mcp-server-neon

import crypto from 'crypto';

export const generateRandomString = (length: number): string => {
  const charset =
    'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
  const array = new Uint8Array(length);
  crypto.getRandomValues(array);
  return Array.from(array, (byte) => charset[byte % charset.length]).join('');
};

export const verifyPKCE = (
  codeChallenge: string,
  codeChallengeMethod: string,
  codeVerifier: string,
): boolean => {
  if (!codeChallenge || !codeChallengeMethod || !codeVerifier) {
    return false;
  }

  if (codeChallengeMethod === 'S256') {
    const hash = crypto
      .createHash('sha256')
      .update(codeVerifier)
      .digest('base64url');
    return codeChallenge === hash;
  }

  if (codeChallengeMethod === 'plain') {
    return codeChallenge === codeVerifier;
  }

  return false;
};