IOS常用加密GTMBase64

GTMDefines.h

//

// GTMDefines.h

//

//  Copyright 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.

//



// ============================================================================



#include <AvailabilityMacros.h>



// Not all MAC_OS_X_VERSION_10_X macros defined in past SDKs

#ifndef MAC_OS_X_VERSION_10_5

#define MAC_OS_X_VERSION_10_5 1050

#endif

#ifndef MAC_OS_X_VERSION_10_6

#define MAC_OS_X_VERSION_10_6 1060

#endif



// ----------------------------------------------------------------------------

// CPP symbols that can be overridden in a prefix to control how the toolbox

// is compiled.

// ----------------------------------------------------------------------------





// GTMHTTPFetcher will support logging by default but only hook its input

// stream support for logging when requested.  You can control the inclusion of

// the code by providing your own definitions for these w/in a prefix header.

//

#ifndef GTM_HTTPFETCHER_ENABLE_LOGGING

#define GTM_HTTPFETCHER_ENABLE_LOGGING 1

#endif // GTM_HTTPFETCHER_ENABLE_LOGGING

#ifndef GTM_HTTPFETCHER_ENABLE_INPUTSTREAM_LOGGING

#define GTM_HTTPFETCHER_ENABLE_INPUTSTREAM_LOGGING 0

#endif // GTM_HTTPFETCHER_ENABLE_INPUTSTREAM_LOGGING



// By setting the GTM_CONTAINERS_VALIDATION_FAILED_LOG and

// GTM_CONTAINERS_VALIDATION_FAILED_ASSERT macros you can control what happens

// when a validation fails. If you implement your own validators, you may want

// to control their internals using the same macros for consistency.

#ifndef GTM_CONTAINERS_VALIDATION_FAILED_ASSERT

#define GTM_CONTAINERS_VALIDATION_FAILED_ASSERT 0

#endif



// Give ourselves a consistent way to do inlines.  Apple's macros even use

// a few different actual definitions, so we're based off of the foundation

// one.

#if !defined(GTM_INLINE)

#if defined (__GNUC__) && (__GNUC__ == 4)

#define GTM_INLINE static __inline__ __attribute__((always_inline))

#else

#define GTM_INLINE static __inline__

#endif

#endif



// Give ourselves a consistent way of doing externs that links up nicely

// when mixing objc and objc++

#if !defined (GTM_EXTERN)

#if defined __cplusplus

#define GTM_EXTERN extern "C"

#else

#define GTM_EXTERN extern

#endif

#endif



// Give ourselves a consistent way of exporting things if we have visibility

// set to hidden.

#if !defined (GTM_EXPORT)

#define GTM_EXPORT __attribute__((visibility("default")))

#endif



// _GTMDevLog & _GTMDevAssert

//

// _GTMDevLog & _GTMDevAssert are meant to be a very lightweight shell for

// developer level errors.  This implementation simply macros to NSLog/NSAssert.

// It is not intended to be a general logging/reporting system.

//

// Please see http://code.google.com/p/google-toolbox-for-mac/wiki/DevLogNAssert

// for a little more background on the usage of these macros.

//

//    _GTMDevLog           log some error/problem in debug builds

//    _GTMDevAssert        assert if conditon isn't met w/in a method/function

//                           in all builds.

//

// To replace this system, just provide different macro definitions in your

// prefix header.  Remember, any implementation you provide *must* be thread

// safe since this could be called by anything in what ever situtation it has

// been placed in.

//



// We only define the simple macros if nothing else has defined this.

#ifndef _GTMDevLog



#ifdef DEBUG

#define _GTMDevLog(...) NSLog(__VA_ARGS__)

#else

#define _GTMDevLog(...) do { } while (0)

#endif



#endif // _GTMDevLog



// Declared here so that it can easily be used for logging tracking if

// necessary. See GTMUnitTestDevLog.h for details.

@class NSString;

GTM_EXTERN void _GTMUnitTestDevLog(NSString *format, ...);



#ifndef _GTMDevAssert

// we directly invoke the NSAssert handler so we can pass on the varargs

// (NSAssert doesn't have a macro we can use that takes varargs)

#if !defined(NS_BLOCK_ASSERTIONS)

#define _GTMDevAssert(condition, ...)                                       \

do {                                                                      \

if (!(condition)) {                                                     \

[[NSAssertionHandler currentHandler]                                  \

handleFailureInFunction:[NSString stringWithUTF8String:__PRETTY_FUNCTION__] \

file:[NSString stringWithUTF8String:__FILE__]  \

lineNumber:__LINE__                                  \

description:__VA_ARGS__];                             \

}                                                                       \

} while(0)

#else // !defined(NS_BLOCK_ASSERTIONS)

#define _GTMDevAssert(condition, ...) do { } while (0)

#endif // !defined(NS_BLOCK_ASSERTIONS)



#endif // _GTMDevAssert



// _GTMCompileAssert

// _GTMCompileAssert is an assert that is meant to fire at compile time if you

// want to check things at compile instead of runtime. For example if you

// want to check that a wchar is 4 bytes instead of 2 you would use

// _GTMCompileAssert(sizeof(wchar_t) == 4, wchar_t_is_4_bytes_on_OS_X)

// Note that the second "arg" is not in quotes, and must be a valid processor

// symbol in it's own right (no spaces, punctuation etc).



// Wrapping this in an #ifndef allows external groups to define their own

// compile time assert scheme.

#ifndef _GTMCompileAssert

// We got this technique from here:

// http://unixjunkie.blogspot.com/2007/10/better-compile-time-asserts_29.html



#define _GTMCompileAssertSymbolInner(line, msg) _GTMCOMPILEASSERT ## line ## __ ## msg

#define _GTMCompileAssertSymbol(line, msg) _GTMCompileAssertSymbolInner(line, msg)

#define _GTMCompileAssert(test, msg) \

typedef char _GTMCompileAssertSymbol(__LINE__, msg) [ ((test) ? 1 : -1) ]

#endif // _GTMCompileAssert



// Macro to allow fast enumeration when building for 10.5 or later, and

// reliance on NSEnumerator for 10.4.  Remember, NSDictionary w/ FastEnumeration

// does keys, so pick the right thing, nothing is done on the FastEnumeration

// side to be sure you're getting what you wanted.

#ifndef GTM_FOREACH_OBJECT

#if defined(TARGET_OS_IPHONE) || (MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_5)

#define GTM_FOREACH_OBJECT(element, collection) \

for (element in collection)

#define GTM_FOREACH_KEY(element, collection) \

for (element in collection)

#else

#define GTM_FOREACH_OBJECT(element, collection) \

for (NSEnumerator * _ ## element ## _enum = [collection objectEnumerator]; \

(element = [_ ## element ## _enum nextObject]) != nil; )

#define GTM_FOREACH_KEY(element, collection) \

for (NSEnumerator * _ ## element ## _enum = [collection keyEnumerator]; \

(element = [_ ## element ## _enum nextObject]) != nil; )

#endif

#endif



// ============================================================================



// ----------------------------------------------------------------------------

// CPP symbols defined based on the project settings so the GTM code has

// simple things to test against w/o scattering the knowledge of project

// setting through all the code.

// ----------------------------------------------------------------------------



// Provide a single constant CPP symbol that all of GTM uses for ifdefing

// iPhone code.

#include <TargetConditionals.h>

#if TARGET_OS_IPHONE // iPhone SDK

// For iPhone specific stuff

#define GTM_IPHONE_SDK 1

#if TARGET_IPHONE_SIMULATOR

#define GTM_IPHONE_SIMULATOR 1

#else

#define GTM_IPHONE_DEVICE 1

#endif  // TARGET_IPHONE_SIMULATOR

#else

// For MacOS specific stuff

#define GTM_MACOS_SDK 1

#endif



// Provide a symbol to include/exclude extra code for GC support.  (This mainly

// just controls the inclusion of finalize methods).

#ifndef GTM_SUPPORT_GC

#if GTM_IPHONE_SDK

// iPhone never needs GC

#define GTM_SUPPORT_GC 0

#else

// We can't find a symbol to tell if GC is supported/required, so best we

// do on Mac targets is include it if we're on 10.5 or later.

#if MAC_OS_X_VERSION_MAX_ALLOWED <= MAC_OS_X_VERSION_10_4

#define GTM_SUPPORT_GC 0

#else

#define GTM_SUPPORT_GC 1

#endif

#endif

#endif



// To simplify support for 64bit (and Leopard in general), we provide the type

// defines for non Leopard SDKs

#if MAC_OS_X_VERSION_MAX_ALLOWED <= MAC_OS_X_VERSION_10_4

// NSInteger/NSUInteger and Max/Mins

#ifndef NSINTEGER_DEFINED

#if __LP64__ || NS_BUILD_32_LIKE_64

typedef long NSInteger;

typedef unsigned long NSUInteger;

#else

typedef int NSInteger;

typedef unsigned int NSUInteger;

#endif

#define NSIntegerMax    LONG_MAX

#define NSIntegerMin    LONG_MIN

#define NSUIntegerMax   ULONG_MAX

#define NSINTEGER_DEFINED 1

#endif  // NSINTEGER_DEFINED

// CGFloat

#ifndef CGFLOAT_DEFINED

#if defined(__LP64__) && __LP64__

// This really is an untested path (64bit on Tiger?)

typedef double CGFloat;

#define CGFLOAT_MIN DBL_MIN

#define CGFLOAT_MAX DBL_MAX

#define CGFLOAT_IS_DOUBLE 1

#else /* !defined(__LP64__) || !__LP64__ */

typedef float CGFloat;

#define CGFLOAT_MIN FLT_MIN

#define CGFLOAT_MAX FLT_MAX

#define CGFLOAT_IS_DOUBLE 0

#endif /* !defined(__LP64__) || !__LP64__ */

#define CGFLOAT_DEFINED 1

#endif // CGFLOAT_DEFINED

#endif  // MAC_OS_X_VERSION_MAX_ALLOWED <= MAC_OS_X_VERSION_10_4

GTMBase64.h

//

//  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.

//



#import <Foundation/Foundation.h>

#import "GTMDefines.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;



@end

GTMBase64.m

//

//  GTMBase64.m

//

//  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.

//



#import "GTMBase64.h"

#import "GTMDefines.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,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      62/*+*/, 99,      99,      99,      63/*/ */,

    52/*0*/, 53/*1*/, 54/*2*/, 55/*3*/, 56/*4*/, 57/*5*/, 58/*6*/, 59/*7*/,

    60/*8*/, 61/*9*/, 99,      99,      99,      99,      99,      99,

    99,       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*/, 99,      99,      99,      99,      99,

    99,      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,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      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, 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,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      62/*-*/, 99,      99,

    52/*0*/, 53/*1*/, 54/*2*/, 55/*3*/, 56/*4*/, 57/*5*/, 58/*6*/, 59/*7*/,

    60/*8*/, 61/*9*/, 99,      99,      99,      99,      99,      99,

    99,       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*/, 99,      99,      99,      99,      63/*_*/,

    99,      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,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99,

    99,      99,      99,      99,      99,      99,      99,      99

};





// Tests a charact 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.

//

FOUNDATION_STATIC_INLINE 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, 0, 0, 0, 0, 0, 0, 0, 0, 1,  // 0-9

        1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  // 10-19

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 20-29

        0, 0, 1, 0, 0, 0, 0, 0, 0, 0,  // 30-39

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 40-49

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 50-59

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 60-69

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 70-79

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 80-89

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 90-99

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 100-109

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 110-119

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 120-129

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 130-139

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 140-149

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 150-159

        1, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 160-169

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 170-179

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 180-189

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 190-199

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 200-209

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 210-219

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 220-229

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 230-239

        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 240-249

        0, 0, 0, 0, 0, 1,              // 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

//

FOUNDATION_STATIC_INLINE 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.

// Unlinke 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

//

FOUNDATION_STATIC_INLINE 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] ;

    }

    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] ;

    }

    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] ;

    }

    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] ;

    }

    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;

}



@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) {

        _GTMDevAssert(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?

        _GTMDevAssert(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.

            _GTMDevAssert(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) {

                _GTMDevAssert(destLen >= 2, @"our calc for encoded length was wrong");

                curDest[0] = kBase64PaddingChar;

                curDest[1] = kBase64PaddingChar;

                curDest += 2;

                destLen -= 2;

            }

            break;

        case 2:

            // Two bytes left: this encodes to three characters, and (optionally)

            // one pad character to round out the four-character cypherblock.

            _GTMDevAssert(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) {

                _GTMDevAssert(destLen >= 1, @"our calc for encoded length was wrong");

                curDest[0] = kBase64PaddingChar;

                curDest += 1;

                destLen -= 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.

                _GTMDevAssert(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.

                _GTMDevAssert((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.

                _GTMDevAssert((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.

                _GTMDevAssert(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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