chacha20poly1305: remove unused funcs.

Author: dajiaji

packages/chacha20poly1305/src/chacha/_arx.ts

@@ -52,11 +52,9 @@ import {
   checkOpts,
   clean,
   copyBytes,
-  type PRG,
   u32,
   type XorStream,
 } from "./utils.ts";
-import { randomBytes } from "./webcrypto.ts";
 
 // Can't use similar utils.utf8ToBytes, because it uses `TextEncoder` - not available in all envs
 const _utf8ToBytes = (str: string) =>
@@ -116,6 +114,7 @@ const BLOCK_LEN32 = 16;
 const MAX_COUNTER = 2 ** 32 - 1;
 
 const U32_EMPTY = Uint32Array.of();
+
 function runCipher(
   core: CipherCoreFn,
   sigma: Uint32Array,
@@ -256,109 +255,3 @@ export function createCipher(core: CipherCoreFn, opts: CipherOpts): XorStream {
     return output;
   };
 }
-
-/** Internal class which wraps chacha20 or chacha8 to create CSPRNG. */
-export class _XorStreamPRG implements PRG {
-  readonly blockLen: number;
-  readonly keyLen: number;
-  readonly nonceLen: number;
-  private state: Uint8Array;
-  private buf: Uint8Array;
-  private key: Uint8Array;
-  private nonce: Uint8Array;
-  private pos: number;
-  private ctr: number;
-  private cipher: XorStream;
-  constructor(
-    cipher: XorStream,
-    blockLen: number,
-    keyLen: number,
-    nonceLen: number,
-    seed: Uint8Array,
-  ) {
-    this.cipher = cipher;
-    this.blockLen = blockLen;
-    this.keyLen = keyLen;
-    this.nonceLen = nonceLen;
-    this.state = new Uint8Array(this.keyLen + this.nonceLen);
-    this.reseed(seed);
-    this.ctr = 0;
-    this.pos = this.blockLen;
-    this.buf = new Uint8Array(this.blockLen);
-    this.key = this.state.subarray(0, this.keyLen);
-    this.nonce = this.state.subarray(this.keyLen);
-  }
-  private reseed(seed: Uint8Array) {
-    abytes(seed);
-    if (!seed || seed.length === 0) throw new Error("entropy required");
-    for (let i = 0; i < seed.length; i++) {
-      this.state[i % this.state.length] ^= seed[i];
-    }
-    this.ctr = 0;
-    this.pos = this.blockLen;
-  }
-  addEntropy(seed: Uint8Array): void {
-    this.state.set(this.randomBytes(this.state.length));
-    this.reseed(seed);
-  }
-  randomBytes(len: number): Uint8Array {
-    anumber(len);
-    if (len === 0) return new Uint8Array(0);
-    const out = new Uint8Array(len);
-    let outPos = 0;
-    // Leftovers
-    if (this.pos < this.blockLen) {
-      const take = Math.min(len, this.blockLen - this.pos);
-      out.set(this.buf.subarray(this.pos, this.pos + take), 0);
-      this.pos += take;
-      outPos += take;
-      if (outPos === len) return out; // fast path
-    }
-    // Full blocks directly to out
-    const blocks = Math.floor((len - outPos) / this.blockLen);
-    if (blocks > 0) {
-      const blockBytes = blocks * this.blockLen;
-      const b = out.subarray(outPos, outPos + blockBytes);
-      this.cipher(this.key, this.nonce, b, b, this.ctr);
-      this.ctr += blocks;
-      outPos += blockBytes;
-    }
-    // Save leftovers
-    const left = len - outPos;
-    if (left > 0) {
-      this.buf.fill(0);
-      // NOTE: cipher will handle overflow
-      this.cipher(this.key, this.nonce, this.buf, this.buf, this.ctr++);
-      out.set(this.buf.subarray(0, left), outPos);
-      this.pos = left;
-    }
-    return out;
-  }
-  clone(): _XorStreamPRG {
-    return new _XorStreamPRG(
-      this.cipher,
-      this.blockLen,
-      this.keyLen,
-      this.nonceLen,
-      this.randomBytes(this.state.length),
-    );
-  }
-  clean(): void {
-    this.pos = 0;
-    this.ctr = 0;
-    this.buf.fill(0);
-    this.state.fill(0);
-  }
-}
-
-export type XorPRG = (seed?: Uint8Array) => _XorStreamPRG;
-
-export const createPRG = (
-  cipher: XorStream,
-  blockLen: number,
-  keyLen: number,
-  nonceLen: number,
-): XorPRG => {
-  return (seed: Uint8Array = randomBytes(32)): _XorStreamPRG =>
-    new _XorStreamPRG(cipher, blockLen, keyLen, nonceLen, seed);
-};