C

Convert Let's Encrypt PEM Files to a PFX

See more PFX/P12 Examples

Demonstrates how to convert the .pem files provided by Let's Encrypt to a single PFX. C

#include <C_CkStringBuilder.h>
#include <C_CkPfx.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkStringBuilder sbPem;
    HCkStringBuilder sbFullChainPem;
    HCkPfx pfx;
    const char *pfxPassword;

    success = FALSE;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // Let's Encrypt provides four .pem files
    // 1. fullchain.pem
    // 2. privkey.pem
    // 3. cert.pem
    // 4. chain.pem

    // The cert.pem and chain.pem are redundant. 
    // The fullchain.pem is composed of the cert.pem and chain.pem.

    // To convert the PEM's to a single .pfx, we don't need the redundant data.
    // The privkey.pem and fullchain.pem provide the required data.
    // We can ignore cert.pem and chain.pem (because those certs are already found in fullchain.pem).

    // We need a single .pem file that contains both the private key, the cert,
    // and the certs in the chain of authentication.
    // Let's combine priveky.pem and fullchain.pem into a single .pem

    sbPem = CkStringBuilder_Create();
    success = CkStringBuilder_LoadFile(sbPem,"qa_data/pem/lets_encrypt/privkey.pem","utf-8");
    if (success == FALSE) {
        printf("Failed to load privkey.pem\n");
        CkStringBuilder_Dispose(sbPem);
        return;
    }

    // To be safe, append a blank line..
    CkStringBuilder_AppendLine(sbPem,"",FALSE);

    sbFullChainPem = CkStringBuilder_Create();
    success = CkStringBuilder_LoadFile(sbFullChainPem,"qa_data/pem/lets_encrypt/fullchain.pem","utf-8");
    if (success == FALSE) {
        printf("Failed to load fullchain.pem\n");
        CkStringBuilder_Dispose(sbPem);
        CkStringBuilder_Dispose(sbFullChainPem);
        return;
    }

    // Append the full cert chain PEM to the private key PEM.
    CkStringBuilder_AppendSb(sbPem,sbFullChainPem);

    // Load the combined PEM into a Chilkat PFX object.
    pfx = CkPfx_Create();
    success = CkPfx_LoadPem(pfx,CkStringBuilder_getAsString(sbPem),"no password required");
    if (success == FALSE) {
        printf("%s\n",CkPfx_lastErrorText(pfx));
        CkStringBuilder_Dispose(sbPem);
        CkStringBuilder_Dispose(sbFullChainPem);
        CkPfx_Dispose(pfx);
        return;
    }

    // Write the PFX w/ a password.
    pfxPassword = "secret";
    success = CkPfx_ToFile(pfx,pfxPassword,"qa_output/sample.pfx");
    if (success == FALSE) {
        printf("%s\n",CkPfx_lastErrorText(pfx));
        CkStringBuilder_Dispose(sbPem);
        CkStringBuilder_Dispose(sbFullChainPem);
        CkPfx_Dispose(pfx);
        return;
    }

    printf("Success!\n");


    CkStringBuilder_Dispose(sbPem);
    CkStringBuilder_Dispose(sbFullChainPem);
    CkPfx_Dispose(pfx);

    }