libcurl + 인증서 관련 질문입니다.

안녕하세요.

libcurl과 인증서 관련 질문이 있어서 글 올립니다.
다음은 libcurl ssl 사용에 관련 예제 소스 파일입니다.

#include

#include
#include
#include

/* some requirements for this to work:
1. set pCertFile to the file with the client certificate
2. if the key is passphrase protected, set pPassphrase to the
passphrase you use
3. if you are using a crypto engine:
3.1. set a #define USE_ENGINE
3.2. set pEngine to the name of the crypto engine you use
3.3. set pKeyName to the key identifier you want to use
4. if you don't use a crypto engine:
4.1. set pKeyName to the file name of your client key
4.2. if the format of the key file is DER, set pKeyType to "DER"

!! verify of the server certificate is not implemented here !!

**** This example only works with libcurl 7.9.3 and later! ****

*/

int main(int argc, char **argv)
{
CURL *curl;
CURLcode res;
FILE *headerfile;
const char *pPassphrase = NULL;

static const char *pCertFile = "testcert.pem";
static const char *pCACertFile="cacert.pem";

const char *pKeyName;
const char *pKeyType;

const char *pEngine;

#if USE_ENGINE
pKeyName = "rsa_test";
pKeyType = "ENG";
pEngine = "chil"; /* for nChiper HSM... */
#else
pKeyName = "testkey.pem";
pKeyType = "PEM";
pEngine = NULL;
#endif

headerfile = fopen("dumpit", "w");

curl_global_init(CURL_GLOBAL_DEFAULT);

curl = curl_easy_init();
if(curl) {
/* what call to write: */
curl_easy_setopt(curl, CURLOPT_URL, "HTTPS://your.favourite.ssl.site");
curl_easy_setopt(curl, CURLOPT_WRITEHEADER, headerfile);

while(1) /* do some ugly short cut... */
{
if (pEngine) /* use crypto engine */
{
if (curl_easy_setopt(curl, CURLOPT_SSLENGINE,pEngine) != CURLE_OK)
{ /* load the crypto engine */
fprintf(stderr,"can't set crypto engine\n");
break;
}
if (curl_easy_setopt(curl, CURLOPT_SSLENGINE_DEFAULT,1) != CURLE_OK)
{ /* set the crypto engine as default */
/* only needed for the first time you load
a engine in a curl object... */
fprintf(stderr,"can't set crypto engine as default\n");
break;
}
}
/* cert is stored PEM coded in file... */
/* since PEM is default, we needn't set it for PEM */
curl_easy_setopt(curl,CURLOPT_SSLCERTTYPE,"PEM");

/* set the cert for client authentication */
curl_easy_setopt(curl,CURLOPT_SSLCERT,pCertFile);

/* sorry, for engine we must set the passphrase
(if the key has one...) */
if (pPassphrase)
curl_easy_setopt(curl,CURLOPT_KEYPASSWD,pPassphrase);

/* if we use a key stored in a crypto engine,
we must set the key type to "ENG" */
curl_easy_setopt(curl,CURLOPT_SSLKEYTYPE,pKeyType);

/* set the private key (file or ID in engine) */
curl_easy_setopt(curl,CURLOPT_SSLKEY,pKeyName);

/* set the file with the certs vaildating the server */
curl_easy_setopt(curl,CURLOPT_CAINFO,pCACertFile);

/* disconnect if we can't validate server's cert */
curl_easy_setopt(curl,CURLOPT_SSL_VERIFYPEER,1);

res = curl_easy_perform(curl);
break; /* we are done... */
}
/* always cleanup */
curl_easy_cleanup(curl);
}

curl_global_cleanup();

return 0;
}

이소스를 이용해 특정 홈페이지에 접속할려고 하는데..

여기서 pCertFile, pCACertFile
두가지가 필요한데 반드시 둘다 pem 포멧으로 되어야 하나요?
제가 가지고 있는 인증서가 client용 .p12와 CA root용 .der 파일이 있습니다.
p12는 openssl로 변환이 가능한데 der은 키가 없어서 변환이 안된다고
메세지가 뜨더군요.

그리고 ./configure설정시 CA path 및 filename을 설정하는 부분이 있던데
client용은 없나요?

아시는분 답변 부탁드립니다.