// // NSData+DES.m // DESEncryptionDemo // // #import "NSData+DES.h" #import static char encodingTable[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 NSData (DES) - (NSData *)DES3EncryptWithKey:(NSString *)key { // 'key' should be 24 bytes for 3DES, will be null-padded otherwise char keyPtr[kCCKeySize3DES + 1]; // room for terminator (unused) bzero( keyPtr, sizeof( keyPtr ) ); // fill with zeroes (for padding) // fetch key data [key getCString:keyPtr maxLength:sizeof( keyPtr ) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [self length]; //See the doc: For block ciphers, the output size will always be less than or //equal to the input size plus the size of one block. //That's why we need to add the size of one block here size_t bufferSize = dataLength + kCCBlockSize3DES; void *buffer = malloc( bufferSize ); size_t numBytesEncrypted = 0; CCCryptorStatus cryptStatus = CCCrypt( kCCEncrypt, kCCAlgorithm3DES, kCCOptionECBMode + kCCOptionPKCS7Padding, keyPtr, kCCKeySize3DES, NULL /* initialization vector (optional) */, [self bytes], dataLength, /* input */ buffer, bufferSize, /* output */ &numBytesEncrypted ); if( cryptStatus == kCCSuccess ){ //the returned NSData takes ownership of the buffer and will free it on deallocation return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted]; } free( buffer ); //free the buffer return nil; } - (NSData *)DES3DecryptWithKey:(NSString *)key { // 'key' should be 32 bytes for 3DES, will be null-padded otherwise char keyPtr[kCCKeySize3DES +1]; // room for terminator (unused) bzero( keyPtr, sizeof( keyPtr ) ); // fill with zeroes (for padding) // fetch key data [key getCString:keyPtr maxLength:sizeof( keyPtr ) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [self length]; //See the doc: For block ciphers, the output size will always be less than or //equal to the input size plus the size of one block. //That's why we need to add the size of one block here size_t bufferSize = dataLength + kCCBlockSize3DES; void *buffer = malloc( bufferSize ); size_t numBytesDecrypted = 0; CCCryptorStatus cryptStatus = CCCrypt( kCCDecrypt, kCCAlgorithm3DES, kCCOptionECBMode + kCCOptionPKCS7Padding, keyPtr, kCCKeySize3DES, NULL /* initialization vector (optional) */, [self bytes], dataLength, /* input */ buffer, bufferSize, /* output */ &numBytesDecrypted ); if( cryptStatus == kCCSuccess ) { //the returned NSData takes ownership of the buffer and will free it on deallocation return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted]; } free( buffer ); //free the buffer return nil; } #pragma mark - + (NSData *)dataWithBase64EncodedString:(NSString *)string { return [[NSData allocWithZone:nil] initWithBase64EncodedString:string]; } - (id)initWithBase64EncodedString:(NSString *)string { NSMutableData *mutableData = nil; if( string ) { unsigned long ixtext = 0; unsigned long lentext = 0; unsigned char ch = 0; unsigned char inbuf[4], outbuf[3]; short i = 0, ixinbuf = 0; BOOL flignore = NO; BOOL flendtext = NO; NSData *base64Data = nil; const unsigned char *base64Bytes = nil; // Convert the string to ASCII data. base64Data = [string dataUsingEncoding:NSASCIIStringEncoding]; base64Bytes = [base64Data bytes]; mutableData = [NSMutableData dataWithCapacity:base64Data.length]; lentext = base64Data.length; while( YES ) { if( ixtext >= lentext ) break; ch = base64Bytes[ixtext++]; flignore = NO; 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 = YES; else if( ch == '/' ) ch = 63; else flignore = YES; if( ! flignore ) { short ctcharsinbuf = 3; BOOL flbreak = NO; if( flendtext ) { if( ! ixinbuf ) break; if( ( ixinbuf == 1 ) || ( ixinbuf == 2 ) ) ctcharsinbuf = 1; else ctcharsinbuf = 2; ixinbuf = 3; flbreak = YES; } 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++ ) [mutableData appendBytes:&outbuf[i] length:1]; } if( flbreak ) break; } } } self = [self initWithData:mutableData]; return self; } #pragma mark - - (NSString *)base64Encoding { return [self base64EncodingWithLineLength:0]; } - (NSString *)base64EncodingWithLineLength:(NSUInteger)lineLength { const unsigned char *bytes = [self bytes]; NSMutableString *result = [NSMutableString stringWithCapacity:self.length]; unsigned long ixtext = 0; unsigned long lentext = self.length; long ctremaining = 0; unsigned char inbuf[3], outbuf[4]; unsigned short i = 0; unsigned short charsonline = 0, ctcopy = 0; unsigned long ix = 0; while( YES ) { ctremaining = lentext - ixtext; if( ctremaining <= 0 ) break; for( i = 0; i < 3; i++ ) { ix = ixtext + i; if( ix < lentext ) inbuf[i] = bytes[ix]; else inbuf [i] = 0; } outbuf [0] = (inbuf [0] & 0xFC) >> 2; outbuf [1] = ((inbuf [0] & 0x03) << 4) | ((inbuf [1] & 0xF0) >> 4); outbuf [2] = ((inbuf [1] & 0x0F) << 2) | ((inbuf [2] & 0xC0) >> 6); outbuf [3] = inbuf [2] & 0x3F; ctcopy = 4; switch( ctremaining ) { case 1: ctcopy = 2; break; case 2: ctcopy = 3; break; } for( i = 0; i < ctcopy; i++ ) [result appendFormat:@"%c", encodingTable[outbuf[i]]]; for( i = ctcopy; i < 4; i++ ) [result appendString:@"="]; ixtext += 3; charsonline += 4; if( lineLength > 0 ) { if( charsonline >= lineLength ) { charsonline = 0; [result appendString:@"\n"]; } } } return [NSString stringWithString:result]; } #pragma mark - - (BOOL)hasPrefixBytes:(const void *)prefix length:(NSUInteger)length { if( ! prefix || ! length || self.length < length ) return NO; return ( memcmp( [self bytes], prefix, length ) == 0 ); } - (BOOL)hasSuffixBytes:(const void *)suffix length:(NSUInteger)length { if( ! suffix || ! length || self.length < length ) return NO; return ( memcmp( ((const char *)[self bytes] + (self.length - length)), suffix, length ) == 0 ); } @end