(C) Find Certificate by Email Address

See more Cert Store Examples

Demonstrates how to find a certificate having the specified email address either within the cert's subject email, or the RFC822 name.

In an X.509 certificate, an email address can typically be located in two places:

1. RFC822 Name (Subject Alternative Name extension) -
   • The certificate may include an email address in the Subject Alternative Name (SAN) extension under the RFC822 Name field. This is a modern and preferred method because it allows for flexibility and alignment with security best practices.
   • To find it, Chilkat inspects the SAN extension in the certificate details.
2. Subject (Common Name or Email Address attribute) -
   • Older certificates may store the email address directly in the Subject field, typically under the Email Address attribute ("emailAddress") or, less commonly, the Common Name (CN).
   • This method is less preferred in modern standards but can still be encountered in legacy implementations. Chilkat also searches here for the email address.

Note: Requires Chilkat v10.1.2 or later.

Chilkat C/C++ Library Downloads
MS Visual C/C++ C++ Builder Linux C/C++ Alpine Linux C/C++	MacOS C/C++ iOS C/C++ Android C/C++ MinGW C/C++

#include <C_CkCertStore.h>
#include <C_CkJsonObject.h>
#include <C_CkCert.h>

void ChilkatSample(void)
    {
    HCkCertStore certStore;
    BOOL readOnly;
    BOOL success;
    HCkJsonObject json;
    const char *email_address;
    HCkCert cert;

    certStore = CkCertStore_Create();

    // This opens the Current User certificate store on Windows,
    // On MacOS and iOS it opens the default Keychain.
    readOnly = FALSE;
    success = CkCertStore_OpenCurrentUserStore(certStore,readOnly);
    if (success == FALSE) {
        printf("%s\n",CkCertStore_lastErrorText(certStore));
        CkCertStore_Dispose(certStore);
        return;
    }

    // Find the certificate having the specified email address in either the RFC822 Name or in the Subject.
    json = CkJsonObject_Create();
    email_address = "joe@example.com";
    CkJsonObject_UpdateString(json,"email",email_address);

    cert = CkCert_Create();
    success = CkCertStore_FindCert(certStore,json,cert);
    if (success == TRUE) {
        // Show the full distinguished name of the certificate.
        printf("Found: %s\n",CkCert_subjectDN(cert));
    }
    else {
        printf("Not found.\n");
    }



    CkCertStore_Dispose(certStore);
    CkJsonObject_Dispose(json);
    CkCert_Dispose(cert);

    }