| // |
| // NSData+Base64.m |
| // base64 |
| // |
| // Created by Matt Gallagher on 2009/06/03. |
| // Copyright 2009 Matt Gallagher. All rights reserved. |
| // |
| // Permission is given to use this source code file, free of charge, in any |
| // project, commercial or otherwise, entirely at your risk, with the condition |
| // that any redistribution (in part or whole) of source code must retain |
| // this copyright and permission notice. Attribution in compiled projects is |
| // appreciated but not required. |
| // |
| |
| #import "NSData+Base64.h" |
| |
| // |
| // Mapping from 6 bit pattern to ASCII character. |
| // |
| static unsigned char cdvbase64EncodeLookup[65] = |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
| |
| // |
| // Definition for "masked-out" areas of the base64DecodeLookup mapping |
| // |
| #define xx 65 |
| |
| // |
| // Mapping from ASCII character to 6 bit pattern. |
| // |
| static unsigned char cdvbase64DecodeLookup[256] = |
| { |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 62, xx, xx, xx, 63, |
| 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, xx, xx, xx, xx, xx, xx, |
| xx, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, |
| 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, xx, xx, xx, xx, xx, |
| xx, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, |
| 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, xx, xx, xx, xx, xx, |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, |
| xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, |
| }; |
| |
| // |
| // Fundamental sizes of the binary and base64 encode/decode units in bytes |
| // |
| #define CDV_BINARY_UNIT_SIZE 3 |
| #define CDV_BASE64_UNIT_SIZE 4 |
| |
| // |
| // NewBase64Decode |
| // |
| // Decodes the base64 ASCII string in the inputBuffer to a newly malloced |
| // output buffer. |
| // |
| // inputBuffer - the source ASCII string for the decode |
| // length - the length of the string or -1 (to specify strlen should be used) |
| // outputLength - if not-NULL, on output will contain the decoded length |
| // |
| // returns the decoded buffer. Must be freed by caller. Length is given by |
| // outputLength. |
| // |
| void *CDVNewBase64Decode( |
| const char* inputBuffer, |
| size_t length, |
| size_t * outputLength) |
| { |
| if (length == -1) { |
| length = strlen(inputBuffer); |
| } |
| |
| size_t outputBufferSize = (length / CDV_BASE64_UNIT_SIZE) * CDV_BINARY_UNIT_SIZE; |
| unsigned char* outputBuffer = (unsigned char*)malloc(outputBufferSize); |
| |
| size_t i = 0; |
| size_t j = 0; |
| |
| while (i < length) { |
| // |
| // Accumulate 4 valid characters (ignore everything else) |
| // |
| unsigned char accumulated[CDV_BASE64_UNIT_SIZE]; |
| bzero(accumulated, sizeof(unsigned char) * CDV_BASE64_UNIT_SIZE); |
| size_t accumulateIndex = 0; |
| |
| while (i < length) { |
| unsigned char decode = cdvbase64DecodeLookup[inputBuffer[i++]]; |
| if (decode != xx) { |
| accumulated[accumulateIndex] = decode; |
| accumulateIndex++; |
| |
| if (accumulateIndex == CDV_BASE64_UNIT_SIZE) { |
| break; |
| } |
| } |
| } |
| |
| // |
| // Store the 6 bits from each of the 4 characters as 3 bytes |
| // |
| outputBuffer[j] = (accumulated[0] << 2) | (accumulated[1] >> 4); |
| outputBuffer[j + 1] = (accumulated[1] << 4) | (accumulated[2] >> 2); |
| outputBuffer[j + 2] = (accumulated[2] << 6) | accumulated[3]; |
| j += accumulateIndex - 1; |
| } |
| |
| if (outputLength) { |
| *outputLength = j; |
| } |
| return outputBuffer; |
| } |
| |
| // |
| // NewBase64Decode |
| // |
| // Encodes the arbitrary data in the inputBuffer as base64 into a newly malloced |
| // output buffer. |
| // |
| // inputBuffer - the source data for the encode |
| // length - the length of the input in bytes |
| // separateLines - if zero, no CR/LF characters will be added. Otherwise |
| // a CR/LF pair will be added every 64 encoded chars. |
| // outputLength - if not-NULL, on output will contain the encoded length |
| // (not including terminating 0 char) |
| // |
| // returns the encoded buffer. Must be freed by caller. Length is given by |
| // outputLength. |
| // |
| char *CDVNewBase64Encode( |
| const void* buffer, |
| size_t length, |
| bool separateLines, |
| size_t * outputLength) |
| { |
| const unsigned char* inputBuffer = (const unsigned char*)buffer; |
| |
| #define MAX_NUM_PADDING_CHARS 2 |
| #define OUTPUT_LINE_LENGTH 64 |
| #define INPUT_LINE_LENGTH ((OUTPUT_LINE_LENGTH / CDV_BASE64_UNIT_SIZE) * CDV_BINARY_UNIT_SIZE) |
| #define CR_LF_SIZE 0 |
| |
| // |
| // Byte accurate calculation of final buffer size |
| // |
| size_t outputBufferSize = |
| ((length / CDV_BINARY_UNIT_SIZE) |
| + ((length % CDV_BINARY_UNIT_SIZE) ? 1 : 0)) |
| * CDV_BASE64_UNIT_SIZE; |
| if (separateLines) { |
| outputBufferSize += |
| (outputBufferSize / OUTPUT_LINE_LENGTH) * CR_LF_SIZE; |
| } |
| |
| // |
| // Include space for a terminating zero |
| // |
| outputBufferSize += 1; |
| |
| // |
| // Allocate the output buffer |
| // |
| char* outputBuffer = (char*)malloc(outputBufferSize); |
| if (!outputBuffer) { |
| return NULL; |
| } |
| |
| size_t i = 0; |
| size_t j = 0; |
| const size_t lineLength = separateLines ? INPUT_LINE_LENGTH : length; |
| size_t lineEnd = lineLength; |
| |
| while (true) { |
| if (lineEnd > length) { |
| lineEnd = length; |
| } |
| |
| for (; i + CDV_BINARY_UNIT_SIZE - 1 < lineEnd; i += CDV_BINARY_UNIT_SIZE) { |
| // |
| // Inner loop: turn 48 bytes into 64 base64 characters |
| // |
| outputBuffer[j++] = cdvbase64EncodeLookup[(inputBuffer[i] & 0xFC) >> 2]; |
| outputBuffer[j++] = cdvbase64EncodeLookup[((inputBuffer[i] & 0x03) << 4) |
| | ((inputBuffer[i + 1] & 0xF0) >> 4)]; |
| outputBuffer[j++] = cdvbase64EncodeLookup[((inputBuffer[i + 1] & 0x0F) << 2) |
| | ((inputBuffer[i + 2] & 0xC0) >> 6)]; |
| outputBuffer[j++] = cdvbase64EncodeLookup[inputBuffer[i + 2] & 0x3F]; |
| } |
| |
| if (lineEnd == length) { |
| break; |
| } |
| |
| // |
| // Add the newline |
| // |
| // outputBuffer[j++] = '\r'; |
| // outputBuffer[j++] = '\n'; |
| lineEnd += lineLength; |
| } |
| |
| if (i + 1 < length) { |
| // |
| // Handle the single '=' case |
| // |
| outputBuffer[j++] = cdvbase64EncodeLookup[(inputBuffer[i] & 0xFC) >> 2]; |
| outputBuffer[j++] = cdvbase64EncodeLookup[((inputBuffer[i] & 0x03) << 4) |
| | ((inputBuffer[i + 1] & 0xF0) >> 4)]; |
| outputBuffer[j++] = cdvbase64EncodeLookup[(inputBuffer[i + 1] & 0x0F) << 2]; |
| outputBuffer[j++] = '='; |
| } else if (i < length) { |
| // |
| // Handle the double '=' case |
| // |
| outputBuffer[j++] = cdvbase64EncodeLookup[(inputBuffer[i] & 0xFC) >> 2]; |
| outputBuffer[j++] = cdvbase64EncodeLookup[(inputBuffer[i] & 0x03) << 4]; |
| outputBuffer[j++] = '='; |
| outputBuffer[j++] = '='; |
| } |
| outputBuffer[j] = 0; |
| |
| // |
| // Set the output length and return the buffer |
| // |
| if (outputLength) { |
| *outputLength = j; |
| } |
| return outputBuffer; |
| } |
| |
| @implementation NSData (CDVBase64) |
| |
| // |
| // dataFromBase64String: |
| // |
| // Creates an NSData object containing the base64 decoded representation of |
| // the base64 string 'aString' |
| // |
| // Parameters: |
| // aString - the base64 string to decode |
| // |
| // returns the autoreleased NSData representation of the base64 string |
| // |
| + (NSData*)dataFromBase64String:(NSString*)aString |
| { |
| size_t outputLength = 0; |
| void* outputBuffer = CDVNewBase64Decode([aString UTF8String], [aString length], &outputLength); |
| |
| return [NSData dataWithBytesNoCopy:outputBuffer length:outputLength freeWhenDone:YES]; |
| } |
| |
| // |
| // base64EncodedString |
| // |
| // Creates an NSString object that contains the base 64 encoding of the |
| // receiver's data. Lines are broken at 64 characters long. |
| // |
| // returns an autoreleased NSString being the base 64 representation of the |
| // receiver. |
| // |
| - (NSString*)base64EncodedString |
| { |
| size_t outputLength = 0; |
| char* outputBuffer = |
| CDVNewBase64Encode([self bytes], [self length], true, &outputLength); |
| |
| NSString* result = [[NSString alloc] initWithBytesNoCopy:outputBuffer |
| length:outputLength |
| encoding:NSASCIIStringEncoding |
| freeWhenDone:YES]; |
| |
| return result; |
| } |
| |
| @end |