//

 //  Base64.m

 //  MYUtilities

 //

 //  Created by Jens Alfke on 1/27/08.

 //  Copyright 2008 Jens Alfke. All rights reserved.

 //

 //  Adapted from SSCrypto.m by Ed Silva;

 //  Copyright (c) 2003-2006 Septicus Software. All rights reserved.

 //

 #import "Base64.h"

 //NOTE: Using this requires linking against /usr/lib/libcrypto.dylib.

 #import <openssl/bio.h>

 #import <openssl/evp.h>

 @implementation NSData (MYBase64)

 /**

  * Encodes the current data in base64, and creates and returns an NSString from the result.

  * This is the same as piping data through "... | openssl enc -base64" on the command line.

  *

  * Code courtesy of DaveDribin (http://www.dribin.org/dave/)

  * Taken from http://www.cocoadev.com/index.pl?BaseSixtyFour

  **/

 - (NSString *)my_base64String

 {

     return [self my_base64StringWithNewlines: YES];

 }

 /**

  * Encodes the current data in base64, and creates and returns an NSString from the result.

  * This is the same as piping data through "... | openssl enc -base64" on the command line.

  *

  * Code courtesy of DaveDribin (http://www.dribin.org/dave/)

  * Taken from http://www.cocoadev.com/index.pl?BaseSixtyFour

  **/

 - (NSString *)my_base64StringWithNewlines:(BOOL)encodeWithNewlines

 {

     // Create a memory buffer which will contain the Base64 encoded string

     BIO * mem = BIO_new(BIO_s_mem());

     // Push on a Base64 filter so that writing to the buffer encodes the data

     BIO * b64 = BIO_new(BIO_f_base64());

     if (!encodeWithNewlines)

         BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);

     mem = BIO_push(b64, mem);

     // Encode all the data

     BIO_write(mem, [self bytes], [self length]);

     BIO_flush(mem);

     // Create a new string from the data in the memory buffer

     char * base64Pointer;

     long base64Length = BIO_get_mem_data(mem, &base64Pointer);

     NSString * base64String = [NSString stringWithCString:base64Pointer length:base64Length];

     // Clean up and go home

     BIO_free_all(mem);

     return base64String;

 }

 - (NSData *)my_decodeBase64

 {

     return [self my_decodeBase64WithNewLines:YES];

 }

 - (NSData *)my_decodeBase64WithNewLines:(BOOL)encodedWithNewlines

 {

     // Create a memory buffer containing Base64 encoded string data

     BIO * mem = BIO_new_mem_buf((void *) [self bytes], [self length]);

     // Push a Base64 filter so that reading from the buffer decodes it

     BIO * b64 = BIO_new(BIO_f_base64());

     if (!encodedWithNewlines)

         BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);

     mem = BIO_push(b64, mem);

     // Decode into an NSMutableData

     NSMutableData * data = [NSMutableData data];

     char inbuf[512];

     int inlen;

     while ((inlen = BIO_read(mem, inbuf, sizeof(inbuf))) > 0)

         [data appendBytes: inbuf length: inlen];

     // Clean up and go home

     BIO_free_all(mem);

     return data;

 }

 - (NSString *)my_hexString

 {

     const UInt8 *bytes = self.bytes;

     NSUInteger length = self.length;

     char out[2*length+1];

     char *dst = &out[0];

     for( int i=0; i<length; i+=1 )

         dst += sprintf(dst,"%02X",*(bytes++));

     return [[[NSString alloc] initWithBytes: out length: 2*length encoding: NSASCIIStringEncoding]

             autorelease];

 }

 - (NSString *)my_hexDump

 {

     NSMutableString *ret=[NSMutableString stringWithCapacity:[self length]*2];

     /* dumps size bytes of *data to string. Looks like:

      * [0000] 75 6E 6B 6E 6F 77 6E 20

      *                  30 FF 00 00 00 00 39 00 unknown 0.....9.

      * (in a single line of course)

      */

     unsigned int size= [self length];

     const unsigned char *p = [self bytes];

     unsigned char c;

     int n;

     char bytestr[4] = {0};

     char addrstr[10] = {0};

     char hexstr[ 16*3 + 5] = {0};

     char charstr[16*1 + 5] = {0};

     for(n=1;n<=size;n++) {

         if (n%16 == 1) {

             /* store address for this line */

             snprintf(addrstr, sizeof(addrstr), "%.4x",

                      ((unsigned int)p-(unsigned int)self) );

         }

         c = *p;

         if (isalnum(c) == 0) {

             c = '.';

         }

         /* store hex str (for left side) */

         snprintf(bytestr, sizeof(bytestr), "%02X ", *p);

         strncat(hexstr, bytestr, sizeof(hexstr)-strlen(hexstr)-1);

         /* store char str (for right side) */

         snprintf(bytestr, sizeof(bytestr), "%c", c);

         strncat(charstr, bytestr, sizeof(charstr)-strlen(charstr)-1);

         if(n%16 == 0) {

             /* line completed */

             //printf("[%4.4s]   %-50.50s  %s\n", addrstr, hexstr, charstr);

             [ret appendString:[NSString stringWithFormat:@"[%4.4s]   %-50.50s  %s\n",

                                addrstr, hexstr, charstr]];

             hexstr[0] = 0;

             charstr[0] = 0;

         } else if(n%8 == 0) {

             /* half line: add whitespaces */

             strncat(hexstr, "  ", sizeof(hexstr)-strlen(hexstr)-1);

             strncat(charstr, " ", sizeof(charstr)-strlen(charstr)-1);

         }

         p++; /* next byte */

     }

     if (strlen(hexstr) > 0) {

         /* print rest of buffer if not empty */

         //printf("[%4.4s]   %-50.50s  %s\n", addrstr, hexstr, charstr);

         [ret appendString:[NSString stringWithFormat:@"[%4.4s]   %-50.50s  %s\n",

                            addrstr, hexstr, charstr]];

     }

     return ret;

 }

 @end