如何在iPhone上使用Base64編碼

Question

如何在iPhone上使用Base64編碼？

我發現了一些看起來很有前途的例子，但是他們永遠無法讓他們中的任何一個人在手機上工作。

Answer 1

你可以看到一個例子here。

這是用於iOS7 +。

我在這裏複製的代碼，以防萬一：

// Create NSData object 
NSData *nsdata = [@"iOS Developer Tips encoded in Base64" 
    dataUsingEncoding:NSUTF8StringEncoding]; 

// Get NSString from NSData object in Base64 
NSString *base64Encoded = [nsdata base64EncodedStringWithOptions:0]; 

// Print the Base64 encoded string 
NSLog(@"Encoded: %@", base64Encoded); 

// Let's go the other way... 

// NSData from the Base64 encoded str 
NSData *nsdataFromBase64String = [[NSData alloc] 
    initWithBase64EncodedString:base64Encoded options:0]; 

// Decoded NSString from the NSData 
NSString *base64Decoded = [[NSString alloc] 
    initWithData:nsdataFromBase64String encoding:NSUTF8StringEncoding]; 
NSLog(@"Decoded: %@", base64Decoded); 

Answer 2

我也很難找到我可以理解的iPhone的工作代碼。

我終於寫下了這個。

-(NSString *)Base64Encode:(NSData *)data; 

-(NSString *)Base64Encode:(NSData *)data{ 

    //Point to start of the data and set buffer sizes 
    int inLength = [data length]; 
    int outLength = ((((inLength * 4)/3)/4)*4) + (((inLength * 4)/3)%4 ? 4 : 0); 
    const char *inputBuffer = [data bytes]; 
    char *outputBuffer = malloc(outLength+1); 
    outputBuffer[outLength] = 0; 

    //64 digit code 
    static char Encode[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz/"; 

    //Start the count 
    int cycle = 0; 
    int inpos = 0; 
    int outpos = 0; 
    char temp; 

    //Pad the last to bytes, the outbuffer must always be a multiple of 4. 
    outputBuffer[outLength-1] = '='; 
    outputBuffer[outLength-2] = '='; 

    /* http://en.wikipedia.org/wiki/Base64 

     Text content  M   a   n 
     ASCII   77  97  110 
     8 Bit pattern 01001101 01100001 01101110 

     6 Bit pattern 010011 010110 000101 101110 
     Index   19  22  5   46 
     Base64-encoded T   W   F   u 
    */ 

    while (inpos < inLength){ 
     switch (cycle) { 

      case 0: 
       outputBuffer[outpos++] = Encode[(inputBuffer[inpos] & 0xFC) >> 2]; 
       cycle = 1; 
       break; 

      case 1: 
       temp = (inputBuffer[inpos++] & 0x03) << 4; 
       outputBuffer[outpos] = Encode[temp]; 
       cycle = 2; 
       break; 

      case 2: 
       outputBuffer[outpos++] = Encode[temp|(inputBuffer[inpos]&0xF0) >> 4]; 
       temp = (inputBuffer[inpos++] & 0x0F) << 2; 
       outputBuffer[outpos] = Encode[temp]; 
       cycle = 3; 
       break; 

      case 3: 
       outputBuffer[outpos++] = Encode[temp|(inputBuffer[inpos]&0xC0) >> 6]; 
       cycle = 4; 
       break; 

      case 4: 
       outputBuffer[outpos++] = Encode[inputBuffer[inpos++] & 0x3f]; 
       cycle = 0; 
       break; 

      default: 
       cycle = 0; 
       break; 
     } 
    } 
    NSString *pictemp = [NSString stringWithUTF8String:outputBuffer]; 
    free(outputBuffer); 
    return pictemp; 
} 

Answer 3

使用this庫來編碼Base64。

它還支持ARC

Answer 4

的方法，一類NSData

- (NSString*)encodeBase64 {  
    static char* alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz/="; 

    unsigned int length = self.length; 
    unsigned const char* rawData = self.bytes; 

    //empty data = empty output 
    if (length == 0) { 
     return @""; 
    } 

    unsigned int outputLength = (((length + 2)/3) * 4); 

    //let's allocate buffer for the output 
    char* rawOutput = malloc(outputLength + 1); 

    //with each step we get 3 bytes from the input and write 4 bytes to the output 
    for (unsigned int i = 0, outputIndex = 0; i < length; i += 3, outputIndex += 4) { 
     BOOL triple = NO; 
     BOOL quad = NO; 

     //get 3 bytes (or only 1 or 2 when we have reached the end of input) 
     unsigned int value = rawData[i]; 
     value <<= 8; 

     if (i + 1 < length) { 
      value |= rawData[i + 1]; 
      triple = YES; 
     } 

     value <<= 8; 

     if (i + 2 < length) { 
      value |= rawData[i + 2]; 
      quad = YES; 
     } 

     //3 * 8 bits written as 4 * 6 bits (indexing the 64 chars of the alphabet) 
     //write = if end of input reached 
     rawOutput[outputIndex + 3] = (quad) ? alphabet[value & 0x3F] : '='; 
     value >>= 6; 
     rawOutput[outputIndex + 2] = (triple) ? alphabet[value & 0x3F] : '='; 
     value >>= 6; 
     rawOutput[outputIndex + 1] = alphabet[value & 0x3F]; 
     value >>= 6; 
     rawOutput[outputIndex] = alphabet[value & 0x3F]; 
    } 

    rawOutput[outputLength] = 0; 

    NSString* output = [NSString stringWithCString:rawOutput encoding:NSASCIIStringEncoding]; 

    free(rawOutput); 

    return output; 
} 

Answer 5

我做我自己的實現，其中已被刪除循環中的所有檢查。所以在大量的數據上，它的運行速度更快。您可以將其作爲自己解決方案的基礎。

static char *alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz/"; 

+ (NSString *)encodeString:(NSString *)data 
{ 
    const char *input = [data cStringUsingEncoding:NSUTF8StringEncoding]; 
    unsigned long inputLength = [data length]; 
    unsigned long modulo = inputLength % 3; 
    unsigned long outputLength = (inputLength/3) * 4 + (modulo ? 4 : 0); 
    unsigned long j = 0; 

    // Do not forget about trailing zero 
    unsigned char *output = malloc(outputLength + 1); 
    output[outputLength] = 0; 

    // Here are no checks inside the loop, so it works much faster than other implementations 
    for (unsigned long i = 0; i < inputLength; i += 3) { 
     output[j++] = alphabet[ (input[i] & 0xFC) >> 2 ]; 
     output[j++] = alphabet[ ((input[i] & 0x03) << 4) | ((input[i + 1] & 0xF0) >> 4) ]; 
     output[j++] = alphabet[ ((input[i + 1] & 0x0F)) << 2 | ((input[i + 2] & 0xC0) >> 6) ]; 
     output[j++] = alphabet[ (input[i + 2] & 0x3F) ]; 
    } 
    // Padding in the end of encoded string directly depends of modulo 
    if (modulo > 0) { 
     output[outputLength - 1] = '='; 
     if (modulo == 1) 
      output[outputLength - 2] = '='; 
    } 
    NSString *s = [NSString stringWithUTF8String:(const char *)output]; 
    free(output); 
    return s; 
} 

Answer 6

試試這個...這個工作完全用於me.create類別Base64.h和基地64.m，導入到你想使用和使用單線爲基數64編碼調用任何類發生。

// 
// Base64.h 
// CryptTest 
// Created by SURAJ K THOMAS on 02/05/2013. 


#import <Foundation/Foundation.h> 


@interface Base64 : NSObject { 

} 
+ (void) initialize; 
+ (NSString*) encode:(const uint8_t*) input length:(NSInteger) length; 
+ (NSString*) encode:(NSData*) rawBytes; 
+ (NSData*) decode:(const char*) string length:(NSInteger) inputLength; 
+ (NSData*) decode:(NSString*) string; 
@end 





#import "Base64.h" 


@implementation Base64 
#define ArrayLength(x) (sizeof(x)/sizeof(*(x))) 

static char encodingTable[] = 
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz/"; 
static char decodingTable[128]; 

+ (void) initialize { 
if (self == [Base64 class]) { 
    memset(decodingTable, 0, ArrayLength(decodingTable)); 
    for (NSInteger i = 0; i < ArrayLength(encodingTable); i++) { 
     decodingTable[encodingTable[i]] = i; 
    } 
} 
} 


+ (NSString*) encode:(const uint8_t*) input length:(NSInteger) length { 
NSMutableData* data = [NSMutableData dataWithLength:((length + 2)/3) * 4]; 
uint8_t* output = (uint8_t*)data.mutableBytes; 

for (NSInteger i = 0; i < length; i += 3) { 
    NSInteger value = 0; 
    for (NSInteger j = i; j < (i + 3); j++) { 
     value <<= 8; 

     if (j < length) { 
      value |= (0xFF & input[j]); 
     } 
    } 

    NSInteger index = (i/3) * 4; 
    output[index + 0] =     encodingTable[(value >> 18) & 0x3F]; 
    output[index + 1] =     encodingTable[(value >> 12) & 0x3F]; 
    output[index + 2] = (i + 1) < length ? encodingTable[(value >> 6) & 0x3F] : '='; 
    output[index + 3] = (i + 2) < length ? encodingTable[(value >> 0) & 0x3F] : '='; 
} 

return [[NSString alloc] initWithData:data 
           encoding:NSASCIIStringEncoding]; 
} 


+ (NSString*) encode:(NSData*) rawBytes { 
return [self encode:(const uint8_t*) rawBytes.bytes length:rawBytes.length]; 
} 


+ (NSData*) decode:(const char*) string length:(NSInteger) inputLength { 
if ((string == NULL) || (inputLength % 4 != 0)) { 
    return nil; 
} 

while (inputLength > 0 && string[inputLength - 1] == '=') { 
    inputLength--; 
} 

NSInteger outputLength = inputLength * 3/4; 
NSMutableData* data = [NSMutableData dataWithLength:outputLength]; 
uint8_t* output = data.mutableBytes; 

NSInteger inputPoint = 0; 
NSInteger outputPoint = 0; 
while (inputPoint < inputLength) { 
    char i0 = string[inputPoint++]; 
    char i1 = string[inputPoint++]; 
    char i2 = inputPoint < inputLength ? string[inputPoint++] : 'A'; /* 'A' will 
decode to \0 */ 
    char i3 = inputPoint < inputLength ? string[inputPoint++] : 'A'; 

    output[outputPoint++] = (decodingTable[i0] << 2) | (decodingTable[i1] >> 4); 
    if (outputPoint < outputLength) { 
     output[outputPoint++] = ((decodingTable[i1] & 0xf) << 4) | 
(decodingTable[i2] >> 2); 
    } 
    if (outputPoint < outputLength) { 
     output[outputPoint++] = ((decodingTable[i2] & 0x3) << 6) | 
decodingTable[i3]; 
    } 
} 

return data; 
} 


+ (NSData*) decode:(NSString*) string { 
return [self decode:[string cStringUsingEncoding:NSASCIIStringEncoding] 
length:string.length]; 
} 

@end

now import the above category to any class and convert the string like below 


NSString *authString = [[NSString stringWithFormat:@"OD0EK819OJFIFT6OJZZXT09Y1YUT1EJ2"] 
stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; 


NSData *inputData = [authString dataUsingEncoding:NSUTF8StringEncoding]; 

NSString *finalAuth =[Base64 encode:inputData]; 
NSLog(@"Encoded string =%@", finalAuth); 

Answer 7

下載從GitHub

Base64.h 
Base64.m 

以下兩個文件中所需的文件，這些文件添加到您的項目

導入頭文件

#import "Base64.h" 

而作爲使用編碼

NSString *plainText = @"Your String"; 

NSString *base64String = [plainText base64EncodedStringWithWrapWidth:0]; 

您也可以作爲

NSString *plainText = [base64String base64DecodedString]; 

Answer 8

解碼似乎適用於iOS 7，你不再需要任何圖書館的Base64編碼。在NSData下列方法可用於Base64編碼：

• base64EncodedDataWithOptions： - base64EncodedStringWithOptions：

Answer 9

reference

NSString *plainString = @"foo"; 

編碼

NSData *plainData = [plainString dataUsingEncoding:NSUTF8StringEncoding]; 
NSString *base64String = [plainData base64EncodedStringWithOptions:0]; 
NSLog(@"%@", base64String); // Zm9v 

解碼

NSData *decodedData = [[NSData alloc] initWithBase64EncodedString:base64String options:0]; 
NSString *decodedString = [[NSString alloc] initWithData:decodedData encoding:NSUTF8StringEncoding]; 
NSLog(@"%@", decodedString); // foo