SSL_set_retry_verify.3ossl - Man Page

 #include <openssl/ssl.h>

 int SSL_set_retry_verify(SSL *ssl);

SSL_set_retry_verify() should be called from the certificate verification callback on a client when the application wants to indicate that the handshake should be suspended and the control should be returned to the application. SSL_want_retry_verify(3) will return 1 as a consequence until the handshake is resumed again by the application, retrying the verification step.

Please refer to SSL_CTX_set_cert_verify_callback(3) for further details.

The effect of calling SSL_set_retry_verify() outside of the certificate verification callback on the client side is undefined.

SSL_set_retry verify() returns 1 on success, 0 otherwise.

The following code snippet shows how to obtain the SSL object associated with the X509_STORE_CTX to call the SSL_set_retry_verify() function:

    int idx = SSL_get_ex_data_X509_STORE_CTX_idx();
    SSL *ssl;

    /* this should not happen but check anyway */
    if (idx < 0
        || (ssl = X509_STORE_CTX_get_ex_data(ctx, idx)) == NULL) 
        return 0;

    if (/* we need to retry verification callback */)
        return SSL_set_retry_verify(ssl);

    /* do normal processing of the verification callback */

ssl(7), SSL_connect(3), SSL_CTX_set_cert_verify_callback(3), SSL_want_retry_verify(3)

SSL_set_retry_verify() was added in OpenSSL 3.0.2 to replace backwards incompatible handling of a negative return value from the verification callback.

Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License").  You may not use this file except in compliance with the License.  You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

SSL_CTX_set_cert_verify_callback.3ossl(3), SSL_CTX_set_verify.3ossl(3), SSL_want.3ossl(3).