76 lines
4.1 KiB
Swift
76 lines
4.1 KiB
Swift
import CryptoSwift
|
|
import PromiseKit
|
|
import SessionUtilitiesKit
|
|
|
|
internal extension OnionRequestAPI {
|
|
|
|
static func encode(ciphertext: Data, json: JSON) throws -> Data {
|
|
// The encoding of V2 onion requests looks like: | 4 bytes: size N of ciphertext | N bytes: ciphertext | json as utf8 |
|
|
guard JSONSerialization.isValidJSONObject(json) else { throw HTTP.Error.invalidJSON }
|
|
let jsonAsData = try JSONSerialization.data(withJSONObject: json, options: [ .fragmentsAllowed ])
|
|
let ciphertextSize = Int32(ciphertext.count).littleEndian
|
|
let ciphertextSizeAsData = withUnsafePointer(to: ciphertextSize) { Data(bytes: $0, count: MemoryLayout<Int32>.size) }
|
|
return ciphertextSizeAsData + ciphertext + jsonAsData
|
|
}
|
|
|
|
/// Encrypts `payload` for `destination` and returns the result. Use this to build the core of an onion request.
|
|
static func encrypt(_ payload: JSON, for destination: Destination) -> Promise<AESGCM.EncryptionResult> {
|
|
let (promise, seal) = Promise<AESGCM.EncryptionResult>.pending()
|
|
DispatchQueue.global(qos: .userInitiated).async {
|
|
do {
|
|
guard JSONSerialization.isValidJSONObject(payload) else { return seal.reject(HTTP.Error.invalidJSON) }
|
|
// Wrapping isn't needed for file server or open group onion requests
|
|
switch destination {
|
|
case .snode(let snode):
|
|
let snodeX25519PublicKey = snode.publicKeySet.x25519Key
|
|
let payloadAsData = try JSONSerialization.data(withJSONObject: payload, options: [ .fragmentsAllowed ])
|
|
let plaintext = try encode(ciphertext: payloadAsData, json: [ "headers" : "" ])
|
|
let result = try AESGCM.encrypt(plaintext, for: snodeX25519PublicKey)
|
|
seal.fulfill(result)
|
|
case .server(_, _, let serverX25519PublicKey, _, _):
|
|
let plaintext = try JSONSerialization.data(withJSONObject: payload, options: [ .fragmentsAllowed ])
|
|
let result = try AESGCM.encrypt(plaintext, for: serverX25519PublicKey)
|
|
seal.fulfill(result)
|
|
}
|
|
} catch (let error) {
|
|
seal.reject(error)
|
|
}
|
|
}
|
|
return promise
|
|
}
|
|
|
|
/// Encrypts the previous encryption result (i.e. that of the hop after this one) for this hop. Use this to build the layers of an onion request.
|
|
static func encryptHop(from lhs: Destination, to rhs: Destination, using previousEncryptionResult: AESGCM.EncryptionResult) -> Promise<AESGCM.EncryptionResult> {
|
|
let (promise, seal) = Promise<AESGCM.EncryptionResult>.pending()
|
|
DispatchQueue.global(qos: .userInitiated).async {
|
|
var parameters: JSON
|
|
switch rhs {
|
|
case .snode(let snode):
|
|
let snodeED25519PublicKey = snode.publicKeySet.ed25519Key
|
|
parameters = [ "destination" : snodeED25519PublicKey ]
|
|
case .server(let host, let target, _, let scheme, let port):
|
|
let scheme = scheme ?? "https"
|
|
let port = port ?? (scheme == "https" ? 443 : 80)
|
|
parameters = [ "host" : host, "target" : target, "method" : "POST", "protocol" : scheme, "port" : port ]
|
|
}
|
|
parameters["ephemeral_key"] = previousEncryptionResult.ephemeralPublicKey.toHexString()
|
|
let x25519PublicKey: String
|
|
switch lhs {
|
|
case .snode(let snode):
|
|
let snodeX25519PublicKey = snode.publicKeySet.x25519Key
|
|
x25519PublicKey = snodeX25519PublicKey
|
|
case .server(_, _, let serverX25519PublicKey, _, _):
|
|
x25519PublicKey = serverX25519PublicKey
|
|
}
|
|
do {
|
|
let plaintext = try encode(ciphertext: previousEncryptionResult.ciphertext, json: parameters)
|
|
let result = try AESGCM.encrypt(plaintext, for: x25519PublicKey)
|
|
seal.fulfill(result)
|
|
} catch (let error) {
|
|
seal.reject(error)
|
|
}
|
|
}
|
|
return promise
|
|
}
|
|
}
|