|
1 | | -import { |
2 | | - ASN1Construction, |
3 | | - ASN1TagClass, |
4 | | - ASN1UniversalType, |
5 | | - DERElement, |
6 | | - ObjectIdentifier, |
7 | | -} from 'asn1-ts' |
8 | | - |
9 | | -/** |
10 | | - * Represents an ASN.1 AlgorithmIdentifier structure commonly used in cryptographic protocols. |
11 | | - * This class handles the construction and DER encoding of an algorithm identifier, which typically |
12 | | - * consists of an algorithm OID and optional parameters. |
13 | | - */ |
14 | | -class AlgorithmIdentifier { |
15 | | - public algorithm: ObjectIdentifier |
16 | | - public parameters: null |
17 | | - |
18 | | - /** |
19 | | - * Creates an instance of AlgorithmIdentifier. |
20 | | - * |
21 | | - * @param algorithm The ObjectIdentifier of the algorithm. |
22 | | - * @param parameters The parameters of the algorithm, generally null in many cryptographic uses. |
23 | | - */ |
24 | | - constructor(algorithm: ObjectIdentifier, parameters: null = null) { |
25 | | - this.algorithm = algorithm |
26 | | - this.parameters = parameters |
27 | | - } |
28 | | - |
29 | | - /** |
30 | | - * Encodes this AlgorithmIdentifier into its DER (Distinguished Encoding Rules) format. |
31 | | - * |
32 | | - * @returns Uint8Array containing the DER encoded bytes of the AlgorithmIdentifier. |
33 | | - */ |
34 | | - public toDER(): Uint8Array { |
35 | | - const sequenceElement = new DERElement( |
36 | | - ASN1TagClass.universal, |
37 | | - ASN1Construction.constructed, |
38 | | - ASN1UniversalType.sequence, |
39 | | - ) |
40 | | - |
41 | | - const oidElement = new DERElement( |
42 | | - ASN1TagClass.universal, |
43 | | - ASN1Construction.primitive, |
44 | | - ASN1UniversalType.objectIdentifier, |
45 | | - ) |
46 | | - oidElement.objectIdentifier = this.algorithm |
47 | | - |
48 | | - const nullElement = new DERElement( |
49 | | - ASN1TagClass.universal, |
50 | | - ASN1Construction.primitive, |
51 | | - ASN1UniversalType.nill, |
52 | | - ) |
53 | | - |
54 | | - sequenceElement.sequence = [oidElement, nullElement] |
55 | | - |
56 | | - return sequenceElement.toBytes() |
57 | | - } |
58 | | -} |
| 1 | +import { ObjectIdentifier } from 'asn1js' |
59 | 2 |
|
60 | 3 | /** |
61 | 4 | * Encodes a given string representation of an OID into its DER format. |
62 | 5 | * This function is specifically used to encode signature algorithm OIDs. |
63 | 6 | * |
64 | 7 | * @param oid The string representation of the ObjectIdentifier to be encoded. |
65 | | - * @returns Uint8Array containing the DER encoded OID. |
66 | | - * @example |
67 | | - * ```ts |
68 | | - * const oid = '1.2.840.113549.1.1.11' // Example OID for SHA-256 with RSA Encryption |
69 | | - * const derEncodedOID = derEncodeSignatureAlgorithmOID(oid) |
70 | | - * console.log(new Uint8Array(derEncodedOID)) // Logs the DER encoded bytes |
71 | | - * ``` |
| 8 | + * @returns Uint8Array containing the DER encoded OID along with NULL params of X.509 signature algorithm. |
72 | 9 | */ |
73 | 10 | export function derEncodeSignatureAlgorithmOID(oid: string): Uint8Array { |
74 | | - const numbers = oid.split('.').map((n) => parseInt(n, 10)) // Convert the string parts to numbers |
75 | | - const algorithmIdentifier = new AlgorithmIdentifier(new ObjectIdentifier(numbers)) |
76 | | - return algorithmIdentifier.toDER() |
| 11 | + const objectIdentifier = new ObjectIdentifier({ value: oid }) |
| 12 | + const berArrayBuffer = objectIdentifier.toBER(false) |
| 13 | + |
| 14 | + // Typically, in X.509, the algorithm identifier is followed by parameters; for many algorithms, this is just NULL. |
| 15 | + const nullParameter = [0x05, 0x00] // DER encoding for NULL |
| 16 | + |
| 17 | + // Calculate the total length including OID and NULL parameter |
| 18 | + const totalLength = berArrayBuffer.byteLength + nullParameter.length |
| 19 | + |
| 20 | + const sequenceHeader = [0x30, totalLength] // 0x30 is the DER tag for SEQUENCE |
| 21 | + |
| 22 | + return new Uint8Array([...sequenceHeader, ...new Uint8Array(berArrayBuffer), ...nullParameter]) |
77 | 23 | } |
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