xref: /openbmc/bmcweb/src/ssl_key_handler.cpp (revision 730b00f42c206bd84664b577113aedc263016877)
1 // SPDX-License-Identifier: Apache-2.0
2 // SPDX-FileCopyrightText: Copyright OpenBMC Authors
3 #include "ssl_key_handler.hpp"
4 
5 #include "bmcweb_config.h"
6 
7 #include "forward_unauthorized.hpp"
8 #include "logging.hpp"
9 #include "ossl_random.hpp"
10 #include "sessions.hpp"
11 
12 #include <boost/asio/buffer.hpp>
13 #include <boost/asio/ssl/context.hpp>
14 #include <boost/asio/ssl/verify_mode.hpp>
15 #include <boost/beast/core/file_base.hpp>
16 #include <boost/beast/core/file_posix.hpp>
17 #include <boost/system/error_code.hpp>
18 
19 extern "C"
20 {
21 #include <nghttp2/nghttp2.h>
22 #include <openssl/asn1.h>
23 #include <openssl/bio.h>
24 #include <openssl/ec.h>
25 #include <openssl/err.h>
26 #include <openssl/evp.h>
27 #include <openssl/obj_mac.h>
28 #include <openssl/pem.h>
29 #include <openssl/ssl.h>
30 #include <openssl/tls1.h>
31 #include <openssl/types.h>
32 #include <openssl/x509.h>
33 #include <openssl/x509_vfy.h>
34 #include <openssl/x509v3.h>
35 }
36 
37 #include <bit>
38 #include <cstddef>
39 #include <filesystem>
40 #include <limits>
41 #include <memory>
42 #include <optional>
43 #include <random>
44 #include <string>
45 #include <system_error>
46 #include <utility>
47 
48 namespace ensuressl
49 {
50 
51 static EVP_PKEY* createEcKey();
52 
53 // Mozilla intermediate cipher suites v5.7
54 // Sourced from: https://ssl-config.mozilla.org/guidelines/5.7.json
55 constexpr const char* mozillaIntermediate =
56     "ECDHE-ECDSA-AES128-GCM-SHA256:"
57     "ECDHE-RSA-AES128-GCM-SHA256:"
58     "ECDHE-ECDSA-AES256-GCM-SHA384:"
59     "ECDHE-RSA-AES256-GCM-SHA384:"
60     "ECDHE-ECDSA-CHACHA20-POLY1305:"
61     "ECDHE-RSA-CHACHA20-POLY1305:"
62     "DHE-RSA-AES128-GCM-SHA256:"
63     "DHE-RSA-AES256-GCM-SHA384:"
64     "DHE-RSA-CHACHA20-POLY1305";
65 
66 // Trust chain related errors.`
isTrustChainError(int errnum)67 bool isTrustChainError(int errnum)
68 {
69     return (errnum == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT) ||
70            (errnum == X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN) ||
71            (errnum == X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY) ||
72            (errnum == X509_V_ERR_CERT_UNTRUSTED) ||
73            (errnum == X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE);
74 }
75 
validateCertificate(X509 * const cert)76 bool validateCertificate(X509* const cert)
77 {
78     // Create an empty X509_STORE structure for certificate validation.
79     X509_STORE* x509Store = X509_STORE_new();
80     if (x509Store == nullptr)
81     {
82         BMCWEB_LOG_ERROR("Error occurred during X509_STORE_new call");
83         return false;
84     }
85 
86     // Load Certificate file into the X509 structure.
87     X509_STORE_CTX* storeCtx = X509_STORE_CTX_new();
88     if (storeCtx == nullptr)
89     {
90         BMCWEB_LOG_ERROR("Error occurred during X509_STORE_CTX_new call");
91         X509_STORE_free(x509Store);
92         return false;
93     }
94 
95     int errCode = X509_STORE_CTX_init(storeCtx, x509Store, cert, nullptr);
96     if (errCode != 1)
97     {
98         BMCWEB_LOG_ERROR("Error occurred during X509_STORE_CTX_init call");
99         X509_STORE_CTX_free(storeCtx);
100         X509_STORE_free(x509Store);
101         return false;
102     }
103 
104     errCode = X509_verify_cert(storeCtx);
105     if (errCode == 1)
106     {
107         BMCWEB_LOG_INFO("Certificate verification is success");
108         X509_STORE_CTX_free(storeCtx);
109         X509_STORE_free(x509Store);
110         return true;
111     }
112     if (errCode == 0)
113     {
114         errCode = X509_STORE_CTX_get_error(storeCtx);
115         X509_STORE_CTX_free(storeCtx);
116         X509_STORE_free(x509Store);
117         if (isTrustChainError(errCode))
118         {
119             BMCWEB_LOG_DEBUG("Ignoring Trust Chain error. Reason: {}",
120                              X509_verify_cert_error_string(errCode));
121             return true;
122         }
123         BMCWEB_LOG_ERROR("Certificate verification failed. Reason: {}",
124                          X509_verify_cert_error_string(errCode));
125         return false;
126     }
127 
128     BMCWEB_LOG_ERROR(
129         "Error occurred during X509_verify_cert call. ErrorCode: {}", errCode);
130     X509_STORE_CTX_free(storeCtx);
131     X509_STORE_free(x509Store);
132     return false;
133 }
134 
verifyOpensslKeyCert(const std::string & filepath)135 std::string verifyOpensslKeyCert(const std::string& filepath)
136 {
137     bool privateKeyValid = false;
138 
139     BMCWEB_LOG_INFO("Checking certs in file {}", filepath);
140     boost::beast::file_posix file;
141     boost::system::error_code ec;
142     file.open(filepath.c_str(), boost::beast::file_mode::read, ec);
143     if (ec)
144     {
145         return "";
146     }
147     bool certValid = false;
148     std::string fileContents;
149     fileContents.resize(static_cast<size_t>(file.size(ec)), '\0');
150     file.read(fileContents.data(), fileContents.size(), ec);
151     if (ec)
152     {
153         BMCWEB_LOG_ERROR("Failed to read file");
154         return "";
155     }
156 
157     BIO* bufio = BIO_new_mem_buf(static_cast<void*>(fileContents.data()),
158                                  static_cast<int>(fileContents.size()));
159     EVP_PKEY* pkey = PEM_read_bio_PrivateKey(bufio, nullptr, nullptr, nullptr);
160     BIO_free(bufio);
161     if (pkey != nullptr)
162     {
163         EVP_PKEY_CTX* pkeyCtx =
164             EVP_PKEY_CTX_new_from_pkey(nullptr, pkey, nullptr);
165 
166         if (pkeyCtx == nullptr)
167         {
168             BMCWEB_LOG_ERROR("Unable to allocate pkeyCtx {}", ERR_get_error());
169         }
170         else if (EVP_PKEY_check(pkeyCtx) == 1)
171         {
172             privateKeyValid = true;
173         }
174         else
175         {
176             BMCWEB_LOG_ERROR("Key not valid error number {}", ERR_get_error());
177         }
178 
179         if (privateKeyValid)
180         {
181             BIO* bufio2 =
182                 BIO_new_mem_buf(static_cast<void*>(fileContents.data()),
183                                 static_cast<int>(fileContents.size()));
184             X509* x509 = PEM_read_bio_X509(bufio2, nullptr, nullptr, nullptr);
185             BIO_free(bufio2);
186             if (x509 == nullptr)
187             {
188                 BMCWEB_LOG_ERROR("error getting x509 cert {}", ERR_get_error());
189             }
190             else
191             {
192                 certValid = validateCertificate(x509);
193                 X509_free(x509);
194             }
195         }
196 
197         EVP_PKEY_CTX_free(pkeyCtx);
198         EVP_PKEY_free(pkey);
199     }
200     if (!certValid)
201     {
202         return "";
203     }
204     return fileContents;
205 }
206 
loadCert(const std::string & filePath)207 X509* loadCert(const std::string& filePath)
208 {
209     BIO* certFileBio = BIO_new_file(filePath.c_str(), "rb");
210     if (certFileBio == nullptr)
211     {
212         BMCWEB_LOG_ERROR("Error occurred during BIO_new_file call, FILE= {}",
213                          filePath);
214         return nullptr;
215     }
216 
217     X509* cert = X509_new();
218     if (cert == nullptr)
219     {
220         BMCWEB_LOG_ERROR("Error occurred during X509_new call, {}",
221                          ERR_get_error());
222         BIO_free(certFileBio);
223         return nullptr;
224     }
225 
226     if (PEM_read_bio_X509(certFileBio, &cert, nullptr, nullptr) == nullptr)
227     {
228         BMCWEB_LOG_ERROR(
229             "Error occurred during PEM_read_bio_X509 call, FILE= {}", filePath);
230 
231         BIO_free(certFileBio);
232         X509_free(cert);
233         return nullptr;
234     }
235     BIO_free(certFileBio);
236     return cert;
237 }
238 
addExt(X509 * cert,int nid,const char * value)239 int addExt(X509* cert, int nid, const char* value)
240 {
241     X509_EXTENSION* ex = nullptr;
242     X509V3_CTX ctx{};
243     X509V3_set_ctx(&ctx, cert, cert, nullptr, nullptr, 0);
244 
245     // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
246     ex = X509V3_EXT_conf_nid(nullptr, &ctx, nid, const_cast<char*>(value));
247     if (ex == nullptr)
248     {
249         BMCWEB_LOG_ERROR("Error: In X509V3_EXT_conf_nidn: {}", value);
250         return -1;
251     }
252     X509_add_ext(cert, ex, -1);
253     X509_EXTENSION_free(ex);
254     return 0;
255 }
256 
257 // Writes a certificate to a path, ignoring errors
writeCertificateToFile(const std::string & filepath,const std::string & certificate)258 void writeCertificateToFile(const std::string& filepath,
259                             const std::string& certificate)
260 {
261     boost::system::error_code ec;
262     boost::beast::file_posix file;
263     file.open(filepath.c_str(), boost::beast::file_mode::write, ec);
264     if (!ec)
265     {
266         file.write(certificate.data(), certificate.size(), ec);
267         // ignore result
268     }
269 }
270 
constructX509(const std::string & cn,EVP_PKEY * pPrivKey)271 static std::string constructX509(const std::string& cn, EVP_PKEY* pPrivKey)
272 {
273     std::string buffer;
274     X509* x509 = X509_new();
275     if (x509 == nullptr)
276     {
277         return buffer;
278     }
279 
280     // get a random number from the RNG for the certificate serial
281     // number If this is not random, regenerating certs throws browser
282     // errors
283     bmcweb::OpenSSLGenerator gen;
284     std::uniform_int_distribution<int> dis(1, std::numeric_limits<int>::max());
285     int serial = dis(gen);
286 
287     ASN1_INTEGER_set(X509_get_serialNumber(x509), serial);
288 
289     // not before this moment
290     X509_gmtime_adj(X509_get_notBefore(x509), 0);
291     // Cert is valid for 10 years
292     X509_gmtime_adj(X509_get_notAfter(x509), 60L * 60L * 24L * 365L * 10L);
293 
294     // set the public key to the key we just generated
295     X509_set_pubkey(x509, pPrivKey);
296 
297     // get the subject name
298     X509_NAME* name = X509_get_subject_name(x509);
299 
300     using x509String = const unsigned char;
301     // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
302     const auto* country = reinterpret_cast<x509String*>("US");
303     // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
304     const auto* company = reinterpret_cast<x509String*>("OpenBMC");
305     // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
306     const auto* cnStr = reinterpret_cast<x509String*>(cn.c_str());
307 
308     X509_NAME_add_entry_by_txt(name, "C", MBSTRING_ASC, country, -1, -1, 0);
309     X509_NAME_add_entry_by_txt(name, "O", MBSTRING_ASC, company, -1, -1, 0);
310     X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, cnStr, -1, -1, 0);
311     // set the CSR options
312     X509_set_issuer_name(x509, name);
313 
314     X509_set_version(x509, 2);
315     addExt(x509, NID_basic_constraints, ("critical,CA:TRUE"));
316     addExt(x509, NID_subject_alt_name, ("DNS:" + cn).c_str());
317     addExt(x509, NID_subject_key_identifier, ("hash"));
318     addExt(x509, NID_authority_key_identifier, ("keyid"));
319     addExt(x509, NID_key_usage, ("digitalSignature, keyEncipherment"));
320     addExt(x509, NID_ext_key_usage, ("serverAuth"));
321     addExt(x509, NID_netscape_comment, (x509Comment));
322 
323     // Sign the certificate with our private key
324     X509_sign(x509, pPrivKey, EVP_sha256());
325 
326     BIO* bufio = BIO_new(BIO_s_mem());
327 
328     int pkeyRet = PEM_write_bio_PrivateKey(bufio, pPrivKey, nullptr, nullptr, 0,
329                                            nullptr, nullptr);
330     if (pkeyRet <= 0)
331     {
332         BMCWEB_LOG_ERROR("Failed to write pkey with code {}.  Ignoring.",
333                          pkeyRet);
334     }
335 
336     char* data = nullptr;
337     long int dataLen = BIO_get_mem_data(bufio, &data);
338     buffer += std::string_view(data, static_cast<size_t>(dataLen));
339     BIO_free(bufio);
340 
341     bufio = BIO_new(BIO_s_mem());
342     pkeyRet = PEM_write_bio_X509(bufio, x509);
343     if (pkeyRet <= 0)
344     {
345         BMCWEB_LOG_ERROR("Failed to write X509 with code {}.  Ignoring.",
346                          pkeyRet);
347     }
348     dataLen = BIO_get_mem_data(bufio, &data);
349     buffer += std::string_view(data, static_cast<size_t>(dataLen));
350 
351     BIO_free(bufio);
352     BMCWEB_LOG_INFO("Cert size is {}", buffer.size());
353     X509_free(x509);
354     return buffer;
355 }
356 
generateSslCertificate(const std::string & cn)357 std::string generateSslCertificate(const std::string& cn)
358 {
359     BMCWEB_LOG_INFO("Generating new keys");
360 
361     std::string buffer;
362     BMCWEB_LOG_INFO("Generating EC key");
363     EVP_PKEY* pPrivKey = createEcKey();
364     if (pPrivKey != nullptr)
365     {
366         BMCWEB_LOG_INFO("Generating x509 Certificates");
367         // Use this code to directly generate a certificate
368         buffer = constructX509(cn, pPrivKey);
369     }
370 
371     EVP_PKEY_free(pPrivKey);
372 
373     return buffer;
374 }
375 
createEcKey()376 EVP_PKEY* createEcKey()
377 {
378     EVP_PKEY* pKey = nullptr;
379 
380     // Create context for curve parameter generation.
381     std::unique_ptr<EVP_PKEY_CTX, decltype(&::EVP_PKEY_CTX_free)> ctx{
382         EVP_PKEY_CTX_new_id(EVP_PKEY_EC, nullptr), &::EVP_PKEY_CTX_free};
383     if (!ctx)
384     {
385         return nullptr;
386     }
387 
388     // Set up curve parameters.
389     EVP_PKEY* params = nullptr;
390     if ((EVP_PKEY_paramgen_init(ctx.get()) <= 0) ||
391         (EVP_PKEY_CTX_set_ec_param_enc(ctx.get(), OPENSSL_EC_NAMED_CURVE) <=
392          0) ||
393         (EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx.get(), NID_secp384r1) <=
394          0) ||
395         (EVP_PKEY_paramgen(ctx.get(), &params) <= 0))
396     {
397         return nullptr;
398     }
399 
400     // Set up RAII holder for params.
401     std::unique_ptr<EVP_PKEY, decltype(&::EVP_PKEY_free)> pparams{
402         params, &::EVP_PKEY_free};
403 
404     // Set new context for key generation, using curve parameters.
405     ctx.reset(EVP_PKEY_CTX_new_from_pkey(nullptr, params, nullptr));
406     if (!ctx || (EVP_PKEY_keygen_init(ctx.get()) <= 0))
407     {
408         return nullptr;
409     }
410 
411     // Generate key.
412     if (EVP_PKEY_keygen(ctx.get(), &pKey) <= 0)
413     {
414         return nullptr;
415     }
416 
417     return pKey;
418 }
419 
ensureOpensslKeyPresentAndValid(const std::string & filepath)420 std::string ensureOpensslKeyPresentAndValid(const std::string& filepath)
421 {
422     std::string cert = verifyOpensslKeyCert(filepath);
423 
424     if (cert.empty())
425     {
426         BMCWEB_LOG_WARNING("Error in verifying signature, regenerating");
427         cert = generateSslCertificate("testhost");
428         if (cert.empty())
429         {
430             BMCWEB_LOG_ERROR("Failed to generate cert");
431         }
432         else
433         {
434             writeCertificateToFile(filepath, cert);
435         }
436     }
437     return cert;
438 }
439 
ensureCertificate()440 static std::string ensureCertificate()
441 {
442     namespace fs = std::filesystem;
443     // Cleanup older certificate file existing in the system
444     fs::path oldcertPath = fs::path("/home/root/server.pem");
445     std::error_code ec;
446     fs::remove(oldcertPath, ec);
447     // Ignore failure to remove;  File might not exist.
448 
449     fs::path certPath = "/etc/ssl/certs/https/";
450     // if path does not exist create the path so that
451     // self signed certificate can be created in the
452     // path
453     fs::path certFile = certPath / "server.pem";
454 
455     if (!fs::exists(certPath, ec))
456     {
457         fs::create_directories(certPath, ec);
458     }
459     BMCWEB_LOG_INFO("Building SSL Context file= {}", certFile.string());
460     std::string sslPemFile(certFile);
461     return ensuressl::ensureOpensslKeyPresentAndValid(sslPemFile);
462 }
463 
nextProtoCallback(SSL *,const unsigned char ** data,unsigned int * len,void *)464 static int nextProtoCallback(SSL* /*unused*/, const unsigned char** data,
465                              unsigned int* len, void* /*unused*/)
466 {
467     // First byte is the length.
468     constexpr std::string_view h2 = "\x02h2";
469     *data = std::bit_cast<const unsigned char*>(h2.data());
470     *len = static_cast<unsigned int>(h2.size());
471     return SSL_TLSEXT_ERR_OK;
472 }
473 
alpnSelectProtoCallback(SSL *,const unsigned char ** out,unsigned char * outlen,const unsigned char * in,unsigned int inlen,void *)474 static int alpnSelectProtoCallback(
475     SSL* /*unused*/, const unsigned char** out, unsigned char* outlen,
476     const unsigned char* in, unsigned int inlen, void* /*unused*/)
477 {
478     int rv = nghttp2_select_alpn(out, outlen, in, inlen);
479     if (rv == -1)
480     {
481         return SSL_TLSEXT_ERR_NOACK;
482     }
483     if (rv == 1)
484     {
485         BMCWEB_LOG_DEBUG("Selected HTTP2");
486     }
487     return SSL_TLSEXT_ERR_OK;
488 }
489 
getSslContext(boost::asio::ssl::context & mSslContext,const std::string & sslPemFile)490 static bool getSslContext(boost::asio::ssl::context& mSslContext,
491                           const std::string& sslPemFile)
492 {
493     mSslContext.set_options(
494         boost::asio::ssl::context::default_workarounds |
495         boost::asio::ssl::context::no_sslv2 |
496         boost::asio::ssl::context::no_sslv3 |
497         boost::asio::ssl::context::single_dh_use |
498         boost::asio::ssl::context::no_tlsv1 |
499         boost::asio::ssl::context::no_tlsv1_1);
500 
501     BMCWEB_LOG_DEBUG("Using default TrustStore location: {}", trustStorePath);
502     mSslContext.add_verify_path(trustStorePath);
503 
504     if (!sslPemFile.empty())
505     {
506         boost::system::error_code ec;
507 
508         boost::asio::const_buffer buf(sslPemFile.data(), sslPemFile.size());
509         mSslContext.use_certificate_chain(buf, ec);
510         if (ec)
511         {
512             return false;
513         }
514         mSslContext.use_private_key(buf, boost::asio::ssl::context::pem, ec);
515         if (ec)
516         {
517             BMCWEB_LOG_CRITICAL("Failed to open ssl pkey");
518             return false;
519         }
520     }
521 
522     if (SSL_CTX_set_cipher_list(mSslContext.native_handle(),
523                                 mozillaIntermediate) != 1)
524     {
525         BMCWEB_LOG_ERROR("Error setting cipher list");
526         return false;
527     }
528     return true;
529 }
530 
getSslServerContext()531 std::shared_ptr<boost::asio::ssl::context> getSslServerContext()
532 {
533     boost::asio::ssl::context sslCtx(boost::asio::ssl::context::tls_server);
534 
535     auto certFile = ensureCertificate();
536     if (!getSslContext(sslCtx, certFile))
537     {
538         BMCWEB_LOG_CRITICAL("Couldn't get server context");
539         return nullptr;
540     }
541     const persistent_data::AuthConfigMethods& c =
542         persistent_data::SessionStore::getInstance().getAuthMethodsConfig();
543 
544     boost::asio::ssl::verify_mode mode = boost::asio::ssl::verify_none;
545     if (c.tlsStrict)
546     {
547         BMCWEB_LOG_DEBUG("Setting verify peer and fail if no peer cert");
548         mode |= boost::asio::ssl::verify_peer;
549         mode |= boost::asio::ssl::verify_fail_if_no_peer_cert;
550     }
551     else if (!forward_unauthorized::hasWebuiRoute())
552     {
553         // This is a HACK
554         // If the webui is installed, and TLSSTrict is false, we don't want to
555         // force the mtls popup to occur, which would happen if we requested a
556         // client cert by setting verify_peer. But, if the webui isn't
557         // installed, we'd like clients to be able to optionally log in with
558         // MTLS, which won't happen if we don't expose the MTLS client cert
559         // request.  So, in this case detect if the webui is installed, and
560         // only request peer authentication if it's not present.
561         // This will likely need revisited in the future.
562         BMCWEB_LOG_DEBUG("Setting verify peer only");
563         mode |= boost::asio::ssl::verify_peer;
564     }
565 
566     boost::system::error_code ec;
567     sslCtx.set_verify_mode(mode, ec);
568     if (ec)
569     {
570         BMCWEB_LOG_DEBUG("Failed to set verify mode {}", ec.message());
571         return nullptr;
572     }
573 
574     SSL_CTX_set_options(sslCtx.native_handle(), SSL_OP_NO_RENEGOTIATION);
575 
576     if constexpr (BMCWEB_HTTP2)
577     {
578         SSL_CTX_set_next_protos_advertised_cb(sslCtx.native_handle(),
579                                               nextProtoCallback, nullptr);
580 
581         SSL_CTX_set_alpn_select_cb(sslCtx.native_handle(),
582                                    alpnSelectProtoCallback, nullptr);
583     }
584 
585     return std::make_shared<boost::asio::ssl::context>(std::move(sslCtx));
586 }
587 
getSSLClientContext(VerifyCertificate verifyCertificate)588 std::optional<boost::asio::ssl::context> getSSLClientContext(
589     VerifyCertificate verifyCertificate)
590 {
591     namespace fs = std::filesystem;
592 
593     boost::asio::ssl::context sslCtx(boost::asio::ssl::context::tls_client);
594 
595     // NOTE, this path is temporary;  In the future it will need to change to
596     // be set per subscription.  Do not rely on this.
597     fs::path certPath = "/etc/ssl/certs/https/client.pem";
598     std::string cert = verifyOpensslKeyCert(certPath);
599 
600     if (!getSslContext(sslCtx, cert))
601     {
602         return std::nullopt;
603     }
604 
605     // Add a directory containing certificate authority files to be used
606     // for performing verification.
607     boost::system::error_code ec;
608     sslCtx.set_default_verify_paths(ec);
609     if (ec)
610     {
611         BMCWEB_LOG_ERROR("SSL context set_default_verify failed");
612         return std::nullopt;
613     }
614 
615     int mode = boost::asio::ssl::verify_peer;
616     if (verifyCertificate == VerifyCertificate::NoVerify)
617     {
618         mode = boost::asio::ssl::verify_none;
619     }
620 
621     // Verify the remote server's certificate
622     sslCtx.set_verify_mode(mode, ec);
623     if (ec)
624     {
625         BMCWEB_LOG_ERROR("SSL context set_verify_mode failed");
626         return std::nullopt;
627     }
628 
629     if (SSL_CTX_set_cipher_list(sslCtx.native_handle(), mozillaIntermediate) !=
630         1)
631     {
632         BMCWEB_LOG_ERROR("SSL_CTX_set_cipher_list failed");
633         return std::nullopt;
634     }
635 
636     return {std::move(sslCtx)};
637 }
638 
639 } // namespace ensuressl
640