How to encode Base64 on iPhone

Question

How can I make Base64 encoding on iPhone?

I found several examples that looked promising, but could never get them to work on the phone.

Answer 1

Here you can see an example.

This is for iOS7 +.

I copy the code here, just in case:

// 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 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

I was also unable to find working code for the iPhone that I could understand.

I finally wrote this.

 -(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[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; //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 an ASCII 77 97 110 8 Bit pattern 01001101 01100001 01101110 6 Bit pattern 010011 010110 000101 101110 Index 19 22 5 46 Base64-encoded TWF 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

Use this library to encode Base64.

It also supports ARC

Answer 4

Try this ... it worked perfectly for me. Create the categories Base64.h and Base 64.m. Import into any class you want to use and call it using a single line to encode base 64.

 // // 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[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; 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 5

Download two files from GitHub

 Base64.h Base64.m 

Add these files to your project

Import header file to desired file

 #import "Base64.h" 

And use for coding

 NSString *plainText = @"Your String"; NSString *base64String = [plainText base64EncodedStringWithWrapWidth:0]; 

You can also decode it as

 NSString *plainText = [base64String base64DecodedString]; 

Answer 6

It seems that with iOS 7 you no longer need libraries for encoding in Base64. The following NSData methods can be used to encode Base64:

• base64EncodedDataWithOptions: - base64EncodedStringWithOptions:

Answer 7

link

 NSString *plainString = @"foo"; 

Encoding

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

Decoding

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

Answer 8

Method in category NSData

 - (NSString*)encodeBase64 { static char* alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; 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 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 9

I performed my own implementation, where all the checks inside the loop were deleted. Thus, on a large amount of data, it works faster. You can take this as the basis for your own decision.

 static char *alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + (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; }