/**
 * Traditional PKWARE ZIP encryption (ZipCrypto).
 *
 * This implements the "traditional ZIP encryption" algorithm as specified
 * in the PKWARE APPNOTE.TXT (section 6.1.5 "Traditional PKWARE Encryption").
 *
 * WARNING: ZipCrypto is cryptographically weak and should only be used
 * for backward compatibility. Use AES encryption for new archives.
 *
 * References:
 * - PKWARE APPNOTE.TXT 6.1.5 - Traditional Encryption
 * - https://www.forensicfocus.com/stable/wp-content/uploads/2009/04/zip_encryption.pdf
 */
/**
 * ZipCrypto encryption header size.
 * The first 12 bytes of encrypted data are the encryption header.
 */
export declare const ZIP_CRYPTO_HEADER_SIZE = 12;
/**
 * Internal state for ZipCrypto cipher.
 * Uses three 32-bit keys updated with each byte processed.
 */
export interface ZipCryptoState {
    key0: number;
    key1: number;
    key2: number;
}
/**
 * Initialize ZipCrypto state with a password.
 */
export declare function zipCryptoInitKeys(password: string | Uint8Array): ZipCryptoState;
/**
 * Update the cipher state with a single byte.
 */
export declare function zipCryptoUpdateKeys(state: ZipCryptoState, byte: number): void;
/**
 * Get the next stream byte for encryption/decryption.
 */
export declare function zipCryptoGetStreamByte(state: ZipCryptoState): number;
/**
 * Decrypt a single byte and update state.
 */
export declare function zipCryptoDecryptByte(state: ZipCryptoState, cipher: number): number;
/**
 * Encrypt a single byte and update state.
 */
export declare function zipCryptoEncryptByte(state: ZipCryptoState, plain: number): number;
/**
 * Decrypt the encryption header and verify.
 *
 * @param state - Initialized cipher state
 * @param header - 12-byte encryption header from encrypted data
 * @param crc32 - Expected CRC32 of the uncompressed data (for verification)
 * @param lastModTime - Last modified time field (alternative verification)
 * @returns true if header passes verification
 */
export declare function zipCryptoDecryptHeader(state: ZipCryptoState, header: Uint8Array, crc32: number, lastModTime?: number): boolean;
/**
 * Generate an encryption header for writing.
 *
 * @param state - Initialized cipher state
 * @param crc32 - CRC32 of the uncompressed data
 * @param getRandomBytes - Function to generate random bytes
 * @returns 12-byte encrypted header
 */
export declare function zipCryptoCreateHeader(state: ZipCryptoState, crc32: number, getRandomBytes: (length: number) => Uint8Array): Uint8Array;
/**
 * Decrypt data in-place after header decryption.
 */
export declare function zipCryptoDecryptData(state: ZipCryptoState, data: Uint8Array): Uint8Array;
/**
 * Encrypt data after header encryption.
 */
export declare function zipCryptoEncryptData(state: ZipCryptoState, data: Uint8Array): Uint8Array;
/**
 * High-level decryption interface for ZipCrypto.
 *
 * @param encryptedData - Full encrypted data including 12-byte header
 * @param password - Password string or bytes
 * @param crc32 - Expected CRC32 for header verification
 * @param lastModTime - Optional last modified time for alternative verification
 * @returns Decrypted data (excluding header) or null if verification fails
 */
export declare function zipCryptoDecrypt(encryptedData: Uint8Array, password: string | Uint8Array, crc32: number, lastModTime?: number): Uint8Array | null;
/**
 * High-level encryption interface for ZipCrypto.
 *
 * @param data - Plain data to encrypt
 * @param password - Password string or bytes
 * @param crc32 - CRC32 of the data
 * @param getRandomBytes - Function to generate random bytes
 * @returns Encrypted data including 12-byte header
 */
export declare function zipCryptoEncrypt(data: Uint8Array, password: string | Uint8Array, crc32: number, getRandomBytes: (length: number) => Uint8Array): Uint8Array;
/**
 * Check if a password is valid for ZipCrypto-encrypted data without full decryption.
 * This only verifies the encryption header check byte.
 *
 * @param encryptedData - Full encrypted data including 12-byte header
 * @param password - Password string or bytes
 * @param crc32 - Expected CRC32 for header verification
 * @param lastModTime - Optional last modified time for alternative verification
 * @returns true if password verification passes, false otherwise
 */
export declare function zipCryptoCheckPassword(encryptedData: Uint8Array, password: string | Uint8Array, crc32: number, lastModTime?: number): boolean;