Ciao,

  sorry if this is a FAQ, with the following program:

#include <stdio.h>
#include <stdlib.h>
#include <curl/curl.h>

#define COK(CALL) \
  do { \
    e = (CALL); \
    if (CURLE_OK != e) { \
      fprintf(stderr, curl_easy_strerror(e)); \
      exit(EXIT_FAILURE); \
    } \
  } while (0)

size_t
cb (void * buffer, size_t item_size, size_t item_number, void * custom)
{
  /* fwrite(buffer, item_size, item_number, stderr); */
  return (item_size * item_number);
}
int
main (int argc, const char *const argv[])
{
  CURL * handle = curl_easy_init();
  int num_certs = 0;
  int e;
  fprintf(stderr, "connecting to gna\n");
  COK(curl_easy_setopt(handle, CURLOPT_URL, "https://gna.org/"));
  COK(curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, cb));
  COK(curl_easy_setopt(handle, CURLOPT_WRITEDATA, NULL));
  COK(curl_easy_setopt(handle, CURLOPT_SSL_VERIFYPEER, 0));
  COK(curl_easy_setopt(handle, CURLOPT_CERTINFO, 1));
  COK(curl_easy_perform(handle));
  COK(curl_easy_getinfo(handle, CURLINFO_CERTINFO, &num_certs));
  fprintf(stderr, "num certs %d\n", num_certs);
  exit(EXIT_SUCCESS);
}

I get outputs like:

connecting to gna
num certs 157484972

which is obviously bad; what am I doing wrong? When
issuing:

  $ curl -v -k "https://gna.org"

I correctly get:

* Server certificate:
* subject: CN=gna.org
* start date: 2009-11-01 20:54:13 GMT
* expire date: 2010-04-30 20:54:13 GMT
* common name: gna.org (matched)
* issuer: O=Root CA; OU=http://www.cacert.org; CN=CA Cert Signing Authority; emailAddress=support@cacert.org

  The other operations with cURL I tested so far seem to
work fine. If I am not mistaken, the source of the "curl"
program does not make use of the CURLINFO_CERTINFO option;
it is not clear to me how it can print certinfos (I only see
code using GNU TLS).

  My cURL is:

libcurl/7.19.7 OpenSSL/0.9.8i zlib/1.2.3 c-ares/1.6.0 libidn/1.12
version-info age: 3
version-info version: "7.19.7"
version-info version-num: "71307"
version-info host: "i686-pc-linux-gnu"
version-info features:
        (CURLDEBUG CONV SSPI IDN LARGEFILE SPNEGO
         ASYNCHDNS DEBUG GSSNEGOTIATE NTLM LIBZ SSL
         KERBEROS4 IPV6)
version-info ssl-version: "OpenSSL/0.9.8i"
version-info ssl-version-num: 0
version-info libz-version: "1.2.3"
version-info protocols:
        (tftp ftp telnet dict ldap http file https ftps)
version-info ares: "1.6.0"
version-info ares-num: 67072
version-info iconv: 0
version-info libssh-version: #f

and:

  $ ldd /usr/local/bin/curl

   linux-gate.so.1 => (0xb8016000)
   libcurl.so.4 => /usr/local/lib/libcurl.so.4 (0xb7fb6000)
   libfbopenssl.so => /usr/local/lib/libfbopenssl.so (0xb7fb2000)
   libcares.so.2 => /usr/local/lib/libcares.so.2 (0xb7fa5000)
   libidn.so.11 => /usr/local/lib/libidn.so.11 (0xb7f74000)
   libiconv.so.2 => /usr/local/lib/libiconv.so.2 (0xb7e94000)
   libldap-2.3.so.0 => /usr/lib/libldap-2.3.so.0 (0xb7e5e000)
   liblber-2.3.so.0 => /usr/lib/liblber-2.3.so.0 (0xb7e51000)
   libsasl2.so.2 => /usr/lib/libsasl2.so.2 (0xb7e3a000)
   libdl.so.2 => /lib/libdl.so.2 (0xb7e36000)
   libresolv.so.2 => /lib/libresolv.so.2 (0xb7e23000)
   libssl.so.0 => /usr/lib/libssl.so.0 (0xb7de2000)
   libcrypto.so.0 => /usr/lib/libcrypto.so.0 (0xb7ca5000)
   librt.so.1 => /lib/librt.so.1 (0xb7c9b000)
   libz.so.1 => /usr/lib/libz.so.1 (0xb7c87000)
   libc.so.6 => /lib/libc.so.6 (0xb7b3b000)
   /lib/ld-linux.so.2 (0xb8017000)
   libpthread.so.0 => /lib/libpthread.so.0 (0xb7b24000)

TIA

-- 
Marco Maggi
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