CREATE FUNCTION base64_decode ( @encoded_text varchar(8000) ) RETURNS varchar(6000) AS BEGIN --local variables DECLARE @output varchar(8000), @block_start int, @encoded_length int, @decoded_length int, @mapr binary(122) --IF @encoded_text COLLATE LATIN1_GENERAL_BIN -- LIKE '%[^ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=]%' -- COLLATE LATIN1_GENERAL_BIN -- RETURN NULL --IF LEN(@encoded_text) & 3 > 0 -- RETURN NULL SET @output = '' -- The nth byte of @mapr contains the base64 value -- of the character with an ASCII value of n. -- EG, 65th byte = 0x00 = 0 = value of 'A' SET @mapr = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF -- 1-33 + 0xFFFFFFFFFFFFFFFFFFFF3EFFFFFF3F3435363738393A3B3C3DFFFFFF00FFFFFF -- 33-64 + 0x000102030405060708090A0B0C0D0E0F10111213141516171819FFFFFFFFFFFF -- 65-96 + 0x1A1B1C1D1E1F202122232425262728292A2B2C2D2E2F30313233 -- 97-122 --get the number of blocks to be decoded SET @encoded_length = LEN(@encoded_text) SET @decoded_length = @encoded_length / 4 * 3 --for each block SET @block_start = 1 WHILE @block_start < @encoded_length BEGIN --decode the block and add to output --BINARY values between 1 and 4 bytes can be implicitly cast to INT SET @output = @output + CAST(CAST(CAST( substring( @mapr, ascii( substring( @encoded_text, @block_start , 1) ), 1) * 262144 + substring( @mapr, ascii( substring( @encoded_text, @block_start + 1, 1) ), 1) * 4096 + substring( @mapr, ascii( substring( @encoded_text, @block_start + 2, 1) ), 1) * 64 + substring( @mapr, ascii( substring( @encoded_text, @block_start + 3, 1) ), 1) AS INTEGER) AS BINARY(3)) AS VARCHAR(3)) SET @block_start = @block_start + 4 END IF RIGHT(@encoded_text, 2) = '==' SET @decoded_length = @decoded_length - 2 ELSE IF RIGHT(@encoded_text, 1) = '=' SET @decoded_length = @decoded_length - 1 --IF SUBSTRING(@output, @decoded_length, 1) = CHAR(0) -- SET @decoded_length = @decoded_length - 1 --return the decoded string RETURN LEFT(@output, @decoded_length) END GO select dbo.base64_decode('amluamF6eg==')
xp_encode_base64.dll和
xp_decode_base64.dll两个动态库,里面就有编码和解码的扩展存储过程
(
@encoded_text varchar(8000)
)
RETURNS
varchar(6000)
AS BEGIN
--local variables
DECLARE
@output varchar(8000),
@block_start int,
@encoded_length int,
@decoded_length int,
@mapr binary(122)
--IF @encoded_text COLLATE LATIN1_GENERAL_BIN
-- LIKE '%[^ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=]%'
-- COLLATE LATIN1_GENERAL_BIN
-- RETURN NULL
--IF LEN(@encoded_text) & 3 > 0
-- RETURN NULL
SET @output = ''
-- The nth byte of @mapr contains the base64 value
-- of the character with an ASCII value of n.
-- EG, 65th byte = 0x00 = 0 = value of 'A'
SET @mapr =
0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF -- 1-33
+ 0xFFFFFFFFFFFFFFFFFFFF3EFFFFFF3F3435363738393A3B3C3DFFFFFF00FFFFFF -- 33-64
+ 0x000102030405060708090A0B0C0D0E0F10111213141516171819FFFFFFFFFFFF -- 65-96
+ 0x1A1B1C1D1E1F202122232425262728292A2B2C2D2E2F30313233 -- 97-122
--get the number of blocks to be decoded
SET @encoded_length = LEN(@encoded_text)
SET @decoded_length = @encoded_length / 4 * 3
--for each block
SET @block_start = 1
WHILE @block_start < @encoded_length BEGIN
--decode the block and add to output
--BINARY values between 1 and 4 bytes can be implicitly cast to INT
SET @output = @output + CAST(CAST(CAST(
substring( @mapr, ascii( substring( @encoded_text, @block_start , 1) ), 1) * 262144
+ substring( @mapr, ascii( substring( @encoded_text, @block_start + 1, 1) ), 1) * 4096
+ substring( @mapr, ascii( substring( @encoded_text, @block_start + 2, 1) ), 1) * 64
+ substring( @mapr, ascii( substring( @encoded_text, @block_start + 3, 1) ), 1)
AS INTEGER) AS BINARY(3)) AS VARCHAR(3))
SET @block_start = @block_start + 4
END
IF RIGHT(@encoded_text, 2) = '=='
SET @decoded_length = @decoded_length - 2
ELSE IF RIGHT(@encoded_text, 1) = '='
SET @decoded_length = @decoded_length - 1
--IF SUBSTRING(@output, @decoded_length, 1) = CHAR(0)
-- SET @decoded_length = @decoded_length - 1
--return the decoded string
RETURN LEFT(@output, @decoded_length)
END
GO select dbo.base64_decode('amluamF6eg==')
你先要搞清楚你在c#中把字符串转为byte数组的编码用的是什么。
public static string Encrypt(string value)
{ if (value != "")
{
DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
MemoryStream stream = new MemoryStream();
CryptoStream stream2=new CryptoStream(stream,provider.CreateEncryptor(KEY_64,IV_64),CryptoStreamMode.Write);
StreamWriter writer=new StreamWriter(stream2);
writer.Write(value);
writer.Flush();
stream2.FlushFinalBlock();
stream.Flush();
return Convert.ToBase64String(stream.GetBuffer(),0,(int)stream.Length);
}
return "";
}