---
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Title: CURLOPT_CAINFO_BLOB
Section: 3
Source: libcurl
Protocol:
  - TLS
See-also:
  - CURLOPT_CAINFO (3)
  - CURLOPT_CAPATH (3)
  - CURLOPT_SSL_VERIFYHOST (3)
  - CURLOPT_SSL_VERIFYPEER (3)
TLS-backend:
  - OpenSSL
  - GnuTLS
  - mbedTLS
  - Rustls
  - wolfSSL
  - Schannel
Added-in: 7.77.0
---

# NAME

CURLOPT_CAINFO_BLOB - Certificate Authority (CA) bundle in PEM format

# SYNOPSIS

~~~c
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CAINFO_BLOB,
                          struct curl_blob *stblob);
~~~

# DESCRIPTION

Pass a pointer to a curl_blob structure, which contains information (pointer
and size) about a memory block with binary data of PEM encoded content holding
one or more certificates to verify the HTTPS server with.

If the blob is initialized with the flags member of struct curl_blob set to
CURL_BLOB_COPY, the application does not have to keep the buffer around after
setting this.

If CURLOPT_SSL_VERIFYPEER(3) is zero and you avoid verifying the
server's certificate, CURLOPT_CAINFO_BLOB(3) is not needed.

This option overrides CURLOPT_CAINFO(3).

# DEFAULT

NULL

# %PROTOCOLS%

# EXAMPLE

~~~c
#include <stdint.h> /* for uintptr_t */
#include <string.h>

int main(void)
{
  static const char *strpem = "PEMDATA"; /* must point to a PEM string */
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    struct curl_blob blob;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    blob.data = (void *)(uintptr_t)(const void *)strpem; /* strip const */
    blob.len = strlen(strpem);
    blob.flags = CURL_BLOB_COPY;
    curl_easy_setopt(curl, CURLOPT_CAINFO_BLOB, &blob);
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
~~~

# HISTORY

This option is supported by the mbedTLS (since 7.81.0), Rustls (since 7.82.0),
wolfSSL (since 8.2.0), GnuTLS (since 8.18.0), OpenSSL and Schannel backends.

# %AVAILABILITY%

# RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see
libcurl-errors(3).
