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/*
* Copyright (c) 2019-2020, AuriStor, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "sanon_locl.h"
int
_gss_sanon_available_p(gss_const_cred_id_t claimant_cred_handle,
gss_const_name_t target_name,
OM_uint32 req_flags)
{
OM_uint32 minor;
gss_name_t initiator_name = GSS_C_NO_NAME;
int available;
if (claimant_cred_handle != GSS_C_NO_CREDENTIAL) {
_gss_sanon_inquire_cred(&minor, claimant_cred_handle,
&initiator_name, NULL, NULL, NULL);
heim_assert(initiator_name != GSS_C_NO_NAME,
"Invalid null SAnon initiator name");
}
/*
* SAnon is available if one of the following is true:
*
* The caller set anon_req_flag (GSS_C_ANON_FLAG)
* The claimant_cred_handle identity is anonymous
* The claimant_cred_handle is the default credential
* and target_name is anonymous
*/
if (req_flags & GSS_C_ANON_FLAG)
available = TRUE;
else if (initiator_name == _gss_sanon_anonymous_identity)
available = TRUE;
else if (claimant_cred_handle == GSS_C_NO_CREDENTIAL &&
target_name == _gss_sanon_anonymous_identity)
available = TRUE;
else
available = FALSE;
_gss_sanon_release_name(&minor, &initiator_name);
return available;
}
OM_uint32 GSSAPI_CALLCONV
_gss_sanon_init_sec_context(OM_uint32 *minor,
gss_const_cred_id_t cred_handle,
gss_ctx_id_t *context_handle,
gss_const_name_t target_name,
const gss_OID mech_type,
OM_uint32 req_flags,
OM_uint32 time_req,
const gss_channel_bindings_t input_chan_bindings,
const gss_buffer_t input_token,
gss_OID *actual_mech_type,
gss_buffer_t output_token,
OM_uint32 *ret_flags,
OM_uint32 *time_rec)
{
gss_buffer_desc mech_token = GSS_C_EMPTY_BUFFER;
OM_uint32 major, tmp;
sanon_ctx sc = (sanon_ctx)*context_handle;
OM_uint32 flags;
gss_buffer_desc session_key = GSS_C_EMPTY_BUFFER;
*minor = 0;
_mg_buffer_zero(output_token);
if (!_gss_sanon_available_p(cred_handle, target_name, req_flags)) {
major = GSS_S_UNAVAILABLE;
goto out;
}
/* we always support the following flags */
flags = GSS_C_REPLAY_FLAG | GSS_C_SEQUENCE_FLAG | GSS_C_CONF_FLAG |
GSS_C_INTEG_FLAG | GSS_C_ANON_FLAG;
/* we support the following optional flags */
flags |= req_flags & SANON_PROTOCOL_FLAG_MASK;
if (sc == NULL) {
uint8_t pk_and_flags[crypto_scalarmult_curve25519_BYTES + 8];
if (input_token != GSS_C_NO_BUFFER && input_token->length != 0) {
major = GSS_S_DEFECTIVE_TOKEN;
goto out;
}
sc = calloc(1, sizeof(*sc));
if (sc == NULL) {
*minor = ENOMEM;
major = GSS_S_FAILURE;
goto out;
}
sc->is_initiator = 1;
/* compute public and secret keys */
major = _gss_sanon_curve25519_base(minor, sc);
if (major != GSS_S_COMPLETE)
goto out;
if (flags & SANON_PROTOCOL_FLAG_MASK) {
memcpy(pk_and_flags, sc->pk, sizeof(sc->pk));
_gss_mg_encode_be_uint32(0, &pk_and_flags[sizeof(sc->pk)]);
_gss_mg_encode_be_uint32(flags & SANON_PROTOCOL_FLAG_MASK,
&pk_and_flags[sizeof(sc->pk) + 4]);
mech_token.length = sizeof(pk_and_flags);
mech_token.value = pk_and_flags;
} else {
mech_token.length = sizeof(sc->pk);
mech_token.value = sc->pk;
}
/* send public key to acceptor */
major = gss_encapsulate_token(&mech_token,
GSS_SANON_X25519_MECHANISM,
output_token);
if (major != GSS_S_COMPLETE)
goto out;
*context_handle = (gss_ctx_id_t)sc;
major = GSS_S_CONTINUE_NEEDED;
} else {
static gss_buffer_desc empty = GSS_C_EMPTY_BUFFER;
gss_buffer_desc pk, hok_mic;
if (input_token == GSS_C_NO_BUFFER ||
input_token->length < crypto_scalarmult_curve25519_BYTES) {
major = GSS_S_DEFECTIVE_TOKEN;
goto out;
} else if (sc->rfc4121 != GSS_C_NO_CONTEXT || !(sc->is_initiator)) {
major = GSS_S_BAD_STATUS;
goto out;
}
pk.length = crypto_scalarmult_curve25519_BYTES;
pk.value = input_token->value;
/* compute shared secret */
major = _gss_sanon_curve25519(minor, sc, &pk,
flags & SANON_PROTOCOL_FLAG_MASK,
input_chan_bindings, &session_key);
if (major != GSS_S_COMPLETE)
goto out;
flags |= GSS_C_TRANS_FLAG;
major = _gss_sanon_import_rfc4121_context(minor, sc, flags, &session_key);
if (major != GSS_S_COMPLETE)
goto out;
/* verify holder of key MIC */
hok_mic.length = input_token->length - pk.length;
hok_mic.value = (uint8_t *)input_token->value + pk.length;
major = _gss_sanon_verify_mic(minor, (gss_const_ctx_id_t)sc,
&empty, &hok_mic, NULL);
if (major != GSS_S_COMPLETE)
goto out;
}
if (ret_flags)
*ret_flags = flags;
if (time_rec)
*time_rec = GSS_C_INDEFINITE;
out:
if (actual_mech_type)
*actual_mech_type = GSS_SANON_X25519_MECHANISM;
if (GSS_ERROR(major)) {
_gss_sanon_delete_sec_context(&tmp, (gss_ctx_id_t *)&sc, GSS_C_NO_BUFFER);
*context_handle = GSS_C_NO_CONTEXT;
}
_gss_secure_release_buffer(&tmp, &session_key);
return major;
}
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