| Copyright | (c) 2019-2026 Emily Pillmore |
|---|---|
| License | BSD-style |
| Maintainer | Emily Pillmore <emilypi@cohomolo.gy> |
| Stability | stable |
| Portability | non-portable |
| Safe Haskell | None |
| Language | Haskell2010 |
Data.Text.Lazy.Encoding.Base64
Description
This module contains Text-valued combinators
implementing the RFC 4648 specification for the Base64
encoding format. This includes lenient decoding variants, and
external + internal validations for canonicity.
Synopsis
- encodeBase64 :: Text -> Base64 'StdPadded Text
- decodeBase64 :: forall (k :: Alphabet). StdAlphabet k => Base64 k Text -> Text
- decodeBase64Untyped :: Text -> Either Text Text
- decodeBase64UntypedWith :: (ByteString -> Either err Text) -> ByteString -> Either (Base64Error err) Text
- decodeBase64Lenient :: Text -> Text
- parseBase64 :: Text -> Either Text (Base64 'StdPadded Text)
Encoding
encodeBase64 :: Text -> Base64 'StdPadded Text Source #
Encode a Text value in Base64 with padding.
See: RFC-4648 section 4
Examples:
>>>encodeBase64 "Sun""U3Vu"
Decoding
decodeBase64 :: forall (k :: Alphabet). StdAlphabet k => Base64 k Text -> Text Source #
Decode a padded Base64-encoded Text value
See: RFC-4648 section 4
Examples:
>>>decodeBase64 $ assertBase64 @'StdPadded "U3Vu""Sun"
decodeBase64Untyped :: Text -> Either Text Text Source #
Decode a padded, untyped Base64-encoded Text value
See: RFC-4648 section 4
Examples:
>>>decodeBase64Untyped "U3Vu"Right "Sun"
>>>decodeBase64Untyped "U3V"Left "Base64-encoded bytestring requires padding"
>>>decodeBase64Untyped "U3V="Left "non-canonical encoding detected at offset: 2"
decodeBase64UntypedWith Source #
Arguments
| :: (ByteString -> Either err Text) | convert a bytestring to text (e.g. |
| -> ByteString | Input text to decode |
| -> Either (Base64Error err) Text |
Attempt to decode a ByteString value as Base64, converting from
ByteString to Text according to some encoding function. In practice,
This is something like decodeUtf8', which may produce an error.
See: RFC-4648 section 4
Example:
decodeBase64UntypedWithdecodeUtf8'::ByteString->Either(Base64ErrorUnicodeException)Text
decodeBase64Lenient :: Text -> Text Source #
Leniently decode an untyped Base64-encoded Text value. This function
will not generate parse errors. If input data contains padding chars,
then the input will be parsed up until the first pad character.
Note: This is not RFC 4648-compliant.
Examples:
>>>decodeBase64Lenient "U3Vu""Sun"
>>>decodeBase64Lenient "U3V""Su"
>>>decodeBase64Lenient "U3V=""Su"
Parsing
parseBase64 :: Text -> Either Text (Base64 'StdPadded Text) Source #
Parse a canonical, padded Base64-encoded Text value.
Checks the alphabet, length, padding, and unused padding bits. On success,
returns the original encoded value wrapped in Base64, ready for
decodeBase64. On failure, returns the same error as decodeBase64Untyped.
The input is neither decoded nor normalized in the returned value.
This validates the Base64 encoding, not the UTF-8 validity of the decoded
bytes. Use decodeBase64UntypedWith to check the decoded text encoding.
The entire input is validated before returning Right; the original
chunk boundaries are preserved in the result.
Examples:
>>>parseBase64 "U3Vu"Right "U3Vu"
>>>fmap decodeBase64 (parseBase64 "U3Vu")Right "Sun"
>>>parseBase64 "U3V"Left "Base64-encoded bytestring requires padding"
>>>parseBase64 "U3V="Left "non-canonical encoding detected at offset: 2"
Since: 2.0