StackOverflow2013

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copied!<p>Here is a base 64 encode function for <code>NSString</code> to <code>NSString</code>:</p> <pre><code>+(NSString *) encodeString:(NSString *)inString { NSData *data = [inString dataUsingEncoding:NSUTF8StringEncoding]; //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); outputBuffer[outLength] = 0; //64 digit code static char Encode[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; //start the count int cycle = 0; int inpos = 0; int outpos = 0; char temp; outputBuffer[outLength-1] = '='; outputBuffer[outLength-2] = '='; 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; } </code></pre> <p>and Here is a base 64 decode function for <code>NSString</code> to <code>NSString</code>:</p> <pre><code>+(NSString *) decodeString:(NSString *)inString { const char* string = [inString cStringUsingEncoding:NSASCIIStringEncoding]; NSInteger inputLength = inString.length; static char decodingTable[128]; static char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; for (NSInteger i = 0; i < 128; i++) { decodingTable[encodingTable[i]] = i; } 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]; } } NSLog(@"%@",data); NSString *finalString = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding]; return finalString; } </code></pre> <p>These were pieced together from examples I found in various places on the internet when I was searching for them a while ago. They, may be easier for you to implement. I just created a <code>Base64</code> class and placed these methods in it.</p>

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