xref: /openbmc/bmcweb/http/mutual_tls.hpp (revision 23f1c96e6bc9060b54ff08a6b4d6cf8b8e0c3b23)
1 #pragma once
2 
3 #include "logging.hpp"
4 #include "persistent_data.hpp"
5 
6 #include <openssl/crypto.h>
7 #include <openssl/ssl.h>
8 
9 #include <boost/asio/ip/address.hpp>
10 #include <boost/asio/ssl/verify_context.hpp>
11 
12 #include <memory>
13 #include <span>
14 
15 inline std::shared_ptr<persistent_data::UserSession>
16     verifyMtlsUser(const boost::asio::ip::address& clientIp,
17                    boost::asio::ssl::verify_context& ctx)
18 {
19     // do nothing if TLS is disabled
20     if (!persistent_data::SessionStore::getInstance()
21              .getAuthMethodsConfig()
22              .tls)
23     {
24         BMCWEB_LOG_DEBUG("TLS auth_config is disabled");
25         return nullptr;
26     }
27 
28     X509_STORE_CTX* cts = ctx.native_handle();
29     if (cts == nullptr)
30     {
31         BMCWEB_LOG_DEBUG("Cannot get native TLS handle.");
32         return nullptr;
33     }
34 
35     // Get certificate
36     X509* peerCert = X509_STORE_CTX_get_current_cert(ctx.native_handle());
37     if (peerCert == nullptr)
38     {
39         BMCWEB_LOG_DEBUG("Cannot get current TLS certificate.");
40         return nullptr;
41     }
42 
43     // Check if certificate is OK
44     int ctxError = X509_STORE_CTX_get_error(cts);
45     if (ctxError != X509_V_OK)
46     {
47         BMCWEB_LOG_INFO("Last TLS error is: {}", ctxError);
48         return nullptr;
49     }
50 
51     // Check that we have reached final certificate in chain
52     int32_t depth = X509_STORE_CTX_get_error_depth(cts);
53     if (depth != 0)
54     {
55         BMCWEB_LOG_DEBUG(
56             "Certificate verification in progress (depth {}), waiting to reach final depth",
57             depth);
58         return nullptr;
59     }
60 
61     BMCWEB_LOG_DEBUG("Certificate verification of final depth");
62 
63     if (X509_check_purpose(peerCert, X509_PURPOSE_SSL_CLIENT, 0) != 1)
64     {
65         BMCWEB_LOG_DEBUG(
66             "Chain does not allow certificate to be used for SSL client authentication");
67         return nullptr;
68     }
69 
70     std::string sslUser;
71     // Extract username contained in CommonName
72     sslUser.resize(256, '\0');
73 
74     int status = X509_NAME_get_text_by_NID(X509_get_subject_name(peerCert),
75                                            NID_commonName, sslUser.data(),
76                                            static_cast<int>(sslUser.size()));
77 
78     if (status == -1)
79     {
80         BMCWEB_LOG_DEBUG("TLS cannot get username to create session");
81         return nullptr;
82     }
83 
84     size_t lastChar = sslUser.find('\0');
85     if (lastChar == std::string::npos || lastChar == 0)
86     {
87         BMCWEB_LOG_DEBUG("Invalid TLS user name");
88         return nullptr;
89     }
90     sslUser.resize(lastChar);
91     std::string unsupportedClientId;
92     return persistent_data::SessionStore::getInstance().generateUserSession(
93         sslUser, clientIp, unsupportedClientId,
94         persistent_data::PersistenceType::TIMEOUT);
95 }
96