/
DataRSAPublicKey.swift
62 lines (52 loc) · 2.13 KB
/
DataRSAPublicKey.swift
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
//
// DataRSAPublicKey.swift
// JOSESwift
//
// Created by Daniel Egger on 06.02.18.
//
// ---------------------------------------------------------------------------
// Copyright 2019 Airside Mobile Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ---------------------------------------------------------------------------
//
import Foundation
extension Data: ExpressibleAsRSAPublicKeyComponents {
public static func representing(rsaPublicKeyComponents components: RSAPublicKeyComponents) throws -> Data {
var modulusBytes = [UInt8](components.modulus)
let exponentBytes = [UInt8](components.exponent)
// Ensure the modulus is prefixed with 0x00.
if let prefix = modulusBytes.first, prefix != 0x00 {
modulusBytes.insert(0x00, at: 0)
}
let modulusEncoded = modulusBytes.encode(as: .integer)
let exponentEncoded = exponentBytes.encode(as: .integer)
let sequenceEncoded = (modulusEncoded + exponentEncoded).encode(as: .sequence)
return Data(sequenceEncoded)
}
public func rsaPublicKeyComponents() throws -> RSAPublicKeyComponents {
let publicKeyBytes = [UInt8](self)
let sequence = try publicKeyBytes.read(.sequence)
var modulus = try sequence.read(.integer)
let exponent = try sequence.skip(.integer).read(.integer)
// Remove potential leading zero byte.
// See https://tools.ietf.org/html/rfc7518#section-6.3.1.1.
if modulus.first == 0x00 {
modulus = Array(modulus.dropFirst())
}
return (
Data(modulus),
Data(exponent)
)
}
}