1 files changed, 182 insertions, 0 deletions
diff --git a/comm/third_party/asn1js/src/internals/LocalLengthBlock.ts b/comm/third_party/asn1js/src/internals/LocalLengthBlock.ts
new file mode 100644
index 0000000000..a4c7940b02
--- /dev/null
+++ b/comm/third_party/asn1js/src/internals/LocalLengthBlock.ts
@@ -0,0 +1,182 @@
+import * as pvtsutils from "pvtsutils";
+import * as pvutils from "pvutils";
+import { IBerConvertible } from "../types";
+import { EMPTY_BUFFER } from "./constants";
+import { LocalBaseBlock, LocalBaseBlockJson } from "./LocalBaseBlock";
+import { checkBufferParams } from "./utils";
+
+export interface ILocalLengthBlock {
+  isIndefiniteForm: boolean;
+  longFormUsed: boolean;
+  length: number;
+}
+
+export interface LocalLengthBlockParams {
+  lenBlock?: Partial<ILocalLengthBlock>;
+}
+
+export interface LocalLengthBlockJson extends LocalBaseBlockJson, ILocalLengthBlock {
+  isIndefiniteForm: boolean;
+  longFormUsed: boolean;
+  length: number;
+}
+
+export class LocalLengthBlock extends LocalBaseBlock implements ILocalLengthBlock, IBerConvertible {
+
+  public static override NAME = "lengthBlock";
+
+  public isIndefiniteForm: boolean;
+  public longFormUsed: boolean;
+  public length: number;
+
+  constructor({
+    lenBlock = {},
+  }: LocalLengthBlockParams = {}) {
+    super();
+
+    this.isIndefiniteForm = lenBlock.isIndefiniteForm ?? false;
+    this.longFormUsed = lenBlock.longFormUsed ?? false;
+    this.length = lenBlock.length ?? 0;
+  }
+
+
+  public fromBER(inputBuffer: ArrayBuffer | Uint8Array, inputOffset: number, inputLength: number): number {
+    const view = pvtsutils.BufferSourceConverter.toUint8Array(inputBuffer);
+    // Basic check for parameters
+    if (!checkBufferParams(this, view, inputOffset, inputLength)) {
+      return -1;
+    }
+    //#region Getting Uint8Array from ArrayBuffer
+    const intBuffer = view.subarray(inputOffset, inputOffset + inputLength);
+    //#endregion
+    //#region Initial checks
+    if (intBuffer.length === 0) {
+      this.error = "Zero buffer length";
+
+      return -1;
+    }
+
+    if (intBuffer[0] === 0xFF) {
+      this.error = "Length block 0xFF is reserved by standard";
+
+      return -1;
+    }
+    //#endregion
+    //#region Check for length form type
+    this.isIndefiniteForm = intBuffer[0] === 0x80;
+    //#endregion
+    //#region Stop working in case of indefinite length form
+    if (this.isIndefiniteForm) {
+      this.blockLength = 1;
+
+      return (inputOffset + this.blockLength);
+    }
+    //#endregion
+    //#region Check is long form of length encoding using
+    this.longFormUsed = !!(intBuffer[0] & 0x80);
+    //#endregion
+    //#region Stop working in case of short form of length value
+    if (this.longFormUsed === false) {
+      this.length = (intBuffer[0]);
+      this.blockLength = 1;
+
+      return (inputOffset + this.blockLength);
+    }
+    //#endregion
+    //#region Calculate length value in case of long form
+    const count = intBuffer[0] & 0x7F;
+
+    if (count > 8) // Too big length value
+    {
+      this.error = "Too big integer";
+
+      return -1;
+    }
+
+    if ((count + 1) > intBuffer.length) {
+      this.error = "End of input reached before message was fully decoded";
+
+      return -1;
+    }
+
+    const lenOffset = inputOffset + 1;
+    const lengthBufferView = view.subarray(lenOffset, lenOffset + count);
+
+    if (lengthBufferView[count - 1] === 0x00)
+      this.warnings.push("Needlessly long encoded length");
+
+    this.length = pvutils.utilFromBase(lengthBufferView, 8);
+
+    if (this.longFormUsed && (this.length <= 127))
+      this.warnings.push("Unnecessary usage of long length form");
+
+    this.blockLength = count + 1;
+    //#endregion
+
+    return (inputOffset + this.blockLength); // Return current offset in input buffer
+  }
+
+  public toBER(sizeOnly = false): ArrayBuffer {
+    //#region Initial variables
+    let retBuf: ArrayBuffer;
+    let retView: Uint8Array;
+    //#endregion
+    if (this.length > 127)
+      this.longFormUsed = true;
+
+    if (this.isIndefiniteForm) {
+      retBuf = new ArrayBuffer(1);
+
+      if (sizeOnly === false) {
+        retView = new Uint8Array(retBuf);
+        retView[0] = 0x80;
+      }
+
+      return retBuf;
+    }
+
+    if (this.longFormUsed) {
+      const encodedBuf = pvutils.utilToBase(this.length, 8);
+
+      if (encodedBuf.byteLength > 127) {
+        this.error = "Too big length";
+
+        return (EMPTY_BUFFER);
+      }
+
+      retBuf = new ArrayBuffer(encodedBuf.byteLength + 1);
+
+      if (sizeOnly)
+        return retBuf;
+
+      const encodedView = new Uint8Array(encodedBuf);
+      retView = new Uint8Array(retBuf);
+
+      retView[0] = encodedBuf.byteLength | 0x80;
+
+      for (let i = 0; i < encodedBuf.byteLength; i++)
+        retView[i + 1] = encodedView[i];
+
+      return retBuf;
+    }
+
+    retBuf = new ArrayBuffer(1);
+
+    if (sizeOnly === false) {
+      retView = new Uint8Array(retBuf);
+
+      retView[0] = this.length;
+    }
+
+    return retBuf;
+  }
+
+  public override toJSON(): LocalLengthBlockJson {
+    return {
+      ...super.toJSON(),
+      isIndefiniteForm: this.isIndefiniteForm,
+      longFormUsed: this.longFormUsed,
+      length: this.length,
+    };
+  }
+}