6 SSL - OpenSSL SSL/TLS library
12 The OpenSSL B<ssl> library implements the Secure Sockets Layer (SSL v2/v3) and
13 Transport Layer Security (TLS v1) protocols. It provides a rich API which is
18 Currently the OpenSSL B<ssl> library provides the following C header files
19 containing the prototypes for the data structures and and functions:
25 That's the common header file for the SSL/TLS API. Include it into your
26 program to make the API of the B<ssl> library available. It internally
27 includes both more private SSL headers and headers from the B<crypto> library.
28 Whenever you need hard-core details on the internals of the SSL API, look
29 inside this header file.
33 That's the sub header file dealing with the SSLv2 protocol only.
34 I<Usually you don't have to include it explicitly because
35 it's already included by ssl.h>.
39 That's the sub header file dealing with the SSLv3 protocol only.
40 I<Usually you don't have to include it explicitly because
41 it's already included by ssl.h>.
45 That's the sub header file dealing with the combined use of the SSLv2 and
47 I<Usually you don't have to include it explicitly because
48 it's already included by ssl.h>.
52 That's the sub header file dealing with the TLSv1 protocol only.
53 I<Usually you don't have to include it explicitly because
54 it's already included by ssl.h>.
58 =head1 DATA STRUCTURES
60 Currently the OpenSSL B<ssl> library functions deals with the following data
65 =item B<SSL_METHOD> (SSL Method)
67 That's a dispatch structure describing the internal B<ssl> library
68 methods/functions which implement the various protocol versions (SSLv1, SSLv2
69 and TLSv1). It's needed to create an B<SSL_CTX>.
71 =item B<SSL_CIPHER> (SSL Cipher)
73 This structure holds the algorithm information for a particular cipher which
74 are a core part of the SSL/TLS protocol. The available ciphers are configured
75 on a B<SSL_CTX> basis and the actually used ones are then part of the
78 =item B<SSL_CTX> (SSL Context)
80 That's the global context structure which is created by a server or client
81 once per program life-time and which holds mainly default values for the
82 B<SSL> structures which are later created for the connections.
84 =item B<SSL_SESSION> (SSL Session)
86 This is a structure containing the current SSL session details for a
87 connection: B<SSL_CIPHER>s, client and server certificates, keys, etc.
89 =item B<SSL> (SSL Connection)
91 That's the main SSL/TLS structure which is created by a server or client per
92 established connection. This actually is the core structure in the SSL API.
93 Under run-time the application usually deals with this structure which has
94 links to mostly all other structures.
100 Currently the OpenSSL B<ssl> library exports 214 API functions.
101 They are documented in the following:
103 =head2 DEALING WITH PROTOCOL METHODS
105 Here we document the various API functions which deal with the SSL/TLS
106 protocol methods defined in B<SSL_METHOD> structures.
110 =item SSL_METHOD *B<SSLv2_client_method>(void);
112 Constructor for the SSLv2 SSL_METHOD structure for a dedicated client.
114 =item SSL_METHOD *B<SSLv2_server_method>(void);
116 Constructor for the SSLv2 SSL_METHOD structure for a dedicated server.
118 =item SSL_METHOD *B<SSLv2_method>(void);
120 Constructor for the SSLv2 SSL_METHOD structure for combined client and server.
122 =item SSL_METHOD *B<SSLv3_client_method>(void);
124 Constructor for the SSLv3 SSL_METHOD structure for a dedicated client.
126 =item SSL_METHOD *B<SSLv3_server_method>(void);
128 Constructor for the SSLv3 SSL_METHOD structure for a dedicated server.
130 =item SSL_METHOD *B<SSLv3_method>(void);
132 Constructor for the SSLv3 SSL_METHOD structure for combined client and server.
134 =item SSL_METHOD *B<TLSv1_client_method>(void);
136 Constructor for the TLSv1 SSL_METHOD structure for a dedicated client.
138 =item SSL_METHOD *B<TLSv1_server_method>(void);
140 Constructor for the TLSv1 SSL_METHOD structure for a dedicated server.
142 =item SSL_METHOD *B<TLSv1_method>(void);
144 Constructor for the TLSv1 SSL_METHOD structure for combined client and server.
148 =head2 DEALING WITH CIPHERS
150 Here we document the various API functions which deal with the SSL/TLS
151 ciphers defined in B<SSL_CIPHER> structures.
155 =item char *B<SSL_CIPHER_description>(SSL_CIPHER *cipher, char *buf, int len);
157 Write a string to I<buf> (with a maximum size of I<len>) containing a human
158 readable description of I<cipher>. Returns I<buf>.
160 =item int B<SSL_CIPHER_get_bits>(SSL_CIPHER *cipher, int *alg_bits);
162 Determine the number of bits in I<cipher>. Because of export crippled ciphers
163 there are two bits: The bits the algorithm supports in general (stored to
164 I<alg_bits>) and the bits which are actually used (the return value).
166 =item char *B<SSL_CIPHER_get_name>(SSL_CIPHER *cipher);
168 Return the internal name of I<cipher> as a string. These are the various
169 strings defined by the I<SSL2_TXT_xxx>, I<SSL3_TXT_xxx> and I<TLS1_TXT_xxx>
170 definitions in the header files.
172 =item char *B<SSL_CIPHER_get_version>(SSL_CIPHER *cipher);
174 Returns a string like "C<TLSv1/SSLv3>" or "C<SSLv2>" which indicates the
175 SSL/TLS protocol version to which I<cipher> belongs (i.e. where it was defined
176 in the specification the first time).
180 =head2 DEALING WITH PROTOCOL CONTEXTS
182 Here we document the various API functions which deal with the SSL/TLS
183 protocol context defined in the B<SSL_CTX> structure.
187 =item int B<SSL_CTX_add_client_CA>(SSL_CTX *ctx, X509 *x);
189 =item long B<SSL_CTX_add_extra_chain_cert>(SSL_CTX *ctx, X509 *x509);
191 =item int B<SSL_CTX_add_session>(SSL_CTX *ctx, SSL_SESSION *c);
193 =item int B<SSL_CTX_check_private_key>(SSL_CTX *ctx);
195 =item long B<SSL_CTX_ctrl>(SSL_CTX *ctx, int cmd, long larg, char *parg);
197 =item void B<SSL_CTX_flush_sessions>(SSL_CTX *s, long t);
199 =item void B<SSL_CTX_free>(SSL_CTX *a);
201 =item char *B<SSL_CTX_get_app_data>(SSL_CTX *ctx);
203 =item X509_STORE *B<SSL_CTX_get_cert_store>(SSL_CTX *ctx);
205 =item STACK *B<SSL_CTX_get_client_CA_list>(SSL_CTX *ctx);
207 =item int (*B<SSL_CTX_get_client_cert_cb>(SSL_CTX *ctx))(SSL *ssl, X509 **x509, EVP_PKEY **pkey);
209 =item char *B<SSL_CTX_get_ex_data>(SSL_CTX *s, int idx);
211 =item int B<SSL_CTX_get_ex_new_index>(long argl, char *argp, int (*new_func);(void), int (*dup_func)(void), void (*free_func)(void))
213 =item void (*B<SSL_CTX_get_info_callback>(SSL_CTX *ctx))(SSL *ssl, int cb, int ret);
215 =item int B<SSL_CTX_get_quiet_shutdown>(SSL_CTX *ctx);
217 =item int B<SSL_CTX_get_session_cache_mode>(SSL_CTX *ctx);
219 =item long B<SSL_CTX_get_timeout>(SSL_CTX *ctx);
221 =item int (*B<SSL_CTX_get_verify_callback>(SSL_CTX *ctx))(int ok, X509_STORE_CTX *ctx);
223 =item int B<SSL_CTX_get_verify_mode>(SSL_CTX *ctx);
225 =item int B<SSL_CTX_load_verify_locations>(SSL_CTX *ctx, char *CAfile, char *CApath);
227 =item long B<SSL_CTX_need_tmp_RSA>(SSL_CTX *ctx);
229 =item SSL_CTX *B<SSL_CTX_new>(SSL_METHOD *meth);
231 =item int B<SSL_CTX_remove_session>(SSL_CTX *ctx, SSL_SESSION *c);
233 =item int B<SSL_CTX_sess_accept>(SSL_CTX *ctx);
235 =item int B<SSL_CTX_sess_accept_good>(SSL_CTX *ctx);
237 =item int B<SSL_CTX_sess_accept_renegotiate>(SSL_CTX *ctx);
239 =item int B<SSL_CTX_sess_cache_full>(SSL_CTX *ctx);
241 =item int B<SSL_CTX_sess_cb_hits>(SSL_CTX *ctx);
243 =item int B<SSL_CTX_sess_connect>(SSL_CTX *ctx);
245 =item int B<SSL_CTX_sess_connect_good>(SSL_CTX *ctx);
247 =item int B<SSL_CTX_sess_connect_renegotiate>(SSL_CTX *ctx);
249 =item int B<SSL_CTX_sess_get_cache_size>(SSL_CTX *ctx);
251 =item SSL_SESSION *(*B<SSL_CTX_sess_get_get_cb>(SSL_CTX *ctx))(SSL *ssl, unsigned char *data, int len, int *copy);
253 =item int (*B<SSL_CTX_sess_get_new_cb>(SSL_CTX *ctx)(SSL *ssl, SSL_SESSION *sess);
255 =item void (*B<SSL_CTX_sess_get_remove_cb>(SSL_CTX *ctx)(SSL_CTX *ctx, SSL_SESSION *sess);
257 =item int B<SSL_CTX_sess_hits>(SSL_CTX *ctx);
259 =item int B<SSL_CTX_sess_misses>(SSL_CTX *ctx);
261 =item int B<SSL_CTX_sess_number>(SSL_CTX *ctx);
263 =item void B<SSL_CTX_sess_set_cache_size>(SSL_CTX *ctx,t);
265 =item void B<SSL_CTX_sess_set_get_cb>(SSL_CTX *ctx, SSL_SESSION *(*cb)(SSL *ssl, unsigned char *data, int len, int *copy));
267 =item void B<SSL_CTX_sess_set_new_cb>(SSL_CTX *ctx, int (*cb)(SSL *ssl, SSL_SESSION *sess));
269 =item void B<SSL_CTX_sess_set_remove_cb>(SSL_CTX *ctx, void (*cb)(SSL_CTX *ctx, SSL_SESSION *sess));
271 =item int B<SSL_CTX_sess_timeouts>(SSL_CTX *ctx);
273 =item LHASH *B<SSL_CTX_sessions>(SSL_CTX *ctx);
275 =item void B<SSL_CTX_set_app_data>(SSL_CTX *ctx, void *arg);
277 =item void B<SSL_CTX_set_cert_store>(SSL_CTX *ctx, X509_STORE *cs);
279 =item void B<SSL_CTX_set_cert_verify_cb>(SSL_CTX *ctx, int (*cb)(SSL_CTX *), char *arg)
281 =item int B<SSL_CTX_set_cipher_list>(SSL_CTX *ctx, char *str);
283 =item void B<SSL_CTX_set_client_CA_list>(SSL_CTX *ctx, STACK *list);
285 =item void B<SSL_CTX_set_client_cert_cb>(SSL_CTX *ctx, int (*cb)(SSL *ssl, X509 **x509, EVP_PKEY **pkey));
287 =item void B<SSL_CTX_set_default_passwd_cb>(SSL_CTX *ctx, int (*cb);(void))
289 =item void B<SSL_CTX_set_default_read_ahead>(SSL_CTX *ctx, int m);
291 =item int B<SSL_CTX_set_default_verify_paths>(SSL_CTX *ctx);
293 =item int B<SSL_CTX_set_ex_data>(SSL_CTX *s, int idx, char *arg);
295 =item void B<SSL_CTX_set_info_callback>(SSL_CTX *ctx, void (*cb)(SSL *ssl, int cb, int ret));
297 =item void B<SSL_CTX_set_options>(SSL_CTX *ctx, unsigned long op);
299 =item void B<SSL_CTX_set_quiet_shutdown>(SSL_CTX *ctx, int mode);
301 =item void B<SSL_CTX_set_session_cache_mode>(SSL_CTX *ctx, int mode);
303 =item int B<SSL_CTX_set_ssl_version>(SSL_CTX *ctx, SSL_METHOD *meth);
305 =item void B<SSL_CTX_set_timeout>(SSL_CTX *ctx, long t);
307 =item long B<SSL_CTX_set_tmp_dh>(SSL_CTX* ctx, DH *dh);
309 =item long B<SSL_CTX_set_tmp_dh_callback>(SSL_CTX *ctx, DH *(*cb)(void));
311 =item long B<SSL_CTX_set_tmp_rsa>(SSL_CTX *ctx, RSA *rsa);
313 =item SSL_CTX_set_tmp_rsa_callback
315 C<long B<SSL_CTX_set_tmp_rsa_callback>(SSL_CTX *B<ctx>, RSA *(*B<cb>)(SSL *B<ssl>, int B<export>, int B<keylength>));>
317 Sets the callback which will be called when a temporary private key is
318 required. The B<C<export>> flag will be set if the reason for needing
319 a temp key is that an export ciphersuite is in use, in which case,
320 B<C<keylength>> will contain the required keylength in bits. Generate a key of
321 appropriate size (using ???) and return it.
323 =item SSL_set_tmp_rsa_callback
325 long B<SSL_set_tmp_rsa_callback>(SSL *ssl, RSA *(*cb)(SSL *ssl, int export, int keylength));
327 The same as L<"SSL_CTX_set_tmp_rsa_callback">, except it operates on an SSL
328 session instead of a context.
330 =item void B<SSL_CTX_set_verify>(SSL_CTX *ctx, int mode, int (*cb);(void))
332 =item int B<SSL_CTX_use_PrivateKey>(SSL_CTX *ctx, EVP_PKEY *pkey);
334 =item int B<SSL_CTX_use_PrivateKey_ASN1>(int type, SSL_CTX *ctx, unsigned char *d, long len);
336 =item int B<SSL_CTX_use_PrivateKey_file>(SSL_CTX *ctx, char *file, int type);
338 =item int B<SSL_CTX_use_RSAPrivateKey>(SSL_CTX *ctx, RSA *rsa);
340 =item int B<SSL_CTX_use_RSAPrivateKey_ASN1>(SSL_CTX *ctx, unsigned char *d, long len);
342 =item int B<SSL_CTX_use_RSAPrivateKey_file>(SSL_CTX *ctx, char *file, int type);
344 =item int B<SSL_CTX_use_certificate>(SSL_CTX *ctx, X509 *x);
346 =item int B<SSL_CTX_use_certificate_ASN1>(SSL_CTX *ctx, int len, unsigned char *d);
348 =item int B<SSL_CTX_use_certificate_file>(SSL_CTX *ctx, char *file, int type);
352 =head2 DEALING WITH SESSIONS
354 Here we document the various API functions which deal with the SSL/TLS
355 sessions defined in the B<SSL_SESSION> structures.
359 =item int B<SSL_SESSION_cmp>(SSL_SESSION *a, SSL_SESSION *b);
361 =item void B<SSL_SESSION_free>(SSL_SESSION *ss);
363 =item char *B<SSL_SESSION_get_app_data>(SSL_SESSION *s);
365 =item char *B<SSL_SESSION_get_ex_data>(SSL_SESSION *s, int idx);
367 =item int B<SSL_SESSION_get_ex_new_index>(long argl, char *argp, int (*new_func);(void), int (*dup_func)(void), void (*free_func)(void))
369 =item long B<SSL_SESSION_get_time>(SSL_SESSION *s);
371 =item long B<SSL_SESSION_get_timeout>(SSL_SESSION *s);
373 =item unsigned long B<SSL_SESSION_hash>(SSL_SESSION *a);
375 =item SSL_SESSION *B<SSL_SESSION_new>(void);
377 =item int B<SSL_SESSION_print>(BIO *bp, SSL_SESSION *x);
379 =item int B<SSL_SESSION_print_fp>(FILE *fp, SSL_SESSION *x);
381 =item void B<SSL_SESSION_set_app_data>(SSL_SESSION *s, char *a);
383 =item int B<SSL_SESSION_set_ex_data>(SSL_SESSION *s, int idx, char *arg);
385 =item long B<SSL_SESSION_set_time>(SSL_SESSION *s, long t);
387 =item long B<SSL_SESSION_set_timeout>(SSL_SESSION *s, long t);
391 =head2 DEALING WITH CONNECTIONS
393 Here we document the various API functions which deal with the SSL/TLS
394 connection defined in the B<SSL> structure.
398 =item int B<SSL_accept>(SSL *ssl);
400 =item int B<SSL_add_dir_cert_subjects_to_stack>(STACK *stack, const char *dir);
402 =item int B<SSL_add_file_cert_subjects_to_stack>(STACK *stack, const char *file);
404 =item int B<SSL_add_client_CA>(SSL *ssl, X509 *x);
406 =item char *B<SSL_alert_desc_string>(int value);
408 =item char *B<SSL_alert_desc_string_long>(int value);
410 =item char *B<SSL_alert_type_string>(int value);
412 =item char *B<SSL_alert_type_string_long>(int value);
414 =item int B<SSL_check_private_key>(SSL *ssl);
416 =item void B<SSL_clear>(SSL *ssl);
418 =item long B<SSL_clear_num_renegotiations>(SSL *ssl);
420 =item int B<SSL_connect>(SSL *ssl);
422 =item void B<SSL_copy_session_id>(SSL *t, SSL *f);
424 =item long B<SSL_ctrl>(SSL *ssl, int cmd, long larg, char *parg);
426 =item int B<SSL_do_handshake>(SSL *ssl);
428 =item SSL *B<SSL_dup>(SSL *ssl);
430 =item STACK *B<SSL_dup_CA_list>(STACK *sk);
432 =item void B<SSL_free>(SSL *ssl);
434 =item SSL_CTX *B<SSL_get_SSL_CTX>(SSL *ssl);
436 =item char *B<SSL_get_app_data>(SSL *ssl);
438 =item X509 *B<SSL_get_certificate>(SSL *ssl);
440 =item SSL_CIPHER *B<SSL_get_cipher>(SSL *ssl);
442 =item int B<SSL_get_cipher_bits>(SSL *ssl, int *alg_bits);
444 =item char *B<SSL_get_cipher_list>(SSL *ssl, int n);
446 =item char *B<SSL_get_cipher_name>(SSL *ssl);
448 =item char *B<SSL_get_cipher_version>(SSL *ssl);
450 =item STACK *B<SSL_get_ciphers>(SSL *ssl);
452 =item STACK *B<SSL_get_client_CA_list>(SSL *ssl);
454 =item SSL_CIPHER *B<SSL_get_current_cipher>(SSL *ssl);
456 =item long B<SSL_get_default_timeout>(SSL *ssl);
458 =item int B<SSL_get_error>(SSL *ssl, int i);
460 =item char *B<SSL_get_ex_data>(SSL *ssl, int idx);
462 =item int B<SSL_get_ex_data_X509_STORE_CTX_idx>(void);
464 =item int B<SSL_get_ex_new_index>(long argl, char *argp, int (*new_func);(void), int (*dup_func)(void), void (*free_func)(void))
466 =item int B<SSL_get_fd>(SSL *ssl);
468 =item void (*B<SSL_get_info_callback>(SSL *ssl);)(void)
470 =item STACK *B<SSL_get_peer_cert_chain>(SSL *ssl);
472 =item X509 *B<SSL_get_peer_certificate>(SSL *ssl);
474 =item EVP_PKEY *B<SSL_get_privatekey>(SSL *ssl);
476 =item int B<SSL_get_quiet_shutdown>(SSL *ssl);
478 =item BIO *B<SSL_get_rbio>(SSL *ssl);
480 =item int B<SSL_get_read_ahead>(SSL *ssl);
482 =item SSL_SESSION *B<SSL_get_session>(SSL *ssl);
484 =item char *B<SSL_get_shared_ciphers>(SSL *ssl, char *buf, int len);
486 =item int B<SSL_get_shutdown>(SSL *ssl);
488 =item SSL_METHOD *B<SSL_get_ssl_method>(SSL *ssl);
490 =item int B<SSL_get_state>(SSL *ssl);
492 =item long B<SSL_get_time>(SSL *ssl);
494 =item long B<SSL_get_timeout>(SSL *ssl);
496 =item int (*B<SSL_get_verify_callback>(SSL *ssl);)(void)
498 =item int B<SSL_get_verify_mode>(SSL *ssl);
500 =item long B<SSL_get_verify_result>(SSL *ssl);
502 =item char *B<SSL_get_version>(SSL *ssl);
504 =item BIO *B<SSL_get_wbio>(SSL *ssl);
506 =item int B<SSL_in_accept_init>(SSL *ssl);
508 =item int B<SSL_in_before>(SSL *ssl);
510 =item int B<SSL_in_connect_init>(SSL *ssl);
512 =item int B<SSL_in_init>(SSL *ssl);
514 =item int B<SSL_is_init_finished>(SSL *ssl);
516 =item STACK *B<SSL_load_client_CA_file>(char *file);
518 =item void B<SSL_load_error_strings>(void);
520 =item SSL *B<SSL_new>(SSL_CTX *ctx);
522 =item long B<SSL_num_renegotiations>(SSL *ssl);
524 =item int B<SSL_peek>(SSL *ssl, char *buf, int num);
526 =item int B<SSL_pending>(SSL *ssl);
528 =item int B<SSL_read>(SSL *ssl, char *buf, int num);
530 =item int B<SSL_renegotiate>(SSL *ssl);
532 =item char *B<SSL_rstate_string>(SSL *ssl);
534 =item char *B<SSL_rstate_string_long>(SSL *ssl);
536 =item long B<SSL_session_reused>(SSL *ssl);
538 =item void B<SSL_set_accept_state>(SSL *ssl);
540 =item void B<SSL_set_app_data>(SSL *ssl, char *arg);
542 =item void B<SSL_set_bio>(SSL *ssl, BIO *rbio, BIO *wbio);
544 =item int B<SSL_set_cipher_list>(SSL *ssl, char *str);
546 =item void B<SSL_set_client_CA_list>(SSL *ssl, STACK *list);
548 =item void B<SSL_set_connect_state>(SSL *ssl);
550 =item int B<SSL_set_ex_data>(SSL *ssl, int idx, char *arg);
552 =item int B<SSL_set_fd>(SSL *ssl, int fd);
554 =item void B<SSL_set_info_callback>(SSL *ssl, void (*cb);(void))
556 =item void B<SSL_set_options>(SSL *ssl, unsigned long op);
558 =item void B<SSL_set_quiet_shutdown>(SSL *ssl, int mode);
560 =item void B<SSL_set_read_ahead>(SSL *ssl, int yes);
562 =item int B<SSL_set_rfd>(SSL *ssl, int fd);
564 =item int B<SSL_set_session>(SSL *ssl, SSL_SESSION *session);
566 =item void B<SSL_set_shutdown>(SSL *ssl, int mode);
568 =item int B<SSL_set_ssl_method>(SSL *ssl, SSL_METHOD *meth);
570 =item void B<SSL_set_time>(SSL *ssl, long t);
572 =item void B<SSL_set_timeout>(SSL *ssl, long t);
574 =item void B<SSL_set_verify>(SSL *ssl, int mode, int (*callback);(void))
576 =item void B<SSL_set_verify_result>(SSL *ssl, long arg);
578 =item int B<SSL_set_wfd>(SSL *ssl, int fd);
580 =item int B<SSL_shutdown>(SSL *ssl);
582 =item int B<SSL_state>(SSL *ssl);
584 =item char *B<SSL_state_string>(SSL *ssl);
586 =item char *B<SSL_state_string_long>(SSL *ssl);
588 =item long B<SSL_total_renegotiations>(SSL *ssl);
590 =item int B<SSL_use_PrivateKey>(SSL *ssl, EVP_PKEY *pkey);
592 =item int B<SSL_use_PrivateKey_ASN1>(int type, SSL *ssl, unsigned char *d, long len);
594 =item int B<SSL_use_PrivateKey_file>(SSL *ssl, char *file, int type);
596 =item int B<SSL_use_RSAPrivateKey>(SSL *ssl, RSA *rsa);
598 =item int B<SSL_use_RSAPrivateKey_ASN1>(SSL *ssl, unsigned char *d, long len);
600 =item int B<SSL_use_RSAPrivateKey_file>(SSL *ssl, char *file, int type);
602 =item int B<SSL_use_certificate>(SSL *ssl, X509 *x);
604 =item int B<SSL_use_certificate_ASN1>(SSL *ssl, int len, unsigned char *d);
606 =item int B<SSL_use_certificate_file>(SSL *ssl, char *file, int type);
608 =item int B<SSL_version>(SSL *ssl);
610 =item int B<SSL_want>(SSL *ssl);
612 =item int B<SSL_want_nothing>(SSL *ssl);
614 =item int B<SSL_want_read>(SSL *ssl);
616 =item int B<SSL_want_write>(SSL *ssl);
618 =item int B<SSL_want_x509_lookup>(s);
620 =item int B<SSL_write>(SSL *ssl, char *buf, int num);
626 openssl(1), crypto(3)
630 The ssl(3) document appeared in OpenSSL 0.9.2