Skip to content
Navigation Menu
{{ message }}
forked from meshtastic/esp32_https_server
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathSSLCert.cpp
More file actions
325 lines (270 loc) · 8.87 KB
/
Copy pathSSLCert.cpp
File metadata and controls
325 lines (270 loc) · 8.87 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
#include "SSLCert.hpp"
namespace httpsserver {
SSLCert::SSLCert(unsigned char * certData, uint16_t certLength, unsigned char * pkData, uint16_t pkLength):
_certLength(certLength),
_certData(certData),
_pkLength(pkLength),
_pkData(pkData) {
}
SSLCert::~SSLCert() {
// TODO Auto-generated destructor stub
}
uint16_t SSLCert::getCertLength() {
return _certLength;
}
uint16_t SSLCert::getPKLength() {
return _pkLength;
}
unsigned char * SSLCert::getCertData() {
return _certData;
}
unsigned char * SSLCert::getPKData() {
return _pkData;
}
void SSLCert::setPK(unsigned char * pkData, uint16_t length) {
_pkData = pkData;
_pkLength = length;
}
void SSLCert::setCert(unsigned char * certData, uint16_t length) {
_certData = certData;
_certLength = length;
}
void SSLCert::clear() {
for(uint16_t i = 0; i < _certLength; i++) _certData[i]=0;
delete _certData;
_certLength = 0;
for(uint16_t i = 0; i < _pkLength; i++) _pkData[i] = 0;
delete _pkData;
_pkLength = 0;
}
#ifndef HTTPS_DISABLE_SELFSIGNING
/**
* Function to create the key for a self-signed certificate.
*
* Writes private key as DER in certCtx
*
* Based on programs/pkey/gen_key.c
*/
static int gen_key(SSLCert &certCtx, SSLKeySize keySize) {
// Initialize the entropy source
mbedtls_entropy_context entropy;
mbedtls_entropy_init( &entropy );
// Initialize the RNG
mbedtls_ctr_drbg_context ctr_drbg;
mbedtls_ctr_drbg_init( &ctr_drbg );
int rngRes = mbedtls_ctr_drbg_seed(
&ctr_drbg, mbedtls_entropy_func, &entropy,
NULL, 0
);
if (rngRes != 0) {
mbedtls_entropy_free( &entropy );
return HTTPS_SERVER_ERROR_KEYGEN_RNG;
}
// Initialize the private key
mbedtls_pk_context key;
mbedtls_pk_init( &key );
int resPkSetup = mbedtls_pk_setup( &key, mbedtls_pk_info_from_type( MBEDTLS_PK_RSA ) );
if ( resPkSetup != 0) {
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
return HTTPS_SERVER_ERROR_KEYGEN_SETUP_PK;
}
// Actual key generation
int resPkGen = mbedtls_rsa_gen_key(
mbedtls_pk_rsa( key ),
mbedtls_ctr_drbg_random,
&ctr_drbg,
keySize,
65537
);
if ( resPkGen != 0) {
mbedtls_pk_free( &key );
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
return HTTPS_SERVER_ERROR_KEYGEN_GEN_PK;
}
// Free the entropy source and the RNG as they are no longer needed
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
// Allocate the space on the heap, as stack size is quite limited
unsigned char * output_buf = new unsigned char[4096];
if (output_buf == NULL) {
mbedtls_pk_free( &key );
return HTTPS_SERVER_ERROR_KEY_OUT_OF_MEM;
}
memset(output_buf, 0, 4096);
// Write the key to the temporary buffer and determine its length
int resPkWrite = mbedtls_pk_write_key_der( &key, output_buf, 4096 );
if (resPkWrite < 0) {
delete[] output_buf;
mbedtls_pk_free( &key );
return HTTPS_SERVER_ERROR_KEY_WRITE_PK;
}
size_t pkLength = resPkWrite;
unsigned char *pkOffset = output_buf + sizeof(unsigned char) * 4096 - pkLength;
// Copy the key into a new, fitting space on the heap
unsigned char * output_pk = new unsigned char[pkLength];
if (output_pk == NULL) {
delete[] output_buf;
mbedtls_pk_free( &key );
return HTTPS_SERVER_ERROR_KEY_WRITE_PK;
}
memcpy(output_pk, pkOffset, pkLength);
// Clean up the temporary buffer and clear the key context
delete[] output_buf;
mbedtls_pk_free( &key );
// Set the private key in the context
certCtx.setPK(output_pk, pkLength);
return 0;
}
/**
* Function to generate the X509 certificate data for a private key
*
* Writes certificate in certCtx
*
* Based on programs/x509/cert_write.c
*/
static int cert_write(SSLCert &certCtx, std::string dn, std::string validityFrom, std::string validityTo) {
int funcRes = 0;
int stepRes = 0;
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
mbedtls_pk_context key;
mbedtls_x509write_cert crt;
mbedtls_mpi serial;
unsigned char * primary_buffer;
unsigned char *certOffset;
unsigned char * output_buffer;
size_t certLength;
// Make a C-friendly version of the distinguished name
char dn_cstr[dn.length()+1];
strcpy(dn_cstr, dn.c_str());
// Initialize the entropy source
mbedtls_entropy_init( &entropy );
// Initialize the RNG
mbedtls_ctr_drbg_init( &ctr_drbg );
stepRes = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy, NULL, 0 );
if (stepRes != 0) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_RNG;
goto error_after_entropy;
}
mbedtls_pk_init( &key );
#if ESP_IDF_VERSION_MAJOR > 4
stepRes = mbedtls_pk_parse_key( &key, certCtx.getPKData(), certCtx.getPKLength(), NULL, 0, mbedtls_entropy_func, &ctr_drbg );
#else
stepRes = mbedtls_pk_parse_key( &key, certCtx.getPKData(), certCtx.getPKLength(), NULL, 0 );
#endif
if (stepRes != 0) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_READKEY;
goto error_after_key;
}
// Start configuring the certificate
mbedtls_x509write_crt_init( &crt );
// Set version and hash algorithm
mbedtls_x509write_crt_set_version( &crt, MBEDTLS_X509_CRT_VERSION_3 );
mbedtls_x509write_crt_set_md_alg( &crt, MBEDTLS_MD_SHA256 );
// Set the keys (same key as we self-sign)
mbedtls_x509write_crt_set_subject_key( &crt, &key );
mbedtls_x509write_crt_set_issuer_key( &crt, &key );
// Set issuer and subject (same, as we self-sign)
stepRes = mbedtls_x509write_crt_set_subject_name( &crt, dn_cstr );
if (stepRes != 0) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_NAME;
goto error_after_cert;
}
stepRes = mbedtls_x509write_crt_set_issuer_name( &crt, dn_cstr );
if (stepRes != 0) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_NAME;
goto error_after_cert;
}
// Set the validity of the certificate. At the moment, it's fixed from 2019 to end of 2029.
stepRes = mbedtls_x509write_crt_set_validity( &crt, validityFrom.c_str(), validityTo.c_str());
if (stepRes != 0) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_VALIDITY;
goto error_after_cert;
}
// Make this a CA certificate
stepRes = mbedtls_x509write_crt_set_basic_constraints( &crt, 1, 0 );
if (stepRes != 0) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_VALIDITY;
goto error_after_cert;
}
// generate random serial number
mbedtls_mpi_init( &serial );
stepRes = mbedtls_mpi_fill_random( &serial, 10, mbedtls_ctr_drbg_random, &ctr_drbg );
if (stepRes != 0) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_SERIAL;
goto error_after_cert_serial;
}
#if ESP_IDF_VERSION_MAJOR > 4
unsigned char serial_bytes[10];
stepRes = mbedtls_mpi_write_binary( &serial, serial_bytes, 10 );
if (stepRes != 0) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_SERIAL;
goto error_after_cert_serial;
}
stepRes = mbedtls_x509write_crt_set_serial_raw( &crt, serial_bytes, 10 );
#else
stepRes = mbedtls_x509write_crt_set_serial( &crt, &serial );
#endif
if (stepRes != 0) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_SERIAL;
goto error_after_cert_serial;
}
// Create buffer to write the certificate
primary_buffer = new unsigned char[4096];
if (primary_buffer == NULL) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_OUT_OF_MEM;
goto error_after_cert_serial;
}
// Write the actual certificate
stepRes = mbedtls_x509write_crt_der(&crt, primary_buffer, 4096, mbedtls_ctr_drbg_random, &ctr_drbg );
if (stepRes < 0) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_WRITE;
goto error_after_primary_buffer;
}
// Create a matching buffer
certLength = stepRes;
certOffset = primary_buffer + sizeof(unsigned char) * 4096 - certLength;
// Copy the cert into a new, fitting space on the heap
output_buffer = new unsigned char[certLength];
if (output_buffer == NULL) {
funcRes = HTTPS_SERVER_ERROR_CERTGEN_OUT_OF_MEM;
goto error_after_primary_buffer;
}
memcpy(output_buffer, certOffset, certLength);
// Configure the cert in the context
certCtx.setCert(output_buffer, certLength);
// Run through the cleanup process
error_after_primary_buffer:
delete[] primary_buffer;
error_after_cert_serial:
mbedtls_mpi_free( &serial );
error_after_cert:
mbedtls_x509write_crt_free( &crt );
error_after_key:
mbedtls_pk_free(&key);
error_after_entropy:
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
return funcRes;
}
int createSelfSignedCert(SSLCert &certCtx, SSLKeySize keySize, std::string dn, std::string validFrom, std::string validUntil) {
// Add the private key
int keyRes = gen_key(certCtx, keySize);
if (keyRes != 0) {
// Key-generation failed, return the failure code
return keyRes;
}
// Add the self-signed certificate
int certRes = cert_write(certCtx, dn, validFrom, validUntil);
if (certRes != 0) {
// Cert writing failed, reset the pk and return failure code
certCtx.setPK(NULL, 0);
return certRes;
}
// If all went well, return 0
return 0;
}
#endif // !HTTPS_DISABLE_SELFSIGNING
} /* namespace httpsserver */
You can’t perform that action at this time.