Copyright | (c) 2019-2020 Emily Pillmore |
---|---|
License | BSD-style |
Maintainer | Emily Pillmore <emilypi@cohomolo.gy> |
Stability | stable |
Portability | non-portable |
Safe Haskell | Trustworthy |
Language | Haskell2010 |
This module contains ByteString
-valued combinators for
implementing the RFC 4648 specification of the Base64
encoding format. This includes lenient decoding variants, as well as
internal and external validation for canonicity.
Synopsis
- encodeBase64 :: ByteString -> Text
- encodeBase64' :: ByteString -> ByteString
- decodeBase64 :: ByteString -> Either Text ByteString
- decodeBase64Lenient :: ByteString -> ByteString
- isBase64 :: ByteString -> Bool
- isValidBase64 :: ByteString -> Bool
Encoding
encodeBase64 :: ByteString -> Text Source #
Encode a ByteString
value as Base64 Text
with padding.
See: RFC-4648 section 4
Examples:
>>>
encodeBase64 "Sun"
"U3Vu"
encodeBase64' :: ByteString -> ByteString Source #
Encode a ByteString
value as a Base64 ByteString
value with padding.
See: RFC-4648 section 4
Examples:
>>>
encodeBase64' "Sun"
"U3Vu"
Decoding
decodeBase64 :: ByteString -> Either Text ByteString Source #
Decode a padded Base64-encoded ByteString
value.
See: RFC-4648 section 4
Examples:
>>>
decodeBase64 "U3Vu"
Right "Sun"
>>>
decodeBase64 "U3V"
Left "Base64-encoded bytestring requires padding"
>>>
decodebase64 "U3V="
Left "non-canonical encoding detected at offset: 2"
decodeBase64Lenient :: ByteString -> ByteString Source #
Leniently decode an unpadded Base64-encoded ByteString
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"
Validation
isBase64 :: ByteString -> Bool Source #
Tell whether a ByteString
value is base64 encoded.
This function will also detect non-canonical encodings such as ZE==
, which are
externally valid Base64url-encoded values, but are internally inconsistent "impossible"
values.
Examples:
>>>
isBase64 "U3Vu"
True
>>>
isBase64 "U3V"
False
>>>
isBase64 "U3V="
False
isValidBase64 :: ByteString -> Bool Source #
Tell whether a ByteString
value is a valid Base64 format.
This will not tell you whether or not this is a correct Base64url representation,
only that it conforms to the correct shape. To check whether it is a true
Base64 encoded ByteString
value, use isBase64
.
Examples:
>>>
isValidBase64 "U3Vu"
True
>>>
isValidBase64 "U3V"
True
>>>
isValidBase64 "U3V="
True
>>>
isValidBase64 "%"
False