Hand back ECDHE split handshakes after the first server message.
This changes the contract for split handshakes such that on the
receiving side, the connection is to be driven until it returns
|SSL_ERROR_HANDBACK|, rather than until SSL_do_handshake() returns
success.
Change-Id: Idd1ebfbd943d88474d7c934f4c0ae757ff3c0f37
Reviewed-on: https://boringssl-review.googlesource.com/26864
Commit-Queue: Matt Braithwaite <mab@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/ssl_key_share.cc b/ssl/ssl_key_share.cc
index 4d76bb2..2a076c3 100644
--- a/ssl/ssl_key_share.cc
+++ b/ssl/ssl_key_share.cc
@@ -124,6 +124,32 @@
return true;
}
+ bool Serialize(CBB *out) override {
+ assert(private_key_);
+ CBB cbb;
+ UniquePtr<EC_GROUP> group(EC_GROUP_new_by_curve_name(nid_));
+ // Padding is added to avoid leaking the length.
+ size_t len = BN_num_bytes(EC_GROUP_get0_order(group.get()));
+ if (!CBB_add_asn1_uint64(out, group_id_) ||
+ !CBB_add_asn1(out, &cbb, CBS_ASN1_OCTETSTRING) ||
+ !BN_bn2cbb_padded(&cbb, len, private_key_.get()) ||
+ !CBB_flush(out)) {
+ return false;
+ }
+ return true;
+ }
+
+ bool Deserialize(CBS *in) override {
+ assert(!private_key_);
+ CBS private_key;
+ if (!CBS_get_asn1(in, &private_key, CBS_ASN1_OCTETSTRING)) {
+ return false;
+ }
+ private_key_.reset(BN_bin2bn(CBS_data(&private_key),
+ CBS_len(&private_key), nullptr));
+ return private_key_ != nullptr;
+ }
+
private:
UniquePtr<BIGNUM> private_key_;
int nid_;
@@ -166,6 +192,21 @@
return true;
}
+ bool Serialize(CBB *out) override {
+ return (CBB_add_asn1_uint64(out, GroupID()) &&
+ CBB_add_asn1_octet_string(out, private_key_, sizeof(private_key_)));
+ }
+
+ bool Deserialize(CBS *in) override {
+ CBS key;
+ if (!CBS_get_asn1(in, &key, CBS_ASN1_OCTETSTRING) ||
+ CBS_len(&key) != sizeof(private_key_) ||
+ !CBS_copy_bytes(&key, private_key_, sizeof(private_key_))) {
+ return false;
+ }
+ return true;
+ }
+
private:
uint8_t private_key_[32];
};
@@ -205,6 +246,19 @@
}
}
+UniquePtr<SSLKeyShare> SSLKeyShare::Create(CBS *in) {
+ uint64_t group;
+ if (!CBS_get_asn1_uint64(in, &group)) {
+ return nullptr;
+ }
+ UniquePtr<SSLKeyShare> key_share = Create(static_cast<uint64_t>(group));
+ if (!key_share->Deserialize(in)) {
+ return nullptr;
+ }
+ return key_share;
+}
+
+
bool SSLKeyShare::Accept(CBB *out_public_key, Array<uint8_t> *out_secret,
uint8_t *out_alert, Span<const uint8_t> peer_key) {
*out_alert = SSL_AD_INTERNAL_ERROR;
