C

Load RSA Public Key from JWK Format (JSON Web Key)

See more RSA Examples

Demonstrates how to load an RSA public key from JWK (JSON Web Key) format.

Note: This example requires Chilkat v9.5.0.66 or later.

C

#include <C_CkJsonObject.h>
#include <C_CkPublicKey.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkJsonObject json;
    const char *jwkStr;
    HCkPublicKey pubKey;
    BOOL bPreferPkcs1;

    success = FALSE;

    // Note: This example requires Chilkat v9.5.0.66 or later.

    // First build a JWK sample to load..
    json = CkJsonObject_Create();
    CkJsonObject_UpdateString(json,"kty","RSA");
    CkJsonObject_UpdateString(json,"n","33TqqLR3eeUmDtHS89qF3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA04DDnEFGAf-kDQiNSe2ZtqC7bnIc8-KSG_qOGQIVaay4Ucr6ovDkykO5Hxn7OU7sJp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwFwnxCsU5-UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUEf0YN3_Q0auBkdbDR_ES2PbgKTJdkjc_rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1WSw");
    CkJsonObject_UpdateString(json,"e","AQAB");

    // The JSON contains the following:
    // { 
    //   "kty": "RSA",
    //   "n": "33TqqLR3eeUmDtHS89qF3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA04DDnEFGAf-kDQiNSe2ZtqC7bnIc8-KSG_qOGQIVaay4Ucr6ovDkykO5Hxn7OU7sJp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwFwnxCsU5-UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUEf0YN3_Q0auBkdbDR_ES2PbgKTJdkjc_rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1WSw",
    //   "e": "AQAB",
    // } 

    // Note: The JSON can contain other members, such as "use", "kid", or anything else.  These will be ignored.
    CkJsonObject_putEmitCompact(json,FALSE);

    // Show the JWK string to be loaded:
    jwkStr = CkJsonObject_emit(json);

    pubKey = CkPublicKey_Create();
    // The LoadFromString method will automatically detect the format.
    success = CkPublicKey_LoadFromString(pubKey,jwkStr);
    if (success != TRUE) {
        printf("%s\n",CkPublicKey_lastErrorText(pubKey));
        CkJsonObject_Dispose(json);
        CkPublicKey_Dispose(pubKey);
        return;
    }

    // OK.. the JWK is loaded.  It can be used in whatever way desired...

    // The key can be retrieved in any other format, such as XML or PEM..
    printf("%s\n",CkPublicKey_getXml(pubKey));

    // XML output:
    // <RSAPublicKey>
    //     <Modulus>33TqqLR3eeUmDtHS89qF3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7sJp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwFwnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUEf0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1WSw==</Modulus>
    //     <Exponent>AQAB</Exponent>
    // </RSAPublicKey>

    // Choose PCKS1 or PCKS8 PEM format..
    bPreferPkcs1 = FALSE;
    printf("%s\n",CkPublicKey_getPem(pubKey,bPreferPkcs1));

    // PEM output
    // -----BEGIN PUBLIC KEY-----
    // MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF
    // 3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA
    // 04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s
    // Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF
    // wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE
    // f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W
    // SwIDAQAB
    // -----END PUBLIC KEY-----


    CkJsonObject_Dispose(json);
    CkPublicKey_Dispose(pubKey);

    }