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php、java、android、ios通用的3des方法

发布时间：2020-12-15 03:21:46 所属栏目：Java 来源：网络整理
导读：今天PHP站长网 52php.cn把收集自互联网的代码分享给大家，仅供参考。 ?phpclass?DES3?{var?$key?=?"my.oschina.net/penngo?#@";var?$iv?=?"01234567";function?encrypt($input){$size?=?mcrypt_get_block_size(MCRYPT_3DE

以下代码由PHP站长网 52php.cn收集自互联网

现在PHP站长网小编把它分享给大家，仅供参考

<?php
class?DES3?{
	var?$key?=?"my.oschina.net/penngo?#@";
	var?$iv?=?"01234567";

	function?encrypt($input){
		$size?=?mcrypt_get_block_size(MCRYPT_3DES,MCRYPT_MODE_CBC);
		$input?=?$this->pkcs5_pad($input,?$size);
		$key?=?str_pad($this->key,24,'0');
		$td?=?mcrypt_module_open(MCRYPT_3DES,?'',?MCRYPT_MODE_CBC,?'');
		if(?$this->iv?==?''?)
		{
			$iv?=?@mcrypt_create_iv?(mcrypt_enc_get_iv_size($td),?MCRYPT_RAND);
		}
		else
		{
			$iv?=?$this->iv;
		}
		@mcrypt_generic_init($td,?$key,?$iv);
		$data?=?mcrypt_generic($td,?$input);
		mcrypt_generic_deinit($td);
		mcrypt_module_close($td);
		$data?=?base64_encode($data);
		return?$data;
	}
	function?decrypt($encrypted){
		$encrypted?=?base64_decode($encrypted);
		$key?=?str_pad($this->key,'',MCRYPT_MODE_CBC,'');
		if(?$this->iv?==?''?)
		{
			$iv?=?@mcrypt_create_iv?(mcrypt_enc_get_iv_size($td),?MCRYPT_RAND);
		}
		else
		{
			$iv?=?$this->iv;
		}
		$ks?=?mcrypt_enc_get_key_size($td);
		@mcrypt_generic_init($td,?$iv);
		$decrypted?=?mdecrypt_generic($td,?$encrypted);
		mcrypt_generic_deinit($td);
		mcrypt_module_close($td);
		$y=$this->pkcs5_unpad($decrypted);
		return?$y;
	}
	function?pkcs5_pad?($text,?$blocksize)?{
		$pad?=?$blocksize?-?(strlen($text)?%?$blocksize);
		return?$text?.?str_repeat(chr($pad),?$pad);
	}
	function?pkcs5_unpad($text){
		$pad?=?ord($text{strlen($text)-1});
		if?($pad?>?strlen($text))?{
			return?false;
		}
		if?(strspn($text,?chr($pad),?strlen($text)?-?$pad)?!=?$pad){
			return?false;
		}
		return?substr($text,?0,?-1?*?$pad);
	}
	function?PaddingPKCS7($data)?{
		$block_size?=?mcrypt_get_block_size(MCRYPT_3DES,?MCRYPT_MODE_CBC);
		$padding_char?=?$block_size?-?(strlen($data)?%?$block_size);
		$data?.=?str_repeat(chr($padding_char),$padding_char);
		return?$data;
	}
}

$des?=?new?DES3();
echo?$ret?=?$des->encrypt("来自http://my.oschina.net/penngo的博客")?.?"n";
echo?$des->decrypt($ret)?.?"n";
import?java.io.ByteArrayOutputStream;
import?java.io.IOException;
import?java.io.OutputStream;
import?java.io.UnsupportedEncodingException;
import?java.security.Key;??

import?javax.crypto.Cipher;??
import?javax.crypto.SecretKeyFactory;??
import?javax.crypto.spec.DESedeKeySpec;??
import?javax.crypto.spec.IvParameterSpec;??
????????
/**?
??*?3DES加密工具类?
??*/?
public?class?DES3?{??
?????//?密钥??
?????private?final?static?String?secretKey?=?"my.oschina.net/penngo?#@"?;???
?????//?向量??
?????private?final?static?String?iv?=?"01234567"?;??
?????//?加解密统一使用的编码方式??
?????private?final?static?String?encoding?=?"utf-8"?;??
????????
?????/**?
??????*?3DES加密?
??????*??
??????*?@param?plainText?普通文本?
??????*?@return?
??????*?@throws?Exception??
??????*/?
?????public?static?String?encode(String?plainText)?throws?Exception?{??
?????????Key?deskey?=?null?;??
?????????DESedeKeySpec?spec?=?new?DESedeKeySpec(secretKey.getBytes());??
?????????SecretKeyFactory?keyfactory?=?SecretKeyFactory.getInstance(?"desede"?);??
?????????deskey?=?keyfactory.generateSecret(spec);??
????????
?????????Cipher?cipher?=?Cipher.getInstance(?"desede/CBC/PKCS5Padding"?);??
?????????IvParameterSpec?ips?=?new?IvParameterSpec(iv.getBytes());??
?????????cipher.init(Cipher.ENCRYPT_MODE,?deskey,?ips);??
?????????byte?[]?encryptData?=?cipher.doFinal(plainText.getBytes(encoding));??
?????????return?Base64.encode(encryptData);??
?????}??
????????
?????/**?
??????*?3DES解密?
??????*??
??????*?@param?encryptText?加密文本?
??????*?@return?
??????*?@throws?Exception?
??????*/?
?????public?static?String?decode(String?encryptText)?throws?Exception?{??
?????????Key?deskey?=?null?;??
?????????DESedeKeySpec?spec?=?new?DESedeKeySpec(secretKey.getBytes());???
?????????SecretKeyFactory?keyfactory?=?SecretKeyFactory.getInstance(?"desede"?);??
?????????deskey?=?keyfactory.generateSecret(spec);??
?????????Cipher?cipher?=?Cipher.getInstance(?"desede/CBC/PKCS5Padding"?);??
?????????IvParameterSpec?ips?=?new?IvParameterSpec(iv.getBytes());??
?????????cipher.init(Cipher.DECRYPT_MODE,?ips);??
????????
?????????byte?[]?decryptData?=?cipher.doFinal(Base64.decode(encryptText));??
????????
?????????return?new?String(decryptData,?encoding);??
?????}??
?????
?	public?static?String?padding(String?str)?{
		byte[]?oldByteArray;
		try?{
			oldByteArray?=?str.getBytes("UTF8");
			int?numberToPad?=?8?-?oldByteArray.length?%?8;
			byte[]?newByteArray?=?new?byte[oldByteArray.length?+?numberToPad];
			System.arraycopy(oldByteArray,?newByteArray,oldByteArray.length);
			for?(int?i?=?oldByteArray.length;?i?<?newByteArray.length;?++i)?{
				newByteArray[i]?=?0;
			}
			return?new?String(newByteArray,?"UTF8");
		}?catch?(UnsupportedEncodingException?e)?{
			System.out.println("Crypter.padding?UnsupportedEncodingException");
		}
		return?null;
	}
	
	/**?
	??*?Base64编码工具类?
	??*?
	??*/?
	public?static?class?Base64?{??
	?????private?static?final?char?[]?legalChars?=?"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"?.toCharArray();??
	????????
	?????public?static?String?encode(?byte?[]?data)?{??
	?????????int?start?=?0?;??
	?????????int?len?=?data.length;??
	?????????StringBuffer?buf?=?new?StringBuffer(data.length?*?3?/?2?);??
	????????
	?????????int?end?=?len?-?3?;??
	?????????int?i?=?start;??
	?????????int?n?=?0?;??
	????????
	?????????while?(i?<=?end)?{??
	?????????????int?d?=?((((?int?)?data[i])?&?0x0ff?)?<<?16?)?|?((((?int?)?data[i?+?1?])?&?0x0ff?)?<<?8?)?|?(((?int?)?data[i?+?2?])?&?0x0ff?);??
	????????
	?????????????buf.append(legalChars[(d?>>?18?)?&?63?]);??
	?????????????buf.append(legalChars[(d?>>?12?)?&?63?]);??
	?????????????buf.append(legalChars[(d?>>?6?)?&?63?]);??
	?????????????buf.append(legalChars[d?&?63?]);??
	????????
	?????????????i?+=?3?;??
	????????
	?????????????if?(n++?>=?14?)?{??
	?????????????????n?=?0?;??
	?????????????????buf.append(?"?"?);??
	?????????????}??
	?????????}??
	????????
	?????????if?(i?==?start?+?len?-?2?)?{??
	?????????????int?d?=?((((?int?)?data[i])?&?0x0ff?)?<<?16?)?|?((((?int?)?data[i?+?1?])?&?255?)?<<?8?);??
	????????
	?????????????buf.append(legalChars[(d?>>?18?)?&?63?]);??
	?????????????buf.append(legalChars[(d?>>?12?)?&?63?]);??
	?????????????buf.append(legalChars[(d?>>?6?)?&?63?]);??
	?????????????buf.append(?"="?);??
	?????????}?else?if?(i?==?start?+?len?-?1?)?{??
	?????????????int?d?=?(((?int?)?data[i])?&?0x0ff?)?<<?16?;??
	????????
	?????????????buf.append(legalChars[(d?>>?18?)?&?63?]);??
	?????????????buf.append(legalChars[(d?>>?12?)?&?63?]);??
	?????????????buf.append(?"=="?);??
	?????????}??
	????????
	?????????return?buf.toString();??
	?????}??
	????????
	?????private?static?int?decode(?char?c)?{??
	?????????if?(c?>=?'A'?&&?c?<=?'Z'?)??
	?????????????return?((?int?)?c)?-?65?;??
	?????????else?if?(c?>=?'a'?&&?c?<=?'z'?)??
	?????????????return?((?int?)?c)?-?97?+?26?;??
	?????????else?if?(c?>=?'0'?&&?c?<=?'9'?)??
	?????????????return?((?int?)?c)?-?48?+?26?+?26?;??
	?????????else?
	?????????????switch?(c)?{??
	?????????????case?'+'?:??
	?????????????????return?62?;??
	?????????????case?'/'?:??
	?????????????????return?63?;??
	?????????????case?'='?:??
	?????????????????return?0?;??
	?????????????default?:??
	?????????????????throw?new?RuntimeException(?"unexpected?code:?"?+?c);??
	?????????????}??
	?????}??
	????????
	?????/**?
	??????*?Decodes?the?given?Base64?encoded?String?to?a?new?byte?array.?The?byte?array?holding?the?decoded?data?is?returned.?
	??????*/?
	????????
	?????public?static?byte?[]?decode(String?s)?{??
	????????
	?????????ByteArrayOutputStream?bos?=?new?ByteArrayOutputStream();??
	?????????try?{??
	?????????????decode(s,?bos);??
	?????????}?catch?(IOException?e)?{??
	?????????????throw?new?RuntimeException();??
	?????????}??
	?????????byte?[]?decodedBytes?=?bos.toByteArray();??
	?????????try?{??
	?????????????bos.close();??
	?????????????bos?=?null?;??
	?????????}?catch?(IOException?ex)?{??
	?????????????System.err.println(?"Error?while?decoding?BASE64:?"?+?ex.toString());??
	?????????}??
	?????????return?decodedBytes;??
	?????}??
	????????
	?????private?static?void?decode(String?s,?OutputStream?os)?throws?IOException?{??
	?????????int?i?=?0?;??
	????????
	?????????int?len?=?s.length();??
	????????
	?????????while?(?true?)?{??
	?????????????while?(i?<?len?&&?s.charAt(i)?<=?'?'?)??
	?????????????????i++;??
	????????
	?????????????if?(i?==?len)??
	?????????????????break?;??
	????????
	?????????????int?tri?=?(decode(s.charAt(i))?<<?18?)?+?(decode(s.charAt(i?+?1?))?<<?12?)?+?(decode(s.charAt(i?+?2?))?<<?6?)?+?(decode(s.charAt(i?+?3?)));??
	????????
	?????????????os.write((tri?>>?16?)?&?255?);??
	?????????????if?(s.charAt(i?+?2?)?==?'='?)??
	?????????????????break?;??
	?????????????os.write((tri?>>?8?)?&?255?);??
	?????????????if?(s.charAt(i?+?3?)?==?'='?)??
	?????????????????break?;??
	?????????????os.write(tri?&?255?);??
	????????
	?????????????i?+=?4?;??
	?????????}??
	?????}??
	}?
?????
?????public?static?void?main(String[]?args)?throws?Exception{
????	?String?plainText?=?"来自http://my.oschina.net/penngo的博客";
????	?String?encryptText?=?DES3.encode(plainText);
????	?System.out.println(encryptText);
????	?System.out.println(DES3.decode(encryptText));

????	?
?????}
}
//??
//??DES3Util.h??
//??
#import?<Foundation/Foundation.h>??
@interface?DES3Util?:?NSObject?{??
}??
//?加密方法??
+?(NSString*)encrypt:(NSString*)plainText;??
//?解密方法??
+?(NSString*)decrypt:(NSString*)encryptText;??
@end?


//??
//??DES3Util.m??
//??
????????
#import?"DES3Util.h"??
#import?<CommonCrypto/CommonCryptor.h>??
#import?"GTMBase64.h"??
#define?gkey????????????@"my.oschina.net/penngo?#@"??
#define?gIv?????????????@"01234567"??
????????
@implementation?DES3Util??
//?加密方法??
+?(NSString*)encrypt:(NSString*)plainText?{??
?????NSData*?data?=?[plainText?dataUsingEncoding:NSUTF8StringEncoding];??
?????size_t?plainTextBufferSize?=?[data?length];??
?????const?void?*vplainText?=?(const?void?*)[data?bytes];??
????????????
?????CCCryptorStatus?ccStatus;??
?????uint8_t?*bufferPtr?=?NULL;??
?????size_t?bufferPtrSize?=?0;??
?????size_t?movedBytes?=?0;??
????????????
?????bufferPtrSize?=?(plainTextBufferSize?+?kCCBlockSize3DES)?&?~(kCCBlockSize3DES?-?1);??
?????bufferPtr?=?malloc(?bufferPtrSize?*?sizeof(uint8_t));??
?????memset((void?*)bufferPtr,?0x0,?bufferPtrSize);??
????????????
?????const?void?*vkey?=?(const?void?*)?[gkey?UTF8String];??
?????const?void?*vinitVec?=?(const?void?*)?[gIv?UTF8String];??
????????????
?????ccStatus?=?CCCrypt(kCCEncrypt,??
????????????????????????kCCAlgorithm3DES,??
????????????????????????kCCOptionPKCS7Padding,??
????????????????????????vkey,??
????????????????????????kCCKeySize3DES,??
????????????????????????vinitVec,??
????????????????????????vplainText,??
????????????????????????plainTextBufferSize,??
????????????????????????(void?*)bufferPtr,??
????????????????????????bufferPtrSize,??
????????????????????????&movedBytes);??
????????????
?????NSData?*myData?=?[NSData?dataWithBytes:(const?void?*)bufferPtr?length:(NSUInteger)movedBytes];??
?????NSString?*result?=?[GTMBase64?stringByEncodingData:myData];??
?????return?result;??
}??
????????
//?解密方法??
+?(NSString*)decrypt:(NSString*)encryptText?{??
?????NSData?*encryptData?=?[GTMBase64?decodeData:[encryptText?dataUsingEncoding:NSUTF8StringEncoding]];??
?????size_t?plainTextBufferSize?=?[encryptData?length];??
?????const?void?*vplainText?=?[encryptData?bytes];??
????????????
?????CCCryptorStatus?ccStatus;??
?????uint8_t?*bufferPtr?=?NULL;??
?????size_t?bufferPtrSize?=?0;??
?????size_t?movedBytes?=?0;??
?????bufferPtrSize?=?(plainTextBufferSize?+?kCCBlockSize3DES)?&?~(kCCBlockSize3DES?-?1);??
?????bufferPtr?=?malloc(?bufferPtrSize?*?sizeof(uint8_t));??
?????memset((void?*)bufferPtr,?bufferPtrSize);?????
?????const?void?*vkey?=?(const?void?*)?[gkey?UTF8String];??
?????const?void?*vinitVec?=?(const?void?*)?[gIv?UTF8String];??
????????????
?????ccStatus?=?CCCrypt(kCCDecrypt,??
????????????????????????&movedBytes);??
????????????
?????NSString?*result?=?[[[NSString?alloc]?initWithData:[NSData?dataWithBytes:(const?void?*)bufferPtr???
?????????????????????????????????length:(NSUInteger)movedBytes]?encoding:NSUTF8StringEncoding]?autorelease];??
?????return?result;??
}??
????????
@end
//
//??GTMBase64.h
//
//??Copyright?2006-2008?Google?Inc.
//
//??Licensed?under?the?Apache?License,?Version?2.0?(the?"License");?you?may?not
//??use?this?file?except?in?compliance?with?the?License.??You?may?obtain?a?copy
//??of?the?License?at
//
//??http://www.apache.org/licenses/LICENSE-2.0
//
//??Unless?required?by?applicable?law?or?agreed?to?in?writing,?software
//??distributed?under?the?License?is?distributed?on?an?"AS?IS"?BASIS,?WITHOUT
//??WARRANTIES?OR?CONDITIONS?OF?ANY?KIND,?either?express?or?implied.??See?the
//??License?for?the?specific?language?governing?permissions?and?limitations?under
//??the?License.

//?David?Lee?make?changes:
//?Remove?dependency?on?GTMDefines.h
//?add?some?string?to?string?function

#import?<Foundation/Foundation.h>

//?GTMBase64
//
///?Helper?for?handling?Base64?and?WebSafeBase64?encodings
//
///?The?webSafe?methods?use?different?character?set?and?also?the?results?aren't
///?always?padded?to?a?multiple?of?4?characters.??This?is?done?so?the?resulting
///?data?can?be?used?in?urls?and?url?query?arguments?without?needing?any
///?encoding.??You?must?use?the?webSafe*?methods?together,?the?data?does?not
///?interop?with?the?RFC?methods.
//
@interface?GTMBase64?:?NSObject

//
//?Standard?Base64?(RFC)?handling
//

//?encodeData:
//
///?Base64?encodes?contents?of?the?NSData?object.
//
///?Returns:
///???A?new?autoreleased?NSData?with?the?encoded?payload.??nil?for?any?error.
//
+(NSData?*)encodeData:(NSData?*)data;

//?decodeData:
//
///?Base64?decodes?contents?of?the?NSData?object.
//
///?Returns:
///???A?new?autoreleased?NSData?with?the?decoded?payload.??nil?for?any?error.
//
+(NSData?*)decodeData:(NSData?*)data;

//?encodeBytes:length:
//
///?Base64?encodes?the?data?pointed?at?by?|bytes|.
//
///?Returns:
///???A?new?autoreleased?NSData?with?the?encoded?payload.??nil?for?any?error.
//
+(NSData?*)encodeBytes:(const?void?*)bytes?length:(NSUInteger)length;

//?decodeBytes:length:
//
///?Base64?decodes?the?data?pointed?at?by?|bytes|.
//
///?Returns:
///???A?new?autoreleased?NSData?with?the?encoded?payload.??nil?for?any?error.
//
+(NSData?*)decodeBytes:(const?void?*)bytes?length:(NSUInteger)length;

//?stringByEncodingData:
//
///?Base64?encodes?contents?of?the?NSData?object.
//
///?Returns:
///???A?new?autoreleased?NSString?with?the?encoded?payload.??nil?for?any?error.
//
+(NSString?*)stringByEncodingData:(NSData?*)data;

//?stringByEncodingBytes:length:
//
///?Base64?encodes?the?data?pointed?at?by?|bytes|.
//
///?Returns:
///???A?new?autoreleased?NSString?with?the?encoded?payload.??nil?for?any?error.
//
+(NSString?*)stringByEncodingBytes:(const?void?*)bytes?length:(NSUInteger)length;

//?decodeString:
//
///?Base64?decodes?contents?of?the?NSString.
//
///?Returns:
///???A?new?autoreleased?NSData?with?the?decoded?payload.??nil?for?any?error.
//
+(NSData?*)decodeString:(NSString?*)string;

//
//?Modified?Base64?encoding?so?the?results?can?go?onto?urls.
//
//?The?changes?are?in?the?characters?generated?and?also?allows?the?result?to
//?not?be?padded?to?a?multiple?of?4.
//?Must?use?the?matching?call?to?encode/decode,?won't?interop?with?the
//?RFC?versions.
//

//?webSafeEncodeData:padded:
//
///?WebSafe?Base64?encodes?contents?of?the?NSData?object.??If?|padded|?is?YES
///?then?padding?characters?are?added?so?the?result?length?is?a?multiple?of?4.
//
///?Returns:
///???A?new?autoreleased?NSData?with?the?encoded?payload.??nil?for?any?error.
//
+(NSData?*)webSafeEncodeData:(NSData?*)data
??????????????????????padded:(BOOL)padded;

//?webSafeDecodeData:
//
///?WebSafe?Base64?decodes?contents?of?the?NSData?object.
//
///?Returns:
///???A?new?autoreleased?NSData?with?the?decoded?payload.??nil?for?any?error.
//
+(NSData?*)webSafeDecodeData:(NSData?*)data;

//?webSafeEncodeBytes:length:padded:
//
///?WebSafe?Base64?encodes?the?data?pointed?at?by?|bytes|.??If?|padded|?is?YES
///?then?padding?characters?are?added?so?the?result?length?is?a?multiple?of?4.
//
///?Returns:
///???A?new?autoreleased?NSData?with?the?encoded?payload.??nil?for?any?error.
//
+(NSData?*)webSafeEncodeBytes:(const?void?*)bytes
???????????????????????length:(NSUInteger)length
???????????????????????padded:(BOOL)padded;

//?webSafeDecodeBytes:length:
//
///?WebSafe?Base64?decodes?the?data?pointed?at?by?|bytes|.
//
///?Returns:
///???A?new?autoreleased?NSData?with?the?encoded?payload.??nil?for?any?error.
//
+(NSData?*)webSafeDecodeBytes:(const?void?*)bytes?length:(NSUInteger)length;

//?stringByWebSafeEncodingData:padded:
//
///?WebSafe?Base64?encodes?contents?of?the?NSData?object.??If?|padded|?is?YES
///?then?padding?characters?are?added?so?the?result?length?is?a?multiple?of?4.
//
///?Returns:
///???A?new?autoreleased?NSString?with?the?encoded?payload.??nil?for?any?error.
//
+(NSString?*)stringByWebSafeEncodingData:(NSData?*)data
??????????????????????????????????padded:(BOOL)padded;

//?stringByWebSafeEncodingBytes:length:padded:
//
///?WebSafe?Base64?encodes?the?data?pointed?at?by?|bytes|.??If?|padded|?is?YES
///?then?padding?characters?are?added?so?the?result?length?is?a?multiple?of?4.
//
///?Returns:
///???A?new?autoreleased?NSString?with?the?encoded?payload.??nil?for?any?error.
//
+(NSString?*)stringByWebSafeEncodingBytes:(const?void?*)bytes
???????????????????????????????????length:(NSUInteger)length
???????????????????????????????????padded:(BOOL)padded;

//?webSafeDecodeString:
//
///?WebSafe?Base64?decodes?contents?of?the?NSString.
//
///?Returns:
///???A?new?autoreleased?NSData?with?the?decoded?payload.??nil?for?any?error.
//
+(NSData?*)webSafeDecodeString:(NSString?*)string;

//?David?Lee?new?added?function
///?Returns:
//?A?new?autoreleased?NSString?with?Base64?encoded?NSString
+(NSString?*)stringByBase64String:(NSString?*)base64String;

//?David?Lee?new?added?function
///?Returns:
//?A?new?autoreleased?Base64?encoded?NSString?with??NSString
+(NSString?*)base64StringBystring:(NSString?*)string;
@end


//
//??GTMBase64.m
//
//??Copyright?2006-2008?Google?Inc.
//
//??Licensed?under?the?Apache?License,?either?express?or?implied.??See?the
//??License?for?the?specific?language?governing?permissions?and?limitations?under
//??the?License.
//?David?Lee?make?changes:
//?Remove?dependency?on?GTMDefines.h
//?add?some?string?to?string?function

#import?"GTMBase64.h"

static?const?char?*kBase64EncodeChars?=?"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static?const?char?*kWebSafeBase64EncodeChars?=?"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
static?const?char?kBase64PaddingChar?=?'=';
static?const?char?kBase64InvalidChar?=?99;

static?const?char?kBase64DecodeChars[]?=?{
????//?This?array?was?generated?by?the?following?code:
????//?#include?<sys/time.h>
????//?#include?<stdlib.h>
????//?#include?<string.h>
????//?main()
????//?{
????//???static?const?char?Base64[]?=
????//?????"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
????//???char?*pos;
????//???int?idx,?i,?j;
????//???printf("????");
????//???for?(i?=?0;?i?<?255;?i?+=?8)?{
????//?????for?(j?=?i;?j?<?i?+?8;?j++)?{
????//???????pos?=?strchr(Base64,?j);
????//???????if?((pos?==?NULL)?||?(j?==?0))
????//?????????idx?=?99;
????//???????else
????//?????????idx?=?pos?-?Base64;
????//???????if?(idx?==?99)
????//?????????printf("?%2d,?????",?idx);
????//???????else
????//?????????printf("?%2d/*%c*/,",?idx,?j);
????//?????}
????//?????printf("n????");
????//???}
????//?}
????99,??????99,????99,??????62/*+*/,?99,??????63/*/?*/,????52/*0*/,?53/*1*/,?54/*2*/,?55/*3*/,?56/*4*/,?57/*5*/,?58/*6*/,?59/*7*/,????60/*8*/,?61/*9*/,???????0/*A*/,??1/*B*/,??2/*C*/,??3/*D*/,??4/*E*/,??5/*F*/,??6/*G*/,????7/*H*/,??8/*I*/,??9/*J*/,?10/*K*/,?11/*L*/,?12/*M*/,?13/*N*/,?14/*O*/,????15/*P*/,?16/*Q*/,?17/*R*/,?18/*S*/,?19/*T*/,?20/*U*/,?21/*V*/,?22/*W*/,????23/*X*/,?24/*Y*/,?25/*Z*/,??????26/*a*/,?27/*b*/,?28/*c*/,?29/*d*/,?30/*e*/,?31/*f*/,?32/*g*/,????33/*h*/,?34/*i*/,?35/*j*/,?36/*k*/,?37/*l*/,?38/*m*/,?39/*n*/,?40/*o*/,????41/*p*/,?42/*q*/,?43/*r*/,?44/*s*/,?45/*t*/,?46/*u*/,?47/*v*/,?48/*w*/,????49/*x*/,?50/*y*/,?51/*z*/,??????99
};

static?const?char?kWebSafeBase64DecodeChars[]?=?{
????//?This?array?was?generated?by?the?following?code:
????//?#include?<sys/time.h>
????//?#include?<stdlib.h>
????//?#include?<string.h>
????//?main()
????//?{
????//???static?const?char?Base64[]?=
????//?????"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
????//???char?*pos;
????//???int?idx,??????62/*-*/,??????63/*_*/,??????99
};


//?Tests?a?character?to?see?if?it's?a?whitespace?character.
//
//?Returns:
//???YES?if?the?character?is?a?whitespace?character.
//???NO?if?the?character?is?not?a?whitespace?character.
//
BOOL?IsSpace(unsigned?char?c)?{
????//?we?use?our?own?mapping?here?because?we?don't?want?anything?w/?locale
????//?support.
????static?BOOL?kSpaces[256]?=?{
????????0,?1,??//?0-9
????????1,??//?10-19
????????0,??//?20-29
????????0,??//?30-39
????????0,??//?40-49
????????0,??//?50-59
????????0,??//?60-69
????????0,??//?70-79
????????0,??//?80-89
????????0,??//?90-99
????????0,??//?100-109
????????0,??//?110-119
????????0,??//?120-129
????????0,??//?130-139
????????0,??//?140-149
????????0,??//?150-159
????????1,??//?160-169
????????0,??//?170-179
????????0,??//?180-189
????????0,??//?190-199
????????0,??//?200-209
????????0,??//?210-219
????????0,??//?220-229
????????0,??//?230-239
????????0,??//?240-249
????????0,??????????????//?250-255
????};
????return?kSpaces[c];
}

//?Calculate?how?long?the?data?will?be?once?it's?base64?encoded.
//
//?Returns:
//???The?guessed?encoded?length?for?a?source?length
//
NSUInteger?CalcEncodedLength(NSUInteger?srcLen,?BOOL?padded)?{
????NSUInteger?intermediate_result?=?8?*?srcLen?+?5;
????NSUInteger?len?=?intermediate_result?/?6;
????if?(padded)?{
????????len?=?((len?+?3)?/?4)?*?4;
????}
????return?len;
}

//?Tries?to?calculate?how?long?the?data?will?be?once?it's?base64?decoded.
//?Unlike?the?above,?this?is?always?an?upperbound,?since?the?source?data
//?could?have?spaces?and?might?end?with?the?padding?characters?on?them.
//
//?Returns:
//???The?guessed?decoded?length?for?a?source?length
//
NSUInteger?GuessDecodedLength(NSUInteger?srcLen)?{
????return?(srcLen?+?3)?/?4?*?3;
}


@interface?GTMBase64?(PrivateMethods)

+(NSData?*)baseEncode:(const?void?*)bytes
???????????????length:(NSUInteger)length
??????????????charset:(const?char?*)charset
???????????????padded:(BOOL)padded;

+(NSData?*)baseDecode:(const?void?*)bytes
???????????????length:(NSUInteger)length
??????????????charset:(const?char*)charset
???????requirePadding:(BOOL)requirePadding;

+(NSUInteger)baseEncode:(const?char?*)srcBytes
?????????????????srcLen:(NSUInteger)srcLen
??????????????destBytes:(char?*)destBytes
????????????????destLen:(NSUInteger)destLen
????????????????charset:(const?char?*)charset
?????????????????padded:(BOOL)padded;

+(NSUInteger)baseDecode:(const?char?*)srcBytes
?????????????????srcLen:(NSUInteger)srcLen
??????????????destBytes:(char?*)destBytes
????????????????destLen:(NSUInteger)destLen
????????????????charset:(const?char?*)charset
?????????requirePadding:(BOOL)requirePadding;

@end


@implementation?GTMBase64

//
//?Standard?Base64?(RFC)?handling
//

+(NSData?*)encodeData:(NSData?*)data?{
????return?[self?baseEncode:[data?bytes]
?????????????????????length:[data?length]
????????????????????charset:kBase64EncodeChars
?????????????????????padded:YES];
}

+(NSData?*)decodeData:(NSData?*)data?{
????return?[self?baseDecode:[data?bytes]
?????????????????????length:[data?length]
????????????????????charset:kBase64DecodeChars
?????????????requirePadding:YES];
}

+(NSData?*)encodeBytes:(const?void?*)bytes?length:(NSUInteger)length?{
????return?[self?baseEncode:bytes
?????????????????????length:length
????????????????????charset:kBase64EncodeChars
?????????????????????padded:YES];
}

+(NSData?*)decodeBytes:(const?void?*)bytes?length:(NSUInteger)length?{
????return?[self?baseDecode:bytes
?????????????????????length:length
????????????????????charset:kBase64DecodeChars
?????????????requirePadding:YES];
}

+(NSString?*)stringByEncodingData:(NSData?*)data?{
????NSString?*result?=?nil;
????NSData?*converted?=?[self?baseEncode:[data?bytes]
??????????????????????????????????length:[data?length]
?????????????????????????????????charset:kBase64EncodeChars
??????????????????????????????????padded:YES];
????if?(converted)?{
????????result?=?[[[NSString?alloc]?initWithData:converted
????????????????????????????????????????encoding:NSASCIIStringEncoding]?autorelease];
????}
????return?result;
}

+(NSString?*)stringByEncodingBytes:(const?void?*)bytes?length:(NSUInteger)length?{
????NSString?*result?=?nil;
????NSData?*converted?=?[self?baseEncode:bytes
??????????????????????????????????length:length
?????????????????????????????????charset:kBase64EncodeChars
??????????????????????????????????padded:YES];
????if?(converted)?{
????????result?=?[[[NSString?alloc]?initWithData:converted
????????????????????????????????????????encoding:NSASCIIStringEncoding]?autorelease];
????}
????return?result;
}

+(NSData?*)decodeString:(NSString?*)string?{
????NSData?*result?=?nil;
????NSData?*data?=?[string?dataUsingEncoding:NSASCIIStringEncoding];
????if?(data)?{
????????result?=?[self?baseDecode:[data?bytes]
???????????????????????????length:[data?length]
??????????????????????????charset:kBase64DecodeChars
???????????????????requirePadding:YES];
????}
????return?result;
}

//
//?Modified?Base64?encoding?so?the?results?can?go?onto?urls.
//
//?The?changes?are?in?the?characters?generated?and?also?the?result?isn't
//?padded?to?a?multiple?of?4.
//?Must?use?the?matching?call?to?encode/decode,?won't?interop?with?the
//?RFC?versions.
//

+(NSData?*)webSafeEncodeData:(NSData?*)data
??????????????????????padded:(BOOL)padded?{
????return?[self?baseEncode:[data?bytes]
?????????????????????length:[data?length]
????????????????????charset:kWebSafeBase64EncodeChars
?????????????????????padded:padded];
}

+(NSData?*)webSafeDecodeData:(NSData?*)data?{
????return?[self?baseDecode:[data?bytes]
?????????????????????length:[data?length]
????????????????????charset:kWebSafeBase64DecodeChars
?????????????requirePadding:NO];
}

+(NSData?*)webSafeEncodeBytes:(const?void?*)bytes
???????????????????????length:(NSUInteger)length
???????????????????????padded:(BOOL)padded?{
????return?[self?baseEncode:bytes
?????????????????????length:length
????????????????????charset:kWebSafeBase64EncodeChars
?????????????????????padded:padded];
}

+(NSData?*)webSafeDecodeBytes:(const?void?*)bytes?length:(NSUInteger)length?{
????return?[self?baseDecode:bytes
?????????????????????length:length
????????????????????charset:kWebSafeBase64DecodeChars
?????????????requirePadding:NO];
}

+(NSString?*)stringByWebSafeEncodingData:(NSData?*)data
??????????????????????????????????padded:(BOOL)padded?{
????NSString?*result?=?nil;
????NSData?*converted?=?[self?baseEncode:[data?bytes]
??????????????????????????????????length:[data?length]
?????????????????????????????????charset:kWebSafeBase64EncodeChars
??????????????????????????????????padded:padded];
????if?(converted)?{
????????result?=?[[[NSString?alloc]?initWithData:converted
????????????????????????????????????????encoding:NSASCIIStringEncoding]?autorelease];
????}
????return?result;
}

+(NSString?*)stringByWebSafeEncodingBytes:(const?void?*)bytes
???????????????????????????????????length:(NSUInteger)length
???????????????????????????????????padded:(BOOL)padded?{
????NSString?*result?=?nil;
????NSData?*converted?=?[self?baseEncode:bytes
??????????????????????????????????length:length
?????????????????????????????????charset:kWebSafeBase64EncodeChars
??????????????????????????????????padded:padded];
????if?(converted)?{
????????result?=?[[[NSString?alloc]?initWithData:converted
????????????????????????????????????????encoding:NSASCIIStringEncoding]?autorelease];
????}
????return?result;
}

+(NSData?*)webSafeDecodeString:(NSString?*)string?{
????NSData?*result?=?nil;
????NSData?*data?=?[string?dataUsingEncoding:NSASCIIStringEncoding];
????if?(data)?{
????????result?=?[self?baseDecode:[data?bytes]
???????????????????????????length:[data?length]
??????????????????????????charset:kWebSafeBase64DecodeChars
???????????????????requirePadding:NO];
????}
????return?result;
}

//?David?Lee?new?added?function
///?Returns:
//?A?new?autoreleased?NSString?with?Base64?encoded?NSString
+(NSString?*)stringByBase64String:(NSString?*)base64String
{
????NSString?*sourceString?=?[[[NSString?alloc]?initWithData:[GTMBase64?decodeData:[base64String?dataUsingEncoding:NSUTF8StringEncoding?allowLossyConversion:NO]]?encoding:NSUTF8StringEncoding]?autorelease];
????return?sourceString;
}

//?David?Lee?new?added?function
///?Returns:
//?A?new?autoreleased?Base64?encoded?NSString?with?NSString
+(NSString?*)base64StringBystring:(NSString?*)string
{
????NSString?*base64String?=?[[[NSString?alloc]?initWithData:[GTMBase64?encodeData:[string?dataUsingEncoding:NSUTF8StringEncoding?allowLossyConversion:NO]]?encoding:NSUTF8StringEncoding]?autorelease];
????return?base64String;
}

@end

@implementation?GTMBase64?(PrivateMethods)

//
//?baseEncode:length:charset:padded:
//
//?Does?the?common?lifting?of?creating?the?dest?NSData.??it?creates?&?sizes?the
//?data?for?the?results.??|charset|?is?the?characters?to?use?for?the?encoding
//?of?the?data.??|padding|?controls?if?the?encoded?data?should?be?padded?to?a
//?multiple?of?4.
//
//?Returns:
//???an?autorelease?NSData?with?the?encoded?data,?nil?if?any?error.
//
+(NSData?*)baseEncode:(const?void?*)bytes
???????????????length:(NSUInteger)length
??????????????charset:(const?char?*)charset
???????????????padded:(BOOL)padded?{
????//?how?big?could?it?be?
????NSUInteger?maxLength?=?CalcEncodedLength(length,?padded);
????//?make?space
????NSMutableData?*result?=?[NSMutableData?data];
????[result?setLength:maxLength];
????//?do?it
????NSUInteger?finalLength?=?[self?baseEncode:bytes
???????????????????????????????????????srcLen:length
????????????????????????????????????destBytes:[result?mutableBytes]
??????????????????????????????????????destLen:[result?length]
??????????????????????????????????????charset:charset
???????????????????????????????????????padded:padded];
????if?(finalLength)?{
????????NSAssert(finalLength?==?maxLength,?@"how?did?we?calc?the?length?wrong?");
????}?else?{
????????//?shouldn't?happen,?this?means?we?ran?out?of?space
????????result?=?nil;
????}
????return?result;
}

//
//?baseDecode:length:charset:requirePadding:
//
//?Does?the?common?lifting?of?creating?the?dest?NSData.??it?creates?&?sizes?the
//?data?for?the?results.??|charset|?is?the?characters?to?use?for?the?decoding
//?of?the?data.
//
//?Returns:
//???an?autorelease?NSData?with?the?decoded?data,?nil?if?any?error.
//
//
+(NSData?*)baseDecode:(const?void?*)bytes
???????????????length:(NSUInteger)length
??????????????charset:(const?char?*)charset
???????requirePadding:(BOOL)requirePadding?{
????//?could?try?to?calculate?what?it?will?end?up?as
????NSUInteger?maxLength?=?GuessDecodedLength(length);
????//?make?space
????NSMutableData?*result?=?[NSMutableData?data];
????[result?setLength:maxLength];
????//?do?it
????NSUInteger?finalLength?=?[self?baseDecode:bytes
???????????????????????????????????????srcLen:length
????????????????????????????????????destBytes:[result?mutableBytes]
??????????????????????????????????????destLen:[result?length]
??????????????????????????????????????charset:charset
???????????????????????????????requirePadding:requirePadding];
????if?(finalLength)?{
????????if?(finalLength?!=?maxLength)?{
????????????//?resize?down?to?how?big?it?was
????????????[result?setLength:finalLength];
????????}
????}?else?{
????????//?either?an?error?in?the?args,?or?we?ran?out?of?space
????????result?=?nil;
????}
????return?result;
}

//
//?baseEncode:srcLen:destBytes:destLen:charset:padded:
//
//?Encodes?the?buffer?into?the?larger.??returns?the?length?of?the?encoded
//?data,?or?zero?for?an?error.
//?|charset|?is?the?characters?to?use?for?the?encoding
//?|padded|?tells?if?the?result?should?be?padded?to?a?multiple?of?4.
//
//?Returns:
//???the?length?of?the?encoded?data.??zero?if?any?error.
//
+(NSUInteger)baseEncode:(const?char?*)srcBytes
?????????????????srcLen:(NSUInteger)srcLen
??????????????destBytes:(char?*)destBytes
????????????????destLen:(NSUInteger)destLen
????????????????charset:(const?char?*)charset
?????????????????padded:(BOOL)padded?{
????if?(!srcLen?||?!destLen?||?!srcBytes?||?!destBytes)?{
????????return?0;
????}
????
????char?*curDest?=?destBytes;
????const?unsigned?char?*curSrc?=?(const?unsigned?char?*)(srcBytes);
????
????//?Three?bytes?of?data?encodes?to?four?characters?of?cyphertext.
????//?So?we?can?pump?through?three-byte?chunks?atomically.
????while?(srcLen?>?2)?{
????????//?space?
????????NSAssert(destLen?>=?4,?@"our?calc?for?encoded?length?was?wrong");
????????curDest[0]?=?charset[curSrc[0]?>>?2];
????????curDest[1]?=?charset[((curSrc[0]?&?0x03)?<<?4)?+?(curSrc[1]?>>?4)];
????????curDest[2]?=?charset[((curSrc[1]?&?0x0f)?<<?2)?+?(curSrc[2]?>>?6)];
????????curDest[3]?=?charset[curSrc[2]?&?0x3f];
????????
????????curDest?+=?4;
????????curSrc?+=?3;
????????srcLen?-=?3;
????????destLen?-=?4;
????}
????
????//?now?deal?with?the?tail?(<=2?bytes)
????switch?(srcLen)?{
????????case?0:
????????????//?Nothing?left;?nothing?more?to?do.
????????????break;
????????case?1:
????????????//?One?byte?left:?this?encodes?to?two?characters,?and?(optionally)
????????????//?two?pad?characters?to?round?out?the?four-character?cypherblock.
????????????NSAssert(destLen?>=?2,?@"our?calc?for?encoded?length?was?wrong");
????????????curDest[0]?=?charset[curSrc[0]?>>?2];
????????????curDest[1]?=?charset[(curSrc[0]?&?0x03)?<<?4];
????????????curDest?+=?2;
????????????destLen?-=?2;
????????????if?(padded)?{
????????????????NSAssert(destLen?>=?2,?@"our?calc?for?encoded?length?was?wrong");
????????????????curDest[0]?=?kBase64PaddingChar;
????????????????curDest[1]?=?kBase64PaddingChar;
????????????????curDest?+=?2;
????????????}
????????????break;
????????case?2:
????????????//?Two?bytes?left:?this?encodes?to?three?characters,?and?(optionally)
????????????//?one?pad?character?to?round?out?the?four-character?cypherblock.
????????????NSAssert(destLen?>=?3,?@"our?calc?for?encoded?length?was?wrong");
????????????curDest[0]?=?charset[curSrc[0]?>>?2];
????????????curDest[1]?=?charset[((curSrc[0]?&?0x03)?<<?4)?+?(curSrc[1]?>>?4)];
????????????curDest[2]?=?charset[(curSrc[1]?&?0x0f)?<<?2];
????????????curDest?+=?3;
????????????destLen?-=?3;
????????????if?(padded)?{
????????????????NSAssert(destLen?>=?1,?@"our?calc?for?encoded?length?was?wrong");
????????????????curDest[0]?=?kBase64PaddingChar;
????????????????curDest?+=?1;
????????????}
????????????break;
????}
????//?return?the?length
????return?(curDest?-?destBytes);
}

//
//?baseDecode:srcLen:destBytes:destLen:charset:requirePadding:
//
//?Decodes?the?buffer?into?the?larger.??returns?the?length?of?the?decoded
//?data,?or?zero?for?an?error.
//?|charset|?is?the?character?decoding?buffer?to?use
//
//?Returns:
//???the?length?of?the?encoded?data.??zero?if?any?error.
//
+(NSUInteger)baseDecode:(const?char?*)srcBytes
?????????????????srcLen:(NSUInteger)srcLen
??????????????destBytes:(char?*)destBytes
????????????????destLen:(NSUInteger)destLen
????????????????charset:(const?char?*)charset
?????????requirePadding:(BOOL)requirePadding?{
????if?(!srcLen?||?!destLen?||?!srcBytes?||?!destBytes)?{
????????return?0;
????}
????
????int?decode;
????NSUInteger?destIndex?=?0;
????int?state?=?0;
????char?ch?=?0;
????while?(srcLen--?&&?(ch?=?*srcBytes++)?!=?0)??{
????????if?(IsSpace(ch))??//?Skip?whitespace
????????????continue;
????????
????????if?(ch?==?kBase64PaddingChar)
????????????break;
????????
????????decode?=?charset[(unsigned?int)ch];
????????if?(decode?==?kBase64InvalidChar)
????????????return?0;
????????
????????//?Four?cyphertext?characters?decode?to?three?bytes.
????????//?Therefore?we?can?be?in?one?of?four?states.
????????switch?(state)?{
????????????case?0:
????????????????//?We're?at?the?beginning?of?a?four-character?cyphertext?block.
????????????????//?This?sets?the?high?six?bits?of?the?first?byte?of?the
????????????????//?plaintext?block.
????????????????NSAssert(destIndex?<?destLen,?@"our?calc?for?decoded?length?was?wrong");
????????????????destBytes[destIndex]?=?decode?<<?2;
????????????????state?=?1;
????????????????break;
????????????case?1:
????????????????//?We're?one?character?into?a?four-character?cyphertext?block.
????????????????//?This?sets?the?low?two?bits?of?the?first?plaintext?byte,????????????????//?and?the?high?four?bits?of?the?second?plaintext?byte.
????????????????NSAssert((destIndex+1)?<?destLen,?@"our?calc?for?decoded?length?was?wrong");
????????????????destBytes[destIndex]?|=?decode?>>?4;
????????????????destBytes[destIndex+1]?=?(decode?&?0x0f)?<<?4;
????????????????destIndex++;
????????????????state?=?2;
????????????????break;
????????????case?2:
????????????????//?We're?two?characters?into?a?four-character?cyphertext?block.
????????????????//?This?sets?the?low?four?bits?of?the?second?plaintext
????????????????//?byte,?and?the?high?two?bits?of?the?third?plaintext?byte.
????????????????//?However,?if?this?is?the?end?of?data,?and?those?two
????????????????//?bits?are?zero,?it?could?be?that?those?two?bits?are
????????????????//?leftovers?from?the?encoding?of?data?that?had?a?length
????????????????//?of?two?mod?three.
????????????????NSAssert((destIndex+1)?<?destLen,?@"our?calc?for?decoded?length?was?wrong");
????????????????destBytes[destIndex]?|=?decode?>>?2;
????????????????destBytes[destIndex+1]?=?(decode?&?0x03)?<<?6;
????????????????destIndex++;
????????????????state?=?3;
????????????????break;
????????????case?3:
????????????????//?We're?at?the?last?character?of?a?four-character?cyphertext?block.
????????????????//?This?sets?the?low?six?bits?of?the?third?plaintext?byte.
????????????????NSAssert(destIndex?<?destLen,?@"our?calc?for?decoded?length?was?wrong");
????????????????destBytes[destIndex]?|=?decode;
????????????????destIndex++;
????????????????state?=?0;
????????????????break;
????????}
????}
????
????//?We?are?done?decoding?Base-64?chars.??Let's?see?if?we?ended
????//??????on?a?byte?boundary,?and/or?with?erroneous?trailing?characters.
????if?(ch?==?kBase64PaddingChar)?{???????????????//?We?got?a?pad?char
????????if?((state?==?0)?||?(state?==?1))?{
????????????return?0;??//?Invalid?'='?in?first?or?second?position
????????}
????????if?(srcLen?==?0)?{
????????????if?(state?==?2)?{?//?We?run?out?of?input?but?we?still?need?another?'='
????????????????return?0;
????????????}
????????????//?Otherwise,?we?are?in?state?3?and?only?need?this?'='
????????}?else?{
????????????if?(state?==?2)?{??//?need?another?'='
????????????????while?((ch?=?*srcBytes++)?&&?(srcLen--?>?0))?{
????????????????????if?(!IsSpace(ch))
????????????????????????break;
????????????????}
????????????????if?(ch?!=?kBase64PaddingChar)?{
????????????????????return?0;
????????????????}
????????????}
????????????//?state?=?1?or?2,?check?if?all?remain?padding?is?space
????????????while?((ch?=?*srcBytes++)?&&?(srcLen--?>?0))?{
????????????????if?(!IsSpace(ch))?{
????????????????????return?0;
????????????????}
????????????}
????????}
????}?else?{
????????//?We?ended?by?seeing?the?end?of?the?string.
????????
????????if?(requirePadding)?{
????????????//?If?we?require?padding,?then?anything?but?state?0?is?an?error.
????????????if?(state?!=?0)?{
????????????????return?0;
????????????}
????????}?else?{
????????????//?Make?sure?we?have?no?partial?bytes?lying?around.??Note?that?we?do?not
????????????//?require?trailing?'=',?so?states?2?and?3?are?okay?too.
????????????if?(state?==?1)?{
????????????????return?0;
????????????}
????????}
????}
????
????//?If?then?next?piece?of?output?was?valid?and?got?written?to?it?means?we?got?a
????//?very?carefully?crafted?input?that?appeared?valid?but?contains?some?trailing
????//?bits?past?the?real?length,?so?just?toss?the?thing.
????if?((destIndex?<?destLen)?&&
????????(destBytes[destIndex]?!=?0))?{
????????return?0;
????}
????
????return?destIndex;
}

@end

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