(C) Encrypt Already Existing Zip

To encrypt an already existing non-encrypted .zip, the application must open the .zip, set the encryption related properties, and then re-write.

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

#include <C_CkZip.h>

void ChilkatSample(void)
    {
    HCkZip zip;
    BOOL success;
    int numFilesUnzipped;

    // This requires the Chilkat Zip API to have been previously unlocked.
    // See Unlock Chilkat Zip for sample code.

    zip = CkZip_Create();

    // Open an unencrypted .zip
    success = CkZip_OpenZip(zip,"qa_data/zips/test.zip");
    if (success != TRUE) {
        printf("%s\n",CkZip_lastErrorText(zip));
        CkZip_Dispose(zip);
        return;
    }

    // Unzip to a temp directory.
    numFilesUnzipped = CkZip_Unzip(zip,"qa_output/tmp");
    if (numFilesUnzipped < 0) {
        printf("%s\n",CkZip_lastErrorText(zip));
        CkZip_Dispose(zip);
        return;
    }

    // Clear the zip object.
    CkZip_NewZip(zip,"qa_output/aesTest.zip");

    // Indicate that 128-bit AES encryption is to be used when writing the .zip
    CkZip_putEncryption(zip,4);
    CkZip_putEncryptKeyLength(zip,128);

    // Set the password.
    CkZip_putEncryptPassword(zip,"secret");

    // Append the files.
    CkZip_putAppendFromDir(zip,"qa_output/tmp");
    success = CkZip_AppendFiles(zip,"*.*",TRUE);
    if (success != TRUE) {
        printf("%s\n",CkZip_lastErrorText(zip));
        CkZip_Dispose(zip);
        return;
    }

    // Write the .zip and close it.
    success = CkZip_WriteZipAndClose(zip);
    if (success != TRUE) {
        printf("%s\n",CkZip_lastErrorText(zip));
        CkZip_Dispose(zip);
        return;
    }

    printf("Success.\n");


    CkZip_Dispose(zip);

    }