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
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
//===----------------------------------------------------------------------===//
//
// This source file is part of the SwiftCertificates open source project
//
// Copyright (c) 2022 Apple Inc. and the SwiftCertificates project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of SwiftCertificates project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
import SwiftASN1
/// Let's talk about OCSP.
///
/// We can provide the needed type definitions from RFC 6960 to construct BasicOCSPResponse:
///
/// ```
/// BasicOCSPResponse ::= SEQUENCE {
/// tbsResponseData ResponseData,
/// signatureAlgorithm AlgorithmIdentifier,
/// signature BIT STRING,
/// certs [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL }
///
/// ResponseData ::= SEQUENCE {
/// version [0] EXPLICIT Version DEFAULT v1,
/// responderID ResponderID,
/// producedAt GeneralizedTime,
/// responses SEQUENCE OF SingleResponse,
/// responseExtensions [1] EXPLICIT Extensions OPTIONAL }
///
/// ResponderID ::= CHOICE {
/// byName [1] Name,
/// byKey [2] KeyHash }
///
/// KeyHash ::= OCTET STRING -- SHA-1 hash of responder's public key
/// (excluding the tag and length fields)
///
/// SingleResponse ::= SEQUENCE {
/// certID CertID,
/// certStatus CertStatus,
/// thisUpdate GeneralizedTime,
/// nextUpdate [0] EXPLICIT GeneralizedTime OPTIONAL,
/// singleExtensions [1] EXPLICIT Extensions OPTIONAL }
///
/// CertStatus ::= CHOICE {
/// good [0] IMPLICIT NULL,
/// revoked [1] IMPLICIT RevokedInfo,
/// unknown [2] IMPLICIT UnknownInfo }
///
/// RevokedInfo ::= SEQUENCE {
/// revocationTime GeneralizedTime,
/// revocationReason [0] EXPLICIT CRLReason OPTIONAL }
///
/// UnknownInfo ::= NULL
///
/// Version ::= INTEGER { v1(0) }
///
/// CertID ::= SEQUENCE {
/// hashAlgorithm AlgorithmIdentifier,
/// issuerNameHash OCTET STRING,
/// issuerKeyHash OCTET STRING,
/// serialNumber CertificateSerialNumber }
/// ```
/// A Basic OCSP Response is laid out as follows:
///
/// ```
/// BasicOCSPResponse ::= SEQUENCE {
/// tbsResponseData ResponseData,
/// signatureAlgorithm AlgorithmIdentifier,
/// signature BIT STRING,
/// certs [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL }
/// ```
///
/// This type is generic because our different backends want to use different bignum representations.
struct BasicOCSPResponse: DERImplicitlyTaggable, Hashable {
static var defaultIdentifier: ASN1Identifier {
.sequence
}
var responseData: OCSPResponseData
var responseDataBytes: ArraySlice<UInt8>
var signatureAlgorithm: AlgorithmIdentifier
var signature: ASN1BitString
var certs: [Certificate]?
init(
responseData: OCSPResponseData,
responseDataBytes: ArraySlice<UInt8>,
signatureAlgorithm: AlgorithmIdentifier,
signature: ASN1BitString,
certs: [Certificate]?
) {
self.responseData = responseData
self.responseDataBytes = responseDataBytes
self.signatureAlgorithm = signatureAlgorithm
self.signature = signature
self.certs = certs
}
init(derEncoded rootNode: ASN1Node, withIdentifier identifier: ASN1Identifier) throws {
self = try DER.sequence(rootNode, identifier: identifier) { nodes in
guard let responseDataNode = nodes.next() else {
throw ASN1Error.invalidASN1Object(reason: "missing OCSP response data")
}
let responseData = try OCSPResponseData(derEncoded: responseDataNode)
let signatureAlgorithm = try AlgorithmIdentifier(derEncoded: &nodes)
let signature = try ASN1BitString(derEncoded: &nodes)
let certs = try DER.optionalExplicitlyTagged(&nodes, tagNumber: 0, tagClass: .contextSpecific) { node in
try DER.sequence(of: Certificate.self, identifier: .sequence, rootNode: node)
}
return .init(
responseData: responseData,
responseDataBytes: responseDataNode.encodedBytes,
signatureAlgorithm: signatureAlgorithm,
signature: signature,
certs: certs
)
}
}
func serialize(into coder: inout DER.Serializer, withIdentifier identifier: ASN1Identifier) throws {
try coder.appendConstructedNode(identifier: identifier) { coder in
coder.serializeRawBytes(self.responseDataBytes)
try coder.serialize(self.signatureAlgorithm)
try coder.serialize(self.signature)
if let certs {
try coder.serialize(explicitlyTaggedWithTagNumber: 0, tagClass: .contextSpecific) { coder in
try coder.serializeSequenceOf(certs)
}
}
}
}
}
enum ResponderID: DERParseable, DERSerializable, Hashable {
case byName(DistinguishedName)
/// SHA-1 hash of responder's public key (excluding the tag and length fields)
case byKey(ASN1OctetString)
private static let nameIdentifier = ASN1Identifier(tagWithNumber: 1, tagClass: .contextSpecific)
private static let keyIdentifier = ASN1Identifier(tagWithNumber: 2, tagClass: .contextSpecific)
init(derEncoded: ASN1Node) throws {
switch derEncoded.identifier {
case ResponderID.nameIdentifier:
guard case .constructed(let nodes) = derEncoded.content else {
throw ASN1Error.invalidASN1Object(reason: "ResponderID content must be constructed.")
}
var iterator = nodes.makeIterator()
guard let rootNode = iterator.next(), iterator.next() == nil else {
throw ASN1Error.invalidASN1Object(reason: "Invalid number of responder nodes.")
}
self = try .byName(.init(derEncoded: rootNode))
case ResponderID.keyIdentifier:
guard case .constructed(let nodes) = derEncoded.content else {
throw ASN1Error.invalidASN1Object(reason: "ResponderID content must be constructed")
}
var iterator = nodes.makeIterator()
guard let rootNode = iterator.next(), iterator.next() == nil else {
throw ASN1Error.invalidASN1Object(reason: "Invalid number of responder nodes")
}
self = try .byKey(.init(derEncoded: rootNode))
default:
throw ASN1Error.unexpectedFieldType(derEncoded.identifier)
}
}
func serialize(into coder: inout DER.Serializer) throws {
switch self {
case .byName(let name):
try coder.appendConstructedNode(identifier: ResponderID.nameIdentifier) { coder in
try name.serialize(into: &coder)
}
case .byKey(let key):
try coder.appendConstructedNode(identifier: ResponderID.keyIdentifier) { coder in
try key.serialize(into: &coder)
}
}
}
}
|
