Services

Business logic layer providing encryption, decryption, and hashing operations.

EncryptionService

Handles all encryption operations with support for AES and PGP methods.

Methods

encrypt_text(secret, password, method="aes")

Encrypt text data.

Parameters: - secret (str): Text to encrypt - password (str): Password (AES) or recipient email (PGP) - method (str): "aes" or "pgp" (default: "aes")

Returns: str - Encrypted data

Raises: - EncryptionError: If encryption fails - InvalidInputError: If parameters are invalid

Example:

service = EncryptionService()
encrypted = service.encrypt_text("secret", "password123")

encrypt_file(file_path, password, method="aes", output_path=None)

Encrypt file contents.

Parameters: - file_path (str): Path to file to encrypt - password (str): Password (AES) or recipient email (PGP) - method (str): "aes" or "pgp" (default: "aes") - output_path (str): Optional output file path

Returns: str - Encrypted data

Raises: - FileOperationError: If file cannot be read - EncryptionError: If encryption fails

Example:

service = EncryptionService()
encrypted = service.encrypt_file("document.pdf", "password123")

encrypt_image(image_path, secret, password, method="aes", stego_method="lsb")

Encrypt and hide data in an image.

Parameters: - image_path (str): Path to PNG image - secret (str): Data to hide (text or file path) - password (str): Encryption password - method (str): "aes" or "pgp" (default: "aes") - stego_method (str): "lsb" or "dct" (default: "lsb")

Returns: bytes - Image with hidden encrypted data

Example:

service = EncryptionService()
encrypted_image = service.encrypt_image(
    "image.png",
    "secret message",
    "password123",
    method="aes",
    stego_method="lsb"
)

DecryptionService

Handles all decryption operations with support for AES and PGP methods.

Methods

decrypt_text(data, password, method="aes")

Decrypt text data.

Parameters: - data (str): Encrypted text - password (str): Decryption password or passphrase - method (str): "aes" or "pgp" (default: "aes")

Returns: str - Decrypted text

Raises: - DecryptionError: If decryption fails - InvalidInputError: If password is incorrect

Example:

service = DecryptionService()
decrypted = service.decrypt_text(encrypted, "password123")

decrypt_file(file_path, password, method="aes", output_path=None)

Decrypt file contents.

Parameters: - file_path (str): Path to encrypted file - password (str): Decryption password - method (str): "aes" or "pgp" (default: "aes") - output_path (str): Optional output file path

Returns: bytes - Decrypted file data

Raises: - FileOperationError: If file cannot be read - DecryptionError: If decryption fails

Example:

service = DecryptionService()
decrypted = service.decrypt_file("document.enc", "password123")

decrypt_image(image_path, password, method="aes", stego_method="lsb")

Extract and decrypt hidden data from image.

Parameters: - image_path (str): Path to image with hidden data - password (str): Decryption password - method (str): "aes" or "pgp" (default: "aes") - stego_method (str): "lsb" or "dct" (default: "lsb")

Returns: str or bytes - Decrypted data

Example:

service = DecryptionService()
data = service.decrypt_image("image.png", "password123", stego_method="lsb")

HashingService

Handles cryptographic hashing operations.

Attributes

ALGORITHMS

Dictionary of available hash algorithms and their implementations.

# List supported algorithms
algorithms = HashingService.ALGORITHMS.keys()
# Output: dict_keys(['MD5', 'SHA1', 'SHA224', 'SHA256', ...])

Methods

hash_text(text, algorithm)

Hash text data.

Parameters: - text (str): Text to hash - algorithm (str): Hash algorithm (case-insensitive)

Returns: str - Hex digest

Raises: - ValueError: If algorithm not supported

Example:

service = HashingService()
hash_result = service.hash_text("data", "SHA256")
print(hash_result)

hash_file(file_path, algorithm)

Hash file contents.

Parameters: - file_path (str): Path to file - algorithm (str): Hash algorithm

Returns: str - Hex digest

Raises: - FileOperationError: If file cannot be read - ValueError: If algorithm not supported

Example:

service = HashingService()
hash_result = service.hash_file("document.pdf", "SHA256")

Usage Examples

Complete Workflow

from encryptocli.services import (
    EncryptionService,
    DecryptionService,
    HashingService
)

# Initialize services
encryptor = EncryptionService()
decryptor = DecryptionService()
hasher = HashingService()

# Hash a file to verify integrity
original_hash = hasher.hash_file("important.pdf", "SHA256")

# Encrypt the file
encrypted_data = encryptor.encrypt_file(
    "important.pdf",
    "strong_password_123",
    method="aes"
)

# Later: decrypt the file
decrypted_data = decryptor.decrypt_file(
    "important.pdf.enc",
    "strong_password_123",
    method="aes"
)

# Verify integrity
new_hash = hasher.hash_file("important.pdf", "SHA256")
assert original_hash == new_hash, "File integrity check failed"

Error Handling

from encryptocli.util.exceptions import (
    EncryptionError,
    InvalidInputError
)
from encryptocli.services import EncryptionService

encryptor = EncryptionService()

try:
    encrypted = encryptor.encrypt_text("secret", "password")
except InvalidInputError as e:
    print(f"Invalid input: {e}")
except EncryptionError as e:
    print(f"Encryption failed: {e}")