Deprecate and simplify SSL_CTX_check_private_key
It is not actually possible to configure an inconsistent certificate and
private key pair (short of mutating the objects after you've configured
them). The functions that configure certificates and private keys will
refuse to get CERT into an inconsistent state.
SSL_CTX_check_private_key is really just checking that you have a
certificate and private key at all. Some callers (notably pyOpenSSL's
tests) are written as if SSL_CTX_check_private_key does something more,
but that's only because they also configure certificate and private key
in the wrong order. If you configure the key first, configuring the
certificate silently drops the mismatched private key because OpenSSL
thinks you're overwriting an identity. SSL_CTX_check_private_key is
really just detecting this case.
Add tests for all this behavior, document that certificates should be
configured first, and then deprecate SSL_CTX_check_private_key because,
in the correct order, this function is superfluous.
This will get shuffled around with SSL_CREDENTIAL, so add some tests
first.
Bug: 249
Change-Id: I3fcc0f51add1826d581583b43ff003c0dea979dd
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/66447
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Bob Beck <bbe@google.com>
diff --git a/ssl/ssl_test.cc b/ssl/ssl_test.cc
index 0b4ad3c..d12d49c 100644
--- a/ssl/ssl_test.cc
+++ b/ssl/ssl_test.cc
@@ -4556,6 +4556,82 @@
ERR_clear_error();
}
+TEST(SSLTest, CertThenKeyMismatch) {
+ bssl::UniquePtr<SSL_CTX> ctx(SSL_CTX_new(TLS_method()));
+ ASSERT_TRUE(ctx);
+
+ bssl::UniquePtr<EVP_PKEY> key = GetTestKey();
+ ASSERT_TRUE(key);
+ bssl::UniquePtr<X509> leaf = GetChainTestCertificate();
+ ASSERT_TRUE(leaf);
+
+ // There is no key or certificate, so |SSL_CTX_check_private_key| fails.
+ EXPECT_FALSE(SSL_CTX_check_private_key(ctx.get()));
+
+ // With only a certificate, |SSL_CTX_check_private_key| still fails.
+ ASSERT_TRUE(SSL_CTX_use_certificate(ctx.get(), leaf.get()));
+ EXPECT_FALSE(SSL_CTX_check_private_key(ctx.get()));
+
+ // The private key does not match the certificate, so it should fail.
+ EXPECT_FALSE(SSL_CTX_use_PrivateKey(ctx.get(), key.get()));
+
+ // Checking the private key fails, but this is really because there is still
+ // no private key.
+ EXPECT_FALSE(SSL_CTX_check_private_key(ctx.get()));
+ EXPECT_EQ(nullptr, SSL_CTX_get0_privatekey(ctx.get()));
+}
+
+TEST(SSLTest, KeyThenCertMismatch) {
+ bssl::UniquePtr<SSL_CTX> ctx(SSL_CTX_new(TLS_method()));
+ ASSERT_TRUE(ctx);
+
+ bssl::UniquePtr<EVP_PKEY> key = GetTestKey();
+ ASSERT_TRUE(key);
+ bssl::UniquePtr<X509> leaf = GetChainTestCertificate();
+ ASSERT_TRUE(leaf);
+
+ // There is no key or certificate, so |SSL_CTX_check_private_key| fails.
+ EXPECT_FALSE(SSL_CTX_check_private_key(ctx.get()));
+
+ // With only a key, |SSL_CTX_check_private_key| still fails.
+ ASSERT_TRUE(SSL_CTX_use_PrivateKey(ctx.get(), key.get()));
+ EXPECT_FALSE(SSL_CTX_check_private_key(ctx.get()));
+
+ // If configuring a certificate that doesn't match the key, configuration
+ // actually succeeds. We just silently drop the private key.
+ ASSERT_TRUE(SSL_CTX_use_certificate(ctx.get(), leaf.get()));
+ EXPECT_EQ(nullptr, SSL_CTX_get0_privatekey(ctx.get()));
+
+ // Some callers configure the private key, then the certificate, and then
+ // expect |SSL_CTX_check_private_key| to check consistency. It does, but only
+ // by way of noticing there is no private key. The actual consistency check
+ // happened in |SSL_CTX_use_certificate|.
+ EXPECT_FALSE(SSL_CTX_check_private_key(ctx.get()));
+}
+
+TEST(SSLTest, OverrideCertAndKey) {
+ // It is possible to override an existing certificate by configuring
+ // certificate, then key, due to |SSL_CTX_use_certificate|'s above silent
+ // dropping behavior.
+ bssl::UniquePtr<SSL_CTX> ctx(SSL_CTX_new(TLS_method()));
+ ASSERT_TRUE(ctx);
+
+ bssl::UniquePtr<EVP_PKEY> key = GetTestKey();
+ ASSERT_TRUE(key);
+ bssl::UniquePtr<X509> leaf = GetTestCertificate();
+ ASSERT_TRUE(leaf);
+ bssl::UniquePtr<EVP_PKEY> key2 = GetChainTestKey();
+ ASSERT_TRUE(key2);
+ bssl::UniquePtr<X509> leaf2 = GetChainTestCertificate();
+ ASSERT_TRUE(leaf2);
+
+ ASSERT_TRUE(SSL_CTX_use_certificate(ctx.get(), leaf.get()));
+ ASSERT_TRUE(SSL_CTX_use_PrivateKey(ctx.get(), key.get()));
+
+ ASSERT_TRUE(SSL_CTX_use_certificate(ctx.get(), leaf2.get()));
+ ASSERT_TRUE(SSL_CTX_use_PrivateKey(ctx.get(), key2.get()));
+}
+
TEST(SSLTest, SetChainAndKeyCtx) {
bssl::UniquePtr<SSL_CTX> client_ctx(SSL_CTX_new(TLS_with_buffers_method()));
ASSERT_TRUE(client_ctx);
