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handoff.cc
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// Copyright 2018 The BoringSSL Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <openssl/ssl.h>
#include <openssl/bytestring.h>
#include <openssl/err.h>
#include "../crypto/internal.h"
#include "internal.h"
BSSL_NAMESPACE_BEGIN
constexpr int kHandoffVersion = 0;
constexpr int kHandbackVersion = 0;
static const CBS_ASN1_TAG kHandoffTagALPS = CBS_ASN1_CONTEXT_SPECIFIC | 0;
// early_data_t represents the state of early data in a more compact way than
// the 3 bits used by the implementation.
enum early_data_t {
early_data_not_offered = 0,
early_data_accepted = 1,
early_data_rejected_hrr = 2,
early_data_skipped = 3,
early_data_max_value = early_data_skipped,
};
// serialize_features adds a description of features supported by this binary to
// |out|. Returns true on success and false on error.
static bool serialize_features(CBB *out) {
CBB ciphers;
if (!CBB_add_asn1(out, &ciphers, CBS_ASN1_OCTETSTRING)) {
return false;
}
Span<const SSL_CIPHER> all_ciphers = AllCiphers();
for (const SSL_CIPHER &cipher : all_ciphers) {
if (!CBB_add_u16(&ciphers, static_cast<uint16_t>(cipher.id))) {
return false;
}
}
CBB groups;
if (!CBB_add_asn1(out, &groups, CBS_ASN1_OCTETSTRING)) {
return false;
}
for (const NamedGroup &g : NamedGroups()) {
if (!CBB_add_u16(&groups, g.group_id)) {
return false;
}
}
// ALPS is a draft protocol and may change over time. The handoff structure
// contains a [0] IMPLICIT OCTET STRING OPTIONAL, containing a list of u16
// ALPS versions that the binary supports. For now we name them by codepoint.
// Once ALPS is finalized and past the support horizon, this field can be
// removed.
CBB alps;
if (!CBB_add_asn1(out, &alps, kHandoffTagALPS) ||
!CBB_add_u16(&alps, TLSEXT_TYPE_application_settings_old) ||
!CBB_add_u16(&alps, TLSEXT_TYPE_application_settings)) {
return false;
}
return CBB_flush(out);
}
bool SSL_serialize_handoff(const SSL *ssl, CBB *out,
SSL_CLIENT_HELLO *out_hello) {
const SSL3_STATE *const s3 = ssl->s3;
if (!ssl->server || //
s3->hs == nullptr || //
s3->rwstate != SSL_ERROR_HANDOFF) {
return false;
}
CBB seq;
SSLMessage msg;
Span<const uint8_t> transcript = s3->hs->transcript.buffer();
if (!CBB_add_asn1(out, &seq, CBS_ASN1_SEQUENCE) ||
!CBB_add_asn1_uint64(&seq, kHandoffVersion) ||
!CBB_add_asn1_octet_string(&seq, transcript.data(), transcript.size()) ||
!CBB_add_asn1_octet_string(&seq,
reinterpret_cast<uint8_t *>(s3->hs_buf->data),
s3->hs_buf->length) ||
!serialize_features(&seq) || !CBB_flush(out) ||
!ssl->method->get_message(ssl, &msg) ||
!SSL_parse_client_hello(ssl, out_hello, CBS_data(&msg.body),
CBS_len(&msg.body))) {
return false;
}
return true;
}
bool SSL_decline_handoff(SSL *ssl) {
const SSL3_STATE *const s3 = ssl->s3;
if (!ssl->server || s3->hs == nullptr || s3->rwstate != SSL_ERROR_HANDOFF) {
return false;
}
s3->hs->config->handoff = false;
return true;
}
// apply_remote_features reads a list of supported features from |in| and
// (possibly) reconfigures |ssl| to disallow the negotation of features whose
// support has not been indicated. (This prevents the the handshake from
// committing to features that are not supported on the handoff/handback side.)
static bool apply_remote_features(SSL *ssl, CBS *in) {
CBS ciphers;
if (!CBS_get_asn1(in, &ciphers, CBS_ASN1_OCTETSTRING)) {
return false;
}
bssl::UniquePtr<STACK_OF(SSL_CIPHER)> supported(sk_SSL_CIPHER_new_null());
if (!supported) {
return false;
}
while (CBS_len(&ciphers)) {
uint16_t id;
if (!CBS_get_u16(&ciphers, &id)) {
return false;
}
const SSL_CIPHER *cipher = SSL_get_cipher_by_value(id);
if (!cipher) {
continue;
}
if (!sk_SSL_CIPHER_push(supported.get(), cipher)) {
return false;
}
}
STACK_OF(SSL_CIPHER) *configured =
ssl->config->cipher_list ? ssl->config->cipher_list->ciphers.get()
: ssl->ctx->cipher_list->ciphers.get();
bssl::UniquePtr<STACK_OF(SSL_CIPHER)> unsupported(sk_SSL_CIPHER_new_null());
if (!unsupported) {
return false;
}
for (const SSL_CIPHER *configured_cipher : configured) {
if (sk_SSL_CIPHER_find(supported.get(), nullptr, configured_cipher)) {
continue;
}
if (!sk_SSL_CIPHER_push(unsupported.get(), configured_cipher)) {
return false;
}
}
if (sk_SSL_CIPHER_num(unsupported.get()) && !ssl->config->cipher_list) {
ssl->config->cipher_list = bssl::MakeUnique<SSLCipherPreferenceList>();
if (!ssl->config->cipher_list ||
!ssl->config->cipher_list->Init(*ssl->ctx->cipher_list)) {
return false;
}
}
for (const SSL_CIPHER *unsupported_cipher : unsupported.get()) {
ssl->config->cipher_list->Remove(unsupported_cipher);
}
if (sk_SSL_CIPHER_num(SSL_get_ciphers(ssl)) == 0) {
return false;
}
CBS groups;
if (!CBS_get_asn1(in, &groups, CBS_ASN1_OCTETSTRING)) {
return false;
}
Array<uint16_t> supported_groups;
if (!supported_groups.InitForOverwrite(CBS_len(&groups) / 2)) {
return false;
}
size_t idx = 0;
while (CBS_len(&groups)) {
uint16_t group;
if (!CBS_get_u16(&groups, &group)) {
return false;
}
supported_groups[idx++] = group;
}
Span<const uint16_t> configured_groups =
tls1_get_grouplist(ssl->s3->hs.get());
Array<uint16_t> new_configured_groups;
if (!new_configured_groups.InitForOverwrite(configured_groups.size())) {
return false;
}
idx = 0;
for (uint16_t configured_group : configured_groups) {
bool ok = false;
for (uint16_t supported_group : supported_groups) {
if (supported_group == configured_group) {
ok = true;
break;
}
}
if (ok) {
new_configured_groups[idx++] = configured_group;
}
}
if (idx == 0) {
return false;
}
new_configured_groups.Shrink(idx);
ssl->config->supported_group_list = std::move(new_configured_groups);
CBS alps;
CBS_init(&alps, nullptr, 0);
if (!CBS_get_optional_asn1(in, &alps, /*out_present=*/nullptr,
kHandoffTagALPS)) {
return false;
}
bool supports_alps = false;
while (CBS_len(&alps) != 0) {
uint16_t id;
if (!CBS_get_u16(&alps, &id)) {
return false;
}
// For now, we support two ALPS codepoints, so we need to extract both
// codepoints, and then filter what the handshaker might try to send.
if ((id == TLSEXT_TYPE_application_settings &&
ssl->config->alps_use_new_codepoint) ||
(id == TLSEXT_TYPE_application_settings_old &&
!ssl->config->alps_use_new_codepoint)) {
supports_alps = true;
break;
}
}
if (!supports_alps) {
ssl->config->alps_configs.clear();
}
return true;
}
// uses_disallowed_feature returns true iff |ssl| enables a feature that
// disqualifies it for split handshakes.
static bool uses_disallowed_feature(const SSL *ssl) {
return ssl->method->is_dtls || !ssl->config->cert->credentials.empty() ||
ssl->config->quic_transport_params.size() > 0 || ssl->ctx->ech_keys;
}
bool SSL_apply_handoff(SSL *ssl, Span<const uint8_t> handoff) {
if (uses_disallowed_feature(ssl)) {
return false;
}
CBS seq, handoff_cbs(handoff);
uint64_t handoff_version;
if (!CBS_get_asn1(&handoff_cbs, &seq, CBS_ASN1_SEQUENCE) ||
!CBS_get_asn1_uint64(&seq, &handoff_version) ||
handoff_version != kHandoffVersion) {
return false;
}
CBS transcript, hs_buf;
if (!CBS_get_asn1(&seq, &transcript, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &hs_buf, CBS_ASN1_OCTETSTRING) ||
!apply_remote_features(ssl, &seq)) {
return false;
}
SSL_set_accept_state(ssl);
SSL3_STATE *const s3 = ssl->s3;
s3->v2_hello_done = true;
s3->has_message = true;
s3->hs_buf.reset(BUF_MEM_new());
if (!s3->hs_buf ||
!BUF_MEM_append(s3->hs_buf.get(), CBS_data(&hs_buf), CBS_len(&hs_buf))) {
return false;
}
if (CBS_len(&transcript) != 0) {
s3->hs->transcript.Update(transcript);
s3->is_v2_hello = true;
}
s3->hs->handback = true;
return true;
}
bool SSL_serialize_handback(const SSL *ssl, CBB *out) {
if (!ssl->server || uses_disallowed_feature(ssl)) {
return false;
}
const SSL3_STATE *const s3 = ssl->s3;
SSL_HANDSHAKE *const hs = s3->hs.get();
handback_t type;
switch (hs->state) {
case state12_read_change_cipher_spec:
type = handback_after_session_resumption;
break;
case state12_read_client_certificate:
type = handback_after_ecdhe;
break;
case state12_finish_server_handshake:
type = handback_after_handshake;
break;
case state12_tls13:
if (hs->tls13_state != state13_send_half_rtt_ticket) {
return false;
}
type = handback_tls13;
break;
default:
return false;
}
size_t hostname_len = 0;
if (s3->hostname) {
hostname_len = strlen(s3->hostname.get());
}
Span<const uint8_t> transcript;
if (type != handback_after_handshake) {
transcript = s3->hs->transcript.buffer();
}
size_t write_iv_len = 0;
const uint8_t *write_iv = nullptr;
if ((type == handback_after_session_resumption ||
type == handback_after_handshake) &&
ssl->s3->version == TLS1_VERSION &&
SSL_CIPHER_is_block_cipher(s3->aead_write_ctx->cipher()) &&
!s3->aead_write_ctx->GetIV(&write_iv, &write_iv_len)) {
return false;
}
size_t read_iv_len = 0;
const uint8_t *read_iv = nullptr;
if (type == handback_after_handshake && //
ssl->s3->version == TLS1_VERSION && //
SSL_CIPHER_is_block_cipher(s3->aead_read_ctx->cipher()) && //
!s3->aead_read_ctx->GetIV(&read_iv, &read_iv_len)) {
return false;
}
// TODO(mab): make sure everything is serialized.
CBB seq, key_share;
const SSL_SESSION *session;
if (type == handback_tls13) {
session = hs->new_session.get();
} else {
session = s3->session_reused ? ssl->session.get() : hs->new_session.get();
}
uint8_t read_sequence[8], write_sequence[8];
CRYPTO_store_u64_be(read_sequence, s3->read_sequence);
CRYPTO_store_u64_be(write_sequence, s3->write_sequence);
static const uint8_t kUnusedChannelID[64] = {0};
if (!CBB_add_asn1(out, &seq, CBS_ASN1_SEQUENCE) ||
!CBB_add_asn1_uint64(&seq, kHandbackVersion) ||
!CBB_add_asn1_uint64(&seq, type) ||
!CBB_add_asn1_octet_string(&seq, read_sequence, sizeof(read_sequence)) ||
!CBB_add_asn1_octet_string(&seq, write_sequence,
sizeof(write_sequence)) ||
!CBB_add_asn1_octet_string(&seq, s3->server_random,
sizeof(s3->server_random)) ||
!CBB_add_asn1_octet_string(&seq, s3->client_random,
sizeof(s3->client_random)) ||
!CBB_add_asn1_octet_string(&seq, read_iv, read_iv_len) ||
!CBB_add_asn1_octet_string(&seq, write_iv, write_iv_len) ||
!CBB_add_asn1_bool(&seq, s3->session_reused) ||
!CBB_add_asn1_bool(&seq, hs->channel_id_negotiated) ||
!ssl_session_serialize(session, &seq) ||
!CBB_add_asn1_octet_string(&seq, s3->next_proto_negotiated.data(),
s3->next_proto_negotiated.size()) ||
!CBB_add_asn1_octet_string(&seq, s3->alpn_selected.data(),
s3->alpn_selected.size()) ||
!CBB_add_asn1_octet_string(
&seq, reinterpret_cast<uint8_t *>(s3->hostname.get()),
hostname_len) ||
!CBB_add_asn1_octet_string(&seq, kUnusedChannelID,
sizeof(kUnusedChannelID)) ||
// These two fields were historically |token_binding_negotiated| and
// |negotiated_token_binding_param|.
!CBB_add_asn1_bool(&seq, 0) || //
!CBB_add_asn1_uint64(&seq, 0) ||
!CBB_add_asn1_bool(&seq, s3->hs->next_proto_neg_seen) ||
!CBB_add_asn1_bool(&seq, s3->hs->cert_request) ||
!CBB_add_asn1_bool(&seq, s3->hs->extended_master_secret) ||
!CBB_add_asn1_bool(&seq, s3->hs->ticket_expected) ||
!CBB_add_asn1_uint64(&seq, SSL_CIPHER_get_id(s3->hs->new_cipher)) ||
!CBB_add_asn1_octet_string(&seq, transcript.data(), transcript.size()) ||
!CBB_add_asn1(&seq, &key_share, CBS_ASN1_SEQUENCE)) {
return false;
}
if (type == handback_after_ecdhe) {
CBB private_key;
if (!CBB_add_asn1_uint64(&key_share, s3->hs->key_shares[0]->GroupID()) ||
!CBB_add_asn1(&key_share, &private_key, CBS_ASN1_OCTETSTRING) ||
!s3->hs->key_shares[0]->SerializePrivateKey(&private_key) ||
!CBB_flush(&key_share)) {
return false;
}
}
if (type == handback_tls13) {
early_data_t early_data;
// Check early data invariants.
if (ssl->enable_early_data ==
(s3->early_data_reason == ssl_early_data_disabled)) {
return false;
}
if (hs->early_data_offered) {
if (s3->early_data_accepted && !s3->skip_early_data) {
early_data = early_data_accepted;
} else if (!s3->early_data_accepted && !s3->skip_early_data) {
early_data = early_data_rejected_hrr;
} else if (!s3->early_data_accepted && s3->skip_early_data) {
early_data = early_data_skipped;
} else {
return false;
}
} else if (!s3->early_data_accepted && !s3->skip_early_data) {
early_data = early_data_not_offered;
} else {
return false;
}
if (!CBB_add_asn1_octet_string(&seq, hs->client_traffic_secret_0.data(),
hs->client_traffic_secret_0.size()) ||
!CBB_add_asn1_octet_string(&seq, hs->server_traffic_secret_0.data(),
hs->server_traffic_secret_0.size()) ||
!CBB_add_asn1_octet_string(&seq, hs->client_handshake_secret.data(),
hs->client_handshake_secret.size()) ||
!CBB_add_asn1_octet_string(&seq, hs->server_handshake_secret.data(),
hs->server_handshake_secret.size()) ||
!CBB_add_asn1_octet_string(&seq, hs->secret.data(),
hs->secret.size()) ||
!CBB_add_asn1_octet_string(&seq, s3->exporter_secret.data(),
s3->exporter_secret.size()) ||
!CBB_add_asn1_bool(&seq, s3->used_hello_retry_request) ||
!CBB_add_asn1_bool(&seq, hs->accept_psk_mode) ||
!CBB_add_asn1_int64(&seq, s3->ticket_age_skew) ||
!CBB_add_asn1_uint64(&seq, s3->early_data_reason) ||
!CBB_add_asn1_uint64(&seq, early_data)) {
return false;
}
if (early_data == early_data_accepted &&
!CBB_add_asn1_octet_string(&seq, hs->early_traffic_secret.data(),
hs->early_traffic_secret.size())) {
return false;
}
if (session->has_application_settings) {
uint16_t alps_codepoint = TLSEXT_TYPE_application_settings_old;
if (hs->config->alps_use_new_codepoint) {
alps_codepoint = TLSEXT_TYPE_application_settings;
}
if (!CBB_add_asn1_uint64(&seq, alps_codepoint)) {
return false;
}
}
}
return CBB_flush(out);
}
static bool CopyExact(Span<uint8_t> out, const CBS *in) {
if (CBS_len(in) != out.size()) {
return false;
}
OPENSSL_memcpy(out.data(), CBS_data(in), out.size());
return true;
}
bool SSL_apply_handback(SSL *ssl, Span<const uint8_t> handback) {
if (ssl->do_handshake != nullptr || //
ssl->method->is_dtls) {
return false;
}
SSL3_STATE *const s3 = ssl->s3;
uint64_t handback_version, unused_token_binding_param, cipher, type_u64,
alps_codepoint;
CBS seq, read_seq, write_seq, server_rand, client_rand, read_iv, write_iv,
next_proto, alpn, hostname, unused_channel_id, transcript, key_share;
int session_reused, channel_id_negotiated, cert_request,
extended_master_secret, ticket_expected, unused_token_binding,
next_proto_neg_seen;
SSL_SESSION *session = nullptr;
CBS handback_cbs(handback);
if (!CBS_get_asn1(&handback_cbs, &seq, CBS_ASN1_SEQUENCE) || //
!CBS_get_asn1_uint64(&seq, &handback_version) || //
handback_version != kHandbackVersion || //
!CBS_get_asn1_uint64(&seq, &type_u64) || //
type_u64 > handback_max_value) {
return false;
}
handback_t type = static_cast<handback_t>(type_u64);
if (!CBS_get_asn1(&seq, &read_seq, CBS_ASN1_OCTETSTRING) ||
CBS_len(&read_seq) != sizeof(s3->read_sequence) ||
!CBS_get_asn1(&seq, &write_seq, CBS_ASN1_OCTETSTRING) ||
CBS_len(&write_seq) != sizeof(s3->write_sequence) ||
!CBS_get_asn1(&seq, &server_rand, CBS_ASN1_OCTETSTRING) ||
CBS_len(&server_rand) != sizeof(s3->server_random) ||
!CBS_copy_bytes(&server_rand, s3->server_random,
sizeof(s3->server_random)) ||
!CBS_get_asn1(&seq, &client_rand, CBS_ASN1_OCTETSTRING) ||
CBS_len(&client_rand) != sizeof(s3->client_random) ||
!CBS_copy_bytes(&client_rand, s3->client_random,
sizeof(s3->client_random)) ||
!CBS_get_asn1(&seq, &read_iv, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &write_iv, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1_bool(&seq, &session_reused) ||
!CBS_get_asn1_bool(&seq, &channel_id_negotiated)) {
return false;
}
s3->hs = ssl_handshake_new(ssl);
if (!s3->hs) {
return false;
}
SSL_HANDSHAKE *const hs = s3->hs.get();
if (!session_reused || type == handback_tls13) {
hs->new_session =
SSL_SESSION_parse(&seq, ssl->ctx->x509_method, ssl->ctx->pool);
session = hs->new_session.get();
} else {
ssl->session =
SSL_SESSION_parse(&seq, ssl->ctx->x509_method, ssl->ctx->pool);
session = ssl->session.get();
}
if (!session || !CBS_get_asn1(&seq, &next_proto, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &alpn, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &hostname, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &unused_channel_id, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1_bool(&seq, &unused_token_binding) ||
!CBS_get_asn1_uint64(&seq, &unused_token_binding_param) ||
!CBS_get_asn1_bool(&seq, &next_proto_neg_seen) ||
!CBS_get_asn1_bool(&seq, &cert_request) ||
!CBS_get_asn1_bool(&seq, &extended_master_secret) ||
!CBS_get_asn1_bool(&seq, &ticket_expected) ||
!CBS_get_asn1_uint64(&seq, &cipher)) {
return false;
}
if ((hs->new_cipher =
SSL_get_cipher_by_value(static_cast<uint16_t>(cipher))) == nullptr) {
return false;
}
if (!CBS_get_asn1(&seq, &transcript, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &key_share, CBS_ASN1_SEQUENCE)) {
return false;
}
CBS client_handshake_secret, server_handshake_secret, client_traffic_secret_0,
server_traffic_secret_0, secret, exporter_secret, early_traffic_secret;
if (type == handback_tls13) {
int used_hello_retry_request, accept_psk_mode;
uint64_t early_data, early_data_reason;
int64_t ticket_age_skew;
if (!CBS_get_asn1(&seq, &client_traffic_secret_0, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &server_traffic_secret_0, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &client_handshake_secret, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &server_handshake_secret, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &secret, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1(&seq, &exporter_secret, CBS_ASN1_OCTETSTRING) ||
!CBS_get_asn1_bool(&seq, &used_hello_retry_request) ||
!CBS_get_asn1_bool(&seq, &accept_psk_mode) ||
!CBS_get_asn1_int64(&seq, &ticket_age_skew) ||
!CBS_get_asn1_uint64(&seq, &early_data_reason) ||
early_data_reason > ssl_early_data_reason_max_value ||
!CBS_get_asn1_uint64(&seq, &early_data) ||
early_data > early_data_max_value) {
return false;
}
early_data_t early_data_type = static_cast<early_data_t>(early_data);
if (early_data_type == early_data_accepted &&
!CBS_get_asn1(&seq, &early_traffic_secret, CBS_ASN1_OCTETSTRING)) {
return false;
}
if (session->has_application_settings) {
// Making it optional to keep compatibility with older handshakers.
// Older handshakers won't send the field.
if (CBS_len(&seq) == 0) {
hs->config->alps_use_new_codepoint = false;
} else {
if (!CBS_get_asn1_uint64(&seq, &alps_codepoint)) {
return false;
}
if (alps_codepoint == TLSEXT_TYPE_application_settings) {
hs->config->alps_use_new_codepoint = true;
} else if (alps_codepoint == TLSEXT_TYPE_application_settings_old) {
hs->config->alps_use_new_codepoint = false;
} else {
OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_ALPS_CODEPOINT);
return false;
}
}
}
if (ticket_age_skew > std::numeric_limits<int32_t>::max() ||
ticket_age_skew < std::numeric_limits<int32_t>::min()) {
return false;
}
s3->ticket_age_skew = static_cast<int32_t>(ticket_age_skew);
s3->used_hello_retry_request = used_hello_retry_request;
hs->accept_psk_mode = accept_psk_mode;
s3->early_data_reason =
static_cast<ssl_early_data_reason_t>(early_data_reason);
ssl->enable_early_data = s3->early_data_reason != ssl_early_data_disabled;
s3->skip_early_data = false;
s3->early_data_accepted = false;
hs->early_data_offered = false;
switch (early_data_type) {
case early_data_not_offered:
break;
case early_data_accepted:
s3->early_data_accepted = true;
hs->early_data_offered = true;
hs->can_early_write = true;
hs->can_early_read = true;
hs->in_early_data = true;
break;
case early_data_rejected_hrr:
hs->early_data_offered = true;
break;
case early_data_skipped:
s3->skip_early_data = true;
hs->early_data_offered = true;
break;
default:
return false;
}
} else {
s3->early_data_reason = ssl_early_data_protocol_version;
}
ssl->s3->version = session->ssl_version;
if (!ssl_method_supports_version(ssl->method, ssl->s3->version) ||
session->cipher != hs->new_cipher ||
ssl_protocol_version(ssl) < SSL_CIPHER_get_min_version(session->cipher) ||
SSL_CIPHER_get_max_version(session->cipher) < ssl_protocol_version(ssl)) {
return false;
}
ssl->do_handshake = ssl_server_handshake;
ssl->server = true;
switch (type) {
case handback_after_session_resumption:
hs->state = state12_read_change_cipher_spec;
if (!session_reused) {
return false;
}
break;
case handback_after_ecdhe:
hs->state = state12_read_client_certificate;
if (session_reused) {
return false;
}
break;
case handback_after_handshake:
hs->state = state12_finish_server_handshake;
break;
case handback_tls13:
hs->state = state12_tls13;
hs->tls13_state = state13_send_half_rtt_ticket;
break;
default:
return false;
}
s3->session_reused = session_reused;
hs->channel_id_negotiated = channel_id_negotiated;
if (!s3->next_proto_negotiated.CopyFrom(next_proto) ||
!s3->alpn_selected.CopyFrom(alpn)) {
return false;
}
const size_t hostname_len = CBS_len(&hostname);
if (hostname_len == 0) {
s3->hostname.reset();
} else {
char *hostname_str = nullptr;
if (!CBS_strdup(&hostname, &hostname_str)) {
return false;
}
s3->hostname.reset(hostname_str);
}
hs->next_proto_neg_seen = next_proto_neg_seen;
hs->wait = ssl_hs_flush;
hs->extended_master_secret = extended_master_secret;
hs->ticket_expected = ticket_expected;
hs->cert_request = cert_request;
if (type != handback_after_handshake &&
(!hs->transcript.Init() ||
!hs->transcript.InitHash(ssl_protocol_version(ssl), hs->new_cipher) ||
!hs->transcript.Update(transcript))) {
return false;
}
if (type == handback_tls13) {
if (!hs->client_traffic_secret_0.TryCopyFrom(client_traffic_secret_0) ||
!hs->server_traffic_secret_0.TryCopyFrom(server_traffic_secret_0) ||
!hs->client_handshake_secret.TryCopyFrom(client_handshake_secret) ||
!hs->server_handshake_secret.TryCopyFrom(server_handshake_secret) ||
!hs->secret.TryCopyFrom(secret) ||
!s3->exporter_secret.TryCopyFrom(exporter_secret)) {
return false;
}
if (s3->early_data_accepted &&
!hs->early_traffic_secret.TryCopyFrom(early_traffic_secret)) {
return false;
}
}
Array<uint8_t> key_block;
switch (type) {
case handback_after_session_resumption:
// The write keys are installed after server Finished, but the client
// keys must wait for ChangeCipherSpec.
if (!tls1_configure_aead(ssl, evp_aead_seal, &key_block, session,
write_iv)) {
return false;
}
break;
case handback_after_ecdhe:
// The premaster secret is not yet computed, so install no keys.
break;
case handback_after_handshake:
// The handshake is complete, so both keys are installed.
if (!tls1_configure_aead(ssl, evp_aead_seal, &key_block, session,
write_iv) ||
!tls1_configure_aead(ssl, evp_aead_open, &key_block, session,
read_iv)) {
return false;
}
break;
case handback_tls13:
// After server Finished, the application write keys are installed, but
// none of the read keys. The read keys are installed in the state machine
// immediately after processing handback.
if (!tls13_set_traffic_key(ssl, ssl_encryption_application, evp_aead_seal,
hs->new_session.get(),
hs->server_traffic_secret_0)) {
return false;
}
break;
}
uint8_t read_sequence[8], write_sequence[8];
if (!CopyExact(read_sequence, &read_seq) ||
!CopyExact(write_sequence, &write_seq)) {
return false;
}
s3->read_sequence = CRYPTO_load_u64_be(read_sequence);
s3->write_sequence = CRYPTO_load_u64_be(write_sequence);
if (type == handback_after_ecdhe) {
uint64_t group_id;
CBS private_key;
if (!CBS_get_asn1_uint64(&key_share, &group_id) || //
group_id > 0xffff ||
!CBS_get_asn1(&key_share, &private_key, CBS_ASN1_OCTETSTRING)) {
return false;
}
hs->key_shares[0] = SSLKeyShare::Create(group_id);
if (!hs->key_shares[0] ||
!hs->key_shares[0]->DeserializePrivateKey(&private_key)) {
return false;
}
}
return true; // Trailing data allowed for extensibility.
}
BSSL_NAMESPACE_END
using namespace bssl;
int SSL_serialize_capabilities(const SSL *ssl, CBB *out) {
CBB seq;
if (!CBB_add_asn1(out, &seq, CBS_ASN1_SEQUENCE) ||
!serialize_features(&seq) || //
!CBB_flush(out)) {
return 0;
}
return 1;
}
int SSL_request_handshake_hints(SSL *ssl, const uint8_t *client_hello,
size_t client_hello_len,
const uint8_t *capabilities,
size_t capabilities_len) {
if (SSL_is_dtls(ssl)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
return 0;
}
CBS cbs, seq;
CBS_init(&cbs, capabilities, capabilities_len);
UniquePtr<SSL_HANDSHAKE_HINTS> hints = MakeUnique<SSL_HANDSHAKE_HINTS>();
if (hints == nullptr || //
!CBS_get_asn1(&cbs, &seq, CBS_ASN1_SEQUENCE) || //
!apply_remote_features(ssl, &seq)) {
return 0;
}
SSL3_STATE *const s3 = ssl->s3;
s3->v2_hello_done = true;
s3->has_message = true;
Array<uint8_t> client_hello_msg;
ScopedCBB client_hello_cbb;
CBB client_hello_body;
if (!ssl->method->init_message(ssl, client_hello_cbb.get(),
&client_hello_body, SSL3_MT_CLIENT_HELLO) ||
!CBB_add_bytes(&client_hello_body, client_hello, client_hello_len) ||
!ssl->method->finish_message(ssl, client_hello_cbb.get(),
&client_hello_msg)) {
return 0;
}
s3->hs_buf.reset(BUF_MEM_new());
if (!s3->hs_buf || !BUF_MEM_append(s3->hs_buf.get(), client_hello_msg.data(),
client_hello_msg.size())) {
return 0;
}
s3->hs->hints_requested = true;
s3->hs->hints = std::move(hints);
return 1;
}
// |SSL_HANDSHAKE_HINTS| is serialized as the following ASN.1 structure. We use
// implicit tagging to make it a little more compact.
//
// HandshakeHints ::= SEQUENCE {
// serverRandomTLS13 [0] IMPLICIT OCTET STRING OPTIONAL,
// keyShareHint [1] IMPLICIT KeyShareHint OPTIONAL,
// signatureHint [2] IMPLICIT SignatureHint OPTIONAL,
// -- At most one of decryptedPSKHint or ignorePSKHint may be present. It
// -- corresponds to the first entry in pre_shared_keys. TLS 1.2 session
// -- tickets use a separate hint, to ensure the caller does not apply the
// -- hint to the wrong field.
// decryptedPSKHint [3] IMPLICIT OCTET STRING OPTIONAL,
// ignorePSKHint [4] IMPLICIT NULL OPTIONAL,
// compressCertificateHint [5] IMPLICIT CompressCertificateHint OPTIONAL,
// -- TLS 1.2 and 1.3 use different server random hints because one contains
// -- a timestamp while the other doesn't. If the hint was generated
// -- assuming TLS 1.3 but we actually negotiate TLS 1.2, mixing the two
// -- will break this.
// serverRandomTLS12 [6] IMPLICIT OCTET STRING OPTIONAL,
// ecdheHint [7] IMPLICIT ECDHEHint OPTIONAL
// -- At most one of decryptedTicketHint or ignoreTicketHint may be present.
// -- renewTicketHint requires decryptedTicketHint.
// decryptedTicketHint [8] IMPLICIT OCTET STRING OPTIONAL,
// renewTicketHint [9] IMPLICIT NULL OPTIONAL,
// ignoreTicketHint [10] IMPLICIT NULL OPTIONAL,
// }
//
// KeyShareHint ::= SEQUENCE {
// groupId INTEGER,
// ciphertext OCTET STRING,
// secret OCTET STRING,
// }
//
// SignatureHint ::= SEQUENCE {
// algorithm INTEGER,
// input OCTET STRING,
// subjectPublicKeyInfo OCTET STRING,
// signature OCTET STRING,
// }
//
// CompressCertificateHint ::= SEQUENCE {
// algorithm INTEGER,
// input OCTET STRING,
// compressed OCTET STRING,
// }
//
// ECDHEHint ::= SEQUENCE {
// groupId INTEGER,
// publicKey OCTET STRING,
// privateKey OCTET STRING,
// }
// HandshakeHints tags.
static const CBS_ASN1_TAG kServerRandomTLS13Tag = CBS_ASN1_CONTEXT_SPECIFIC | 0;
static const CBS_ASN1_TAG kKeyShareHintTag =
CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 1;
static const CBS_ASN1_TAG kSignatureHintTag =
CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 2;
static const CBS_ASN1_TAG kDecryptedPSKTag = CBS_ASN1_CONTEXT_SPECIFIC | 3;
static const CBS_ASN1_TAG kIgnorePSKTag = CBS_ASN1_CONTEXT_SPECIFIC | 4;
static const CBS_ASN1_TAG kCompressCertificateTag =
CBS_ASN1_CONTEXT_SPECIFIC | 5;
static const CBS_ASN1_TAG kServerRandomTLS12Tag = CBS_ASN1_CONTEXT_SPECIFIC | 6;
static const CBS_ASN1_TAG kECDHEHintTag = CBS_ASN1_CONSTRUCTED | 7;
static const CBS_ASN1_TAG kDecryptedTicketTag = CBS_ASN1_CONTEXT_SPECIFIC | 8;
static const CBS_ASN1_TAG kRenewTicketTag = CBS_ASN1_CONTEXT_SPECIFIC | 9;
static const CBS_ASN1_TAG kIgnoreTicketTag = CBS_ASN1_CONTEXT_SPECIFIC | 10;
int SSL_serialize_handshake_hints(const SSL *ssl, CBB *out) {
const SSL_HANDSHAKE *hs = ssl->s3->hs.get();
if (!ssl->server || !hs->hints_requested) {
OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
return 0;
}
const SSL_HANDSHAKE_HINTS *hints = hs->hints.get();
CBB seq, child;
if (!CBB_add_asn1(out, &seq, CBS_ASN1_SEQUENCE)) {
return 0;
}
if (!hints->server_random_tls13.empty()) {
if (!CBB_add_asn1(&seq, &child, kServerRandomTLS13Tag) ||
!CBB_add_bytes(&child, hints->server_random_tls13.data(),
hints->server_random_tls13.size())) {
return 0;
}
}
if (hints->key_share_group_id != 0 && !hints->key_share_ciphertext.empty() &&
!hints->key_share_secret.empty()) {
if (!CBB_add_asn1(&seq, &child, kKeyShareHintTag) ||
!CBB_add_asn1_uint64(&child, hints->key_share_group_id) ||
!CBB_add_asn1_octet_string(&child, hints->key_share_ciphertext.data(),
hints->key_share_ciphertext.size()) ||
!CBB_add_asn1_octet_string(&child, hints->key_share_secret.data(),
hints->key_share_secret.size())) {
return 0;
}
}
if (hints->signature_algorithm != 0 && !hints->signature_input.empty() &&
!hints->signature.empty()) {
if (!CBB_add_asn1(&seq, &child, kSignatureHintTag) ||
!CBB_add_asn1_uint64(&child, hints->signature_algorithm) ||
!CBB_add_asn1_octet_string(&child, hints->signature_input.data(),
hints->signature_input.size()) ||
!CBB_add_asn1_octet_string(&child, hints->signature_spki.data(),
hints->signature_spki.size()) ||
!CBB_add_asn1_octet_string(&child, hints->signature.data(),
hints->signature.size())) {
return 0;
}
}
if (!hints->decrypted_psk.empty()) {
if (!CBB_add_asn1(&seq, &child, kDecryptedPSKTag) ||
!CBB_add_bytes(&child, hints->decrypted_psk.data(),
hints->decrypted_psk.size())) {
return 0;
}
}
if (hints->ignore_psk && //
!CBB_add_asn1(&seq, &child, kIgnorePSKTag)) {
return 0;
}
if (hints->cert_compression_alg_id != 0 &&
!hints->cert_compression_input.empty() &&
!hints->cert_compression_output.empty()) {
if (!CBB_add_asn1(&seq, &child, kCompressCertificateTag) ||
!CBB_add_asn1_uint64(&child, hints->cert_compression_alg_id) ||
!CBB_add_asn1_octet_string(&child, hints->cert_compression_input.data(),
hints->cert_compression_input.size()) ||
!CBB_add_asn1_octet_string(&child,
hints->cert_compression_output.data(),
hints->cert_compression_output.size())) {
return 0;
}
}
if (!hints->server_random_tls12.empty()) {
if (!CBB_add_asn1(&seq, &child, kServerRandomTLS12Tag) ||
!CBB_add_bytes(&child, hints->server_random_tls12.data(),
hints->server_random_tls12.size())) {
return 0;
}
}
if (hints->ecdhe_group_id != 0 && !hints->ecdhe_public_key.empty() &&
!hints->ecdhe_private_key.empty()) {
if (!CBB_add_asn1(&seq, &child, kECDHEHintTag) ||
!CBB_add_asn1_uint64(&child, hints->ecdhe_group_id) ||
!CBB_add_asn1_octet_string(&child, hints->ecdhe_public_key.data(),
hints->ecdhe_public_key.size()) ||
!CBB_add_asn1_octet_string(&child, hints->ecdhe_private_key.data(),
hints->ecdhe_private_key.size())) {
return 0;
}
}
if (!hints->decrypted_ticket.empty()) {
if (!CBB_add_asn1(&seq, &child, kDecryptedTicketTag) ||
!CBB_add_bytes(&child, hints->decrypted_ticket.data(),
hints->decrypted_ticket.size())) {
return 0;
}
}