The R13B03 release.OTP_R13B03

1 files changed, 304 insertions, 0 deletions

diff --git a/lib/stdlib/src/base64.erl b/lib/stdlib/src/base64.erl
new file mode 100644
index 0000000000..ebef998ee1
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+++ b/lib/stdlib/src/base64.erl
@@ -0,0 +1,304 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2007-2009. All Rights Reserved.
+%% 
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%% 
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%% 
+%% %CopyrightEnd%
+%%
+%% Description: Implements base 64 encode and decode. See RFC4648.
+
+-module(base64).
+
+-export([encode/1, decode/1, mime_decode/1,
+	 encode_to_string/1, decode_to_string/1, mime_decode_to_string/1]).
+
+%%-------------------------------------------------------------------------
+%% The following type is a subtype of string() for return values
+%% of (some) functions of this module.
+%%-------------------------------------------------------------------------
+
+-type ascii_string() :: [1..255].
+
+%%-------------------------------------------------------------------------
+%% encode_to_string(ASCII) -> Base64String
+%%	ASCII - string() | binary()
+%%	Base64String - string()
+%%                                   
+%% Description: Encodes a plain ASCII string (or binary) into base64.
+%%-------------------------------------------------------------------------
+
+-spec encode_to_string(string() | binary()) -> ascii_string().
+
+encode_to_string(Bin) when is_binary(Bin) ->
+    encode_to_string(binary_to_list(Bin));
+encode_to_string(List) when is_list(List) ->
+    encode_l(List).
+
+%%-------------------------------------------------------------------------
+%% encode(ASCII) -> Base64
+%%	ASCII - string() | binary()
+%%	Base64 - binary()
+%%                                   
+%% Description: Encodes a plain ASCII string (or binary) into base64.
+%%-------------------------------------------------------------------------
+
+-spec encode(string() | binary()) -> binary().
+
+encode(Bin) when is_binary(Bin) ->
+    encode_binary(Bin);
+encode(List) when is_list(List) ->
+    list_to_binary(encode_l(List)).
+
+-spec encode_l(string()) -> ascii_string().
+
+encode_l([]) ->
+    [];
+encode_l([A]) ->
+    [b64e(A bsr 2),
+     b64e((A band 3) bsl 4), $=, $=];
+encode_l([A,B]) ->
+    [b64e(A bsr 2),
+     b64e(((A band 3) bsl 4) bor (B bsr 4)), 
+     b64e((B band 15) bsl 2), $=];
+encode_l([A,B,C|Ls]) ->
+    BB = (A bsl 16) bor (B bsl 8) bor C,
+    [b64e(BB bsr 18),
+     b64e((BB bsr 12) band 63), 
+     b64e((BB bsr 6) band 63),
+     b64e(BB band 63) | encode_l(Ls)].
+
+encode_binary(Bin) ->
+    Split = 3*(byte_size(Bin) div 3),
+    <<Main0:Split/binary,Rest/binary>> = Bin,
+    Main = << <<(b64e(C)):8>> || <<C:6>> <= Main0 >>,
+    case Rest of
+	<<A:6,B:6,C:4>> ->
+	    <<Main/binary,(b64e(A)):8,(b64e(B)):8,(b64e(C bsl 2)):8,$=:8>>;
+	<<A:6,B:2>> ->
+	    <<Main/binary,(b64e(A)):8,(b64e(B bsl 4)):8,$=:8,$=:8>>;
+	<<>> ->
+	    Main
+    end.
+
+%%-------------------------------------------------------------------------
+%% mime_decode(Base64) -> ASCII
+%% decode(Base64) -> ASCII
+%%	Base64 - string() | binary()
+%%	ASCII - binary()
+%%                                    
+%% Description: Decodes an base64 encoded string to plain ASCII.
+%% mime_decode strips away all characters not Base64 before converting,
+%% whereas decode crashes if an illegal character is found
+%%-------------------------------------------------------------------------
+
+-spec decode(string() | binary()) -> binary().
+
+decode(Bin) when is_binary(Bin) ->
+    decode_binary(<<>>, Bin);
+decode(List) when is_list(List) ->
+    list_to_binary(decode_l(List)).
+
+-spec mime_decode(string() | binary()) -> binary().
+
+mime_decode(Bin) when is_binary(Bin) ->
+    mime_decode_binary(<<>>, Bin);
+mime_decode(List) when is_list(List) ->
+    list_to_binary(mime_decode_l(List)).
+
+-spec decode_l(string()) -> string().
+
+decode_l(List) ->
+    L = strip_spaces(List, []),
+    decode(L, []).
+
+-spec mime_decode_l(string()) -> string().
+
+mime_decode_l(List) ->
+    L = strip_illegal(List, []),
+    decode(L, []).
+
+%%-------------------------------------------------------------------------
+%% mime_decode_to_string(Base64) -> ASCII
+%% decode_to_string(Base64) -> ASCII
+%%	Base64 - string() | binary()
+%%	ASCII - binary()
+%%
+%% Description: Decodes an base64 encoded string to plain ASCII.
+%% mime_decode strips away all characters not Base64 before converting,
+%% whereas decode crashes if an illegal character is found
+%%-------------------------------------------------------------------------
+
+-spec decode_to_string(string() | binary()) -> string().
+
+decode_to_string(Bin) when is_binary(Bin) ->
+    decode_to_string(binary_to_list(Bin));
+decode_to_string(List) when is_list(List) ->
+    decode_l(List).
+
+-spec mime_decode_to_string(string() | binary()) -> string().
+
+mime_decode_to_string(Bin) when is_binary(Bin) ->
+    mime_decode_to_string(binary_to_list(Bin));
+mime_decode_to_string(List) when is_list(List) ->
+    mime_decode_l(List).
+
+%% One-based decode map.
+-define(DECODE_MAP,
+	{bad,bad,bad,bad,bad,bad,bad,bad,ws,ws,bad,bad,ws,bad,bad, %1-15
+	 bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad, %16-31
+	 ws,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,62,bad,bad,bad,63, %32-47
+	 52,53,54,55,56,57,58,59,60,61,bad,bad,bad,eq,bad,bad, %48-63
+	 bad,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,
+	 15,16,17,18,19,20,21,22,23,24,25,bad,bad,bad,bad,bad,
+	 bad,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,
+	 41,42,43,44,45,46,47,48,49,50,51,bad,bad,bad,bad,bad,
+	 bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,
+	 bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,
+	 bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,
+	 bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,
+	 bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,
+	 bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,
+	 bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,
+	 bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad,bad}).
+
+decode_binary(Result0, <<C:8,T0/bits>>) ->
+    case element(C, ?DECODE_MAP) of
+	bad ->
+	    erlang:error({badarg,C});
+	ws ->
+	    decode_binary(Result0, T0);
+	eq ->
+	    case strip_ws(T0) of
+		<<$=:8,T/binary>> ->
+		    <<>> = strip_ws(T),
+		    Split = byte_size(Result0) - 1,
+		    <<Result:Split/bytes,_:4>> = Result0,
+		    Result;
+		T ->
+		    <<>> = strip_ws(T),
+		    Split = byte_size(Result0) - 1,
+		    <<Result:Split/bytes,_:2>> = Result0,
+		    Result
+	    end;
+	Bits ->
+	    decode_binary(<<Result0/bits,Bits:6>>, T0)
+    end;
+decode_binary(Result, <<>>) ->
+    true = is_binary(Result),
+    Result.
+
+mime_decode_binary(Result, <<0:8,T/bits>>) ->
+    mime_decode_binary(Result, T);
+mime_decode_binary(Result0, <<C:8,T/bits>>) ->
+    case element(C, ?DECODE_MAP) of
+	Bits when is_integer(Bits) ->
+	    mime_decode_binary(<<Result0/bits,Bits:6>>, T);
+	eq ->
+	    case tail_contains_equal(T) of
+		true ->
+		    Split = byte_size(Result0) - 1,
+		    <<Result:Split/bytes,_:4>> = Result0,
+		    Result;
+		false ->
+		    Split = byte_size(Result0) - 1,
+		    <<Result:Split/bytes,_:2>> = Result0,
+		    Result
+	    end;
+	_ ->
+	    mime_decode_binary(Result0, T)
+    end;
+mime_decode_binary(Result, <<>>) ->
+    true = is_binary(Result),
+    Result.
+
+decode([], A) -> A;
+decode([$=,$=,C2,C1|Cs], A) ->
+    Bits2x6 = (b64d(C1) bsl 18) bor (b64d(C2) bsl 12),
+    Octet1 = Bits2x6 bsr 16,
+    decode(Cs, [Octet1|A]);
+decode([$=,C3,C2,C1|Cs], A) ->
+    Bits3x6 = (b64d(C1) bsl 18) bor (b64d(C2) bsl 12)
+	bor (b64d(C3) bsl 6),
+    Octet1 = Bits3x6 bsr 16,
+    Octet2 = (Bits3x6 bsr 8) band 16#ff,
+    decode(Cs, [Octet1,Octet2|A]);
+decode([C4,C3,C2,C1| Cs], A) ->
+    Bits4x6 = (b64d(C1) bsl 18) bor (b64d(C2) bsl 12)
+	bor (b64d(C3) bsl 6) bor b64d(C4),
+    Octet1 = Bits4x6 bsr 16,
+    Octet2 = (Bits4x6 bsr 8) band 16#ff,
+    Octet3 = Bits4x6 band 16#ff,
+    decode(Cs, [Octet1,Octet2,Octet3|A]).
+
+%%%========================================================================
+%%% Internal functions
+%%%========================================================================
+
+strip_spaces([], A) -> A;
+strip_spaces([$\s|Cs], A) -> strip_spaces(Cs, A);
+strip_spaces([$\t|Cs], A) -> strip_spaces(Cs, A);
+strip_spaces([$\r|Cs], A) -> strip_spaces(Cs, A);
+strip_spaces([$\n|Cs], A) -> strip_spaces(Cs, A);
+strip_spaces([C|Cs], A) -> strip_spaces(Cs, [C | A]).
+
+strip_ws(<<$\t,T/binary>>) ->
+    strip_ws(T);
+strip_ws(<<$\n,T/binary>>) ->
+    strip_ws(T);
+strip_ws(<<$\r,T/binary>>) ->
+    strip_ws(T);
+strip_ws(<<$\s,T/binary>>) ->
+    strip_ws(T);
+strip_ws(T) -> T.
+
+strip_illegal([0|Cs], A) ->
+    strip_illegal(Cs, A);
+strip_illegal([C|Cs], A) ->
+    case element(C, ?DECODE_MAP) of
+	bad -> strip_illegal(Cs, A);
+	ws -> strip_illegal(Cs, A);
+	eq -> strip_illegal_end(Cs, [$=|A]);
+	_ -> strip_illegal(Cs, [C|A])
+    end;
+strip_illegal([], A) -> A.
+
+strip_illegal_end([0|Cs], A) ->
+    strip_illegal_end(Cs, A);
+strip_illegal_end([C|Cs], A) ->
+    case element(C, ?DECODE_MAP) of
+	bad -> strip_illegal(Cs, A);
+	ws -> strip_illegal(Cs, A);
+	eq -> [C|A];
+	_ -> strip_illegal(Cs, [C|A])
+    end;
+strip_illegal_end([], A) -> A.
+
+tail_contains_equal(<<$=,_/binary>>) -> true;
+tail_contains_equal(<<_,T/binary>>) -> tail_contains_equal(T);
+tail_contains_equal(<<>>) -> false.
+    
+%% accessors 
+b64e(X) ->
+    element(X+1,
+	    {$A, $B, $C, $D, $E, $F, $G, $H, $I, $J, $K, $L, $M, $N,
+	     $O, $P, $Q, $R, $S, $T, $U, $V, $W, $X, $Y, $Z,
+	     $a, $b, $c, $d, $e, $f, $g, $h, $i, $j, $k, $l, $m, $n,
+	     $o, $p, $q, $r, $s, $t, $u, $v, $w, $x, $y, $z,
+	     $0, $1, $2, $3, $4, $5, $6, $7, $8, $9, $+, $/}).
+
+
+b64d(X) ->
+    b64d_ok(element(X, ?DECODE_MAP)).
+
+b64d_ok(I) when is_integer(I) -> I.