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