(Visual FoxPro) How to Generate a JSON Web Key (JWK)

Demonstrates how to generate the following types of JSON Web Keys:

• RSA key pair
• EC key pair
• Octet sequence key (HMAC-256)
• 192-bit AES GCM key

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loRsa
LOCAL lnSuccess
LOCAL loRsaKey
LOCAL lcRsaJwkStr
LOCAL loJson
LOCAL loPrng
LOCAL loEcc
LOCAL loEcKey
LOCAL lcEcJwkStr
LOCAL loCrypt
LOCAL loJwkHmac
LOCAL loJwkAes

* This requires the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* ----------------------------------------------
* Generate an RSA key pair in JWK format.
* (Examples for generating other key types are shown below...)
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Rsa')
loRsa = CreateObject('Chilkat.Rsa')
lnSuccess = loRsa.GenerateKey(2048)
loRsaKey = loRsa.ExportPrivateKeyObj()
lcRsaJwkStr = loRsaKey.GetJwk()

* The string returned is the most compact possible, and therefore it is not
* very readable.  To pretty-print, load into a JSON object and emit..
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')
loJson.EmitCompact = 0
loJson.Load(lcRsaJwkStr)
? loJson.Emit()

RELEASE loRsaKey

* Sample RSA JWK:

* { 
*   "kty": "RSA",
*   "n": "6w1Xpof7gKmytJ3yc_yjI5_K3MvVXnBYBDy5Oh2W6Xqu_fOl3W18SjS2AU5xJrTHlB_j84yQjPyXJh_ixjACK4K4dCSYqlLmn3R7QJ84vnHLIEkqwUICqOHdCBjK5xhMrdZxIhuNlJzbARY-3u9RqjsT3HYTjA6JNHUWTYBBRou4gYGm4cJgvX4uexdikqxnze014RmZMaOV_4MR--WL4G8QfNJ2pRBEXQeKyije89H6M5oTSK7KZqFTIqu9hwNtx2oGpGAIcS0Jv5xVl-hDtwXZNwQJaOxMzLw1nwnb2kMliJa67EabQFrQY_xthQNsfzcHJJlpqYiMprW8wRkzmQ",
*   "e": "AQAB",
*   "d": "1_bnXMw-SeYhmxAwb19lqVqtMpdaES5ZwHLmoT4EpbsiQ5T1BfENrMSnoaWoEy8w3Kk8cU7qlY-TdOUBIKWFqOKvhY8GciA_Y6zLfgGNSnYVczGmxfBXr0HvKvxUmWZbNbH9OqBkQnKoSmRdGcp7l1Q2mG4o4ZuNdxRJjKXV0_DTrNLUJzst0hsfoZ6mWUrQcn39XGvvLjz9ySS-DYGI1vli3ayx8jVNuw0rU8UXVs9WmPQLvZO_ZDMhoLEeKsdejnNkUNPAUjqxcSOZRojt4BfCmbt-_1slFb0NsoaqnDVZGezd9J9ocxGuyIWHAJu9GGZEcdaFyiDDs_WA1IS_fQ",
*   "p": "9dU8f6yOklRcpV6ayVMKpyQ6AMuBTF3rZmB498eAvvTkVG1-upm8IkikTVNpPjEalc82Sxuq8oF4N5x1-F33sgVEoCZG-1WFZTn-rnPnXSALES9hqSaVYEwnh61EiY8ckjBVr9jD2nL1JKdbfgVVeo69-9PdjnKYYDVL8eLNPwM",
*   "q": "9MX2sW0GyaOsZ86AYe3eG2ZgcgKHvhJa573gih5Jvi2e-Nv-L0EVK29_DA7n0Pjm-gl9zVAsGsMMkphJyEF9QgyUlJ-59XLqWnECS5gO6WZdtHrJxVvcO-_AOrLIxeYnYcwhmaVaxs_UEpqGzupKHCWgf4cfXe49lrIsqGKH4jM",
*   "dp": "IQgj9uvSxGq9gCL0HXUhC1Bc0tqFZyN_i-QOnQybig0R2R5VVvFtTBYCrbk1fPvQHK0ZGIKBN9CZvK8zUsodjDgU_ofmJcNaBz4BsKM2RVcW5Zo-PyJGFAhnj12CxhEKv8Hq4ZP4zROBSQmLy6Uf1TX05S-Up51SSCshJ0FYXs0",
*   "dq": "RijsMiUfGfL5OvP85pUI4e-xW1yQThHyzpQlZVGTL5jiBVEBhcfw6ndWAj3Pgp2ljyvjTFNboPwhgW93Tpg-8AytFgDGi605sVzNHJ_kPlBiMZY0eYaAFQn-npSaaecziJu7UdAMugneLsruMycCwRij7Ynsmr7sFmLR3B4J9vM",
*   "qi": "jZE-a1pa8YjflpCSH5oqp1f6f6I6-hpZcLdamLCoAcjVSIPk86gtXtOFES4411-DqYzYIZM6B_g_SRYY6JpKAOuZ40mmMTlnIEoVf8BHiGl3g6bBAiN1yQGXrwXJsg2OYnocyRA-xWNdcMSSFA52SwEdar2Mmw29qVzxtC1QbpA"
* }

* ----------------------------------------------
* Generate an EC P-256 key pair in JWK format

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Prng')
loPrng = CreateObject('Chilkat.Prng')
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Ecc')
loEcc = CreateObject('Chilkat.Ecc')
loEcKey = loEcc.GenEccKey("P-256",loPrng)
IF (loEcc.LastMethodSuccess <> 1) THEN
    ? loEcc.LastErrorText
    RELEASE loRsa
    RELEASE loJson
    RELEASE loPrng
    RELEASE loEcc
    CANCEL
ENDIF

lcEcJwkStr = loEcKey.GetJwk()
loJson.Load(lcEcJwkStr)
? loJson.Emit()

RELEASE loEcKey

* Sample EC JWK Key:
* { 
*   "kty": "EC",
*   "crv": "P-256",
*   "x": "tDeeYABgKEAbWicYPCEEI8sP4SRIhHKcHDW7VqrB4LA",
*   "y": "J08HOoIZ0rX2Me3bNFZUltfxIk1Hrc8FsLu8VaSxsMI",
*   "d": "-bqt1T0wNAN8sP5ruycQZRVlMlt3V_dSwlJ60xAX5io"
* }

* ----------------------------------------------
* Octet sequence keys are intended for representing secret keys, such as HMAC keys and AES keys.

* We'll use crypt to generate a random UUID..
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Crypt2')
loCrypt = CreateObject('Chilkat.Crypt2')

* AES and HMAC keys are simply random arrays of bytes
* For these, we can just build the JSON directly,
* with the help of the PRNG object.

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJwkHmac = CreateObject('Chilkat.JsonObject')
loJwkHmac.EmitCompact = 0

* Generate a 256-bit HMAK key (32 bytes)
loJwkHmac.AppendString("kty","oct")
* Give the key an optional ID, which can be anything, even strings as simple as "1", "2", etc.
loJwkHmac.AppendString("kid",loCrypt.GenerateUuid())
* Indicate the intended key alg (optional)
loJwkHmac.AppendString("alg","HS256")
* Generate the actual key bytes
loJwkHmac.AppendString("k",loPrng.GenRandom(32,"base64url"))

? loJwkHmac.Emit()

* Sample HMAC-256 JWK:

* { 
*   "kty": "oct",
*   "kid": "06c2515d-41fb-e436-e405-3abb361f5f7a",
*   "alg": "HS256",
*   "k": "wR32w7yiMe5Lhb1vkW2koBpoMxpXTFYuxOYCCIEKjdE"
* }

* ----------------------------------------------
* Now generate a 192-bit (24 byte) key that could be used with AES192GCM

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJwkAes = CreateObject('Chilkat.JsonObject')
loJwkAes.EmitCompact = 0

loJwkAes.AppendString("kty","oct")
loJwkAes.AppendString("kid","2")
loJwkAes.AppendString("k",loPrng.GenRandom(24,"base64url"))

? loJwkAes.Emit()

* Sample AES key:
* { 
*   "kty": "oct",
*   "kid": "2",
*   "k": "akAkq-L_ZTZ6-tEIhDUMtU2ENhsEgL-p"
* }

RELEASE loRsa
RELEASE loJson
RELEASE loPrng
RELEASE loEcc
RELEASE loCrypt
RELEASE loJwkHmac
RELEASE loJwkAes