Refactor mtls callbacks into their own file
Mutual TLS is non-trivial enough that it definitely shouldn't be done in
an inline lambda method. This commit moves the code.
Tested: WIP. This is a pretty negligible code move; Minimal touch
testing should be good.
Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I7a15a6bc66f4d8fb090411509549628f6d1045a5
diff --git a/http/mutual_tls.hpp b/http/mutual_tls.hpp
new file mode 100644
index 0000000..aee85c2
--- /dev/null
+++ b/http/mutual_tls.hpp
@@ -0,0 +1,154 @@
+#pragma once
+
+#include "logging.hpp"
+#include "persistent_data.hpp"
+
+#include <openssl/crypto.h>
+#include <openssl/ssl.h>
+
+#include <boost/asio/ip/address.hpp>
+#include <boost/asio/ssl/verify_context.hpp>
+
+#include <memory>
+
+inline std::shared_ptr<persistent_data::UserSession>
+ verifyMtlsUser(const boost::asio::ip::address& clientIp,
+ boost::asio::ssl::verify_context& ctx)
+{
+ // do nothing if TLS is disabled
+ if (!persistent_data::SessionStore::getInstance()
+ .getAuthMethodsConfig()
+ .tls)
+ {
+ BMCWEB_LOG_DEBUG << "TLS auth_config is disabled";
+ return nullptr;
+ }
+
+ X509_STORE_CTX* cts = ctx.native_handle();
+ if (cts == nullptr)
+ {
+ BMCWEB_LOG_DEBUG << "Cannot get native TLS handle.";
+ return nullptr;
+ }
+
+ // Get certificate
+ X509* peerCert = X509_STORE_CTX_get_current_cert(ctx.native_handle());
+ if (peerCert == nullptr)
+ {
+ BMCWEB_LOG_DEBUG << "Cannot get current TLS certificate.";
+ return nullptr;
+ }
+
+ // Check if certificate is OK
+ int ctxError = X509_STORE_CTX_get_error(cts);
+ if (ctxError != X509_V_OK)
+ {
+ BMCWEB_LOG_INFO << "Last TLS error is: " << ctxError;
+ return nullptr;
+ }
+ // Check that we have reached final certificate in chain
+ int32_t depth = X509_STORE_CTX_get_error_depth(cts);
+ if (depth != 0)
+
+ {
+ BMCWEB_LOG_DEBUG << "Certificate verification in progress (depth "
+ << depth << "), waiting to reach final depth";
+ return nullptr;
+ }
+
+ BMCWEB_LOG_DEBUG << "Certificate verification of final depth";
+
+ // Verify KeyUsage
+ bool isKeyUsageDigitalSignature = false;
+ bool isKeyUsageKeyAgreement = false;
+
+ ASN1_BIT_STRING* usage = static_cast<ASN1_BIT_STRING*>(
+ X509_get_ext_d2i(peerCert, NID_key_usage, nullptr, nullptr));
+
+ if (usage == nullptr)
+ {
+ BMCWEB_LOG_DEBUG << "TLS usage is null";
+ return nullptr;
+ }
+
+ for (int i = 0; i < usage->length; i++)
+ {
+ // NOLINTNEXTLINE(cppcoreguidelines-pro-bounds-pointer-arithmetic)
+ unsigned char usageChar = usage->data[i];
+ if (KU_DIGITAL_SIGNATURE & usageChar)
+ {
+ isKeyUsageDigitalSignature = true;
+ }
+ if (KU_KEY_AGREEMENT & usageChar)
+ {
+ isKeyUsageKeyAgreement = true;
+ }
+ }
+ ASN1_BIT_STRING_free(usage);
+
+ if (!isKeyUsageDigitalSignature || !isKeyUsageKeyAgreement)
+ {
+ BMCWEB_LOG_DEBUG << "Certificate ExtendedKeyUsage does "
+ "not allow provided certificate to "
+ "be used for user authentication";
+ return nullptr;
+ }
+
+ // Determine that ExtendedKeyUsage includes Client Auth
+
+ stack_st_ASN1_OBJECT* extUsage = static_cast<stack_st_ASN1_OBJECT*>(
+ X509_get_ext_d2i(peerCert, NID_ext_key_usage, nullptr, nullptr));
+
+ if (extUsage == nullptr)
+ {
+ BMCWEB_LOG_DEBUG << "TLS extUsage is null";
+ return nullptr;
+ }
+
+ bool isExKeyUsageClientAuth = false;
+ for (int i = 0; i < sk_ASN1_OBJECT_num(extUsage); i++)
+ {
+ // NOLINTNEXTLINE(cppcoreguidelines-pro-type-cstyle-cast)
+ int nid = OBJ_obj2nid(sk_ASN1_OBJECT_value(extUsage, i));
+ if (NID_client_auth == nid)
+ {
+ isExKeyUsageClientAuth = true;
+ break;
+ }
+ }
+ sk_ASN1_OBJECT_free(extUsage);
+
+ // Certificate has to have proper key usages set
+ if (!isExKeyUsageClientAuth)
+ {
+ BMCWEB_LOG_DEBUG << "Certificate ExtendedKeyUsage does "
+ "not allow provided certificate to "
+ "be used for user authentication";
+ return nullptr;
+ }
+ std::string sslUser;
+ // Extract username contained in CommonName
+ sslUser.resize(256, '\0');
+
+ int status = X509_NAME_get_text_by_NID(X509_get_subject_name(peerCert),
+ NID_commonName, sslUser.data(),
+ static_cast<int>(sslUser.size()));
+
+ if (status == -1)
+ {
+ BMCWEB_LOG_DEBUG << "TLS cannot get username to create session";
+ return nullptr;
+ }
+
+ size_t lastChar = sslUser.find('\0');
+ if (lastChar == std::string::npos || lastChar == 0)
+ {
+ BMCWEB_LOG_DEBUG << "Invalid TLS user name";
+ return nullptr;
+ }
+ sslUser.resize(lastChar);
+ std::string unsupportedClientId;
+ return persistent_data::SessionStore::getInstance().generateUserSession(
+ sslUser, clientIp, unsupportedClientId,
+ persistent_data::PersistenceType::TIMEOUT);
+}