C

How to Parse a X.509 Certificate and Extract its Public Key

See more Certificates Examples

Demonstrates how to load an X.509 certificate and extract the public key. Chilkat supports many certificate encodings:

• DER (binary) encoded certificates (.crt/.cer)
• PEM (BASE64) encoded certificates (.pem)
• Load Certificates Directly from Windows Certificate Stores
• PFX/PKCS12 (.pfx/.p12)
• Java KeyStore (.jks)
• Cryptographic Message Syntax Standard - PKCS #7 Certificates (.P7B)

C

#include <C_CkCert.h>
#include <C_CkPublicKey.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkCert cert;
    HCkPublicKey pubKey;

    success = FALSE;

    cert = CkCert_Create();

    // Load a DER (binary) encoded certificate.
    // To load from a .pem or .p7b, or any other file format that contains
    // just one certificate, call LoadFromFile in exactly the same way.
    // The LoadFromFile method automatically detects the format and loads the certificate.
    success = CkCert_LoadFromFile(cert,"qa_data/certs/testCert.cer");
    if (success == FALSE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkCert_Dispose(cert);
        return;
    }

    // Get the public key:
    pubKey = CkPublicKey_Create();
    CkCert_GetPublicKey(cert,pubKey);

    // Examine the key type.
    // A PublicKey object can contain an RSA, ECC, or DSA public key.
    // The KeyType property will contain "rsa", "ecc", or "dsa".
    printf("key type = %s\n",CkPublicKey_keyType(pubKey));


    CkCert_Dispose(cert);
    CkPublicKey_Dispose(pubKey);

    }