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 Base64url
encoding format. This includes strictly padded/unpadded and lenient decoding
variants, as well as internal and external validation for canonicity.
Synopsis
- encodeBase64 :: ByteString -> Text
- encodeBase64' :: ByteString -> ByteString
- encodeBase64Unpadded :: ByteString -> Text
- encodeBase64Unpadded' :: ByteString -> ByteString
- decodeBase64 :: ByteString -> Either Text ByteString
- decodeBase64Unpadded :: ByteString -> Either Text ByteString
- decodeBase64Padded :: ByteString -> Either Text ByteString
- decodeBase64Lenient :: ByteString -> ByteString
- isBase64Url :: ByteString -> Bool
- isValidBase64Url :: ByteString -> Bool
Encoding
encodeBase64 :: ByteString -> Text Source #
Encode a ByteString
value as a Base64url Text
value with padding.
See: RFC-4648 section 5
Examples:
>>>
encodeBase64 "<<?>>"
"PDw_Pj4="
encodeBase64' :: ByteString -> ByteString Source #
Encode a ByteString
as a Base64url ByteString
value with padding.
See: RFC-4648 section 5
Examples:
>>>
encodeBase64' "<<?>>"
"PDw_Pj4="
encodeBase64Unpadded :: ByteString -> Text Source #
Encode a ByteString
value as Base64url Text
without padding. Note that for Base64url,
padding is optional. If you call this function, you will simply be encoding
as Base64url and stripping padding chars from the output.
See: RFC-4648 section 3.2
Examples:
>>>
encodeBase64Unpadded "<<?>>"
"PDw_Pj4"
encodeBase64Unpadded' :: ByteString -> ByteString Source #
Encode a ByteString
value as Base64url without padding. Note that for Base64url,
padding is optional. If you call this function, you will simply be encoding
as Base64url and stripping padding chars from the output.
See: RFC-4648 section 3.2
Examples:
>>>
encodeBase64Unpadded' "<<?>>"
"PDw_Pj4"
Decoding
decodeBase64 :: ByteString -> Either Text ByteString Source #
Decode a padded Base64url encoded ByteString
value. If its length is not a multiple
of 4, then padding chars will be added to fill out the input to a multiple of
4 for safe decoding as Base64url-encoded values are optionally padded.
For a decoder that fails on unpadded input of incorrect size, use decodeBase64Unpadded
.
See: RFC-4648 section 4
Examples:
>>>
decodeBase64 "PDw_Pj4="
Right "<<?>>"
>>>
decodeBase64 "PDw_Pj4"
Right "<<?>>"
>>>
decodeBase64 "PDw-Pg="
Left "Base64-encoded bytestring has invalid padding"
>>>
decodeBase64 "PDw-Pg"
Right "<<>>"
decodeBase64Unpadded :: ByteString -> Either Text ByteString Source #
Decode an unpadded Base64url-encoded ByteString
value. Input strings are
required to be unpadded, and will undergo validation prior to decoding to
confirm.
In general, unless unpadded Base64url is explicitly required, it is
safer to call decodeBase64
.
See: RFC-4648 section 4
Examples:
>>>
decodeBase64Unpadded "PDw_Pj4"
Right "<<?>>"
>>>
decodeBase64Unpadded "PDw_Pj4="
Left "Base64-encoded bytestring has invalid padding"
decodeBase64Padded :: ByteString -> Either Text ByteString Source #
Decode a padded Base64url-encoded ByteString
value. Input strings are
required to be correctly padded, and will be validated prior to decoding
to confirm.
In general, unless padded Base64url is explicitly required, it is
safer to call decodeBase64
.
See: RFC-4648 section 4
Examples:
>>>
decodeBase64Padded "PDw_Pj4="
Right "<<?>>"
>>>
decodeBase64Padded "PDw_Pj4"
Left "Base64-encoded bytestring requires padding"
decodeBase64Lenient :: ByteString -> ByteString Source #
Leniently decode an unpadded Base64url-encoded ByteString
. 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 "PDw_Pj4="
"<<?>>"
>>>
decodeBase64Lenient "PDw_%%%$}Pj4"
"<<?>>"
Validation
isBase64Url :: ByteString -> Bool Source #
Tell whether a ByteString
is encoded in padded or unpadded Base64url format.
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:
>>>
isBase64Url "PDw_Pj4="
True
>>>
isBase64Url "PDw_Pj4"
True
>>>
isBase64Url "PDw_Pj"
False
isValidBase64Url :: ByteString -> Bool Source #
Tell whether a ByteString
is a valid Base64url 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 isBase64Url
.
Examples:
>>>
isValidBase64Url "PDw_Pj4="
True
>>>
isValidBase64Url "PDw_Pj"
True
>>>
isValidBase64Url "%"
False