krb5_error_code KRB5_LIB_FUNCTION
krb5_get_forwarded_creds (krb5_context context,
krb5_auth_context auth_context,
krb5_ccache ccache,
krb5_flags flags,
const char *hostname,
krb5_creds *in_creds,
krb5_data *out_data)
{
krb5_error_code ret;
krb5_creds *out_creds;
krb5_addresses addrs, *paddrs;
KRB_CRED cred;
KrbCredInfo *krb_cred_info;
EncKrbCredPart enc_krb_cred_part;
size_t len;
unsigned char *buf;
size_t buf_size;
krb5_kdc_flags kdc_flags;
krb5_crypto crypto;
struct addrinfo *ai;
int save_errno;
krb5_creds *ticket;
char *realm;
if (in_creds->client && in_creds->client->realm)
realm = in_creds->client->realm;
else
realm = in_creds->server->realm;
addrs.len = 0;
addrs.val = NULL;
paddrs = &addrs;
/*
* If tickets are address-less, forward address-less tickets.
*/
ret = _krb5_get_krbtgt (context,
ccache,
realm,
&ticket);
if(ret == 0) {
if (ticket->addresses.len == 0)
paddrs = NULL;
krb5_free_creds (context, ticket);
}
if (paddrs != NULL) {
ret = getaddrinfo (hostname, NULL, NULL, &ai);
if (ret) {
save_errno = errno;
krb5_set_error_string(context, "resolving %s: %s",
hostname, gai_strerror(ret));
return krb5_eai_to_heim_errno(ret, save_errno);
}
ret = add_addrs (context, &addrs, ai);
freeaddrinfo (ai);
if (ret)
return ret;
}
kdc_flags.b = int2KDCOptions(flags);
ret = krb5_get_kdc_cred (context,
ccache,
kdc_flags,
paddrs,
NULL,
in_creds,
&out_creds);
krb5_free_addresses (context, &addrs);
if (ret) {
return ret;
}
memset (&cred, 0, sizeof(cred));
cred.pvno = 5;
cred.msg_type = krb_cred;
ALLOC_SEQ(&cred.tickets, 1);
if (cred.tickets.val == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto out2;
}
ret = decode_Ticket(out_creds->ticket.data,
out_creds->ticket.length,
cred.tickets.val, &len);
if (ret)
goto out3;
memset (&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part));
ALLOC_SEQ(&enc_krb_cred_part.ticket_info, 1);
if (enc_krb_cred_part.ticket_info.val == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto out4;
}
if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
krb5_timestamp sec;
int32_t usec;
krb5_us_timeofday (context, &sec, &usec);
ALLOC(enc_krb_cred_part.timestamp, 1);
if (enc_krb_cred_part.timestamp == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto out4;
}
*enc_krb_cred_part.timestamp = sec;
ALLOC(enc_krb_cred_part.usec, 1);
if (enc_krb_cred_part.usec == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto out4;
}
*enc_krb_cred_part.usec = usec;
} else {
enc_krb_cred_part.timestamp = NULL;
enc_krb_cred_part.usec = NULL;
}
if (auth_context->local_address && auth_context->local_port) {
krb5_boolean noaddr;
krb5_const_realm realm;
realm = krb5_principal_get_realm(context, out_creds->server);
krb5_appdefault_boolean(context, NULL, realm, "no-addresses", paddrs == NULL,
&noaddr);
if (!noaddr) {
ret = krb5_make_addrport (context,
&enc_krb_cred_part.s_address,
auth_context->local_address,
auth_context->local_port);
if (ret)
goto out4;
}
}
if (auth_context->remote_address) {
if (auth_context->remote_port) {
krb5_boolean noaddr;
krb5_const_realm realm;
realm = krb5_principal_get_realm(context, out_creds->server);
/* Is this correct, and should we use the paddrs == NULL
trick here as well? Having an address-less ticket may
indicate that we don't know our own global address, but
it does not necessary mean that we don't know the
server's. */
krb5_appdefault_boolean(context, NULL, realm, "no-addresses",
FALSE, &noaddr);
if (!noaddr) {
ret = krb5_make_addrport (context,
&enc_krb_cred_part.r_address,
auth_context->remote_address,
auth_context->remote_port);
if (ret)
goto out4;
}
} else {
ALLOC(enc_krb_cred_part.r_address, 1);
if (enc_krb_cred_part.r_address == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "malloc: out of memory");
goto out4;
}
ret = krb5_copy_address (context, auth_context->remote_address,
enc_krb_cred_part.r_address);
if (ret)
goto out4;
}
}
/* fill ticket_info.val[0] */
enc_krb_cred_part.ticket_info.len = 1;
krb_cred_info = enc_krb_cred_part.ticket_info.val;
copy_EncryptionKey (&out_creds->session, &krb_cred_info->key);
ALLOC(krb_cred_info->prealm, 1);
copy_Realm (&out_creds->client->realm, krb_cred_info->prealm);
ALLOC(krb_cred_info->pname, 1);
copy_PrincipalName(&out_creds->client->name, krb_cred_info->pname);
ALLOC(krb_cred_info->flags, 1);
*krb_cred_info->flags = out_creds->flags.b;
ALLOC(krb_cred_info->authtime, 1);
*krb_cred_info->authtime = out_creds->times.authtime;
ALLOC(krb_cred_info->starttime, 1);
*krb_cred_info->starttime = out_creds->times.starttime;
ALLOC(krb_cred_info->endtime, 1);
*krb_cred_info->endtime = out_creds->times.endtime;
ALLOC(krb_cred_info->renew_till, 1);
*krb_cred_info->renew_till = out_creds->times.renew_till;
ALLOC(krb_cred_info->srealm, 1);
copy_Realm (&out_creds->server->realm, krb_cred_info->srealm);
ALLOC(krb_cred_info->sname, 1);
copy_PrincipalName (&out_creds->server->name, krb_cred_info->sname);
ALLOC(krb_cred_info->caddr, 1);
copy_HostAddresses (&out_creds->addresses, krb_cred_info->caddr);
krb5_free_creds (context, out_creds);
/* encode EncKrbCredPart */
ASN1_MALLOC_ENCODE(EncKrbCredPart, buf, buf_size,
&enc_krb_cred_part, &len, ret);
free_EncKrbCredPart (&enc_krb_cred_part);
if (ret) {
free_KRB_CRED(&cred);
return ret;
}
if(buf_size != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
if (auth_context->flags & KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED) {
cred.enc_part.etype = ENCTYPE_NULL;
cred.enc_part.kvno = NULL;
cred.enc_part.cipher.data = buf;
cred.enc_part.cipher.length = buf_size;
} else {
krb5_keyblock *key;
if (auth_context->local_subkey)
key = auth_context->local_subkey;
else if (auth_context->remote_subkey)
key = auth_context->remote_subkey;
else
key = auth_context->keyblock;
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret) {
free(buf);
free_KRB_CRED(&cred);
return ret;
}
ret = krb5_encrypt_EncryptedData (context,
crypto,
KRB5_KU_KRB_CRED,
buf,
len,
0,
&cred.enc_part);
free(buf);
krb5_crypto_destroy(context, crypto);
if (ret) {
free_KRB_CRED(&cred);
return ret;
}
}
ASN1_MALLOC_ENCODE(KRB_CRED, buf, buf_size, &cred, &len, ret);
free_KRB_CRED (&cred);
if (ret)
return ret;
if(buf_size != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
out_data->length = len;
out_data->data = buf;
return 0;
out4:
free_EncKrbCredPart(&enc_krb_cred_part);
out3:
free_KRB_CRED(&cred);
out2:
krb5_free_creds (context, out_creds);
return ret;
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_cred(krb5_context context,
krb5_auth_context auth_context,
krb5_data *in_data,
krb5_creds ***ret_creds,
krb5_replay_data *outdata)
{
krb5_error_code ret;
size_t len;
KRB_CRED cred;
EncKrbCredPart enc_krb_cred_part;
krb5_data enc_krb_cred_part_data;
krb5_crypto crypto;
int i;
memset(&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part));
if ((auth_context->flags &
(KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
outdata == NULL)
return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
*ret_creds = NULL;
ret = decode_KRB_CRED(in_data->data, in_data->length,
&cred, &len);
if(ret) {
krb5_clear_error_message(context);
return ret;
}
if (cred.pvno != 5) {
ret = KRB5KRB_AP_ERR_BADVERSION;
krb5_clear_error_message (context);
goto out;
}
if (cred.msg_type != krb_cred) {
ret = KRB5KRB_AP_ERR_MSG_TYPE;
krb5_clear_error_message (context);
goto out;
}
if (cred.enc_part.etype == ETYPE_NULL) {
/* DK: MIT GSS-API Compatibility */
enc_krb_cred_part_data.length = cred.enc_part.cipher.length;
enc_krb_cred_part_data.data = cred.enc_part.cipher.data;
} else {
/* Try both subkey and session key.
*
* RFC4120 claims we should use the session key, but Heimdal
* before 0.8 used the remote subkey if it was send in the
* auth_context.
*/
if (auth_context->remote_subkey) {
ret = krb5_crypto_init(context, auth_context->remote_subkey,
0, &crypto);
if (ret)
goto out;
ret = krb5_decrypt_EncryptedData(context,
crypto,
KRB5_KU_KRB_CRED,
&cred.enc_part,
&enc_krb_cred_part_data);
krb5_crypto_destroy(context, crypto);
}
/*
* If there was not subkey, or we failed using subkey,
* retry using the session key
*/
if (auth_context->remote_subkey == NULL || ret == KRB5KRB_AP_ERR_BAD_INTEGRITY)
{
ret = krb5_crypto_init(context, auth_context->keyblock,
0, &crypto);
if (ret)
goto out;
ret = krb5_decrypt_EncryptedData(context,
crypto,
KRB5_KU_KRB_CRED,
&cred.enc_part,
&enc_krb_cred_part_data);
krb5_crypto_destroy(context, crypto);
}
if (ret)
goto out;
}
ret = decode_EncKrbCredPart(enc_krb_cred_part_data.data,
enc_krb_cred_part_data.length,
&enc_krb_cred_part,
&len);
if (enc_krb_cred_part_data.data != cred.enc_part.cipher.data)
krb5_data_free(&enc_krb_cred_part_data);
if (ret) {
krb5_set_error_message(context, ret,
N_("Failed to decode "
"encrypte credential part", ""));
goto out;
}
/* check sender address */
if (enc_krb_cred_part.s_address
&& auth_context->remote_address
&& auth_context->remote_port) {
krb5_address *a;
ret = krb5_make_addrport (context, &a,
auth_context->remote_address,
auth_context->remote_port);
if (ret)
goto out;
ret = compare_addrs(context, a, enc_krb_cred_part.s_address,
N_("sender address is wrong "
"in received creds", ""));
krb5_free_address(context, a);
free(a);
if(ret)
goto out;
}
/* check receiver address */
if (enc_krb_cred_part.r_address
&& auth_context->local_address) {
if(auth_context->local_port &&
enc_krb_cred_part.r_address->addr_type == KRB5_ADDRESS_ADDRPORT) {
krb5_address *a;
ret = krb5_make_addrport (context, &a,
auth_context->local_address,
auth_context->local_port);
if (ret)
goto out;
ret = compare_addrs(context, a, enc_krb_cred_part.r_address,
N_("receiver address is wrong "
"in received creds", ""));
krb5_free_address(context, a);
free(a);
if(ret)
goto out;
} else {
ret = compare_addrs(context, auth_context->local_address,
enc_krb_cred_part.r_address,
N_("receiver address is wrong "
"in received creds", ""));
if(ret)
goto out;
}
}
/* check timestamp */
if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
krb5_timestamp sec;
krb5_timeofday (context, &sec);
if (enc_krb_cred_part.timestamp == NULL ||
enc_krb_cred_part.usec == NULL ||
abs(*enc_krb_cred_part.timestamp - sec)
> context->max_skew) {
krb5_clear_error_message (context);
ret = KRB5KRB_AP_ERR_SKEW;
goto out;
}
}
if ((auth_context->flags &
(KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) {
/* if these fields are not present in the cred-part, silently
return zero */
memset(outdata, 0, sizeof(*outdata));
if(enc_krb_cred_part.timestamp)
outdata->timestamp = *enc_krb_cred_part.timestamp;
if(enc_krb_cred_part.usec)
outdata->usec = *enc_krb_cred_part.usec;
if(enc_krb_cred_part.nonce)
outdata->seq = *enc_krb_cred_part.nonce;
}
/* Convert to NULL terminated list of creds */
*ret_creds = calloc(enc_krb_cred_part.ticket_info.len + 1,
sizeof(**ret_creds));
if (*ret_creds == NULL) {
ret = ENOMEM;
krb5_set_error_message(context, ret,
N_("malloc: out of memory", ""));
goto out;
}
for (i = 0; i < enc_krb_cred_part.ticket_info.len; ++i) {
KrbCredInfo *kci = &enc_krb_cred_part.ticket_info.val[i];
krb5_creds *creds;
creds = calloc(1, sizeof(*creds));
if(creds == NULL) {
ret = ENOMEM;
krb5_set_error_message(context, ret,
N_("malloc: out of memory", ""));
goto out;
}
ASN1_MALLOC_ENCODE(Ticket, creds->ticket.data, creds->ticket.length,
&cred.tickets.val[i], &len, ret);
if (ret) {
free(creds);
goto out;
}
if(creds->ticket.length != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
copy_EncryptionKey (&kci->key, &creds->session);
if (kci->prealm && kci->pname)
_krb5_principalname2krb5_principal (context,
&creds->client,
*kci->pname,
*kci->prealm);
if (kci->flags)
creds->flags.b = *kci->flags;
if (kci->authtime)
creds->times.authtime = *kci->authtime;
if (kci->starttime)
creds->times.starttime = *kci->starttime;
if (kci->endtime)
creds->times.endtime = *kci->endtime;
if (kci->renew_till)
creds->times.renew_till = *kci->renew_till;
if (kci->srealm && kci->sname)
_krb5_principalname2krb5_principal (context,
&creds->server,
*kci->sname,
*kci->srealm);
if (kci->caddr)
krb5_copy_addresses (context,
kci->caddr,
&creds->addresses);
(*ret_creds)[i] = creds;
}
(*ret_creds)[i] = NULL;
free_KRB_CRED (&cred);
free_EncKrbCredPart(&enc_krb_cred_part);
return 0;
out:
free_EncKrbCredPart(&enc_krb_cred_part);
free_KRB_CRED (&cred);
if(*ret_creds) {
for(i = 0; (*ret_creds)[i]; i++)
krb5_free_creds(context, (*ret_creds)[i]);
free(*ret_creds);
*ret_creds = NULL;
}
return ret;
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_forwarded_creds (krb5_context context,
krb5_auth_context auth_context,
krb5_ccache ccache,
krb5_flags flags,
const char *hostname,
krb5_creds *in_creds,
krb5_data *out_data)
{
krb5_error_code ret;
krb5_creds *out_creds;
krb5_addresses addrs, *paddrs;
KRB_CRED cred;
KrbCredInfo *krb_cred_info;
EncKrbCredPart enc_krb_cred_part;
size_t len;
unsigned char *buf;
size_t buf_size;
krb5_kdc_flags kdc_flags;
krb5_crypto crypto;
struct addrinfo *ai;
krb5_creds *ticket;
paddrs = NULL;
addrs.len = 0;
addrs.val = NULL;
ret = krb5_get_credentials(context, 0, ccache, in_creds, &ticket);
if(ret == 0) {
if (ticket->addresses.len)
paddrs = &addrs;
krb5_free_creds (context, ticket);
} else {
krb5_boolean noaddr;
krb5_appdefault_boolean(context, NULL,
krb5_principal_get_realm(context,
in_creds->client),
"no-addresses", KRB5_ADDRESSLESS_DEFAULT,
&noaddr);
if (!noaddr)
paddrs = &addrs;
}
/*
* If tickets have addresses, get the address of the remote host.
*/
if (paddrs != NULL) {
ret = getaddrinfo (hostname, NULL, NULL, &ai);
if (ret) {
krb5_error_code ret2 = krb5_eai_to_heim_errno(ret, errno);
krb5_set_error_message(context, ret2,
N_("resolving host %s failed: %s",
"hostname, error"),
hostname, gai_strerror(ret));
return ret2;
}
ret = add_addrs (context, &addrs, ai);
freeaddrinfo (ai);
if (ret)
return ret;
}
kdc_flags.b = int2KDCOptions(flags);
ret = krb5_get_kdc_cred (context,
ccache,
kdc_flags,
paddrs,
NULL,
in_creds,
&out_creds);
krb5_free_addresses (context, &addrs);
if (ret)
return ret;
memset (&cred, 0, sizeof(cred));
cred.pvno = 5;
cred.msg_type = krb_cred;
ALLOC_SEQ(&cred.tickets, 1);
if (cred.tickets.val == NULL) {
ret = ENOMEM;
krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
goto out2;
}
ret = decode_Ticket(out_creds->ticket.data,
out_creds->ticket.length,
cred.tickets.val, &len);
if (ret)
goto out3;
memset (&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part));
ALLOC_SEQ(&enc_krb_cred_part.ticket_info, 1);
if (enc_krb_cred_part.ticket_info.val == NULL) {
ret = ENOMEM;
krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
goto out4;
}
if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
krb5_timestamp sec;
int32_t usec;
krb5_us_timeofday (context, &sec, &usec);
ALLOC(enc_krb_cred_part.timestamp, 1);
if (enc_krb_cred_part.timestamp == NULL) {
ret = ENOMEM;
krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
goto out4;
}
*enc_krb_cred_part.timestamp = sec;
ALLOC(enc_krb_cred_part.usec, 1);
if (enc_krb_cred_part.usec == NULL) {
ret = ENOMEM;
krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
goto out4;
}
*enc_krb_cred_part.usec = usec;
} else {
enc_krb_cred_part.timestamp = NULL;
enc_krb_cred_part.usec = NULL;
}
if (auth_context->local_address && auth_context->local_port && paddrs) {
ret = krb5_make_addrport (context,
&enc_krb_cred_part.s_address,
auth_context->local_address,
auth_context->local_port);
if (ret)
goto out4;
}
if (auth_context->remote_address) {
if (auth_context->remote_port) {
krb5_boolean noaddr;
krb5_const_realm srealm;
srealm = krb5_principal_get_realm(context, out_creds->server);
/* Is this correct, and should we use the paddrs == NULL
trick here as well? Having an address-less ticket may
indicate that we don't know our own global address, but
it does not necessary mean that we don't know the
server's. */
krb5_appdefault_boolean(context, NULL, srealm, "no-addresses",
FALSE, &noaddr);
if (!noaddr) {
ret = krb5_make_addrport (context,
&enc_krb_cred_part.r_address,
auth_context->remote_address,
auth_context->remote_port);
if (ret)
goto out4;
}
} else {
ALLOC(enc_krb_cred_part.r_address, 1);
if (enc_krb_cred_part.r_address == NULL) {
ret = ENOMEM;
krb5_set_error_message(context, ret,
N_("malloc: out of memory", ""));
goto out4;
}
ret = krb5_copy_address (context, auth_context->remote_address,
enc_krb_cred_part.r_address);
if (ret)
goto out4;
}
}
/* fill ticket_info.val[0] */
enc_krb_cred_part.ticket_info.len = 1;
krb_cred_info = enc_krb_cred_part.ticket_info.val;
copy_EncryptionKey (&out_creds->session, &krb_cred_info->key);
ALLOC(krb_cred_info->prealm, 1);
copy_Realm (&out_creds->client->realm, krb_cred_info->prealm);
ALLOC(krb_cred_info->pname, 1);
copy_PrincipalName(&out_creds->client->name, krb_cred_info->pname);
ALLOC(krb_cred_info->flags, 1);
*krb_cred_info->flags = out_creds->flags.b;
ALLOC(krb_cred_info->authtime, 1);
*krb_cred_info->authtime = out_creds->times.authtime;
ALLOC(krb_cred_info->starttime, 1);
*krb_cred_info->starttime = out_creds->times.starttime;
ALLOC(krb_cred_info->endtime, 1);
*krb_cred_info->endtime = out_creds->times.endtime;
ALLOC(krb_cred_info->renew_till, 1);
*krb_cred_info->renew_till = out_creds->times.renew_till;
ALLOC(krb_cred_info->srealm, 1);
copy_Realm (&out_creds->server->realm, krb_cred_info->srealm);
ALLOC(krb_cred_info->sname, 1);
copy_PrincipalName (&out_creds->server->name, krb_cred_info->sname);
ALLOC(krb_cred_info->caddr, 1);
copy_HostAddresses (&out_creds->addresses, krb_cred_info->caddr);
krb5_free_creds (context, out_creds);
/* encode EncKrbCredPart */
ASN1_MALLOC_ENCODE(EncKrbCredPart, buf, buf_size,
&enc_krb_cred_part, &len, ret);
free_EncKrbCredPart (&enc_krb_cred_part);
if (ret) {
free_KRB_CRED(&cred);
return ret;
}
if(buf_size != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
/**
* Some older of the MIT gssapi library used clear-text tickets
* (warped inside AP-REQ encryption), use the krb5_auth_context
* flag KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED to support those
* tickets. The session key is used otherwise to encrypt the
* forwarded ticket.
*/
if (auth_context->flags & KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED) {
cred.enc_part.etype = KRB5_ENCTYPE_NULL;
cred.enc_part.kvno = NULL;
cred.enc_part.cipher.data = buf;
cred.enc_part.cipher.length = buf_size;
} else {
/*
* Here older versions then 0.7.2 of Heimdal used the local or
* remote subkey. That is wrong, the session key should be
* used. Heimdal 0.7.2 and newer have code to try both in the
* receiving end.
*/
ret = krb5_crypto_init(context, auth_context->keyblock, 0, &crypto);
if (ret) {
free(buf);
free_KRB_CRED(&cred);
return ret;
}
ret = krb5_encrypt_EncryptedData (context,
crypto,
KRB5_KU_KRB_CRED,
buf,
len,
0,
&cred.enc_part);
free(buf);
krb5_crypto_destroy(context, crypto);
if (ret) {
free_KRB_CRED(&cred);
return ret;
}
}
ASN1_MALLOC_ENCODE(KRB_CRED, buf, buf_size, &cred, &len, ret);
free_KRB_CRED (&cred);
if (ret)
return ret;
if(buf_size != len)
krb5_abortx(context, "internal error in ASN.1 encoder");
out_data->length = len;
out_data->data = buf;
return 0;
out4:
free_EncKrbCredPart(&enc_krb_cred_part);
out3:
free_KRB_CRED(&cred);
out2:
krb5_free_creds (context, out_creds);
return ret;
}