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Xbase++ Requires Chilkat v11.0.0+

JWE using RSAES-OAEP and AES GCM

See more JSON Web Encryption (JWE) Examples

This example duplicates the example A.1 in RFC 7516 for JSON Web Encryption (JWE).

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LOCAL nSuccess
LOCAL cPlaintext
LOCAL oJweProtHdr
LOCAL oSbJwk
LOCAL oRsaPrivKey
LOCAL oRsaPubKey
LOCAL oJwe
LOCAL cStrJwe
LOCAL oJwe2
LOCAL cOriginalPlaintext
LOCAL oSbJwe

nSuccess := 0

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

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

cPlaintext := "The true sign of intelligence is not knowledge but imagination."

//  ---------------------------------
//  A.1.1 JOSE Header
//  First build the JWE Protected Header.
//  We want to build this: {"alg":"RSA-OAEP","enc":"A256GCM"}
oJweProtHdr := CreateObject("Chilkat.JsonObject")
oJweProtHdr:AppendString("alg", "RSA-OAEP")
oJweProtHdr:AppendString("enc", "A256GCM")
? "JWE Protected Header: " + oJweProtHdr:Emit()
? "--"

//  ---------------------------------
//  A.1.2 Content Encryption Key
//  Note: Chilkat automatically generates the random CEK internally.
//  The application does not need to explicitly take this step.

//  ---------------------------------
//  A.1.3.  Key Encryption
//  The application should load an RSA private key from any format.
//  However, the application does not need to explicitly construct the JWE Encrypted Key.
//  Chilkat automatically does it internally.
//  The design of the Chilkat JWE API is to allow the application to create the JWE
//  after specifying the inputs.  (This is in contrast to forcing the application developer
//  to painstakingly go through each step of the JWE construction process.)

//  The specific RSA key used in the A.1 example is the following JWK:
oSbJwk := CreateObject("Chilkat.StringBuilder")
oSbJwk:Append('{"kty": "RSA",')
oSbJwk:Append('"n": "oahUIoWw0K0usKNuOR6H4wkf4oBUXHTxRvgb48E-BVvxkeDNjbC4he8rUW')
oSbJwk:Append("cJoZmds2h7M70imEVhRU5djINXtqllXI4DFqcI1DgjT9LewND8MW2Krf3S")
oSbJwk:Append("psk_ZkoFnilakGygTwpZ3uesH-PFABNIUYpOiN15dsQRkgr0vEhxN92i2a")
oSbJwk:Append("sbOenSZeyaxziK72UwxrrKoExv6kc5twXTq4h-QChLOln0_mtUZwfsRaMS")
oSbJwk:Append("tPs6mS6XrgxnxbWhojf663tuEQueGC-FCMfra36C9knDFGzKsNa7LZK2dj")
oSbJwk:Append('YgyD3JR_MB_4NUJW_TqOQtwHYbxevoJArm-L5StowjzGy-_bq6Gw",')
oSbJwk:Append('"e": "AQAB",')
oSbJwk:Append('"d": "kLdtIj6GbDks_ApCSTYQtelcNttlKiOyPzMrXHeI-yk1F7-kpDxY4-WY5N')
oSbJwk:Append("WV5KntaEeXS1j82E375xxhWMHXyvjYecPT9fpwR_M9gV8n9Hrh2anTpTD9")
oSbJwk:Append("3Dt62ypW3yDsJzBnTnrYu1iwWRgBKrEYY46qAZIrA2xAwnm2X7uGR1hghk")
oSbJwk:Append("qDp0Vqj3kbSCz1XyfCs6_LehBwtxHIyh8Ripy40p24moOAbgxVw3rxT_vl")
oSbJwk:Append("t3UVe4WO3JkJOzlpUf-KTVI2Ptgm-dARxTEtE-id-4OJr0h-K-VFs3VSnd")
oSbJwk:Append('VTIznSxfyrj8ILL6MG_Uv8YAu7VILSB3lOW085-4qE3DzgrTjgyQ",')
oSbJwk:Append('"p": "1r52Xk46c-LsfB5P442p7atdPUrxQSy4mti_tZI3Mgf2EuFVbUoDBvaRQ-')
oSbJwk:Append("SWxkbkmoEzL7JXroSBjSrK3YIQgYdMgyAEPTPjXv_hI2_1eTSPVZfzL0lf")
oSbJwk:Append('fNn03IXqWF5MDFuoUYE0hzb2vhrlN_rKrbfDIwUbTrjjgieRbwC6Cl0",')
oSbJwk:Append('"q": "wLb35x7hmQWZsWJmB_vle87ihgZ19S8lBEROLIsZG4ayZVe9Hi9gDVCOBm')
oSbJwk:Append("UDdaDYVTSNx_8Fyw1YYa9XGrGnDew00J28cRUoeBB_jKI1oma0Orv1T9aX")
oSbJwk:Append('IWxKwd4gvxFImOWr3QRL9KEBRzk2RatUBnmDZJTIAfwTs0g68UZHvtc",')
oSbJwk:Append('"dp": "ZK-YwE7diUh0qR1tR7w8WHtolDx3MZ_OTowiFvgfeQ3SiresXjm9gZ5KL')
oSbJwk:Append("hMXvo-uz-KUJWDxS5pFQ_M0evdo1dKiRTjVw_x4NyqyXPM5nULPkcpU827")
oSbJwk:Append('rnpZzAJKpdhWAgqrXGKAECQH0Xt4taznjnd_zVpAmZZq60WPMBMfKcuE",')
oSbJwk:Append('"dq": "Dq0gfgJ1DdFGXiLvQEZnuKEN0UUmsJBxkjydc3j4ZYdBiMRAy86x0vHCj')
oSbJwk:Append("ywcMlYYg4yoC4YZa9hNVcsjqA3FeiL19rk8g6Qn29Tt0cj8qqyFpz9vNDB")
oSbJwk:Append('UfCAiJVeESOjJDZPYHdHY8v1b-o-Z2X5tvLx-TCekf7oxyeKDUqKWjis",')
oSbJwk:Append('"qi": "VIMpMYbPf47dT1w_zDUXfPimsSegnMOA1zTaX7aGk_8urY6R8-ZW1FxU7')
oSbJwk:Append("AlWAyLWybqq6t16VFd7hQd0y6flUK4SlOydB61gwanOsXGOAOv82cHq0E3")
oSbJwk:Append('eL4HrtZkUuKvnPrMnsUUFlfUdybVzxyjz9JF_XyaY14ardLSjf4L_FNY"}')

//  Load this JWK into a Chilkat private key object.
oRsaPrivKey := CreateObject("Chilkat.PrivateKey")
nSuccess := oRsaPrivKey:LoadJwk(oSbJwk:GetAsString())
IF (nSuccess == 0)
    ? oRsaPrivKey:LastErrorText
    oJweProtHdr:destroy()
    oSbJwk:destroy()
    oRsaPrivKey:destroy()
    RETURN
ENDIF

//  The public key is used to encrypt (i.e. create the JWE), 
//  and the private key is used to decrypt.
//  The RSA public key is simply a subset of the private key.  The RSA public key
//  is composed of the "n" and "e" members shown above.  These are also known as the
//  modulus and exponent.
//  We can simply get the public key object from the private key object
oRsaPubKey := CreateObject("Chilkat.PublicKey")
oRsaPrivKey:ToPublicKey(oRsaPubKey)

//  ---------------------------------
//  A.1.4.  Initialization Vector
//  Chilkat automatically generates the necessary random IV internally.  
//  The application does not need to do this explicitly.

//  ---------------------------------
//  A.1.5.  Additional Authenticated Data
//  The Additional Authenticated Data encryption parameter is
//  ASCII(BASE64URL(UTF8(JWE Protected Header))).
//  Again, Chilkat automatically takes care of this internally.
//  The application does not need to explicitly take this step.

//  ---------------------------------
//  A.1.6.  Content Encryption
//  Again... this step is handled by Chilkat internally.

//  ---------------------------------
//  A.1.7.  Complete Representation
//  The application need only call the Encrypt, EncryptSb, or EncryptBd method
//  return the fully assembled JWE.  
//  The final representation in the Compact Serialization 
//  is the string BASE64URL(UTF8(JWE Protected Header)) || '.' ||
//  BASE64URL(JWE Encrypted Key) || '.' || BASE64URL(JWE Initialization
//  Vector) || '.' || BASE64URL(JWE Ciphertext) || '.' || BASE64URL(JWE
//  Authentication Tag).

oJwe := CreateObject("Chilkat.Jwe")
oJwe:SetProtectedHeader(oJweProtHdr)
oJwe:SetPublicKey(0, oRsaPubKey)

cStrJwe := oJwe:Encrypt(cPlaintext, "utf-8")
IF (oJwe:LastMethodSuccess == 0)
    ? oJwe:LastErrorText
    oJweProtHdr:destroy()
    oSbJwk:destroy()
    oRsaPrivKey:destroy()
    oRsaPubKey:destroy()
    oJwe:destroy()
    RETURN
ENDIF

//  Note: The RSA OAEP algorithm uses random padding bytes internally.
//  Therefore, the results will appear different each time -- even if the
//  identical plaintext is encrypted with the identical RSA key. 
//  (Do not expect the appearance of the results to be the same as what
//  is published in the RFC.  However, what is published in the RFC *should*
//  be decryptable using the code that follows.)
? cStrJwe

//  Let's decrypt the JWE that was just produced.
//  Do the following to decrypt a JWE:
//  1) Load the JWE.
//  2) Set the private key for decryption.
//  3) Decrypt.
oJwe2 := CreateObject("Chilkat.Jwe")
nSuccess := oJwe2:LoadJwe(cStrJwe)
IF (nSuccess == 0)
    ? oJwe2:LastErrorText
    oJweProtHdr:destroy()
    oSbJwk:destroy()
    oRsaPrivKey:destroy()
    oRsaPubKey:destroy()
    oJwe:destroy()
    oJwe2:destroy()
    RETURN
ENDIF

//  Provide the RSA private key for decryption.
//  (The JWE was encrypted for a single recipient at index 0.)
oJwe2:SetPrivateKey(0, oRsaPrivKey)

//  Decrypt.
cOriginalPlaintext := oJwe2:Decrypt(0, "utf-8")
IF (oJwe2:LastMethodSuccess == 0)
    ? oJwe2:LastErrorText
    oJweProtHdr:destroy()
    oSbJwk:destroy()
    oRsaPrivKey:destroy()
    oRsaPubKey:destroy()
    oJwe:destroy()
    oJwe2:destroy()
    RETURN
ENDIF

? "original text: "
? cOriginalPlaintext

//  ---------------------------------------------------------------------------------
//  It should also be possible to decrypt the JWE as shown in RFC 7516, Appendix A.1.7
//  because it was produced using the same RSA key.

oSbJwe := CreateObject("Chilkat.StringBuilder")
oSbJwe:Append("eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ.")
oSbJwe:Append("OKOawDo13gRp2ojaHV7LFpZcgV7T6DVZKTyKOMTYUmKoTCVJRgckCL9kiMT03JGe")
oSbJwe:Append("ipsEdY3mx_etLbbWSrFr05kLzcSr4qKAq7YN7e9jwQRb23nfa6c9d-StnImGyFDb")
oSbJwe:Append("Sv04uVuxIp5Zms1gNxKKK2Da14B8S4rzVRltdYwam_lDp5XnZAYpQdb76FdIKLaV")
oSbJwe:Append("mqgfwX7XWRxv2322i-vDxRfqNzo_tETKzpVLzfiwQyeyPGLBIO56YJ7eObdv0je8")
oSbJwe:Append("1860ppamavo35UgoRdbYaBcoh9QcfylQr66oc6vFWXRcZ_ZT2LawVCWTIy3brGPi")
oSbJwe:Append("6UklfCpIMfIjf7iGdXKHzg.")
oSbJwe:Append("48V1_ALb6US04U3b.")
oSbJwe:Append("5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji")
oSbJwe:Append("SdiwkIr3ajwQzaBtQD_A.")
oSbJwe:Append("XFBoMYUZodetZdvTiFvSkQ")

nSuccess := oJwe2:LoadJweSb(oSbJwe)
IF (nSuccess == 0)
    ? oJwe2:LastErrorText
    oJweProtHdr:destroy()
    oSbJwk:destroy()
    oRsaPrivKey:destroy()
    oRsaPubKey:destroy()
    oJwe:destroy()
    oJwe2:destroy()
    oSbJwe:destroy()
    RETURN
ENDIF

//  Provide the RSA private key for decryption.
oJwe2:SetPrivateKey(0, oRsaPrivKey)

//  Decrypt.
cOriginalPlaintext := oJwe2:Decrypt(0, "utf-8")
IF (oJwe2:LastMethodSuccess == 0)
    ? oJwe2:LastErrorText
    oJweProtHdr:destroy()
    oSbJwk:destroy()
    oRsaPrivKey:destroy()
    oRsaPubKey:destroy()
    oJwe:destroy()
    oJwe2:destroy()
    oSbJwe:destroy()
    RETURN
ENDIF

? cOriginalPlaintext

oJweProtHdr:destroy()
oSbJwk:destroy()
oRsaPrivKey:destroy()
oRsaPubKey:destroy()
oJwe:destroy()
oJwe2:destroy()
oSbJwe:destroy()