1 #pragma once
2 
3 #include "logging.hpp"
4 #include "random.hpp"
5 
6 extern "C"
7 {
8 #include <nghttp2/nghttp2.h>
9 }
10 #include <openssl/bio.h>
11 #include <openssl/dh.h>
12 #include <openssl/dsa.h>
13 #include <openssl/err.h>
14 #include <openssl/evp.h>
15 #include <openssl/pem.h>
16 #include <openssl/rand.h>
17 #include <openssl/rsa.h>
18 #include <openssl/ssl.h>
19 
20 #include <boost/asio/ssl/context.hpp>
21 
22 #include <optional>
23 #include <random>
24 #include <string>
25 
26 namespace ensuressl
27 {
28 constexpr const char* trustStorePath = "/etc/ssl/certs/authority";
29 constexpr const char* x509Comment = "Generated from OpenBMC service";
30 static void initOpenssl();
31 static EVP_PKEY* createEcKey();
32 
33 // Trust chain related errors.`
34 inline bool isTrustChainError(int errnum)
35 {
36     return (errnum == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT) ||
37            (errnum == X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN) ||
38            (errnum == X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY) ||
39            (errnum == X509_V_ERR_CERT_UNTRUSTED) ||
40            (errnum == X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE);
41 }
42 
43 inline bool validateCertificate(X509* const cert)
44 {
45     // Create an empty X509_STORE structure for certificate validation.
46     X509_STORE* x509Store = X509_STORE_new();
47     if (x509Store == nullptr)
48     {
49         BMCWEB_LOG_ERROR << "Error occurred during X509_STORE_new call";
50         return false;
51     }
52 
53     // Load Certificate file into the X509 structure.
54     X509_STORE_CTX* storeCtx = X509_STORE_CTX_new();
55     if (storeCtx == nullptr)
56     {
57         BMCWEB_LOG_ERROR << "Error occurred during X509_STORE_CTX_new call";
58         X509_STORE_free(x509Store);
59         return false;
60     }
61 
62     int errCode = X509_STORE_CTX_init(storeCtx, x509Store, cert, nullptr);
63     if (errCode != 1)
64     {
65         BMCWEB_LOG_ERROR << "Error occurred during X509_STORE_CTX_init call";
66         X509_STORE_CTX_free(storeCtx);
67         X509_STORE_free(x509Store);
68         return false;
69     }
70 
71     errCode = X509_verify_cert(storeCtx);
72     if (errCode == 1)
73     {
74         BMCWEB_LOG_INFO << "Certificate verification is success";
75         X509_STORE_CTX_free(storeCtx);
76         X509_STORE_free(x509Store);
77         return true;
78     }
79     if (errCode == 0)
80     {
81         errCode = X509_STORE_CTX_get_error(storeCtx);
82         X509_STORE_CTX_free(storeCtx);
83         X509_STORE_free(x509Store);
84         if (isTrustChainError(errCode))
85         {
86             BMCWEB_LOG_DEBUG << "Ignoring Trust Chain error. Reason: "
87                              << X509_verify_cert_error_string(errCode);
88             return true;
89         }
90         BMCWEB_LOG_ERROR << "Certificate verification failed. Reason: "
91                          << X509_verify_cert_error_string(errCode);
92         return false;
93     }
94 
95     BMCWEB_LOG_ERROR
96         << "Error occurred during X509_verify_cert call. ErrorCode: "
97         << errCode;
98     X509_STORE_CTX_free(storeCtx);
99     X509_STORE_free(x509Store);
100     return false;
101 }
102 
103 inline bool verifyOpensslKeyCert(const std::string& filepath)
104 {
105     bool privateKeyValid = false;
106     bool certValid = false;
107 
108     std::cout << "Checking certs in file " << filepath << "\n";
109 
110     FILE* file = fopen(filepath.c_str(), "r");
111     if (file != nullptr)
112     {
113         EVP_PKEY* pkey = PEM_read_PrivateKey(file, nullptr, nullptr, nullptr);
114         if (pkey != nullptr)
115         {
116 #if (OPENSSL_VERSION_NUMBER < 0x30000000L)
117             RSA* rsa = EVP_PKEY_get1_RSA(pkey);
118             if (rsa != nullptr)
119             {
120                 std::cout << "Found an RSA key\n";
121                 if (RSA_check_key(rsa) == 1)
122                 {
123                     privateKeyValid = true;
124                 }
125                 else
126                 {
127                     std::cerr << "Key not valid error number "
128                               << ERR_get_error() << "\n";
129                 }
130                 RSA_free(rsa);
131             }
132             else
133             {
134                 EC_KEY* ec = EVP_PKEY_get1_EC_KEY(pkey);
135                 if (ec != nullptr)
136                 {
137                     std::cout << "Found an EC key\n";
138                     if (EC_KEY_check_key(ec) == 1)
139                     {
140                         privateKeyValid = true;
141                     }
142                     else
143                     {
144                         std::cerr << "Key not valid error number "
145                                   << ERR_get_error() << "\n";
146                     }
147                     EC_KEY_free(ec);
148                 }
149             }
150 #else
151             EVP_PKEY_CTX* pkeyCtx = EVP_PKEY_CTX_new_from_pkey(nullptr, pkey,
152                                                                nullptr);
153 
154             if (pkeyCtx == nullptr)
155             {
156                 std::cerr << "Unable to allocate pkeyCtx " << ERR_get_error()
157                           << "\n";
158             }
159             else if (EVP_PKEY_check(pkeyCtx) == 1)
160             {
161                 privateKeyValid = true;
162             }
163             else
164             {
165                 std::cerr << "Key not valid error number " << ERR_get_error()
166                           << "\n";
167             }
168 #endif
169 
170             if (privateKeyValid)
171             {
172                 // If the order is certificate followed by key in input file
173                 // then, certificate read will fail. So, setting the file
174                 // pointer to point beginning of file to avoid certificate and
175                 // key order issue.
176                 fseek(file, 0, SEEK_SET);
177 
178                 X509* x509 = PEM_read_X509(file, nullptr, nullptr, nullptr);
179                 if (x509 == nullptr)
180                 {
181                     std::cout << "error getting x509 cert " << ERR_get_error()
182                               << "\n";
183                 }
184                 else
185                 {
186                     certValid = validateCertificate(x509);
187                     X509_free(x509);
188                 }
189             }
190 
191 #if (OPENSSL_VERSION_NUMBER > 0x30000000L)
192             EVP_PKEY_CTX_free(pkeyCtx);
193 #endif
194             EVP_PKEY_free(pkey);
195         }
196         fclose(file);
197     }
198     return certValid;
199 }
200 
201 inline X509* loadCert(const std::string& filePath)
202 {
203     BIO* certFileBio = BIO_new_file(filePath.c_str(), "rb");
204     if (certFileBio == nullptr)
205     {
206         BMCWEB_LOG_ERROR << "Error occured during BIO_new_file call, "
207                          << "FILE= " << filePath;
208         return nullptr;
209     }
210 
211     X509* cert = X509_new();
212     if (cert == nullptr)
213     {
214         BMCWEB_LOG_ERROR << "Error occured during X509_new call, "
215                          << ERR_get_error();
216         BIO_free(certFileBio);
217         return nullptr;
218     }
219 
220     if (PEM_read_bio_X509(certFileBio, &cert, nullptr, nullptr) == nullptr)
221     {
222         BMCWEB_LOG_ERROR << "Error occured during PEM_read_bio_X509 call, "
223                          << "FILE= " << filePath;
224 
225         BIO_free(certFileBio);
226         X509_free(cert);
227         return nullptr;
228     }
229     BIO_free(certFileBio);
230     return cert;
231 }
232 
233 inline int addExt(X509* cert, int nid, const char* value)
234 {
235     X509_EXTENSION* ex = nullptr;
236     X509V3_CTX ctx{};
237     X509V3_set_ctx(&ctx, cert, cert, nullptr, nullptr, 0);
238 
239     // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
240     ex = X509V3_EXT_conf_nid(nullptr, &ctx, nid, const_cast<char*>(value));
241     if (ex == nullptr)
242     {
243         BMCWEB_LOG_ERROR << "Error: In X509V3_EXT_conf_nidn: " << value;
244         return -1;
245     }
246     X509_add_ext(cert, ex, -1);
247     X509_EXTENSION_free(ex);
248     return 0;
249 }
250 
251 inline void generateSslCertificate(const std::string& filepath,
252                                    const std::string& cn)
253 {
254     FILE* pFile = nullptr;
255     std::cout << "Generating new keys\n";
256     initOpenssl();
257 
258     std::cerr << "Generating EC key\n";
259     EVP_PKEY* pPrivKey = createEcKey();
260     if (pPrivKey != nullptr)
261     {
262         std::cerr << "Generating x509 Certificate\n";
263         // Use this code to directly generate a certificate
264         X509* x509 = X509_new();
265         if (x509 != nullptr)
266         {
267             // get a random number from the RNG for the certificate serial
268             // number If this is not random, regenerating certs throws broswer
269             // errors
270             bmcweb::OpenSSLGenerator gen;
271             std::uniform_int_distribution<int> dis(
272                 1, std::numeric_limits<int>::max());
273             int serial = dis(gen);
274 
275             ASN1_INTEGER_set(X509_get_serialNumber(x509), serial);
276 
277             // not before this moment
278             X509_gmtime_adj(X509_get_notBefore(x509), 0);
279             // Cert is valid for 10 years
280             X509_gmtime_adj(X509_get_notAfter(x509),
281                             60L * 60L * 24L * 365L * 10L);
282 
283             // set the public key to the key we just generated
284             X509_set_pubkey(x509, pPrivKey);
285 
286             // get the subject name
287             X509_NAME* name = X509_get_subject_name(x509);
288 
289             using x509String = const unsigned char;
290             // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
291             x509String* country = reinterpret_cast<x509String*>("US");
292             // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
293             x509String* company = reinterpret_cast<x509String*>("OpenBMC");
294             // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
295             x509String* cnStr = reinterpret_cast<x509String*>(cn.c_str());
296 
297             X509_NAME_add_entry_by_txt(name, "C", MBSTRING_ASC, country, -1, -1,
298                                        0);
299             X509_NAME_add_entry_by_txt(name, "O", MBSTRING_ASC, company, -1, -1,
300                                        0);
301             X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, cnStr, -1, -1,
302                                        0);
303             // set the CSR options
304             X509_set_issuer_name(x509, name);
305 
306             X509_set_version(x509, 2);
307             addExt(x509, NID_basic_constraints, ("critical,CA:TRUE"));
308             addExt(x509, NID_subject_alt_name, ("DNS:" + cn).c_str());
309             addExt(x509, NID_subject_key_identifier, ("hash"));
310             addExt(x509, NID_authority_key_identifier, ("keyid"));
311             addExt(x509, NID_key_usage, ("digitalSignature, keyEncipherment"));
312             addExt(x509, NID_ext_key_usage, ("serverAuth"));
313             addExt(x509, NID_netscape_comment, (x509Comment));
314 
315             // Sign the certificate with our private key
316             X509_sign(x509, pPrivKey, EVP_sha256());
317 
318             pFile = fopen(filepath.c_str(), "wt");
319 
320             if (pFile != nullptr)
321             {
322                 PEM_write_PrivateKey(pFile, pPrivKey, nullptr, nullptr, 0,
323                                      nullptr, nullptr);
324 
325                 PEM_write_X509(pFile, x509);
326                 fclose(pFile);
327                 pFile = nullptr;
328             }
329 
330             X509_free(x509);
331         }
332 
333         EVP_PKEY_free(pPrivKey);
334         pPrivKey = nullptr;
335     }
336 
337     // cleanup_openssl();
338 }
339 
340 EVP_PKEY* createEcKey()
341 {
342     EVP_PKEY* pKey = nullptr;
343 
344 #if (OPENSSL_VERSION_NUMBER < 0x30000000L)
345     int eccgrp = 0;
346     eccgrp = OBJ_txt2nid("secp384r1");
347 
348     EC_KEY* myecc = EC_KEY_new_by_curve_name(eccgrp);
349     if (myecc != nullptr)
350     {
351         EC_KEY_set_asn1_flag(myecc, OPENSSL_EC_NAMED_CURVE);
352         EC_KEY_generate_key(myecc);
353         pKey = EVP_PKEY_new();
354         if (pKey != nullptr)
355         {
356             if (EVP_PKEY_assign(pKey, EVP_PKEY_EC, myecc) != 0)
357             {
358                 /* pKey owns myecc from now */
359                 if (EC_KEY_check_key(myecc) <= 0)
360                 {
361                     std::cerr << "EC_check_key failed.\n";
362                 }
363             }
364         }
365     }
366 #else
367     // Create context for curve parameter generation.
368     std::unique_ptr<EVP_PKEY_CTX, decltype(&::EVP_PKEY_CTX_free)> ctx{
369         EVP_PKEY_CTX_new_id(EVP_PKEY_EC, nullptr), &::EVP_PKEY_CTX_free};
370     if (!ctx)
371     {
372         return nullptr;
373     }
374 
375     // Set up curve parameters.
376     EVP_PKEY* params = nullptr;
377     if ((EVP_PKEY_paramgen_init(ctx.get()) <= 0) ||
378         (EVP_PKEY_CTX_set_ec_param_enc(ctx.get(), OPENSSL_EC_NAMED_CURVE) <=
379          0) ||
380         (EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx.get(), NID_secp384r1) <=
381          0) ||
382         (EVP_PKEY_paramgen(ctx.get(), &params) <= 0))
383     {
384         return nullptr;
385     }
386 
387     // Set up RAII holder for params.
388     std::unique_ptr<EVP_PKEY, decltype(&::EVP_PKEY_free)> pparams{
389         params, &::EVP_PKEY_free};
390 
391     // Set new context for key generation, using curve parameters.
392     ctx.reset(EVP_PKEY_CTX_new_from_pkey(nullptr, params, nullptr));
393     if (!ctx || (EVP_PKEY_keygen_init(ctx.get()) <= 0))
394     {
395         return nullptr;
396     }
397 
398     // Generate key.
399     if (EVP_PKEY_keygen(ctx.get(), &pKey) <= 0)
400     {
401         return nullptr;
402     }
403 #endif
404 
405     return pKey;
406 }
407 
408 void initOpenssl()
409 {
410 #if OPENSSL_VERSION_NUMBER < 0x10100000L
411     SSL_load_error_strings();
412     OpenSSL_add_all_algorithms();
413     RAND_load_file("/dev/urandom", 1024);
414 #endif
415 }
416 
417 inline void ensureOpensslKeyPresentAndValid(const std::string& filepath)
418 {
419     bool pemFileValid = false;
420 
421     pemFileValid = verifyOpensslKeyCert(filepath);
422 
423     if (!pemFileValid)
424     {
425         std::cerr << "Error in verifying signature, regenerating\n";
426         generateSslCertificate(filepath, "testhost");
427     }
428 }
429 
430 inline int nextProtoCallback(SSL* /*unused*/, const unsigned char** data,
431                              unsigned int* len, void* /*unused*/)
432 {
433     // First byte is the length.
434     constexpr std::string_view h2 = "\x02h2";
435     *data = std::bit_cast<const unsigned char*>(h2.data());
436     *len = static_cast<unsigned int>(h2.size());
437     return SSL_TLSEXT_ERR_OK;
438 }
439 
440 inline int alpnSelectProtoCallback(SSL* /*unused*/, const unsigned char** out,
441                                    unsigned char* outlen,
442                                    const unsigned char* in, unsigned int inlen,
443                                    void* /*unused*/)
444 {
445     // There's a mismatch in constness for nghttp2_select_next_protocol.  The
446     // examples in nghttp2 don't show this problem.  Unclear what the right fix
447     // is here.
448 
449     // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
450     unsigned char** outNew = const_cast<unsigned char**>(out);
451     int rv = nghttp2_select_next_protocol(outNew, outlen, in, inlen);
452     if (rv != 1)
453     {
454         return SSL_TLSEXT_ERR_NOACK;
455     }
456 
457     return SSL_TLSEXT_ERR_OK;
458 }
459 
460 inline std::shared_ptr<boost::asio::ssl::context>
461     getSslContext(const std::string& sslPemFile)
462 {
463     std::shared_ptr<boost::asio::ssl::context> mSslContext =
464         std::make_shared<boost::asio::ssl::context>(
465             boost::asio::ssl::context::tls_server);
466     mSslContext->set_options(boost::asio::ssl::context::default_workarounds |
467                              boost::asio::ssl::context::no_sslv2 |
468                              boost::asio::ssl::context::no_sslv3 |
469                              boost::asio::ssl::context::single_dh_use |
470                              boost::asio::ssl::context::no_tlsv1 |
471                              boost::asio::ssl::context::no_tlsv1_1);
472 
473     // BIG WARNING: This needs to stay disabled, as there will always be
474     // unauthenticated endpoints
475     // mSslContext->set_verify_mode(boost::asio::ssl::verify_peer);
476 
477     SSL_CTX_set_options(mSslContext->native_handle(), SSL_OP_NO_RENEGOTIATION);
478 
479     BMCWEB_LOG_DEBUG << "Using default TrustStore location: " << trustStorePath;
480     mSslContext->add_verify_path(trustStorePath);
481 
482     mSslContext->use_certificate_file(sslPemFile,
483                                       boost::asio::ssl::context::pem);
484     mSslContext->use_private_key_file(sslPemFile,
485                                       boost::asio::ssl::context::pem);
486 
487     if constexpr (bmcwebEnableHTTP2)
488     {
489         SSL_CTX_set_next_protos_advertised_cb(mSslContext->native_handle(),
490                                               nextProtoCallback, nullptr);
491 
492         SSL_CTX_set_alpn_select_cb(mSslContext->native_handle(),
493                                    alpnSelectProtoCallback, nullptr);
494     }
495     // Set up EC curves to auto (boost asio doesn't have a method for this)
496     // There is a pull request to add this.  Once this is included in an asio
497     // drop, use the right way
498     // http://stackoverflow.com/questions/18929049/boost-asio-with-ecdsa-certificate-issue
499     if (SSL_CTX_set_ecdh_auto(mSslContext->native_handle(), 1) != 1)
500     {
501         BMCWEB_LOG_ERROR << "Error setting tmp ecdh list\n";
502     }
503 
504     // Mozilla intermediate cipher suites v5.7
505     // Sourced from: https://ssl-config.mozilla.org/guidelines/5.7.json
506     const char* mozillaIntermediate = "ECDHE-ECDSA-AES128-GCM-SHA256:"
507                                       "ECDHE-RSA-AES128-GCM-SHA256:"
508                                       "ECDHE-ECDSA-AES256-GCM-SHA384:"
509                                       "ECDHE-RSA-AES256-GCM-SHA384:"
510                                       "ECDHE-ECDSA-CHACHA20-POLY1305:"
511                                       "ECDHE-RSA-CHACHA20-POLY1305:"
512                                       "DHE-RSA-AES128-GCM-SHA256:"
513                                       "DHE-RSA-AES256-GCM-SHA384:"
514                                       "DHE-RSA-CHACHA20-POLY1305";
515 
516     if (SSL_CTX_set_cipher_list(mSslContext->native_handle(),
517                                 mozillaIntermediate) != 1)
518     {
519         BMCWEB_LOG_ERROR << "Error setting cipher list\n";
520     }
521     return mSslContext;
522 }
523 
524 inline std::optional<boost::asio::ssl::context> getSSLClientContext()
525 {
526     boost::asio::ssl::context sslCtx(boost::asio::ssl::context::tls_client);
527 
528     boost::system::error_code ec;
529 
530     // Support only TLS v1.2 & v1.3
531     sslCtx.set_options(boost::asio::ssl::context::default_workarounds |
532                            boost::asio::ssl::context::no_sslv2 |
533                            boost::asio::ssl::context::no_sslv3 |
534                            boost::asio::ssl::context::single_dh_use |
535                            boost::asio::ssl::context::no_tlsv1 |
536                            boost::asio::ssl::context::no_tlsv1_1,
537                        ec);
538     if (ec)
539     {
540         BMCWEB_LOG_ERROR << "SSL context set_options failed";
541         return std::nullopt;
542     }
543 
544     // Add a directory containing certificate authority files to be used
545     // for performing verification.
546     sslCtx.set_default_verify_paths(ec);
547     if (ec)
548     {
549         BMCWEB_LOG_ERROR << "SSL context set_default_verify failed";
550         return std::nullopt;
551     }
552 
553     // Verify the remote server's certificate
554     sslCtx.set_verify_mode(boost::asio::ssl::verify_peer, ec);
555     if (ec)
556     {
557         BMCWEB_LOG_ERROR << "SSL context set_verify_mode failed";
558         return std::nullopt;
559     }
560 
561     // All cipher suites are set as per OWASP datasheet.
562     // https://cheatsheetseries.owasp.org/cheatsheets/TLS_Cipher_String_Cheat_Sheet.html
563     constexpr const char* sslCiphers = "ECDHE-ECDSA-AES128-GCM-SHA256:"
564                                        "ECDHE-RSA-AES128-GCM-SHA256:"
565                                        "ECDHE-ECDSA-AES256-GCM-SHA384:"
566                                        "ECDHE-RSA-AES256-GCM-SHA384:"
567                                        "ECDHE-ECDSA-CHACHA20-POLY1305:"
568                                        "ECDHE-RSA-CHACHA20-POLY1305:"
569                                        "DHE-RSA-AES128-GCM-SHA256:"
570                                        "DHE-RSA-AES256-GCM-SHA384"
571                                        "TLS_AES_128_GCM_SHA256:"
572                                        "TLS_AES_256_GCM_SHA384:"
573                                        "TLS_CHACHA20_POLY1305_SHA256";
574 
575     if (SSL_CTX_set_cipher_list(sslCtx.native_handle(), sslCiphers) != 1)
576     {
577         BMCWEB_LOG_ERROR << "SSL_CTX_set_cipher_list failed";
578         return std::nullopt;
579     }
580 
581     return sslCtx;
582 }
583 
584 } // namespace ensuressl
585