Created
February 18, 2019 22:09
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| // | |
| // mini_asn1_der.swift | |
| // miniasn1 | |
| // | |
| // Created by Ales Teska on 18.2.19. | |
| // Copyright © 2019 TeskaLabs. All rights reserved. | |
| // | |
| import Foundation | |
| func asn1_int_to_bytes(x: UInt) -> [UInt8] { | |
| var l = x | |
| var d:[UInt8] = [] | |
| while (l > 0) { | |
| d.append(UInt8(l & 0xFF)) | |
| l = l >> 8 | |
| } | |
| return d | |
| } | |
| func asn1_il(tag: UInt8, length: UInt) -> [UInt8] { | |
| if (length < 128) { | |
| return [tag, UInt8(length)] | |
| } | |
| let d = asn1_int_to_bytes(x:length) | |
| return [tag, 0x80 | UInt8(d.count)] + d | |
| } | |
| func asn1_SEQUENCE(elements: [[UInt8]?], implicit_tagging: Bool = true) -> [UInt8] { | |
| var d:[UInt8] = [] | |
| var n: UInt8 = 0 | |
| for e:[UInt8]? in elements { | |
| guard (e != nil) else { | |
| n += 1 | |
| continue | |
| } | |
| var identifier: UInt8 = e![0] | |
| if implicit_tagging { | |
| let e0 = e![0] | |
| if (((e0 & 0x1F) == 0x10) || ((e0 & 0x1F) == 0x11) || (e0 == 0xA0)) { | |
| // the element is constructed | |
| identifier = 0xA0 | |
| } else { | |
| // the element is primitive | |
| identifier = 0x80 | |
| } | |
| } | |
| else { | |
| identifier = e![0] | |
| } | |
| d.append(identifier + n) | |
| d += e![1..<e!.count] | |
| n += 1 | |
| } | |
| return asn1_il(tag:0x30, length:UInt(d.count)) + d | |
| } | |
| func asn1_SEQUENCE_OF(elements: [[UInt8]?], implicit_tagging: Bool = true) -> [UInt8] { | |
| return asn1_SEQUENCE(elements: elements, implicit_tagging: false) | |
| } | |
| func asn1_INTEGER(value: UInt) -> [UInt8] { | |
| // TODO: Support for negative numbers | |
| if (value == 0) { | |
| return asn1_il(tag: 0x02, length: 1) + [0] | |
| } | |
| var b = asn1_int_to_bytes(x: value) | |
| if (b[0] & 0x80 == 0x80){ | |
| b.insert(0, at: 0) | |
| } | |
| return asn1_il(tag: 0x02, length: UInt(b.count)) + b | |
| } | |
| func asn1_OCTEC_STRING(value: Data) -> [UInt8] { | |
| return asn1_il(tag:0x04, length:UInt(value.count)) + value | |
| } | |
| func asn1_IA5STRING(value: String) -> [UInt8] { | |
| let b = value.data(using: .ascii)! | |
| return asn1_il(tag:0x16, length:UInt(b.count)) + b | |
| } | |
| func asn1_BITSTRING(value: Data) -> [UInt8] { | |
| return asn1_il(tag:0x03, length:UInt(value.count)+1) + [0] + value | |
| } | |
| func asn1_UTF8String(value: String) -> [UInt8] { | |
| let b = value.data(using: .utf8)! | |
| return asn1_il(tag:12, length:UInt(b.count)) + b | |
| } |
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