binder: abstract out key/cert config
This change allows certificates and keys to be configured in
a custom way.
Bug: 199344157
Fixes: 200195645
Test: pass
Change-Id: I7b88f21652142fd78e99bc5352f1e78000ca050f
diff --git a/libs/binder/RpcTransportTls.cpp b/libs/binder/RpcTransportTls.cpp
index 8c066ee..f8cd71d 100644
--- a/libs/binder/RpcTransportTls.cpp
+++ b/libs/binder/RpcTransportTls.cpp
@@ -44,8 +44,6 @@
namespace android {
namespace {
-constexpr const int kCertValidDays = 30;
-
// Implement BIO for socket that ignores SIGPIPE.
int socketNew(BIO* bio) {
BIO_set_data(bio, reinterpret_cast<void*>(-1));
@@ -100,49 +98,6 @@
return ret;
}
-bssl::UniquePtr<EVP_PKEY> makeKeyPairForSelfSignedCert() {
- bssl::UniquePtr<EC_KEY> ec_key(EC_KEY_new_by_curve_name(NID_X9_62_prime256v1));
- if (ec_key == nullptr || !EC_KEY_generate_key(ec_key.get())) {
- ALOGE("Failed to generate key pair.");
- return nullptr;
- }
- bssl::UniquePtr<EVP_PKEY> evp_pkey(EVP_PKEY_new());
- // Use set1 instead of assign to avoid leaking ec_key when assign fails. set1 increments
- // the refcount of the ec_key, so it is okay to release it at the end of this function.
- if (evp_pkey == nullptr || !EVP_PKEY_set1_EC_KEY(evp_pkey.get(), ec_key.get())) {
- ALOGE("Failed to assign key pair.");
- return nullptr;
- }
- return evp_pkey;
-}
-
-bssl::UniquePtr<X509> makeSelfSignedCert(EVP_PKEY* evp_pkey, const int valid_days) {
- bssl::UniquePtr<X509> x509(X509_new());
- bssl::UniquePtr<BIGNUM> serial(BN_new());
- bssl::UniquePtr<BIGNUM> serialLimit(BN_new());
- TEST_AND_RETURN(nullptr, BN_lshift(serialLimit.get(), BN_value_one(), 128));
- TEST_AND_RETURN(nullptr, BN_rand_range(serial.get(), serialLimit.get()));
- TEST_AND_RETURN(nullptr, BN_to_ASN1_INTEGER(serial.get(), X509_get_serialNumber(x509.get())));
- TEST_AND_RETURN(nullptr, X509_gmtime_adj(X509_getm_notBefore(x509.get()), 0));
- TEST_AND_RETURN(nullptr,
- X509_gmtime_adj(X509_getm_notAfter(x509.get()), 60 * 60 * 24 * valid_days));
-
- X509_NAME* subject = X509_get_subject_name(x509.get());
- TEST_AND_RETURN(nullptr,
- X509_NAME_add_entry_by_txt(subject, "O", MBSTRING_ASC,
- reinterpret_cast<const uint8_t*>("Android"), -1, -1,
- 0));
- TEST_AND_RETURN(nullptr,
- X509_NAME_add_entry_by_txt(subject, "CN", MBSTRING_ASC,
- reinterpret_cast<const uint8_t*>("BinderRPC"), -1,
- -1, 0));
- TEST_AND_RETURN(nullptr, X509_set_issuer_name(x509.get(), subject));
-
- TEST_AND_RETURN(nullptr, X509_set_pubkey(x509.get(), evp_pkey));
- TEST_AND_RETURN(nullptr, X509_sign(x509.get(), evp_pkey, EVP_sha256()));
- return x509;
-}
-
[[maybe_unused]] void sslDebugLog(const SSL* ssl, int type, int value) {
switch (type) {
case SSL_CB_HANDSHAKE_START:
@@ -437,7 +392,7 @@
template <typename Impl,
typename = std::enable_if_t<std::is_base_of_v<RpcTransportCtxTls, Impl>>>
static std::unique_ptr<RpcTransportCtxTls> create(
- std::shared_ptr<RpcCertificateVerifier> verifier);
+ std::shared_ptr<RpcCertificateVerifier> verifier, RpcAuth* auth);
std::unique_ptr<RpcTransport> newTransport(android::base::unique_fd fd,
FdTrigger* fdTrigger) const override;
std::vector<uint8_t> getCertificate(RpcCertificateFormat) const override;
@@ -479,16 +434,15 @@
// provided as a template argument so that this function can initialize an |Impl| object.
template <typename Impl, typename>
std::unique_ptr<RpcTransportCtxTls> RpcTransportCtxTls::create(
- std::shared_ptr<RpcCertificateVerifier> verifier) {
+ std::shared_ptr<RpcCertificateVerifier> verifier, RpcAuth* auth) {
bssl::UniquePtr<SSL_CTX> ctx(SSL_CTX_new(TLS_method()));
TEST_AND_RETURN(nullptr, ctx != nullptr);
- auto evp_pkey = makeKeyPairForSelfSignedCert();
- TEST_AND_RETURN(nullptr, evp_pkey != nullptr);
- auto cert = makeSelfSignedCert(evp_pkey.get(), kCertValidDays);
- TEST_AND_RETURN(nullptr, cert != nullptr);
- TEST_AND_RETURN(nullptr, SSL_CTX_use_PrivateKey(ctx.get(), evp_pkey.get()));
- TEST_AND_RETURN(nullptr, SSL_CTX_use_certificate(ctx.get(), cert.get()));
+ if (status_t authStatus = auth->configure(ctx.get()); authStatus != OK) {
+ ALOGE("%s: Failed to configure auth info: %s", __PRETTY_FUNCTION__,
+ statusToString(authStatus).c_str());
+ return nullptr;
+ };
// Enable two-way authentication by setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT on server.
// Client ignores SSL_VERIFY_FAIL_IF_NO_PEER_CERT flag.
@@ -538,11 +492,13 @@
} // namespace
std::unique_ptr<RpcTransportCtx> RpcTransportCtxFactoryTls::newServerCtx() const {
- return android::RpcTransportCtxTls::create<RpcTransportCtxTlsServer>(mCertVerifier);
+ return android::RpcTransportCtxTls::create<RpcTransportCtxTlsServer>(mCertVerifier,
+ mAuth.get());
}
std::unique_ptr<RpcTransportCtx> RpcTransportCtxFactoryTls::newClientCtx() const {
- return android::RpcTransportCtxTls::create<RpcTransportCtxTlsClient>(mCertVerifier);
+ return android::RpcTransportCtxTls::create<RpcTransportCtxTlsClient>(mCertVerifier,
+ mAuth.get());
}
const char* RpcTransportCtxFactoryTls::toCString() const {
@@ -550,13 +506,17 @@
}
std::unique_ptr<RpcTransportCtxFactory> RpcTransportCtxFactoryTls::make(
- std::shared_ptr<RpcCertificateVerifier> verifier) {
+ std::shared_ptr<RpcCertificateVerifier> verifier, std::unique_ptr<RpcAuth> auth) {
if (verifier == nullptr) {
ALOGE("%s: Must provide a certificate verifier", __PRETTY_FUNCTION__);
return nullptr;
}
+ if (auth == nullptr) {
+ ALOGE("%s: Must provide an auth provider", __PRETTY_FUNCTION__);
+ return nullptr;
+ }
return std::unique_ptr<RpcTransportCtxFactoryTls>(
- new RpcTransportCtxFactoryTls(std::move(verifier)));
+ new RpcTransportCtxFactoryTls(std::move(verifier), std::move(auth)));
}
} // namespace android
diff --git a/libs/binder/include_tls/binder/RpcAuth.h b/libs/binder/include_tls/binder/RpcAuth.h
new file mode 100644
index 0000000..4c2f296
--- /dev/null
+++ b/libs/binder/include_tls/binder/RpcAuth.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * 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
+ *
+ * http://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.
+ */
+
+#pragma once
+
+#include <openssl/ssl.h>
+#include <utils/Errors.h>
+
+namespace android {
+
+// An interface with a function that configures the SSL_CTX object with authentication information,
+// including certificates and private keys.
+class RpcAuth {
+public:
+ virtual ~RpcAuth() = default;
+
+ // The keys and certificates to provide is up to the implementation. Multiple calls to
+ // |configure()| may configure |ctx| with the same keys / certificates, or generate a
+ // different key / certificate every time |configure()| is called.
+ //
+ // It is guaranteed that, when a context object (RpcTransportCtx) is created,
+ // libbinder_tls calls |configure()| on server RpcAuth exactly once.
+ //
+ // The implementation may use the following function to set the private
+ // keys and certificates:
+ // - SSL_CTX_use_PrivateKey
+ // - SSL_CTX_use_certificate
+ // - SSL_CTX_set*_chain
+ // - SSL_CTX_add0_chain_cert
+ virtual status_t configure(SSL_CTX* ctx) = 0;
+};
+
+} // namespace android
diff --git a/libs/binder/include_tls/binder/RpcTransportTls.h b/libs/binder/include_tls/binder/RpcTransportTls.h
index f26a3e9..8a11125 100644
--- a/libs/binder/include_tls/binder/RpcTransportTls.h
+++ b/libs/binder/include_tls/binder/RpcTransportTls.h
@@ -18,6 +18,7 @@
#pragma once
+#include <binder/RpcAuth.h>
#include <binder/RpcCertificateVerifier.h>
#include <binder/RpcTransport.h>
@@ -26,17 +27,20 @@
// RpcTransportCtxFactory with TLS enabled with self-signed certificate.
class RpcTransportCtxFactoryTls : public RpcTransportCtxFactory {
public:
- static std::unique_ptr<RpcTransportCtxFactory> make(std::shared_ptr<RpcCertificateVerifier>);
+ static std::unique_ptr<RpcTransportCtxFactory> make(std::shared_ptr<RpcCertificateVerifier>,
+ std::unique_ptr<RpcAuth>);
std::unique_ptr<RpcTransportCtx> newServerCtx() const override;
std::unique_ptr<RpcTransportCtx> newClientCtx() const override;
const char* toCString() const override;
private:
- RpcTransportCtxFactoryTls(std::shared_ptr<RpcCertificateVerifier> verifier)
- : mCertVerifier(std::move(verifier)){};
+ RpcTransportCtxFactoryTls(std::shared_ptr<RpcCertificateVerifier> verifier,
+ std::unique_ptr<RpcAuth> auth)
+ : mCertVerifier(std::move(verifier)), mAuth(std::move(auth)){};
std::shared_ptr<RpcCertificateVerifier> mCertVerifier;
+ std::unique_ptr<RpcAuth> mAuth;
};
} // namespace android
diff --git a/libs/binder/tests/Android.bp b/libs/binder/tests/Android.bp
index 1968058..6f3c6e2 100644
--- a/libs/binder/tests/Android.bp
+++ b/libs/binder/tests/Android.bp
@@ -153,6 +153,7 @@
srcs: [
"binderRpcTest.cpp",
+ "RpcAuthTesting.cpp",
"RpcCertificateVerifierSimple.cpp",
],
shared_libs: [
diff --git a/libs/binder/tests/RpcAuthTesting.cpp b/libs/binder/tests/RpcAuthTesting.cpp
new file mode 100644
index 0000000..76f7bce
--- /dev/null
+++ b/libs/binder/tests/RpcAuthTesting.cpp
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * 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
+ *
+ * http://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 "RpcAuthTesting.h"
+#include "../Utils.h" // for TEST_AND_RETURN
+
+namespace android {
+
+bssl::UniquePtr<EVP_PKEY> makeKeyPairForSelfSignedCert() {
+ bssl::UniquePtr<EC_KEY> ec_key(EC_KEY_new_by_curve_name(NID_X9_62_prime256v1));
+ if (ec_key == nullptr || !EC_KEY_generate_key(ec_key.get())) {
+ ALOGE("Failed to generate key pair.");
+ return nullptr;
+ }
+ bssl::UniquePtr<EVP_PKEY> pkey(EVP_PKEY_new());
+ // Use set1 instead of assign to avoid leaking ec_key when assign fails. set1 increments
+ // the refcount of the ec_key, so it is okay to release it at the end of this function.
+ if (pkey == nullptr || !EVP_PKEY_set1_EC_KEY(pkey.get(), ec_key.get())) {
+ ALOGE("Failed to assign key pair.");
+ return nullptr;
+ }
+ return pkey;
+}
+
+bssl::UniquePtr<X509> makeSelfSignedCert(EVP_PKEY* pkey, const uint32_t validSeconds) {
+ bssl::UniquePtr<X509> x509(X509_new());
+ bssl::UniquePtr<BIGNUM> serial(BN_new());
+ bssl::UniquePtr<BIGNUM> serialLimit(BN_new());
+ TEST_AND_RETURN(nullptr, BN_lshift(serialLimit.get(), BN_value_one(), 128));
+ TEST_AND_RETURN(nullptr, BN_rand_range(serial.get(), serialLimit.get()));
+ TEST_AND_RETURN(nullptr, BN_to_ASN1_INTEGER(serial.get(), X509_get_serialNumber(x509.get())));
+ TEST_AND_RETURN(nullptr, X509_gmtime_adj(X509_getm_notBefore(x509.get()), 0));
+ TEST_AND_RETURN(nullptr, X509_gmtime_adj(X509_getm_notAfter(x509.get()), validSeconds));
+
+ X509_NAME* subject = X509_get_subject_name(x509.get());
+ TEST_AND_RETURN(nullptr,
+ X509_NAME_add_entry_by_txt(subject, "O", MBSTRING_ASC,
+ reinterpret_cast<const uint8_t*>("Android"), -1, -1,
+ 0));
+ TEST_AND_RETURN(nullptr,
+ X509_NAME_add_entry_by_txt(subject, "CN", MBSTRING_ASC,
+ reinterpret_cast<const uint8_t*>("BinderRPC"), -1,
+ -1, 0));
+ TEST_AND_RETURN(nullptr, X509_set_issuer_name(x509.get(), subject));
+
+ TEST_AND_RETURN(nullptr, X509_set_pubkey(x509.get(), pkey));
+ TEST_AND_RETURN(nullptr, X509_sign(x509.get(), pkey, EVP_sha256()));
+ return x509;
+}
+
+status_t RpcAuthSelfSigned::configure(SSL_CTX* ctx) {
+ auto pkey = makeKeyPairForSelfSignedCert();
+ TEST_AND_RETURN(UNKNOWN_ERROR, pkey != nullptr);
+ auto cert = makeSelfSignedCert(pkey.get(), mValidSeconds);
+ TEST_AND_RETURN(UNKNOWN_ERROR, cert != nullptr);
+ TEST_AND_RETURN(INVALID_OPERATION, SSL_CTX_use_PrivateKey(ctx, pkey.get()));
+ TEST_AND_RETURN(INVALID_OPERATION, SSL_CTX_use_certificate(ctx, cert.get()));
+ return OK;
+}
+
+} // namespace android
diff --git a/libs/binder/tests/RpcAuthTesting.h b/libs/binder/tests/RpcAuthTesting.h
new file mode 100644
index 0000000..fdc731d
--- /dev/null
+++ b/libs/binder/tests/RpcAuthTesting.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * 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
+ *
+ * http://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.
+ */
+
+#pragma once
+
+#include <binder/RpcAuth.h>
+
+namespace android {
+
+constexpr const uint32_t kCertValidSeconds = 30 * (60 * 60 * 24); // 30 days
+bssl::UniquePtr<EVP_PKEY> makeKeyPairForSelfSignedCert();
+bssl::UniquePtr<X509> makeSelfSignedCert(EVP_PKEY* pKey, uint32_t validSeconds);
+
+// An implementation of RpcAuth that generates a key pair and a self-signed
+// certificate every time configure() is called.
+class RpcAuthSelfSigned : public RpcAuth {
+public:
+ RpcAuthSelfSigned(uint32_t validSeconds = kCertValidSeconds) : mValidSeconds(validSeconds) {}
+ status_t configure(SSL_CTX* ctx) override;
+
+private:
+ const uint32_t mValidSeconds;
+};
+
+} // namespace android
diff --git a/libs/binder/tests/binderRpcTest.cpp b/libs/binder/tests/binderRpcTest.cpp
index cc1d2fa..05c5030 100644
--- a/libs/binder/tests/binderRpcTest.cpp
+++ b/libs/binder/tests/binderRpcTest.cpp
@@ -48,8 +48,9 @@
#include "../FdTrigger.h"
#include "../RpcSocketAddress.h" // for testing preconnected clients
-#include "../RpcState.h" // for debugging
-#include "../vm_sockets.h" // for VMADDR_*
+#include "../RpcState.h" // for debugging
+#include "../vm_sockets.h" // for VMADDR_*
+#include "RpcAuthTesting.h"
#include "RpcCertificateVerifierSimple.h"
using namespace std::chrono_literals;
@@ -71,7 +72,8 @@
}
static inline std::unique_ptr<RpcTransportCtxFactory> newFactory(
- RpcSecurity rpcSecurity, std::shared_ptr<RpcCertificateVerifier> verifier = nullptr) {
+ RpcSecurity rpcSecurity, std::shared_ptr<RpcCertificateVerifier> verifier = nullptr,
+ std::unique_ptr<RpcAuth> auth = nullptr) {
switch (rpcSecurity) {
case RpcSecurity::RAW:
return RpcTransportCtxFactoryRaw::make();
@@ -79,7 +81,10 @@
if (verifier == nullptr) {
verifier = std::make_shared<RpcCertificateVerifierSimple>();
}
- return RpcTransportCtxFactoryTls::make(std::move(verifier));
+ if (auth == nullptr) {
+ auth = std::make_unique<RpcAuthSelfSigned>();
+ }
+ return RpcTransportCtxFactoryTls::make(std::move(verifier), std::move(auth));
}
default:
LOG_ALWAYS_FATAL("Unknown RpcSecurity %d", rpcSecurity);