- NAME
- SYNOPSIS
- DESCRIPTION
- SEE ALSO
- HISTORY
- COPYRIGHT

# NAME

ct - Certificate Transparency

# SYNOPSIS

     #include <openssl/ct.h>

# DESCRIPTION

This library implements Certificate Transparency (CT) verification for TLS clients, as defined in RFC 6962. This verification can provide some confidence that a certificate has been publicly logged in a set of CT logs.

By default, these checks are disabled. They can be enabled using SSL_CTX_enable_ct(3) or SSL_enable_ct(3).

This library can also be used to parse and examine CT data structures, such as Signed Certificate Timestamps (SCTs), or to read a list of CT logs. There are functions for: - decoding and encoding SCTs in DER and TLS wire format. - printing SCTs. - verifying the authenticity of SCTs. - loading a CT log list from a CONF file.

# SEE ALSO

d2i_SCT_LIST(3), CTLOG_STORE_new(3), CTLOG_STORE_get0_log_by_id(3), SCT_new(3), SCT_print(3), SCT_validate(3), SCT_validate(3), CT_POLICY_EVAL_CTX_new(3), SSL_CTX_set_ct_validation_callback(3)

# HISTORY

The ct library was added in OpenSSL 1.1.0.

# COPYRIGHT

Copyright 2016-2017 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (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.