---
name: "CURLINFO_CERTINFO"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLINFO_CERTINFO"
---

# CURLINFO\_CERTINFO(3)

TLS certificate chain

## NAME

CURLINFO\_CERTINFO - TLS certificate chain

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_CERTINFO,
                           struct curl_certinfo **chainp);
```

## DESCRIPTION

Pass a pointer to a *struct curl\_certinfo \** and it is set to point to a struct that holds info about the server's certificate chain, assuming you had *[CURLOPT\_CERTINFO(3)](/CURLOPT_CERTINFO/3.md)* enabled when the request was made.

```
struct curl_certinfo {
  int num_of_certs;
  struct curl_slist **certinfo;
};
```

The *certinfo* struct member is an array of linked lists of certificate information. The *num\_of\_certs* struct member is the number of certificates which is the number of elements in the array. Each certificate's list has items with textual information in the format "name:content" such as "Subject:Foo", "Issuer:Bar", etc. The items in each list varies depending on the SSL backend and the certificate.

## PROTOCOLS

This functionality affects  all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc. only

This option works only with the following TLS backends: GnuTLS, OpenSSL, Rustls and Schannel

## EXAMPLE

```
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_easy_setopt(curl, CURLOPT_URL, "https://www.example.com/");
    /* connect to any HTTPS site, trusted or not */
    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
    curl_easy_setopt(curl, CURLOPT_CERTINFO, 1L);
    result = curl_easy_perform(curl);
    if(result == CURLE_OK) {
      int i;
      struct curl_certinfo *ci;
      result = curl_easy_getinfo(curl, CURLINFO_CERTINFO, &ci);
      if(result == CURLE_OK) {
        printf("%d certs!\n", ci->num_of_certs);
        for(i = 0; i < ci->num_of_certs; i++) {
          struct curl_slist *slist;
          for(slist = ci->certinfo[i]; slist; slist = slist->next)
            printf("%s\n", slist->data);
        }
      }
    }
    curl_easy_cleanup(curl);
  }
}
```

See also the *certinfo.c* example.

## HISTORY

GnuTLS support added in 7.42.0. Schannel support added in 7.50.0. mbedTLS support added in 8.9.0.

## AVAILABILITY

Added in curl 7.19.1

## RETURN VALUE

*[curl\_easy\_getinfo(3)](/curl_easy_getinfo/3.md)* returns a CURLcode indicating success or error.

CURLE\_OK (0) means everything was OK, non-zero means an error occurred, see *[libcurl-errors(3)](/libcurl-errors/3.md)*.

## SEE ALSO

[**CURLINFO\_CAPATH**(3)](/CURLINFO_CAPATH/3.md), [**curl\_easy\_getinfo**(3)](/curl_easy_getinfo/3.md), [**curl\_easy\_setopt**(3)](/curl_easy_setopt/3.md)