SSL_CTX_SET_VERIFY(3ssl) OpenSSL SSL_CTX_SET_VERIFY(3ssl) SSL_get_ex_data_X509_STORE_CTX_idx, SSL_CTX_set_verify, SSL_set_verify, SSL_CTX_set_verify_depth, SSL_set_verify_depth, SSL_verify_cb, SSL_verify_client_post_handshake, SSL_set_post_handshake_auth, SSL_CTX_set_post_handshake_auth - SSL/TLS #include typedef int (*SSL_verify_cb)(int preverify_ok, X509_STORE_CTX *x509_ctx); void SSL_CTX_set_verify(SSL_CTX *ctx, int mode, SSL_verify_cb verify_callback); void SSL_set_verify(SSL *ssl, int mode, SSL_verify_cb verify_callback); SSL_get_ex_data_X509_STORE_CTX_idx(void); void SSL_CTX_set_verify_depth(SSL_CTX *ctx, int depth); void SSL_set_verify_depth(SSL *ssl, int depth); int SSL_verify_client_post_handshake(SSL *ssl); void SSL_CTX_set_post_handshake_auth(SSL_CTX *ctx, int val); void SSL_set_post_handshake_auth(SSL *ssl, int val); SSL_CTX_set_verify() ctx mode verify_callback . NULL verify_callback. ctx NULL. SSL_set_verify() ssl mode verify_callback . NULL verify_callback. verify_callback ssl. callback ctx ssl SSL_new(3). SSL_get_ex_data_X509_STORE_CTX_idx SSL . verify_callback SSL_set_retry_verify(3) SSL x509_store_ctx ( SSL_get_ex_data_X509_STORE_CTX_idx(3)) 1. . SSL_ERROR_WANT_RETRY_VERIFY. . SSL_connect(3) . . ( ) 0. SSL_CTX_set_verify_depth() depth ctx. SSL_set_verify_depth() depth ssl. SSL_CTX_set_post_handshake_auth() SSL_set_post_handshake_auth() ClientHello . val 0 . . SSL_CTX_set_client_cert_cb() . SSL_verify_client_post_handshake() ssl . SSL_VERIFY_PEER SSL_VERIFY_POST_HANDSHAKE . mode "": SSL_VERIFY_NONE : . : ( ) . TLS/SSL SSL_get_verify_result(3). . SSL_VERIFY_PEER : . ( ). TLS/SSL . SSL_VERIFY_FAIL_IF_NO_PEER_CERT SSL_VERIFY_CLIENT_ONCE SSL_VERIFY_POST_HANDSHAKE. : . TLS/SSL . SSL_VERIFY_PEER. SSL_VERIFY_FAIL_IF_NO_PEER_CERT : TLS/SSL " ". SSL_VERIFY_PEER. : ( ) SSL_VERIFY_CLIENT_ONCE : . . SSL_VERIFY_PEER. : ( ) SSL_VERIFY_POST_HANDSHAKE : SSL_verify_client_post_handshake(). SSL_CTX SSL . SSL_VERIFY_PEER. TLSv1.3 TLSv1.3. : ( ) SSL_VERIFY_NONE . SSL_CTX_set_verify() SSL_set_verify() SSL_VERIFY_NONE. SSL_CTX_set_cert_verify_callback(3). . verify_callback() . SSL_CTX_set_verify_depth() SSL_set_verify_depth() . . +2 X509_V_ERR_CERT_CHAIN_TOO_LONG. " 0: " " 1: CA" " 2: CA " . 2 0 1 2 3 (0 3 ). 100 100 CA . verify_callback SSL_VERIFY_PEER. : preverify_ok (preverify_ok=1) (preverify_ok=0). x509_ctx . ( CA ) . . x509_ctx verify_callback preverify_ok=0. X509_CTX_store_* verify_callback ( ). verify_callback preverify_ok=1 . verify_callback . verify_callback 0 " ". SSL_VERIFY_PEER TLS/SSL. verify_callback 1 . verify_callback 1 TLS/SSL . SSL_get_verify_result(3) verify_callback. verify_callback . preverify_ok TLS/SSL SSL_VERIFY_PEER. SSL_set_post_handshake_auth() . SSL_connect(). SSL_verify_client_post_handshake() . . SSL_do_handshake() SSL_write_ex(). . NewSessionTicket . QUIC. SSL_set_post_handshake_auth() SSL QUIC. SSL_VERIFY_PEER SSL_VERIFY_NONE . SSL_VERIFY_PEER . SSL*_set_verify*() . SSL_verify_client_post_handshake() 1 0 . . verify_callback TLS/SSL . . . . ex_data / SSL ( CRYPTO_get_ex_new_index(3) SSL_get_ex_data_X509_STORE_CTX_idx(3)). ... typedef struct { int verbose_mode; int verify_depth; int always_continue; } mydata_t; int mydata_index; ... static int verify_callback(int preverify_ok, X509_STORE_CTX *ctx) { char buf[256]; X509 *err_cert; int err, depth; SSL *ssl; mydata_t *mydata; err_cert = X509_STORE_CTX_get_current_cert(ctx); err = X509_STORE_CTX_get_error(ctx); depth = X509_STORE_CTX_get_error_depth(ctx); /* * Retrieve the pointer to the SSL of the connection currently treated * and the application specific data stored into the SSL object. */ ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx()); mydata = SSL_get_ex_data(ssl, mydata_index); X509_NAME_oneline(X509_get_subject_name(err_cert), buf, 256); /* * Catch a too long certificate chain. The depth limit set using * SSL_CTX_set_verify_depth() is by purpose set to "limit+1" so * that whenever the "depth>verify_depth" condition is met, we * have violated the limit and want to log this error condition. * We must do it here, because the CHAIN_TOO_LONG error would not * be found explicitly; only errors introduced by cutting off the * additional certificates would be logged. */ if (depth > mydata->verify_depth) { preverify_ok = 0; err = X509_V_ERR_CERT_CHAIN_TOO_LONG; X509_STORE_CTX_set_error(ctx, err); } if (!preverify_ok) { printf("verify error:num=%d:%s:depth=%d:%s\n", err, X509_verify_cert_error_string(err), depth, buf); } else if (mydata->verbose_mode) { printf("depth=%d:%s\n", depth, buf); } /* * At this point, err contains the last verification error. We can use * it for something special */ if (!preverify_ok && (err == X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT)) { X509_NAME_oneline(X509_get_issuer_name(err_cert), buf, 256); printf("issuer= %s\n", buf); } if (mydata->always_continue) return 1; else return preverify_ok; } ... mydata_t mydata; ... mydata_index = SSL_get_ex_new_index(0, "mydata index", NULL, NULL, NULL); ... SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, verify_callback); /* * Let the verify_callback catch the verify_depth error so that we get * an appropriate error in the logfile. */ SSL_CTX_set_verify_depth(verify_depth + 1); /* * Set up the SSL specific data into "mydata" and store it into th SSL * structure. */ mydata.verify_depth = verify_depth; ... SSL_set_ex_data(ssl, mydata_index, &mydata); ... SSL_accept(ssl); /* check of success left out for clarity */ if (peer = SSL_get_peer_certificate(ssl)) { if (SSL_get_verify_result(ssl) == X509_V_OK) { /* The client sent a certificate which verified OK */ } } ssl(7) SSL_new(3) SSL_CTX_get_verify_mode(3) SSL_get_verify_result(3) SSL_CTX_load_verify_locations(3) SSL_get_peer_certificate(3) SSL_CTX_set_cert_verify_callback(3) SSL_get_ex_data_X509_STORE_CTX_idx(3) SSL_CTX_set_client_cert_cb(3) CRYPTO_get_ex_new_index(3) SSL_VERIFY_POST_HANDSHAKE SSL_verify_client_post_handshake() SSL_set_post_handshake_auth() OpenSSL 1.1.1. 2000-2024 OpenSSL. . Apache 2.0 ( ""). . LICENSE . 3 . . : . 3.6.2 7 2026 SSL_CTX_SET_VERIFY(3ssl)