RSA Encrypt and Decrypt Strings

C sample code to RSA public-key encrypt and decrypt strings using public and private keys.

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#include <C_CkRsa.h>

void ChilkatSample(void)
    {
    HCkRsa rsa;
    BOOL success;
    const char * publicKey;
    const char * privateKey;
    const char * plainText;
    HCkRsa rsaEncryptor;
    BOOL usePrivateKey;
    const char * encryptedStr;
    HCkRsa rsaDecryptor;
    const char * decryptedStr;

    rsa = CkRsa_Create();

    success = CkRsa_UnlockComponent(rsa,"Anything for 30-day trial");
    if (success != TRUE) {
        printf("RSA component unlock failed\n");
        return;
    }

    //  This example also generates the public and private
    //  keys to be used in the RSA encryption.
    //  Normally, you would generate a key pair once,
    //  and distribute the public key to your partner.
    //  Anything encrypted with the public key can be
    //  decrypted with the private key.  The reverse is
    //  also true: anything encrypted using the private
    //  key can be decrypted using the public key.

    //  Generate a 1024-bit key.  Chilkat RSA supports
    //  key sizes ranging from 512 bits to 4096 bits.
    success = CkRsa_GenerateKey(rsa,1024);
    if (success != TRUE) {
        printf("%s\n",CkRsa_lastErrorText(rsa));
        return;
    }

    //  Keys are exported in XML format:

    publicKey = CkRsa_exportPublicKey(rsa);

    privateKey = CkRsa_exportPrivateKey(rsa);

    plainText = "Encrypting and decrypting should be easy!";

    //  Start with a new RSA object to demonstrate that all we
    //  need are the keys previously exported:
    rsaEncryptor = CkRsa_Create();

    //  Encrypted output is always binary.  In this case, we want
    //  to encode the encrypted bytes in a printable string.
    //  Our choices are "hex", "base64", "url", "quoted-printable".
    CkRsa_putEncodingMode(rsaEncryptor,"hex");

    //  We'll encrypt with the public key and decrypt with the private
    //  key.  It's also possible to do the reverse.
    CkRsa_ImportPublicKey(rsaEncryptor,publicKey);

    usePrivateKey = FALSE;

    encryptedStr = CkRsa_encryptStringENC(rsaEncryptor,plainText,usePrivateKey);
    printf("%s\n",encryptedStr);

    //  Now decrypt:
    rsaDecryptor = CkRsa_Create();

    CkRsa_putEncodingMode(rsaDecryptor,"hex");
    CkRsa_ImportPrivateKey(rsaDecryptor,privateKey);

    usePrivateKey = TRUE;

    decryptedStr = CkRsa_decryptStringENC(rsaDecryptor,encryptedStr,usePrivateKey);

    printf("%s\n",decryptedStr);

    CkRsa_Dispose(rsa);
    CkRsa_Dispose(rsaEncryptor);
    CkRsa_Dispose(rsaDecryptor);

    }