Swift
Swift
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).Chilkat Swift Downloads
func chilkatTest() {
var success: Bool = false
// 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.
var plaintext: String? = "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"}
let jweProtHdr = CkoJsonObject()!
jweProtHdr.appendString(name: "alg", value: "RSA-OAEP")
jweProtHdr.appendString(name: "enc", value: "A256GCM")
print("JWE Protected Header: \(jweProtHdr.emit()!)")
print("--")
// ---------------------------------
// 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:
let sbJwk = CkoStringBuilder()!
sbJwk.append(value: "{\"kty\": \"RSA\",")
sbJwk.append(value: "\"n\": \"oahUIoWw0K0usKNuOR6H4wkf4oBUXHTxRvgb48E-BVvxkeDNjbC4he8rUW")
sbJwk.append(value: "cJoZmds2h7M70imEVhRU5djINXtqllXI4DFqcI1DgjT9LewND8MW2Krf3S")
sbJwk.append(value: "psk_ZkoFnilakGygTwpZ3uesH-PFABNIUYpOiN15dsQRkgr0vEhxN92i2a")
sbJwk.append(value: "sbOenSZeyaxziK72UwxrrKoExv6kc5twXTq4h-QChLOln0_mtUZwfsRaMS")
sbJwk.append(value: "tPs6mS6XrgxnxbWhojf663tuEQueGC-FCMfra36C9knDFGzKsNa7LZK2dj")
sbJwk.append(value: "YgyD3JR_MB_4NUJW_TqOQtwHYbxevoJArm-L5StowjzGy-_bq6Gw\",")
sbJwk.append(value: "\"e\": \"AQAB\",")
sbJwk.append(value: "\"d\": \"kLdtIj6GbDks_ApCSTYQtelcNttlKiOyPzMrXHeI-yk1F7-kpDxY4-WY5N")
sbJwk.append(value: "WV5KntaEeXS1j82E375xxhWMHXyvjYecPT9fpwR_M9gV8n9Hrh2anTpTD9")
sbJwk.append(value: "3Dt62ypW3yDsJzBnTnrYu1iwWRgBKrEYY46qAZIrA2xAwnm2X7uGR1hghk")
sbJwk.append(value: "qDp0Vqj3kbSCz1XyfCs6_LehBwtxHIyh8Ripy40p24moOAbgxVw3rxT_vl")
sbJwk.append(value: "t3UVe4WO3JkJOzlpUf-KTVI2Ptgm-dARxTEtE-id-4OJr0h-K-VFs3VSnd")
sbJwk.append(value: "VTIznSxfyrj8ILL6MG_Uv8YAu7VILSB3lOW085-4qE3DzgrTjgyQ\",")
sbJwk.append(value: "\"p\": \"1r52Xk46c-LsfB5P442p7atdPUrxQSy4mti_tZI3Mgf2EuFVbUoDBvaRQ-")
sbJwk.append(value: "SWxkbkmoEzL7JXroSBjSrK3YIQgYdMgyAEPTPjXv_hI2_1eTSPVZfzL0lf")
sbJwk.append(value: "fNn03IXqWF5MDFuoUYE0hzb2vhrlN_rKrbfDIwUbTrjjgieRbwC6Cl0\",")
sbJwk.append(value: "\"q\": \"wLb35x7hmQWZsWJmB_vle87ihgZ19S8lBEROLIsZG4ayZVe9Hi9gDVCOBm")
sbJwk.append(value: "UDdaDYVTSNx_8Fyw1YYa9XGrGnDew00J28cRUoeBB_jKI1oma0Orv1T9aX")
sbJwk.append(value: "IWxKwd4gvxFImOWr3QRL9KEBRzk2RatUBnmDZJTIAfwTs0g68UZHvtc\",")
sbJwk.append(value: "\"dp\": \"ZK-YwE7diUh0qR1tR7w8WHtolDx3MZ_OTowiFvgfeQ3SiresXjm9gZ5KL")
sbJwk.append(value: "hMXvo-uz-KUJWDxS5pFQ_M0evdo1dKiRTjVw_x4NyqyXPM5nULPkcpU827")
sbJwk.append(value: "rnpZzAJKpdhWAgqrXGKAECQH0Xt4taznjnd_zVpAmZZq60WPMBMfKcuE\",")
sbJwk.append(value: "\"dq\": \"Dq0gfgJ1DdFGXiLvQEZnuKEN0UUmsJBxkjydc3j4ZYdBiMRAy86x0vHCj")
sbJwk.append(value: "ywcMlYYg4yoC4YZa9hNVcsjqA3FeiL19rk8g6Qn29Tt0cj8qqyFpz9vNDB")
sbJwk.append(value: "UfCAiJVeESOjJDZPYHdHY8v1b-o-Z2X5tvLx-TCekf7oxyeKDUqKWjis\",")
sbJwk.append(value: "\"qi\": \"VIMpMYbPf47dT1w_zDUXfPimsSegnMOA1zTaX7aGk_8urY6R8-ZW1FxU7")
sbJwk.append(value: "AlWAyLWybqq6t16VFd7hQd0y6flUK4SlOydB61gwanOsXGOAOv82cHq0E3")
sbJwk.append(value: "eL4HrtZkUuKvnPrMnsUUFlfUdybVzxyjz9JF_XyaY14ardLSjf4L_FNY\"}")
// Load this JWK into a Chilkat private key object.
let rsaPrivKey = CkoPrivateKey()!
success = rsaPrivKey.loadJwk(jsonStr: sbJwk.getAsString())
if success == false {
print("\(rsaPrivKey.lastErrorText!)")
return
}
// 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
let rsaPubKey = CkoPublicKey()!
rsaPrivKey.toPublicKey(pubKey: rsaPubKey)
// ---------------------------------
// 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).
let jwe = CkoJwe()!
jwe.setProtectedHeader(json: jweProtHdr)
jwe.setPublicKey(index: 0, pubKey: rsaPubKey)
var strJwe: String? = jwe.encrypt(content: plaintext, charset: "utf-8")
if jwe.lastMethodSuccess == false {
print("\(jwe.lastErrorText!)")
return
}
// 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.)
print("\(strJwe!)")
// 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.
let jwe2 = CkoJwe()!
success = jwe2.load(jwe: strJwe)
if success == false {
print("\(jwe2.lastErrorText!)")
return
}
// Provide the RSA private key for decryption.
// (The JWE was encrypted for a single recipient at index 0.)
jwe2.setPrivateKey(index: 0, privKey: rsaPrivKey)
// Decrypt.
var originalPlaintext: String? = jwe2.decrypt(index: 0, charset: "utf-8")
if jwe2.lastMethodSuccess == false {
print("\(jwe2.lastErrorText!)")
return
}
print("original text: ")
print("\(originalPlaintext!)")
// ---------------------------------------------------------------------------------
// 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.
let sbJwe = CkoStringBuilder()!
sbJwe.append(value: "eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ.")
sbJwe.append(value: "OKOawDo13gRp2ojaHV7LFpZcgV7T6DVZKTyKOMTYUmKoTCVJRgckCL9kiMT03JGe")
sbJwe.append(value: "ipsEdY3mx_etLbbWSrFr05kLzcSr4qKAq7YN7e9jwQRb23nfa6c9d-StnImGyFDb")
sbJwe.append(value: "Sv04uVuxIp5Zms1gNxKKK2Da14B8S4rzVRltdYwam_lDp5XnZAYpQdb76FdIKLaV")
sbJwe.append(value: "mqgfwX7XWRxv2322i-vDxRfqNzo_tETKzpVLzfiwQyeyPGLBIO56YJ7eObdv0je8")
sbJwe.append(value: "1860ppamavo35UgoRdbYaBcoh9QcfylQr66oc6vFWXRcZ_ZT2LawVCWTIy3brGPi")
sbJwe.append(value: "6UklfCpIMfIjf7iGdXKHzg.")
sbJwe.append(value: "48V1_ALb6US04U3b.")
sbJwe.append(value: "5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji")
sbJwe.append(value: "SdiwkIr3ajwQzaBtQD_A.")
sbJwe.append(value: "XFBoMYUZodetZdvTiFvSkQ")
success = jwe2.loadSb(sb: sbJwe)
if success == false {
print("\(jwe2.lastErrorText!)")
return
}
// Provide the RSA private key for decryption.
jwe2.setPrivateKey(index: 0, privKey: rsaPrivKey)
// Decrypt.
originalPlaintext = jwe2.decrypt(index: 0, charset: "utf-8")
if jwe2.lastMethodSuccess == false {
print("\(jwe2.lastErrorText!)")
return
}
print("\(originalPlaintext!)")
}