{
    "mode": "man",
    "parameter": "ct",
    "section": "7ssl",
    "url": "https://www.chedong.com/phpMan.php/man/ct/7ssl/json",
    "generated": "2026-10-08T03:19:29Z",
    "synopsis": "#include <openssl/ct.h>",
    "sections": {
        "NAME": {
            "content": "ct - Certificate Transparency\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "#include <openssl/ct.h>\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "This library implements Certificate Transparency (CT) verification for TLS clients, as\ndefined in RFC 6962. This verification can provide some confidence that a certificate has\nbeen publicly logged in a set of CT logs.\n\nBy default, these checks are disabled. They can be enabled using SSLCTXenablect(3) or\nSSLenablect(3).\n\nThis library can also be used to parse and examine CT data structures, such as Signed\nCertificate Timestamps (SCTs), or to read a list of CT logs. There are functions for: -\ndecoding and encoding SCTs in DER and TLS wire format.  - printing SCTs.  - verifying the\nauthenticity of SCTs.  - loading a CT log list from a CONF file.\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "d2iSCTLIST(3), CTLOGSTOREnew(3), CTLOGSTOREget0logbyid(3), SCTnew(3), SCTprint(3),\nSCTvalidate(3), SCTvalidate(3), CTPOLICYEVALCTXnew(3),\nSSLCTXsetctvalidationcallback(3)\n",
            "subsections": []
        },
        "HISTORY": {
            "content": "The ct library was added in OpenSSL 1.1.0.\n",
            "subsections": []
        },
        "COPYRIGHT": {
            "content": "Copyright 2016-2017 The OpenSSL Project Authors. All Rights Reserved.\n\nLicensed under the Apache License 2.0 (the \"License\").  You may not use this file except in\ncompliance with the License.  You can obtain a copy in the file LICENSE in the source\ndistribution or at <https://www.openssl.org/source/license.html>.\n\n3.0.13                                       2026-07-29                                     CT(7SSL)",
            "subsections": []
        }
    },
    "summary": "ct - Certificate Transparency",
    "flags": [],
    "examples": [],
    "see_also": [
        {
            "name": "d2iSCTLIST",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/d2iSCTLIST/3/json"
        },
        {
            "name": "CTLOGSTOREnew",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/CTLOGSTOREnew/3/json"
        },
        {
            "name": "CTLOGSTOREget0logbyid",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/CTLOGSTOREget0logbyid/3/json"
        },
        {
            "name": "SCTnew",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/SCTnew/3/json"
        },
        {
            "name": "SCTprint",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/SCTprint/3/json"
        },
        {
            "name": "SCTvalidate",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/SCTvalidate/3/json"
        },
        {
            "name": "SCTvalidate",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/SCTvalidate/3/json"
        },
        {
            "name": "CTPOLICYEVALCTXnew",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/CTPOLICYEVALCTXnew/3/json"
        },
        {
            "name": "SSLCTXsetctvalidationcallback",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/SSLCTXsetctvalidationcallback/3/json"
        }
    ]
}