;
krb5_salt salt;
krb5_keyblock *key;
size_t size;
KDCOptions opts;
PA_DATA *pa;
krb5_enctype etype;
krb5_preauthdata *my_preauth = NULL;
unsigned nonce;
int done;
opts = int2KDCOptions(options);
krb5_generate_random_block (&nonce, sizeof(nonce));
nonce &= 0xffffffff;
do {
done = 1;
ret = init_as_req (context,
opts,
creds,
addrs,
etypes,
ptypes,
preauth,
key_proc,
keyseed,
nonce,
&a);
if (my_preauth) {
free_ETYPE_INFO(&my_preauth->val[0].info);
free (my_preauth->val);
my_preauth = NULL;
}
if (ret)
return ret;
ASN1_MALLOC_ENCODE(AS_REQ, req.data, req.length, &a, &len, ret);
free_AS_REQ(&a);
if (ret)
return ret;
if(len != req.length)
krb5_abortx(context, "internal error in ASN.1 encoder");
ret = krb5_sendto_kdc (context, &req, &creds->client->realm, &resp);
krb5_data_free(&req);
if (ret)
return ret;
memset (&rep, 0, sizeof(rep));
ret = decode_AS_REP(resp.data, resp.length, &rep.kdc_rep, &size);
if(ret) {
/* let's try to parse it as a KRB-ERROR */
KRB_ERROR error;
int ret2;
ret2 = krb5_rd_error(context, &resp, &error);
if(ret2 && resp.data && ((char*)resp.data)[0] == 4)
ret = KRB5KRB_AP_ERR_V4_REPLY;
krb5_data_free(&resp);
if (ret2 == 0) {
ret = krb5_error_from_rd_error(context, &error, creds);
/* if no preauth was set and KDC requires it, give it
one more try */
if (!ptypes && !preauth
&& ret == KRB5KDC_ERR_PREAUTH_REQUIRED
#if 0
|| ret == KRB5KDC_ERR_BADOPTION
#endif
&& set_ptypes(context, &error, &ptypes, &my_preauth)) {
done = 0;
preauth = my_preauth;
krb5_free_error_contents(context, &error);
krb5_clear_error_string(context);
continue;
}
if(ret_as_reply)
ret_as_reply->error = error;
else
free_KRB_ERROR (&error);
return ret;
}
return ret;
}
krb5_data_free(&resp);
} while(!done);
pa = NULL;
etype = rep.kdc_rep.enc_part.etype;
if(rep.kdc_rep.padata){
int i = 0;
pa = krb5_find_padata(rep.kdc_rep.padata->val, rep.kdc_rep.padata->len,
KRB5_PADATA_PW_SALT, &i);
if(pa == NULL) {
i = 0;
pa = krb5_find_padata(rep.kdc_rep.padata->val,
rep.kdc_rep.padata->len,
KRB5_PADATA_AFS3_SALT, &i);
}
}
if(pa) {
salt.salttype = pa->padata_type;
salt.saltvalue = pa->padata_value;
ret = (*key_proc)(context, etype, salt, keyseed, &key);
} else {
/* make a v5 salted pa-data */
ret = krb5_get_pw_salt (context, creds->client, &salt);
if (ret)
goto out;
ret = (*key_proc)(context, etype, salt, keyseed, &key);
krb5_free_salt(context, salt);
}
if (ret)
goto out;
{
unsigned flags = 0;
if (opts.request_anonymous)
flags |= EXTRACT_TICKET_ALLOW_SERVER_MISMATCH;
ret = _krb5_extract_ticket(context,
&rep,
creds,
key,
keyseed,
KRB5_KU_AS_REP_ENC_PART,
NULL,
nonce,
flags,
decrypt_proc,
decryptarg);
}
memset (key->keyvalue.data, 0, key->keyvalue.length);
krb5_free_keyblock_contents (context, key);
free (key);
out:
if (ret == 0 && ret_as_reply)
*ret_as_reply = rep;
else
krb5_free_kdc_rep (context, &rep);
return ret;
}