Base64 kodlama ve kod çözme yapmak istiyorum, ama iPhone SDK herhangi bir destek bulamadım. Nasıl base64 kodlama yapabilirim ya da bir kütüphane olmadan çözme?

Bu Amaç için kullanmak iyi bir durumda categories C.

Base64 kodlama:

#import <Foundation/NSString.h>

@interface NSString (NSStringAdditions)

  (NSString *) base64StringFromData:(NSData *)data length:(int)length;

@end

-------------------------------------------

#import "NSStringAdditions.h"

static char base64EncodingTable[64] = {
  'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
  'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
  'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
  'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ' ', '/'
};

@implementation NSString (NSStringAdditions)

  (NSString *) base64StringFromData: (NSData *)data length: (int)length {
  unsigned long ixtext, lentext;
  long ctremaining;
  unsigned char input[3], output[4];
  short i, charsonline = 0, ctcopy;
  const unsigned char *raw;
  NSMutableString *result;

  lentext = [data length]; 
  if (lentext < 1)
    return @"";
  result = [NSMutableString stringWithCapacity: lentext];
  raw = [data bytes];
  ixtext = 0; 

  while (true) {
    ctremaining = lentext - ixtext;
    if (ctremaining <= 0) 
       break;        
    for (i = 0; i < 3; i  ) { 
       unsigned long ix = ixtext   i;
       if (ix < lentext)
          input[i] = raw[ix];
       else
  input[i] = 0;
  }
  output[0] = (input[0] & 0xFC) >> 2;
  output[1] = ((input[0] & 0x03) << 4) | ((input[1] & 0xF0) >> 4);
  output[2] = ((input[1] & 0x0F) << 2) | ((input[2] & 0xC0) >> 6);
  output[3] = input[2] & 0x3F;
  ctcopy = 4;
  switch (ctremaining) {
    case 1: 
      ctcopy = 2; 
      break;
    case 2: 
      ctcopy = 3; 
      break;
  }

  for (i = 0; i < ctcopy; i  )
     [result appendString: [NSString stringWithFormat: @"%c", base64EncodingTable[output[i]]]];

  for (i = ctcopy; i < 4; i  )
     [result appendString: @"="];

  ixtext  = 3;
  charsonline  = 4;

  if ((length > 0) && (charsonline >= length))
    charsonline = 0;
  }     
  return result;
}

@end

Base64 kod çözme:

#import <Foundation/Foundation.h>

@class NSString;

@interface NSData (NSDataAdditions)

  (NSData *) base64DataFromString:(NSString *)string;

@end

-------------------------------------------

#import "NSDataAdditions.h"

@implementation NSData (NSDataAdditions)

  (NSData *)base64DataFromString: (NSString *)string
{
    unsigned long ixtext, lentext;
    unsigned char ch, inbuf[4], outbuf[3];
    short i, ixinbuf;
    Boolean flignore, flendtext = false;
    const unsigned char *tempcstring;
    NSMutableData *theData;

    if (string == nil)
    {
        return [NSData data];
    }

    ixtext = 0;

    tempcstring = (const unsigned char *)[string UTF8String];

    lentext = [string length];

    theData = [NSMutableData dataWithCapacity: lentext];

    ixinbuf = 0;

    while (true)
    {
        if (ixtext >= lentext)
        {
            break;
        }

        ch = tempcstring [ixtext  ];

        flignore = false;

        if ((ch >= 'A') && (ch <= 'Z'))
        {
            ch = ch - 'A';
        }
        else if ((ch >= 'a') && (ch <= 'z'))
        {
            ch = ch - 'a'   26;
        }
        else if ((ch >= '0') && (ch <= '9'))
        {
            ch = ch - '0'   52;
        }
        else if (ch == ' ')
        {
            ch = 62;
        }
        else if (ch == '=')
        {
            flendtext = true;
        }
        else if (ch == '/')
        {
            ch = 63;
        }
        else
        {
            flignore = true; 
        }

        if (!flignore)
        {
            short ctcharsinbuf = 3;
            Boolean flbreak = false;

            if (flendtext)
            {
                if (ixinbuf == 0)
                {
                    break;
                }

                if ((ixinbuf == 1) || (ixinbuf == 2))
                {
                    ctcharsinbuf = 1;
                }
                else
                {
                    ctcharsinbuf = 2;
                }

                ixinbuf = 3;

                flbreak = true;
            }

            inbuf [ixinbuf  ] = ch;

            if (ixinbuf == 4)
            {
                ixinbuf = 0;

                outbuf[0] = (inbuf[0] << 2) | ((inbuf[1] & 0x30) >> 4);
                outbuf[1] = ((inbuf[1] & 0x0F) << 4) | ((inbuf[2] & 0x3C) >> 2);
                outbuf[2] = ((inbuf[2] & 0x03) << 6) | (inbuf[3] & 0x3F);

                for (i = 0; i < ctcharsinbuf; i  )
                {
                    [theData appendBytes: &outbuf[i] length: 1];
                }
            }

            if (flbreak)
            {
                break;
            }
        }
    }

    return theData;
}

    @end