78 lines
2.2 KiB
Haskell
78 lines
2.2 KiB
Haskell
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{-# LANGUAGE CPP #-}
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#if __GLASGOW_HASKELL__ >= 702
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{-# LANGUAGE Trustworthy #-}
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#endif
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-- |
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-- Module : Data.ByteString.Base64
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-- Copyright : (c) 2010 Bryan O'Sullivan
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--
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-- License : BSD-style
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-- Maintainer : Emily Pillmore <emilypi@cohomolo.gy>,
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-- Herbert Valerio Riedel <hvr@gnu.org>,
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-- Mikhail Glushenkov <mikhail.glushenkov@gmail.com>
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-- Stability : experimental
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-- Portability : GHC
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--
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-- Fast and efficient encoding and decoding of base64-encoded strings.
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--
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-- @since 0.1.0.0
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module Data.ByteString.Base64
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( encode
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, decode
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, decodeLenient
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) where
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import Data.ByteString.Base64.Internal
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import qualified Data.ByteString as B
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import Data.ByteString.Internal (ByteString(..))
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import Data.Word (Word8)
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import Foreign.ForeignPtr (ForeignPtr)
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-- | Encode a string into base64 form. The result will always be a
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-- multiple of 4 bytes in length.
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encode :: ByteString -> ByteString
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encode s = encodeWith Padded (mkEncodeTable alphabet) s
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-- | Decode a base64-encoded string. This function strictly follows
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-- the specification in
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-- <http://tools.ietf.org/rfc/rfc4648 RFC 4648>.
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--
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-- (Note: this means that even @"\\n"@ and @"\\r\\n"@ as line breaks are rejected
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-- rather than ignored. If you are using this in the context of a
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-- standard that overrules RFC 4648 such as HTTP multipart mime bodies,
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-- consider using 'decodeLenient'.)
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decode :: ByteString -> Either String ByteString
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decode s = decodeWithTable Padded decodeFP s
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-- | Decode a base64-encoded string. This function is lenient in
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-- following the specification from
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-- <http://tools.ietf.org/rfc/rfc4648 RFC 4648>, and will not
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-- generate parse errors no matter how poor its input.
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decodeLenient :: ByteString -> ByteString
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decodeLenient s = decodeLenientWithTable decodeFP s
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alphabet :: ByteString
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alphabet = B.pack $ [65..90] ++ [97..122] ++ [48..57] ++ [43,47]
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{-# NOINLINE alphabet #-}
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decodeFP :: ForeignPtr Word8
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#if MIN_VERSION_bytestring(0,11,0)
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BS decodeFP _ =
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#else
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PS decodeFP _ _ =
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#endif
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B.pack $ replicate 43 x
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++ [62,x,x,x,63]
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++ [52..61]
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++ [x,x,x,done,x,x,x]
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++ [0..25]
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++ [x,x,x,x,x,x]
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++ [26..51]
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++ replicate 133 x
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{-# NOINLINE decodeFP #-}
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x :: Integral a => a
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x = 255
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{-# INLINE x #-}
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