1 #pragma once
2 #ifdef BMCWEB_ENABLE_SSL
3 
4 #include <openssl/bio.h>
5 #include <openssl/dh.h>
6 #include <openssl/dsa.h>
7 #include <openssl/err.h>
8 #include <openssl/evp.h>
9 #include <openssl/pem.h>
10 #include <openssl/rand.h>
11 #include <openssl/rsa.h>
12 #include <openssl/ssl.h>
13 
14 #include <boost/asio/ssl/context.hpp>
15 
16 #include <random>
17 
18 namespace ensuressl
19 {
20 constexpr char const* trustStorePath = "/etc/ssl/certs/authority";
21 static void initOpenssl();
22 static EVP_PKEY* createEcKey();
23 
24 // Trust chain related errors.`
25 inline bool isTrustChainError(int errnum)
26 {
27     if ((errnum == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT) ||
28         (errnum == X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN) ||
29         (errnum == X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY) ||
30         (errnum == X509_V_ERR_CERT_UNTRUSTED) ||
31         (errnum == X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE))
32     {
33         return true;
34     }
35     else
36     {
37         return false;
38     }
39 }
40 
41 inline bool validateCertificate(X509* const cert)
42 {
43     // Create an empty X509_STORE structure for certificate validation.
44     X509_STORE* x509Store = X509_STORE_new();
45     if (!x509Store)
46     {
47         BMCWEB_LOG_ERROR << "Error occured during X509_STORE_new call";
48         return false;
49     }
50 
51     // Load Certificate file into the X509 structure.
52     X509_STORE_CTX* storeCtx = X509_STORE_CTX_new();
53     if (!storeCtx)
54     {
55         BMCWEB_LOG_ERROR << "Error occured during X509_STORE_CTX_new call";
56         X509_STORE_free(x509Store);
57         return false;
58     }
59 
60     int errCode = X509_STORE_CTX_init(storeCtx, x509Store, cert, nullptr);
61     if (errCode != 1)
62     {
63         BMCWEB_LOG_ERROR << "Error occured during X509_STORE_CTX_init call";
64         X509_STORE_CTX_free(storeCtx);
65         X509_STORE_free(x509Store);
66         return false;
67     }
68 
69     errCode = X509_verify_cert(storeCtx);
70     if (errCode == 1)
71     {
72         BMCWEB_LOG_INFO << "Certificate verification is success";
73         X509_STORE_CTX_free(storeCtx);
74         X509_STORE_free(x509Store);
75         return true;
76     }
77     if (errCode == 0)
78     {
79         errCode = X509_STORE_CTX_get_error(storeCtx);
80         X509_STORE_CTX_free(storeCtx);
81         X509_STORE_free(x509Store);
82         if (isTrustChainError(errCode))
83         {
84             BMCWEB_LOG_DEBUG << "Ignoring Trust Chain error. Reason: "
85                              << X509_verify_cert_error_string(errCode);
86             return true;
87         }
88         else
89         {
90             BMCWEB_LOG_ERROR << "Certificate verification failed. Reason: "
91                              << X509_verify_cert_error_string(errCode);
92             return false;
93         }
94     }
95 
96     BMCWEB_LOG_ERROR
97         << "Error occured during X509_verify_cert call. ErrorCode: " << 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             RSA* rsa = EVP_PKEY_get1_RSA(pkey);
117             if (rsa != nullptr)
118             {
119                 std::cout << "Found an RSA key\n";
120                 if (RSA_check_key(rsa) == 1)
121                 {
122                     privateKeyValid = true;
123                 }
124                 else
125                 {
126                     std::cerr << "Key not valid error number "
127                               << ERR_get_error() << "\n";
128                 }
129                 RSA_free(rsa);
130             }
131             else
132             {
133                 EC_KEY* ec = EVP_PKEY_get1_EC_KEY(pkey);
134                 if (ec != nullptr)
135                 {
136                     std::cout << "Found an EC key\n";
137                     if (EC_KEY_check_key(ec) == 1)
138                     {
139                         privateKeyValid = true;
140                     }
141                     else
142                     {
143                         std::cerr << "Key not valid error number "
144                                   << ERR_get_error() << "\n";
145                     }
146                     EC_KEY_free(ec);
147                 }
148             }
149 
150             if (privateKeyValid)
151             {
152                 // If the order is certificate followed by key in input file
153                 // then, certificate read will fail. So, setting the file
154                 // pointer to point beginning of file to avoid certificate and
155                 // key order issue.
156                 fseek(file, 0, SEEK_SET);
157 
158                 X509* x509 = PEM_read_X509(file, nullptr, nullptr, nullptr);
159                 if (x509 == nullptr)
160                 {
161                     std::cout << "error getting x509 cert " << ERR_get_error()
162                               << "\n";
163                 }
164                 else
165                 {
166                     certValid = validateCertificate(x509);
167                     X509_free(x509);
168                 }
169             }
170 
171             EVP_PKEY_free(pkey);
172         }
173         fclose(file);
174     }
175     return certValid;
176 }
177 
178 inline void generateSslCertificate(const std::string& filepath)
179 {
180     FILE* pFile = nullptr;
181     std::cout << "Generating new keys\n";
182     initOpenssl();
183 
184     std::cerr << "Generating EC key\n";
185     EVP_PKEY* pPrivKey = createEcKey();
186     if (pPrivKey != nullptr)
187     {
188         std::cerr << "Generating x509 Certificate\n";
189         // Use this code to directly generate a certificate
190         X509* x509;
191         x509 = X509_new();
192         if (x509 != nullptr)
193         {
194             // get a random number from the RNG for the certificate serial
195             // number If this is not random, regenerating certs throws broswer
196             // errors
197             std::random_device rd;
198             int serial = static_cast<int>(rd());
199 
200             ASN1_INTEGER_set(X509_get_serialNumber(x509), serial);
201 
202             // not before this moment
203             X509_gmtime_adj(X509_get_notBefore(x509), 0);
204             // Cert is valid for 10 years
205             X509_gmtime_adj(X509_get_notAfter(x509),
206                             60L * 60L * 24L * 365L * 10L);
207 
208             // set the public key to the key we just generated
209             X509_set_pubkey(x509, pPrivKey);
210 
211             // get the subject name
212             X509_NAME* name;
213             name = X509_get_subject_name(x509);
214 
215             X509_NAME_add_entry_by_txt(
216                 name, "C", MBSTRING_ASC,
217                 reinterpret_cast<const unsigned char*>("US"), -1, -1, 0);
218             X509_NAME_add_entry_by_txt(
219                 name, "O", MBSTRING_ASC,
220                 reinterpret_cast<const unsigned char*>("OpenBMC"), -1, -1, 0);
221             X509_NAME_add_entry_by_txt(
222                 name, "CN", MBSTRING_ASC,
223                 reinterpret_cast<const unsigned char*>("testhost"), -1, -1, 0);
224             // set the CSR options
225             X509_set_issuer_name(x509, name);
226 
227             // Sign the certificate with our private key
228             X509_sign(x509, pPrivKey, EVP_sha256());
229 
230             pFile = fopen(filepath.c_str(), "wt");
231 
232             if (pFile != nullptr)
233             {
234                 PEM_write_PrivateKey(pFile, pPrivKey, nullptr, nullptr, 0,
235                                      nullptr, nullptr);
236 
237                 PEM_write_X509(pFile, x509);
238                 fclose(pFile);
239                 pFile = nullptr;
240             }
241 
242             X509_free(x509);
243         }
244 
245         EVP_PKEY_free(pPrivKey);
246         pPrivKey = nullptr;
247     }
248 
249     // cleanup_openssl();
250 }
251 
252 EVP_PKEY* createEcKey()
253 {
254     EVP_PKEY* pKey = nullptr;
255     int eccgrp = 0;
256     eccgrp = OBJ_txt2nid("secp384r1");
257 
258     EC_KEY* myecc = EC_KEY_new_by_curve_name(eccgrp);
259     if (myecc != nullptr)
260     {
261         EC_KEY_set_asn1_flag(myecc, OPENSSL_EC_NAMED_CURVE);
262         EC_KEY_generate_key(myecc);
263         pKey = EVP_PKEY_new();
264         if (pKey != nullptr)
265         {
266             if (EVP_PKEY_assign_EC_KEY(pKey, myecc))
267             {
268                 /* pKey owns myecc from now */
269                 if (EC_KEY_check_key(myecc) <= 0)
270                 {
271                     fprintf(stderr, "EC_check_key failed.\n");
272                 }
273             }
274         }
275     }
276     return pKey;
277 }
278 
279 void initOpenssl()
280 {
281 #if OPENSSL_VERSION_NUMBER < 0x10100000L
282     SSL_load_error_strings();
283     OpenSSL_add_all_algorithms();
284     RAND_load_file("/dev/urandom", 1024);
285 #endif
286 }
287 
288 inline void ensureOpensslKeyPresentAndValid(const std::string& filepath)
289 {
290     bool pemFileValid = false;
291 
292     pemFileValid = verifyOpensslKeyCert(filepath);
293 
294     if (!pemFileValid)
295     {
296         std::cerr << "Error in verifying signature, regenerating\n";
297         generateSslCertificate(filepath);
298     }
299 }
300 
301 inline std::shared_ptr<boost::asio::ssl::context>
302     getSslContext(const std::string& ssl_pem_file)
303 {
304     std::shared_ptr<boost::asio::ssl::context> mSslContext =
305         std::make_shared<boost::asio::ssl::context>(
306             boost::asio::ssl::context::tls_server);
307     mSslContext->set_options(boost::asio::ssl::context::default_workarounds |
308                              boost::asio::ssl::context::no_sslv2 |
309                              boost::asio::ssl::context::no_sslv3 |
310                              boost::asio::ssl::context::single_dh_use |
311                              boost::asio::ssl::context::no_tlsv1 |
312                              boost::asio::ssl::context::no_tlsv1_1);
313 
314     // BIG WARNING: This needs to stay disabled, as there will always be
315     // unauthenticated endpoints
316     // mSslContext->set_verify_mode(boost::asio::ssl::verify_peer);
317 
318     SSL_CTX_set_options(mSslContext->native_handle(), SSL_OP_NO_RENEGOTIATION);
319 
320     BMCWEB_LOG_DEBUG << "Using default TrustStore location: " << trustStorePath;
321     mSslContext->add_verify_path(trustStorePath);
322 
323     mSslContext->use_certificate_file(ssl_pem_file,
324                                       boost::asio::ssl::context::pem);
325     mSslContext->use_private_key_file(ssl_pem_file,
326                                       boost::asio::ssl::context::pem);
327 
328     // Set up EC curves to auto (boost asio doesn't have a method for this)
329     // There is a pull request to add this.  Once this is included in an asio
330     // drop, use the right way
331     // http://stackoverflow.com/questions/18929049/boost-asio-with-ecdsa-certificate-issue
332     if (SSL_CTX_set_ecdh_auto(mSslContext->native_handle(), 1) != 1)
333     {
334         BMCWEB_LOG_ERROR << "Error setting tmp ecdh list\n";
335     }
336 
337     std::string mozillaModern = "ECDHE-ECDSA-AES256-GCM-SHA384:"
338                                 "ECDHE-RSA-AES256-GCM-SHA384:"
339                                 "ECDHE-ECDSA-CHACHA20-POLY1305:"
340                                 "ECDHE-RSA-CHACHA20-POLY1305:"
341                                 "ECDHE-ECDSA-AES128-GCM-SHA256:"
342                                 "ECDHE-RSA-AES128-GCM-SHA256:"
343                                 "ECDHE-ECDSA-AES256-SHA384:"
344                                 "ECDHE-RSA-AES256-SHA384:"
345                                 "ECDHE-ECDSA-AES128-SHA256:"
346                                 "ECDHE-RSA-AES128-SHA256";
347 
348     if (SSL_CTX_set_cipher_list(mSslContext->native_handle(),
349                                 mozillaModern.c_str()) != 1)
350     {
351         BMCWEB_LOG_ERROR << "Error setting cipher list\n";
352     }
353     return mSslContext;
354 }
355 } // namespace ensuressl
356 
357 #endif
358