transparentmeta.crypto package

Submodules

transparentmeta.crypto.character_encoding module

This module defines the CharacterEncoding enumeration, which provides standard character encoding options for string-to-byte conversions.

class transparentmeta.crypto.character_encoding.CharacterEncoding(*values)[source]

Bases: Enum

Enum for character encoding options.

ASCII = 'ascii'
UTF8 = 'utf-8'

transparentmeta.crypto.exceptions module

This module hosts all custom exceptions used in the crypto parckage.

exception transparentmeta.crypto.exceptions.NotEd25519KeyError(message='Loaded key is not an Ed25519 key')[source]

Bases: Exception

Raised when a loaded key is not an Ed25519 key.

__init__(message='Loaded key is not an Ed25519 key')[source]

transparentmeta.crypto.hasher module

This module provides a simple wrapper around Python’s hashlib library to compute cryptographic hash digests using various algorithms such as SHA-256, SHA-512, and MD5.

class transparentmeta.crypto.hasher.Hasher(hash_algorithm_name='sha256')[source]

Bases: object

A utility class for computing hash digests using various cryptographic algorithms.

hash_algorithm_name

The name of the hashing algorithm (e.g., “sha256”).

Type:

str

__init__(hash_algorithm_name='sha256')[source]

Initializes the Hasher with the specified hashing algorithm.

Parameters:

hash_algorithm_name (str, optional) – The name of the hash algorithm to use. Defaults to “sha256”.

Raises:

ValueError – If the specified algorithm is not supported by hashlib.

hash(data)[source]

Computes the hash digest of the given data using the specified algorithm.

Parameters:

data (bytes) – The input data to be hashed.

Returns:

The hexadecimal digest of the

hashed data.

Return type:

hexadecimal_hash_digest (str)

transparentmeta.crypto.key_management module

Ed25519 Key Management Module

This module provides functions for generating, storing, loading, and converting Ed25519 cryptographic key pairs. These keys are used for digital signatures and secure communications. User A can sign a message with their private key, and User B can verify the signature using User A’s public key.

Functions:
generate_key_pair() -> tuple:

Generates a new Ed25519 private and public key pair.

save_private_key_to_pem_file(private_key, filepath) -> None:

Saves a private key to a PEM file.

save_public_key_to_pem_file(public_key, filepath) -> None:

Saves a public key to a PEM file.

load_private_key_from_pem_file(filepath) -> ed25519.Ed25519PrivateKey:

Loads a private key from a PEM file.

load_public_key_from_pem_file(filepath) -> ed25519.Ed25519PublicKey:

Loads a public key from a PEM file.

convert_private_key_to_hex(private_key) -> str:

Converts a private key to a hex string.

convert_public_key_to_hex(public_key) -> str:

Converts a public key to a hex string.

load_private_key_from_hex_string(hex_string) -> ed25519.Ed25519PrivateKey:

Converts a hex-encoded private key back to an Ed25519PrivateKey object.

load_public_key_from_hex_string(hex_string) -> ed25519.Ed25519PublicKey:

Converts a hex-encoded public key back to an Ed25519PublicKey object.

transparentmeta.crypto.key_management.convert_private_key_to_hex(private_key)[source]

Converts a private key to a hex-encoded string.

Parameters:

private_key (ed25519.Ed25519PrivateKey) – The private key to convert.

Returns:

The hex-encoded private key.

Return type:

hexadecimal_encoded_private_key (str)

transparentmeta.crypto.key_management.convert_public_key_to_hex(public_key)[source]

Converts a public key to a hex-encoded string.

Parameters:

public_key (ed25519.Ed25519PublicKey) – The public key to convert.

Returns:

The hex-encoded public key.

Return type:

hexadecimal_encoded_public_key (str)

transparentmeta.crypto.key_management.generate_key_pair()[source]

Generates a new Ed25519 private and public key pair.

Returns:

A tuple containing an Ed25519PrivateKey and Ed25519PublicKey.

Return type:

tuple

transparentmeta.crypto.key_management.load_private_key_from_hex_string(hex_encoded_private_key)[source]

Converts a hex-encoded private key back to an Ed25519PrivateKey object.

Parameters:

hex_string (str) – The hex-encoded private key.

Returns:

The decoded private key

object.

Return type:

private_key (ed25519.Ed25519PrivateKey)

transparentmeta.crypto.key_management.load_private_key_from_pem_file(filepath)[source]

Loads a private key from a PEM file and ensures it is Ed25519.

Parameters:

filepath (Path) – The Path object of the private key to load.

Returns:

The loaded private key object.

Return type:

ed25519.Ed25519PrivateKey

Raises:

NotEd25519KeyError – If the loaded key is not an Ed25519 private key.

transparentmeta.crypto.key_management.load_public_key_from_hex_string(hex_encoded_public_key)[source]

Converts a hex-encoded public key back to an Ed25519PublicKey object.

Parameters:

hex_encoded_public_key (str) – The hex-encoded public key.

Returns:

The decoded public key object.

Return type:

public_key (ed25519.Ed25519PublicKey)

transparentmeta.crypto.key_management.load_public_key_from_pem_file(filepath)[source]

Loads a public key from a PEM file and ensures it is Ed25519.

Parameters:

filepath (Path) – The Path object of the public key to load.

Returns:

The loaded public key object.

Return type:

ed25519.Ed25519PublicKey

Raises:

NotEd25519KeyError – If the loaded key is not an Ed25519 public key.

transparentmeta.crypto.key_management.save_private_key_to_pem_file(private_key, filepath)[source]

Saves a private key to a PEM file.

Parameters:

  • private_key (ed25519.Ed25519PrivateKey) – The private key to save.

  • filepath (Path) – The Path object where the private key should be saved.

Return type:

None

transparentmeta.crypto.key_management.save_public_key_to_pem_file(public_key, filepath)[source]

Saves a public key to a PEM file.

Parameters:

  • public_key (ed25519.Ed25519PublicKey) – The public key to save.

  • filepath (Path) – The Path object where the public key should be saved.

Return type:

None

transparentmeta.crypto.signature_verifier module

This module provides a SignatureVerifier class that enables verifying messages signed with the Ed25519 cryptographic algorithm. It supports different character encodings for message conversion before verification.

class transparentmeta.crypto.signature_verifier.SignatureVerifier(public_key, character_encoding=CharacterEncoding.UTF8)[source]

Bases: object

A utility class for verifying Ed25519 digital signatures.

public_key

The public key used for verifying signatures.

Type:

ed25519.Ed25519PublicKey

character_encoding

The encoding used for converting strings to bytes before verification.

Type:

CharacterEncoding

__init__(public_key, character_encoding=CharacterEncoding.UTF8)[source]

Initializes the verifier with a public key and a character encoding.

Parameters:

  • public_key (ed25519.Ed25519PublicKey) – The public key for verifying signatures.

  • character_encoding (CharacterEncoding) – The encoding used for converting strings to bytes before verification.

is_signature_valid(message, signature)[source]

Verifies an Ed25519 hex-encoded signature for a given message.

Parameters:

  • message (str) – The original message that was signed.

  • signature (str) – The hex-encoded digital signature.

Returns:

True if the signature is valid, False otherwise.

Return type:

bool

transparentmeta.crypto.signer module

This module provides a Signer class that enables signing messages using the Ed25519 cryptographic algorithm. It supports different character encodings for message conversion before signing.

class transparentmeta.crypto.signer.Signer(private_key, character_encoding=CharacterEncoding.UTF8)[source]

Bases: object

A utility class for digitally signing messages using the Ed25519 cryptographic algorithm.

private_key

The private key used for signing messages.

Type:

ed25519.Ed25519PrivateKey

character_encoding

The encoding used for converting strings to bytes before signing.

Type:

CharacterEncoding

__init__(private_key, character_encoding=CharacterEncoding.UTF8)[source]

Initializes the signer with a private key and a character encoding.

Parameters:

  • private_key (ed25519.Ed25519PrivateKey) – The private key for signing messages.

  • character_encoding (CharacterEncoding) – The encoding used for converting strings to bytes before signing.

sign(message)[source]

Signs a message using Ed25519 and returns a hex-encoded signature.

Parameters:

message (str) – The message to sign.

Returns:

Hex-encoded digital signature.

Return type:

str

Module contents