Encrypt Content to a JWE

See more JSON Web Encryption (JWE) Examples

Demonstrates Jwe.Encrypt, which encrypts a string and returns the resulting JWE. The charset argument converts the text to bytes before encryption.

Background. JWE (JSON Web Encryption) protects content with a content-encryption algorithm (the header enc value) while the content-encryption key is managed by the key-management algorithm (the header alg value). This example uses AES key wrapping with a symmetric wrapping key.

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#include <C_CkJwe.h>
#include <C_CkJsonObject.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkJwe jwe;
    HCkJsonObject header;
    const char *base64Key;
    const char *jweCompact;

    success = FALSE;

    jwe = CkJwe_Create();

    //  Set the JWE protected header, specifying the key-management algorithm (alg) and the content-
    //  encryption algorithm (enc).
    header = CkJsonObject_Create();
    CkJsonObject_UpdateString(header,"alg","A256KW");
    CkJsonObject_UpdateString(header,"enc","A256GCM");
    success = CkJwe_SetProtectedHeader(jwe,header);
    if (success == FALSE) {
        printf("%s\n",CkJwe_lastErrorText(jwe));
        CkJwe_Dispose(jwe);
        CkJsonObject_Dispose(header);
        return;
    }

    //  The 256-bit key-wrapping key (base64) for recipient index 0.  In production, obtain the key
    //  from a secure source rather than hard-coding it.
    base64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=";
    success = CkJwe_SetWrappingKey(jwe,0,base64Key,"base64");
    if (success == FALSE) {
        printf("%s\n",CkJwe_lastErrorText(jwe));
        CkJwe_Dispose(jwe);
        CkJsonObject_Dispose(header);
        return;
    }

    //  Encrypt the content.  The 2nd argument is the charset used to convert the text to bytes.  The
    //  returned string is the JWE (compact serialization by default).
    jweCompact = CkJwe_encrypt(jwe,"This is the secret content.","utf-8");
    if (CkJwe_getLastMethodSuccess(jwe) == FALSE) {
        printf("%s\n",CkJwe_lastErrorText(jwe));
        CkJwe_Dispose(jwe);
        CkJsonObject_Dispose(header);
        return;
    }

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


    CkJwe_Dispose(jwe);
    CkJsonObject_Dispose(header);

    }