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 #include <random>
16 
17 namespace ensuressl
18 {
19 constexpr char const *trustStorePath = "/etc/ssl/certs/authority";
20 static void initOpenssl();
21 static EVP_PKEY *createEcKey();
22 
23 // Trust chain related errors.`
24 inline bool isTrustChainError(int errnum)
25 {
26     if ((errnum == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT) ||
27         (errnum == X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN) ||
28         (errnum == X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY) ||
29         (errnum == X509_V_ERR_CERT_UNTRUSTED) ||
30         (errnum == X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE))
31     {
32         return true;
33     }
34     else
35     {
36         return false;
37     }
38 }
39 
40 inline bool validateCertificate(X509 *const cert)
41 {
42     // Create an empty X509_STORE structure for certificate validation.
43     X509_STORE *x509Store = X509_STORE_new();
44     if (!x509Store)
45     {
46         BMCWEB_LOG_ERROR << "Error occured during X509_STORE_new call";
47         return false;
48     }
49 
50     // Load Certificate file into the X509 structure.
51     X509_STORE_CTX *storeCtx = X509_STORE_CTX_new();
52     if (!storeCtx)
53     {
54         BMCWEB_LOG_ERROR << "Error occured during X509_STORE_CTX_new call";
55         X509_STORE_free(x509Store);
56         return false;
57     }
58 
59     int errCode = X509_STORE_CTX_init(storeCtx, x509Store, cert, nullptr);
60     if (errCode != 1)
61     {
62         BMCWEB_LOG_ERROR << "Error occured during X509_STORE_CTX_init call";
63         X509_STORE_CTX_free(storeCtx);
64         X509_STORE_free(x509Store);
65         return false;
66     }
67 
68     errCode = X509_verify_cert(storeCtx);
69     if (errCode == 1)
70     {
71         BMCWEB_LOG_INFO << "Certificate verification is success";
72         X509_STORE_CTX_free(storeCtx);
73         X509_STORE_free(x509Store);
74         return true;
75     }
76     if (errCode == 0)
77     {
78         errCode = X509_STORE_CTX_get_error(storeCtx);
79         X509_STORE_CTX_free(storeCtx);
80         X509_STORE_free(x509Store);
81         if (isTrustChainError(errCode))
82         {
83             BMCWEB_LOG_DEBUG << "Ignoring Trust Chain error. Reason: "
84                              << X509_verify_cert_error_string(errCode);
85             return true;
86         }
87         else
88         {
89             BMCWEB_LOG_ERROR << "Certificate verification failed. Reason: "
90                              << X509_verify_cert_error_string(errCode);
91             return false;
92         }
93     }
94 
95     BMCWEB_LOG_ERROR
96         << "Error occured during X509_verify_cert call. ErrorCode: " << errCode;
97     X509_STORE_CTX_free(storeCtx);
98     X509_STORE_free(x509Store);
99     return false;
100 }
101 
102 inline bool verifyOpensslKeyCert(const std::string &filepath)
103 {
104     bool privateKeyValid = false;
105     bool certValid = false;
106 
107     std::cout << "Checking certs in file " << filepath << "\n";
108 
109     FILE *file = fopen(filepath.c_str(), "r");
110     if (file != nullptr)
111     {
112         EVP_PKEY *pkey = PEM_read_PrivateKey(file, nullptr, nullptr, nullptr);
113         if (pkey != nullptr)
114         {
115             RSA *rsa = EVP_PKEY_get1_RSA(pkey);
116             if (rsa != nullptr)
117             {
118                 std::cout << "Found an RSA key\n";
119                 if (RSA_check_key(rsa) == 1)
120                 {
121                     privateKeyValid = true;
122                 }
123                 else
124                 {
125                     std::cerr << "Key not valid error number "
126                               << ERR_get_error() << "\n";
127                 }
128                 RSA_free(rsa);
129             }
130             else
131             {
132                 EC_KEY *ec = EVP_PKEY_get1_EC_KEY(pkey);
133                 if (ec != nullptr)
134                 {
135                     std::cout << "Found an EC key\n";
136                     if (EC_KEY_check_key(ec) == 1)
137                     {
138                         privateKeyValid = true;
139                     }
140                     else
141                     {
142                         std::cerr << "Key not valid error number "
143                                   << ERR_get_error() << "\n";
144                     }
145                     EC_KEY_free(ec);
146                 }
147             }
148 
149             if (privateKeyValid)
150             {
151                 // If the order is certificate followed by key in input file
152                 // then, certificate read will fail. So, setting the file
153                 // pointer to point beginning of file to avoid certificate and
154                 // key order issue.
155                 fseek(file, 0, SEEK_SET);
156 
157                 X509 *x509 = PEM_read_X509(file, nullptr, nullptr, nullptr);
158                 if (x509 == nullptr)
159                 {
160                     std::cout << "error getting x509 cert " << ERR_get_error()
161                               << "\n";
162                 }
163                 else
164                 {
165                     certValid = validateCertificate(x509);
166                     X509_free(x509);
167                 }
168             }
169 
170             EVP_PKEY_free(pkey);
171         }
172         fclose(file);
173     }
174     return certValid;
175 }
176 
177 inline void generateSslCertificate(const std::string &filepath)
178 {
179     FILE *pFile = nullptr;
180     std::cout << "Generating new keys\n";
181     initOpenssl();
182 
183     std::cerr << "Generating EC key\n";
184     EVP_PKEY *pPrivKey = createEcKey();
185     if (pPrivKey != nullptr)
186     {
187         std::cerr << "Generating x509 Certificate\n";
188         // Use this code to directly generate a certificate
189         X509 *x509;
190         x509 = X509_new();
191         if (x509 != nullptr)
192         {
193             // get a random number from the RNG for the certificate serial
194             // number If this is not random, regenerating certs throws broswer
195             // errors
196             std::random_device rd;
197             int serial = static_cast<int>(rd());
198 
199             ASN1_INTEGER_set(X509_get_serialNumber(x509), serial);
200 
201             // not before this moment
202             X509_gmtime_adj(X509_get_notBefore(x509), 0);
203             // Cert is valid for 10 years
204             X509_gmtime_adj(X509_get_notAfter(x509),
205                             60L * 60L * 24L * 365L * 10L);
206 
207             // set the public key to the key we just generated
208             X509_set_pubkey(x509, pPrivKey);
209 
210             // get the subject name
211             X509_NAME *name;
212             name = X509_get_subject_name(x509);
213 
214             X509_NAME_add_entry_by_txt(
215                 name, "C", MBSTRING_ASC,
216                 reinterpret_cast<const unsigned char *>("US"), -1, -1, 0);
217             X509_NAME_add_entry_by_txt(
218                 name, "O", MBSTRING_ASC,
219                 reinterpret_cast<const unsigned char *>("OpenBMC"), -1, -1, 0);
220             X509_NAME_add_entry_by_txt(
221                 name, "CN", MBSTRING_ASC,
222                 reinterpret_cast<const unsigned char *>("testhost"), -1, -1, 0);
223             // set the CSR options
224             X509_set_issuer_name(x509, name);
225 
226             // Sign the certificate with our private key
227             X509_sign(x509, pPrivKey, EVP_sha256());
228 
229             pFile = fopen(filepath.c_str(), "wt");
230 
231             if (pFile != nullptr)
232             {
233                 PEM_write_PrivateKey(pFile, pPrivKey, nullptr, nullptr, 0,
234                                      nullptr, nullptr);
235 
236                 PEM_write_X509(pFile, x509);
237                 fclose(pFile);
238                 pFile = nullptr;
239             }
240 
241             X509_free(x509);
242         }
243 
244         EVP_PKEY_free(pPrivKey);
245         pPrivKey = nullptr;
246     }
247 
248     // cleanup_openssl();
249 }
250 
251 EVP_PKEY *createEcKey()
252 {
253     EVP_PKEY *pKey = nullptr;
254     int eccgrp = 0;
255     eccgrp = OBJ_txt2nid("secp384r1");
256 
257     EC_KEY *myecc = EC_KEY_new_by_curve_name(eccgrp);
258     if (myecc != nullptr)
259     {
260         EC_KEY_set_asn1_flag(myecc, OPENSSL_EC_NAMED_CURVE);
261         EC_KEY_generate_key(myecc);
262         pKey = EVP_PKEY_new();
263         if (pKey != nullptr)
264         {
265             if (EVP_PKEY_assign_EC_KEY(pKey, myecc))
266             {
267                 /* pKey owns myecc from now */
268                 if (EC_KEY_check_key(myecc) <= 0)
269                 {
270                     fprintf(stderr, "EC_check_key failed.\n");
271                 }
272             }
273         }
274     }
275     return pKey;
276 }
277 
278 void initOpenssl()
279 {
280 #if OPENSSL_VERSION_NUMBER < 0x10100000L
281     SSL_load_error_strings();
282     OpenSSL_add_all_algorithms();
283     RAND_load_file("/dev/urandom", 1024);
284 #endif
285 }
286 
287 inline void ensureOpensslKeyPresentAndValid(const std::string &filepath)
288 {
289     bool pemFileValid = false;
290 
291     pemFileValid = verifyOpensslKeyCert(filepath);
292 
293     if (!pemFileValid)
294     {
295         std::cerr << "Error in verifying signature, regenerating\n";
296         generateSslCertificate(filepath);
297     }
298 }
299 
300 inline std::shared_ptr<boost::asio::ssl::context>
301     getSslContext(const std::string &ssl_pem_file)
302 {
303     std::shared_ptr<boost::asio::ssl::context> mSslContext =
304         std::make_shared<boost::asio::ssl::context>(
305             boost::asio::ssl::context::tls_server);
306     mSslContext->set_options(boost::asio::ssl::context::default_workarounds |
307                              boost::asio::ssl::context::no_sslv2 |
308                              boost::asio::ssl::context::no_sslv3 |
309                              boost::asio::ssl::context::single_dh_use |
310                              boost::asio::ssl::context::no_tlsv1 |
311                              boost::asio::ssl::context::no_tlsv1_1);
312 
313     // BIG WARNING: This needs to stay disabled, as there will always be
314     // unauthenticated endpoints
315     // mSslContext->set_verify_mode(boost::asio::ssl::verify_peer);
316 
317     SSL_CTX_set_options(mSslContext->native_handle(), SSL_OP_NO_RENEGOTIATION);
318 
319     BMCWEB_LOG_DEBUG << "Using default TrustStore location: " << trustStorePath;
320     mSslContext->add_verify_path(trustStorePath);
321 
322     mSslContext->use_certificate_file(ssl_pem_file,
323                                       boost::asio::ssl::context::pem);
324     mSslContext->use_private_key_file(ssl_pem_file,
325                                       boost::asio::ssl::context::pem);
326 
327     // Set up EC curves to auto (boost asio doesn't have a method for this)
328     // There is a pull request to add this.  Once this is included in an asio
329     // drop, use the right way
330     // http://stackoverflow.com/questions/18929049/boost-asio-with-ecdsa-certificate-issue
331     if (SSL_CTX_set_ecdh_auto(mSslContext->native_handle(), 1) != 1)
332     {
333         BMCWEB_LOG_ERROR << "Error setting tmp ecdh list\n";
334     }
335 
336     std::string mozillaModern = "ECDHE-ECDSA-AES256-GCM-SHA384:"
337                                 "ECDHE-RSA-AES256-GCM-SHA384:"
338                                 "ECDHE-ECDSA-CHACHA20-POLY1305:"
339                                 "ECDHE-RSA-CHACHA20-POLY1305:"
340                                 "ECDHE-ECDSA-AES128-GCM-SHA256:"
341                                 "ECDHE-RSA-AES128-GCM-SHA256:"
342                                 "ECDHE-ECDSA-AES256-SHA384:"
343                                 "ECDHE-RSA-AES256-SHA384:"
344                                 "ECDHE-ECDSA-AES128-SHA256:"
345                                 "ECDHE-RSA-AES128-SHA256";
346 
347     if (SSL_CTX_set_cipher_list(mSslContext->native_handle(),
348                                 mozillaModern.c_str()) != 1)
349     {
350         BMCWEB_LOG_ERROR << "Error setting cipher list\n";
351     }
352     return mSslContext;
353 }
354 } // namespace ensuressl
355 
356 #endif
357