/* Construct an AP-REQ message for a TGS request. */
static krb5_error_code
tgs_construct_ap_req(krb5_context context, krb5_data *checksum_data,
krb5_creds *tgt, krb5_keyblock *subkey,
krb5_data **ap_req_asn1_out)
{
krb5_cksumtype cksumtype;
krb5_error_code ret;
krb5_checksum checksum;
krb5_authenticator authent;
krb5_ap_req ap_req;
krb5_data *authent_asn1 = NULL;
krb5_ticket *ticket = NULL;
krb5_enc_data authent_enc;
*ap_req_asn1_out = NULL;
memset(&checksum, 0, sizeof(checksum));
memset(&ap_req, 0, sizeof(ap_req));
memset(&authent_enc, 0, sizeof(authent_enc));
/* Determine the authenticator checksum type. */
switch (tgt->keyblock.enctype) {
case ENCTYPE_DES_CBC_CRC:
case ENCTYPE_DES_CBC_MD4:
case ENCTYPE_DES_CBC_MD5:
case ENCTYPE_ARCFOUR_HMAC:
case ENCTYPE_ARCFOUR_HMAC_EXP:
cksumtype = context->kdc_req_sumtype;
break;
default:
ret = krb5int_c_mandatory_cksumtype(context, tgt->keyblock.enctype,
&cksumtype);
if (ret)
goto cleanup;
}
/* Generate checksum. */
ret = krb5_c_make_checksum(context, cksumtype, &tgt->keyblock,
KRB5_KEYUSAGE_TGS_REQ_AUTH_CKSUM, checksum_data,
&checksum);
if (ret)
goto cleanup;
/* Construct, encode, and encrypt an authenticator. */
authent.subkey = subkey;
authent.seq_number = 0;
authent.checksum = &checksum;
authent.client = tgt->client;
authent.authorization_data = tgt->authdata;
ret = krb5_us_timeofday(context, &authent.ctime, &authent.cusec);
if (ret)
goto cleanup;
ret = encode_krb5_authenticator(&authent, &authent_asn1);
if (ret)
goto cleanup;
ret = krb5_encrypt_helper(context, &tgt->keyblock,
KRB5_KEYUSAGE_TGS_REQ_AUTH, authent_asn1,
&authent_enc);
if (ret)
goto cleanup;
ret = decode_krb5_ticket(&tgt->ticket, &ticket);
if (ret)
goto cleanup;
/* Encode the AP-REQ. */
ap_req.authenticator = authent_enc;
ap_req.ticket = ticket;
ret = encode_krb5_ap_req(&ap_req, ap_req_asn1_out);
cleanup:
free(checksum.contents);
krb5_free_ticket(context, ticket);
krb5_free_data_contents(context, &authent_enc.ciphertext);
if (authent_asn1 != NULL)
zapfree(authent_asn1->data, authent_asn1->length);
free(authent_asn1);
return ret;
}
krb5_error_code KRB5_CALLCONV
krb5_mk_req_extended(krb5_context context, krb5_auth_context *auth_context,
krb5_flags ap_req_options, krb5_data *in_data,
krb5_creds *in_creds, krb5_data *outbuf)
{
krb5_error_code retval;
krb5_checksum checksum;
krb5_checksum *checksump = 0;
krb5_auth_context new_auth_context;
krb5_enctype *desired_etypes = NULL;
krb5_ap_req request;
krb5_data *scratch = 0;
krb5_data *toutbuf;
request.ap_options = ap_req_options & AP_OPTS_WIRE_MASK;
request.authenticator.ciphertext.data = NULL;
request.ticket = 0;
if (!in_creds->ticket.length)
return(KRB5_NO_TKT_SUPPLIED);
if ((ap_req_options & AP_OPTS_ETYPE_NEGOTIATION) &&
!(ap_req_options & AP_OPTS_MUTUAL_REQUIRED))
return(EINVAL);
/* we need a native ticket */
if ((retval = decode_krb5_ticket(&(in_creds)->ticket, &request.ticket)))
return(retval);
/* verify that the ticket is not expired */
if ((retval = krb5int_validate_times(context, &in_creds->times)) != 0)
goto cleanup;
/* generate auth_context if needed */
if (*auth_context == NULL) {
if ((retval = krb5_auth_con_init(context, &new_auth_context)))
goto cleanup;
*auth_context = new_auth_context;
}
if ((*auth_context)->key != NULL) {
krb5_k_free_key(context, (*auth_context)->key);
(*auth_context)->key = NULL;
}
/* set auth context keyblock */
if ((retval = krb5_k_create_key(context, &in_creds->keyblock,
&((*auth_context)->key))))
goto cleanup;
/* generate seq number if needed */
if ((((*auth_context)->auth_context_flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE)
|| ((*auth_context)->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE))
&& ((*auth_context)->local_seq_number == 0)) {
if ((retval = krb5_generate_seq_number(context, &in_creds->keyblock,
&(*auth_context)->local_seq_number)))
goto cleanup;
}
/* generate subkey if needed */
if ((ap_req_options & AP_OPTS_USE_SUBKEY)&&(!(*auth_context)->send_subkey)) {
retval = k5_generate_and_save_subkey(context, *auth_context,
&in_creds->keyblock,
in_creds->keyblock.enctype);
if (retval)
goto cleanup;
}
if (!in_data && (*auth_context)->checksum_func) {
retval = (*auth_context)->checksum_func( context,
*auth_context,
(*auth_context)->checksum_func_data,
&in_data);
if (retval)
goto cleanup;
}
if (in_data) {
if ((*auth_context)->req_cksumtype == 0x8003) {
/* XXX Special hack for GSSAPI */
checksum.checksum_type = 0x8003;
checksum.length = in_data->length;
checksum.contents = (krb5_octet *) in_data->data;
} else {
krb5_enctype enctype = krb5_k_key_enctype(context,
(*auth_context)->key);
krb5_cksumtype cksumtype = ap_req_cksum(context, *auth_context,
enctype);
if ((retval = krb5_k_make_checksum(context,
cksumtype,
(*auth_context)->key,
KRB5_KEYUSAGE_AP_REQ_AUTH_CKSUM,
in_data, &checksum)))
goto cleanup_cksum;
}
checksump = &checksum;
}
/* Generate authenticator */
if (((*auth_context)->authentp = (krb5_authenticator *)malloc(sizeof(
krb5_authenticator))) == NULL) {
retval = ENOMEM;
goto cleanup_cksum;
}
if (ap_req_options & AP_OPTS_ETYPE_NEGOTIATION) {
if ((*auth_context)->permitted_etypes == NULL) {
retval = krb5_get_tgs_ktypes(context, in_creds->server, &desired_etypes);
if (retval)
goto cleanup_cksum;
} else
desired_etypes = (*auth_context)->permitted_etypes;
}
TRACE_MK_REQ(context, in_creds, (*auth_context)->local_seq_number,
(*auth_context)->send_subkey, &in_creds->keyblock);
if ((retval = generate_authenticator(context,
(*auth_context)->authentp,
in_creds->client, checksump,
(*auth_context)->send_subkey,
(*auth_context)->local_seq_number,
in_creds->authdata,
(*auth_context)->ad_context,
desired_etypes,
in_creds->keyblock.enctype)))
goto cleanup_cksum;
/* encode the authenticator */
if ((retval = encode_krb5_authenticator((*auth_context)->authentp,
&scratch)))
goto cleanup_cksum;
/* call the encryption routine */
if ((retval = krb5_encrypt_helper(context, &in_creds->keyblock,
KRB5_KEYUSAGE_AP_REQ_AUTH,
scratch, &request.authenticator)))
goto cleanup_cksum;
if ((retval = encode_krb5_ap_req(&request, &toutbuf)))
goto cleanup_cksum;
*outbuf = *toutbuf;
free(toutbuf);
cleanup_cksum:
/* Null out these fields, to prevent pointer sharing problems;
* they were supplied by the caller
*/
if ((*auth_context)->authentp != NULL) {
(*auth_context)->authentp->client = NULL;
(*auth_context)->authentp->checksum = NULL;
}
if (checksump && checksump->checksum_type != 0x8003)
free(checksump->contents);
cleanup:
if (desired_etypes &&
desired_etypes != (*auth_context)->permitted_etypes)
free(desired_etypes);
if (request.ticket)
krb5_free_ticket(context, request.ticket);
if (request.authenticator.ciphertext.data) {
(void) memset(request.authenticator.ciphertext.data, 0,
request.authenticator.ciphertext.length);
free(request.authenticator.ciphertext.data);
}
if (scratch) {
memset(scratch->data, 0, scratch->length);
free(scratch->data);
free(scratch);
}
return retval;
}
/*
Sends a request to the TGS and waits for a response.
options is used for the options in the KRB_TGS_REQ.
timestruct values are used for from, till, rtime " " "
enctype is used for enctype " " ", and to encrypt the authorization data,
sname is used for sname " " "
addrs, if non-NULL, is used for addresses " " "
authorization_dat, if non-NULL, is used for authorization_dat " " "
second_ticket, if required by options, is used for the 2nd ticket in the req.
in_cred is used for the ticket & session key in the KRB_AP_REQ header " " "
(the KDC realm is extracted from in_cred->server's realm)
The response is placed into *rep.
rep->response.data is set to point at allocated storage which should be
freed by the caller when finished.
returns system errors
*/
static krb5_error_code
krb5_send_tgs_basic(krb5_context context, krb5_data *in_data, krb5_creds *in_cred, krb5_data *outbuf)
{
krb5_error_code retval;
krb5_checksum checksum;
krb5_authenticator authent;
krb5_ap_req request;
krb5_data * scratch;
krb5_data * toutbuf;
/* Generate checksum */
if ((retval = krb5_c_make_checksum(context, context->kdc_req_sumtype,
&in_cred->keyblock,
KRB5_KEYUSAGE_TGS_REQ_AUTH_CKSUM,
in_data, &checksum))) {
free(checksum.contents);
return(retval);
}
/* gen authenticator */
authent.subkey = 0;
authent.seq_number = 0;
authent.checksum = &checksum;
authent.client = in_cred->client;
authent.authorization_data = in_cred->authdata;
if ((retval = krb5_us_timeofday(context, &authent.ctime,
&authent.cusec))) {
free(checksum.contents);
return(retval);
}
/* encode the authenticator */
if ((retval = encode_krb5_authenticator(&authent, &scratch))) {
free(checksum.contents);
return(retval);
}
free(checksum.contents);
request.authenticator.ciphertext.data = 0;
request.authenticator.kvno = 0;
request.ap_options = 0;
request.ticket = 0;
if ((retval = decode_krb5_ticket(&(in_cred)->ticket, &request.ticket)))
/* Cleanup scratch and scratch data */
goto cleanup_data;
/* call the encryption routine */
if ((retval = krb5_encrypt_helper(context, &in_cred->keyblock,
KRB5_KEYUSAGE_TGS_REQ_AUTH,
scratch, &request.authenticator)))
goto cleanup_ticket;
retval = encode_krb5_ap_req(&request, &toutbuf);
/* Solaris Kerberos */
if (retval == 0) {
*outbuf = *toutbuf;
krb5_xfree(toutbuf);
}
memset(request.authenticator.ciphertext.data, 0,
request.authenticator.ciphertext.length);
free(request.authenticator.ciphertext.data);
cleanup_ticket:
krb5_free_ticket(context, request.ticket);
cleanup_data:
memset(scratch->data, 0, scratch->length);
free(scratch->data);
free(scratch);
return retval;
}
