1 /*
2  * SSL/TLS interface definition
3  * Copyright (c) 2004-2013, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #ifndef TLS_H
10 #define TLS_H
11 
12 struct tls_connection;
13 
14 struct tls_keys {
15 	const u8 *client_random;
16 	size_t client_random_len;
17 	const u8 *server_random;
18 	size_t server_random_len;
19 };
20 
21 enum tls_event {
22 	TLS_CERT_CHAIN_SUCCESS,
23 	TLS_CERT_CHAIN_FAILURE,
24 	TLS_PEER_CERTIFICATE,
25 	TLS_ALERT
26 };
27 
28 /*
29  * Note: These are used as identifier with external programs and as such, the
30  * values must not be changed.
31  */
32 enum tls_fail_reason {
33 	TLS_FAIL_UNSPECIFIED = 0,
34 	TLS_FAIL_UNTRUSTED = 1,
35 	TLS_FAIL_REVOKED = 2,
36 	TLS_FAIL_NOT_YET_VALID = 3,
37 	TLS_FAIL_EXPIRED = 4,
38 	TLS_FAIL_SUBJECT_MISMATCH = 5,
39 	TLS_FAIL_ALTSUBJECT_MISMATCH = 6,
40 	TLS_FAIL_BAD_CERTIFICATE = 7,
41 	TLS_FAIL_SERVER_CHAIN_PROBE = 8,
42 	TLS_FAIL_DOMAIN_SUFFIX_MISMATCH = 9,
43 	TLS_FAIL_DOMAIN_MISMATCH = 10,
44 };
45 
46 
47 #define TLS_MAX_ALT_SUBJECT 10
48 
49 union tls_event_data {
50 	struct {
51 		int depth;
52 		const char *subject;
53 		enum tls_fail_reason reason;
54 		const char *reason_txt;
55 		const struct wpabuf *cert;
56 	} cert_fail;
57 
58 	struct {
59 		int depth;
60 		const char *subject;
61 		const struct wpabuf *cert;
62 		const u8 *hash;
63 		size_t hash_len;
64 		const char *altsubject[TLS_MAX_ALT_SUBJECT];
65 		int num_altsubject;
66 	} peer_cert;
67 
68 	struct {
69 		int is_local;
70 		const char *type;
71 		const char *description;
72 	} alert;
73 };
74 
75 struct tls_config {
76 	const char *opensc_engine_path;
77 	const char *pkcs11_engine_path;
78 	const char *pkcs11_module_path;
79 	int fips_mode;
80 	int cert_in_cb;
81 	const char *openssl_ciphers;
82 
83 	void (*event_cb)(void *ctx, enum tls_event ev,
84 			 union tls_event_data *data);
85 	void *cb_ctx;
86 };
87 
88 #define TLS_CONN_ALLOW_SIGN_RSA_MD5 BIT(0)
89 #define TLS_CONN_DISABLE_TIME_CHECKS BIT(1)
90 #define TLS_CONN_DISABLE_SESSION_TICKET BIT(2)
91 #define TLS_CONN_REQUEST_OCSP BIT(3)
92 #define TLS_CONN_REQUIRE_OCSP BIT(4)
93 #define TLS_CONN_DISABLE_TLSv1_1 BIT(5)
94 #define TLS_CONN_DISABLE_TLSv1_2 BIT(6)
95 #define TLS_CONN_EAP_FAST BIT(7)
96 
97 /**
98  * struct tls_connection_params - Parameters for TLS connection
99  * @ca_cert: File or reference name for CA X.509 certificate in PEM or DER
100  * format
101  * @ca_cert_blob: ca_cert as inlined data or %NULL if not used
102  * @ca_cert_blob_len: ca_cert_blob length
103  * @ca_path: Path to CA certificates (OpenSSL specific)
104  * @subject_match: String to match in the subject of the peer certificate or
105  * %NULL to allow all subjects
106  * @altsubject_match: String to match in the alternative subject of the peer
107  * certificate or %NULL to allow all alternative subjects
108  * @suffix_match: String to suffix match in the dNSName or CN of the peer
109  * certificate or %NULL to allow all domain names. This may allow subdomains an
110  * wildcard certificates. Each domain name label must have a full match.
111  * @domain_match: String to match in the dNSName or CN of the peer
112  * certificate or %NULL to allow all domain names. This requires a full,
113  * case-insensitive match.
114  * @client_cert: File or reference name for client X.509 certificate in PEM or
115  * DER format
116  * @client_cert_blob: client_cert as inlined data or %NULL if not used
117  * @client_cert_blob_len: client_cert_blob length
118  * @private_key: File or reference name for client private key in PEM or DER
119  * format (traditional format (RSA PRIVATE KEY) or PKCS#8 (PRIVATE KEY)
120  * @private_key_blob: private_key as inlined data or %NULL if not used
121  * @private_key_blob_len: private_key_blob length
122  * @private_key_passwd: Passphrase for decrypted private key, %NULL if no
123  * passphrase is used.
124  * @dh_file: File name for DH/DSA data in PEM format, or %NULL if not used
125  * @dh_blob: dh_file as inlined data or %NULL if not used
126  * @dh_blob_len: dh_blob length
127  * @engine: 1 = use engine (e.g., a smartcard) for private key operations
128  * (this is OpenSSL specific for now)
129  * @engine_id: engine id string (this is OpenSSL specific for now)
130  * @ppin: pointer to the pin variable in the configuration
131  * (this is OpenSSL specific for now)
132  * @key_id: the private key's id when using engine (this is OpenSSL
133  * specific for now)
134  * @cert_id: the certificate's id when using engine
135  * @ca_cert_id: the CA certificate's id when using engine
136  * @openssl_ciphers: OpenSSL cipher configuration
137  * @flags: Parameter options (TLS_CONN_*)
138  * @ocsp_stapling_response: DER encoded file with cached OCSP stapling response
139  *	or %NULL if OCSP is not enabled
140  *
141  * TLS connection parameters to be configured with tls_connection_set_params()
142  * and tls_global_set_params().
143  *
144  * Certificates and private key can be configured either as a reference name
145  * (file path or reference to certificate store) or by providing the same data
146  * as a pointer to the data in memory. Only one option will be used for each
147  * field.
148  */
149 struct tls_connection_params {
150 	const char *ca_cert;
151 	const u8 *ca_cert_blob;
152 	size_t ca_cert_blob_len;
153 	const char *ca_path;
154 	const char *subject_match;
155 	const char *altsubject_match;
156 	const char *suffix_match;
157 	const char *domain_match;
158 	const char *client_cert;
159 	const u8 *client_cert_blob;
160 	size_t client_cert_blob_len;
161 	const char *private_key;
162 	const u8 *private_key_blob;
163 	size_t private_key_blob_len;
164 	const char *private_key_passwd;
165 	const char *dh_file;
166 	const u8 *dh_blob;
167 	size_t dh_blob_len;
168 
169 	/* OpenSSL specific variables */
170 	int engine;
171 	const char *engine_id;
172 	const char *pin;
173 	const char *key_id;
174 	const char *cert_id;
175 	const char *ca_cert_id;
176 	const char *openssl_ciphers;
177 
178 	unsigned int flags;
179 	const char *ocsp_stapling_response;
180 };
181 
182 
183 /**
184  * tls_init - Initialize TLS library
185  * @conf: Configuration data for TLS library
186  * Returns: Context data to be used as tls_ctx in calls to other functions,
187  * or %NULL on failure.
188  *
189  * Called once during program startup and once for each RSN pre-authentication
190  * session. In other words, there can be two concurrent TLS contexts. If global
191  * library initialization is needed (i.e., one that is shared between both
192  * authentication types), the TLS library wrapper should maintain a reference
193  * counter and do global initialization only when moving from 0 to 1 reference.
194  */
195 void * tls_init(const struct tls_config *conf);
196 
197 /**
198  * tls_deinit - Deinitialize TLS library
199  * @tls_ctx: TLS context data from tls_init()
200  *
201  * Called once during program shutdown and once for each RSN pre-authentication
202  * session. If global library deinitialization is needed (i.e., one that is
203  * shared between both authentication types), the TLS library wrapper should
204  * maintain a reference counter and do global deinitialization only when moving
205  * from 1 to 0 references.
206  */
207 void tls_deinit(void *tls_ctx);
208 
209 /**
210  * tls_get_errors - Process pending errors
211  * @tls_ctx: TLS context data from tls_init()
212  * Returns: Number of found error, 0 if no errors detected.
213  *
214  * Process all pending TLS errors.
215  */
216 int tls_get_errors(void *tls_ctx);
217 
218 /**
219  * tls_connection_init - Initialize a new TLS connection
220  * @tls_ctx: TLS context data from tls_init()
221  * Returns: Connection context data, conn for other function calls
222  */
223 struct tls_connection * tls_connection_init(void *tls_ctx);
224 
225 /**
226  * tls_connection_deinit - Free TLS connection data
227  * @tls_ctx: TLS context data from tls_init()
228  * @conn: Connection context data from tls_connection_init()
229  *
230  * Release all resources allocated for TLS connection.
231  */
232 void tls_connection_deinit(void *tls_ctx, struct tls_connection *conn);
233 
234 /**
235  * tls_connection_established - Has the TLS connection been completed?
236  * @tls_ctx: TLS context data from tls_init()
237  * @conn: Connection context data from tls_connection_init()
238  * Returns: 1 if TLS connection has been completed, 0 if not.
239  */
240 int tls_connection_established(void *tls_ctx, struct tls_connection *conn);
241 
242 /**
243  * tls_connection_shutdown - Shutdown TLS connection
244  * @tls_ctx: TLS context data from tls_init()
245  * @conn: Connection context data from tls_connection_init()
246  * Returns: 0 on success, -1 on failure
247  *
248  * Shutdown current TLS connection without releasing all resources. New
249  * connection can be started by using the same conn without having to call
250  * tls_connection_init() or setting certificates etc. again. The new
251  * connection should try to use session resumption.
252  */
253 int tls_connection_shutdown(void *tls_ctx, struct tls_connection *conn);
254 
255 enum {
256 	TLS_SET_PARAMS_ENGINE_PRV_BAD_PIN = -4,
257 	TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED = -3,
258 	TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED = -2
259 };
260 
261 /**
262  * tls_connection_set_params - Set TLS connection parameters
263  * @tls_ctx: TLS context data from tls_init()
264  * @conn: Connection context data from tls_connection_init()
265  * @params: Connection parameters
266  * Returns: 0 on success, -1 on failure,
267  * TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED (-2) on error causing PKCS#11 engine
268  * failure, or
269  * TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED (-3) on failure to verify the
270  * PKCS#11 engine private key, or
271  * TLS_SET_PARAMS_ENGINE_PRV_BAD_PIN (-4) on PIN error causing PKCS#11 engine
272  * failure.
273  */
274 int __must_check
275 tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
276 			  const struct tls_connection_params *params);
277 
278 /**
279  * tls_global_set_params - Set TLS parameters for all TLS connection
280  * @tls_ctx: TLS context data from tls_init()
281  * @params: Global TLS parameters
282  * Returns: 0 on success, -1 on failure,
283  * TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED (-2) on error causing PKCS#11 engine
284  * failure, or
285  * TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED (-3) on failure to verify the
286  * PKCS#11 engine private key, or
287  * TLS_SET_PARAMS_ENGINE_PRV_BAD_PIN (-4) on PIN error causing PKCS#11 engine
288  * failure.
289  */
290 int __must_check tls_global_set_params(
291 	void *tls_ctx, const struct tls_connection_params *params);
292 
293 /**
294  * tls_global_set_verify - Set global certificate verification options
295  * @tls_ctx: TLS context data from tls_init()
296  * @check_crl: 0 = do not verify CRLs, 1 = verify CRL for the user certificate,
297  * 2 = verify CRL for all certificates
298  * Returns: 0 on success, -1 on failure
299  */
300 int __must_check tls_global_set_verify(void *tls_ctx, int check_crl);
301 
302 /**
303  * tls_connection_set_verify - Set certificate verification options
304  * @tls_ctx: TLS context data from tls_init()
305  * @conn: Connection context data from tls_connection_init()
306  * @verify_peer: 1 = verify peer certificate
307  * Returns: 0 on success, -1 on failure
308  */
309 int __must_check tls_connection_set_verify(void *tls_ctx,
310 					   struct tls_connection *conn,
311 					   int verify_peer);
312 
313 /**
314  * tls_connection_get_keys - Get random data from TLS connection
315  * @tls_ctx: TLS context data from tls_init()
316  * @conn: Connection context data from tls_connection_init()
317  * @keys: Structure of client/server random data (filled on success)
318  * Returns: 0 on success, -1 on failure
319  */
320 int __must_check tls_connection_get_keys(void *tls_ctx,
321 					 struct tls_connection *conn,
322 					 struct tls_keys *keys);
323 
324 /**
325  * tls_connection_prf - Use TLS-PRF to derive keying material
326  * @tls_ctx: TLS context data from tls_init()
327  * @conn: Connection context data from tls_connection_init()
328  * @label: Label (e.g., description of the key) for PRF
329  * @server_random_first: seed is 0 = client_random|server_random,
330  * 1 = server_random|client_random
331  * @skip_keyblock: Skip TLS key block from the beginning of PRF output
332  * @out: Buffer for output data from TLS-PRF
333  * @out_len: Length of the output buffer
334  * Returns: 0 on success, -1 on failure
335  *
336  * This function is optional to implement if tls_connection_get_keys() provides
337  * access to master secret and server/client random values. If these values are
338  * not exported from the TLS library, tls_connection_prf() is required so that
339  * further keying material can be derived from the master secret. If not
340  * implemented, the function will still need to be defined, but it can just
341  * return -1. Example implementation of this function is in tls_prf_sha1_md5()
342  * when it is called with seed set to client_random|server_random (or
343  * server_random|client_random).
344  */
345 int __must_check  tls_connection_prf(void *tls_ctx,
346 				     struct tls_connection *conn,
347 				     const char *label,
348 				     int server_random_first,
349 				     int skip_keyblock,
350 				     u8 *out, size_t out_len);
351 
352 /**
353  * tls_connection_handshake - Process TLS handshake (client side)
354  * @tls_ctx: TLS context data from tls_init()
355  * @conn: Connection context data from tls_connection_init()
356  * @in_data: Input data from TLS server
357  * @appl_data: Pointer to application data pointer, or %NULL if dropped
358  * Returns: Output data, %NULL on failure
359  *
360  * The caller is responsible for freeing the returned output data. If the final
361  * handshake message includes application data, this is decrypted and
362  * appl_data (if not %NULL) is set to point this data. The caller is
363  * responsible for freeing appl_data.
364  *
365  * This function is used during TLS handshake. The first call is done with
366  * in_data == %NULL and the library is expected to return ClientHello packet.
367  * This packet is then send to the server and a response from server is given
368  * to TLS library by calling this function again with in_data pointing to the
369  * TLS message from the server.
370  *
371  * If the TLS handshake fails, this function may return %NULL. However, if the
372  * TLS library has a TLS alert to send out, that should be returned as the
373  * output data. In this case, tls_connection_get_failed() must return failure
374  * (> 0).
375  *
376  * tls_connection_established() should return 1 once the TLS handshake has been
377  * completed successfully.
378  */
379 struct wpabuf * tls_connection_handshake(void *tls_ctx,
380 					 struct tls_connection *conn,
381 					 const struct wpabuf *in_data,
382 					 struct wpabuf **appl_data);
383 
384 struct wpabuf * tls_connection_handshake2(void *tls_ctx,
385 					  struct tls_connection *conn,
386 					  const struct wpabuf *in_data,
387 					  struct wpabuf **appl_data,
388 					  int *more_data_needed);
389 
390 /**
391  * tls_connection_server_handshake - Process TLS handshake (server side)
392  * @tls_ctx: TLS context data from tls_init()
393  * @conn: Connection context data from tls_connection_init()
394  * @in_data: Input data from TLS peer
395  * @appl_data: Pointer to application data pointer, or %NULL if dropped
396  * Returns: Output data, %NULL on failure
397  *
398  * The caller is responsible for freeing the returned output data.
399  */
400 struct wpabuf * tls_connection_server_handshake(void *tls_ctx,
401 						struct tls_connection *conn,
402 						const struct wpabuf *in_data,
403 						struct wpabuf **appl_data);
404 
405 /**
406  * tls_connection_encrypt - Encrypt data into TLS tunnel
407  * @tls_ctx: TLS context data from tls_init()
408  * @conn: Connection context data from tls_connection_init()
409  * @in_data: Plaintext data to be encrypted
410  * Returns: Encrypted TLS data or %NULL on failure
411  *
412  * This function is used after TLS handshake has been completed successfully to
413  * send data in the encrypted tunnel. The caller is responsible for freeing the
414  * returned output data.
415  */
416 struct wpabuf * tls_connection_encrypt(void *tls_ctx,
417 				       struct tls_connection *conn,
418 				       const struct wpabuf *in_data);
419 
420 /**
421  * tls_connection_decrypt - Decrypt data from TLS tunnel
422  * @tls_ctx: TLS context data from tls_init()
423  * @conn: Connection context data from tls_connection_init()
424  * @in_data: Encrypted TLS data
425  * Returns: Decrypted TLS data or %NULL on failure
426  *
427  * This function is used after TLS handshake has been completed successfully to
428  * receive data from the encrypted tunnel. The caller is responsible for
429  * freeing the returned output data.
430  */
431 struct wpabuf * tls_connection_decrypt(void *tls_ctx,
432 				       struct tls_connection *conn,
433 				       const struct wpabuf *in_data);
434 
435 struct wpabuf * tls_connection_decrypt2(void *tls_ctx,
436 					struct tls_connection *conn,
437 					const struct wpabuf *in_data,
438 					int *more_data_needed);
439 
440 /**
441  * tls_connection_resumed - Was session resumption used
442  * @tls_ctx: TLS context data from tls_init()
443  * @conn: Connection context data from tls_connection_init()
444  * Returns: 1 if current session used session resumption, 0 if not
445  */
446 int tls_connection_resumed(void *tls_ctx, struct tls_connection *conn);
447 
448 enum {
449 	TLS_CIPHER_NONE,
450 	TLS_CIPHER_RC4_SHA /* 0x0005 */,
451 	TLS_CIPHER_AES128_SHA /* 0x002f */,
452 	TLS_CIPHER_RSA_DHE_AES128_SHA /* 0x0031 */,
453 	TLS_CIPHER_ANON_DH_AES128_SHA /* 0x0034 */
454 };
455 
456 /**
457  * tls_connection_set_cipher_list - Configure acceptable cipher suites
458  * @tls_ctx: TLS context data from tls_init()
459  * @conn: Connection context data from tls_connection_init()
460  * @ciphers: Zero (TLS_CIPHER_NONE) terminated list of allowed ciphers
461  * (TLS_CIPHER_*).
462  * Returns: 0 on success, -1 on failure
463  */
464 int __must_check tls_connection_set_cipher_list(void *tls_ctx,
465 						struct tls_connection *conn,
466 						u8 *ciphers);
467 
468 /**
469  * tls_get_cipher - Get current cipher name
470  * @tls_ctx: TLS context data from tls_init()
471  * @conn: Connection context data from tls_connection_init()
472  * @buf: Buffer for the cipher name
473  * @buflen: buf size
474  * Returns: 0 on success, -1 on failure
475  *
476  * Get the name of the currently used cipher.
477  */
478 int __must_check tls_get_cipher(void *tls_ctx, struct tls_connection *conn,
479 				char *buf, size_t buflen);
480 
481 /**
482  * tls_connection_enable_workaround - Enable TLS workaround options
483  * @tls_ctx: TLS context data from tls_init()
484  * @conn: Connection context data from tls_connection_init()
485  * Returns: 0 on success, -1 on failure
486  *
487  * This function is used to enable connection-specific workaround options for
488  * buffer SSL/TLS implementations.
489  */
490 int __must_check tls_connection_enable_workaround(void *tls_ctx,
491 						  struct tls_connection *conn);
492 
493 /**
494  * tls_connection_client_hello_ext - Set TLS extension for ClientHello
495  * @tls_ctx: TLS context data from tls_init()
496  * @conn: Connection context data from tls_connection_init()
497  * @ext_type: Extension type
498  * @data: Extension payload (%NULL to remove extension)
499  * @data_len: Extension payload length
500  * Returns: 0 on success, -1 on failure
501  */
502 int __must_check tls_connection_client_hello_ext(void *tls_ctx,
503 						 struct tls_connection *conn,
504 						 int ext_type, const u8 *data,
505 						 size_t data_len);
506 
507 /**
508  * tls_connection_get_failed - Get connection failure status
509  * @tls_ctx: TLS context data from tls_init()
510  * @conn: Connection context data from tls_connection_init()
511  *
512  * Returns >0 if connection has failed, 0 if not.
513  */
514 int tls_connection_get_failed(void *tls_ctx, struct tls_connection *conn);
515 
516 /**
517  * tls_connection_get_read_alerts - Get connection read alert status
518  * @tls_ctx: TLS context data from tls_init()
519  * @conn: Connection context data from tls_connection_init()
520  * Returns: Number of times a fatal read (remote end reported error) has
521  * happened during this connection.
522  */
523 int tls_connection_get_read_alerts(void *tls_ctx, struct tls_connection *conn);
524 
525 /**
526  * tls_connection_get_write_alerts - Get connection write alert status
527  * @tls_ctx: TLS context data from tls_init()
528  * @conn: Connection context data from tls_connection_init()
529  * Returns: Number of times a fatal write (locally detected error) has happened
530  * during this connection.
531  */
532 int tls_connection_get_write_alerts(void *tls_ctx,
533 				    struct tls_connection *conn);
534 
535 /**
536  * tls_capabilities - Get supported TLS capabilities
537  * @tls_ctx: TLS context data from tls_init()
538  * Returns: Bit field of supported TLS capabilities (TLS_CAPABILITY_*)
539  */
540 unsigned int tls_capabilities(void *tls_ctx);
541 
542 typedef int (*tls_session_ticket_cb)
543 (void *ctx, const u8 *ticket, size_t len, const u8 *client_random,
544  const u8 *server_random, u8 *master_secret);
545 
546 int __must_check  tls_connection_set_session_ticket_cb(
547 	void *tls_ctx, struct tls_connection *conn,
548 	tls_session_ticket_cb cb, void *ctx);
549 
550 void tls_connection_set_log_cb(struct tls_connection *conn,
551 			       void (*log_cb)(void *ctx, const char *msg),
552 			       void *ctx);
553 
554 #define TLS_BREAK_VERIFY_DATA BIT(0)
555 #define TLS_BREAK_SRV_KEY_X_HASH BIT(1)
556 #define TLS_BREAK_SRV_KEY_X_SIGNATURE BIT(2)
557 #define TLS_DHE_PRIME_511B BIT(3)
558 #define TLS_DHE_PRIME_767B BIT(4)
559 #define TLS_DHE_PRIME_15 BIT(5)
560 #define TLS_DHE_PRIME_58B BIT(6)
561 #define TLS_DHE_NON_PRIME BIT(7)
562 
563 void tls_connection_set_test_flags(struct tls_connection *conn, u32 flags);
564 
565 int tls_get_library_version(char *buf, size_t buf_len);
566 
567 #endif /* TLS_H */
568