/*
加密中需要的base64是採用 QSUtilities 可以在 https://github.com/mikeho/QSUtilities 取得
MD5 可以參考 http://www.makebetterthings.com/iphone/how-to-get-md5-and-sha1-in-objective-c-ios-sdk/
*/
1 AzDG.h
2
3 #import <Foundation/Foundation.h>
4 @interface AzDG : NSObject
5 {
6
7 }
8
9 -(id) initWithCipher : (NSString*) input;
10
11 -(NSString*) getCipher;
12 -(NSData*) cipherCrypt:(NSData*) inputData;
13 -(NSString*) encode:(NSString*) input;
14 -(NSString*) decode:(NSString*) input;
15
16 @end
17
18
19
20 AzDG.m
21
22 #import "AzDG.h"
23 #import "MD5.h"
24 #import "QSStrings.h"
25
26
27 @implementation AzDG
28
29 NSString* cipher = @"1234567890";
30
31 -(id) initWithCipher : (NSString*) input
32 {
33 self = [super init];
34 if (self != nil && input != nil && [input length] > 0)
35 {
36 cipher = input;
37 }
38 return self;
39 }
40
41 -(NSString*) getCipher{
42 return cipher;
43 }
44
45 -(NSData*) cipherCrypt:(NSData*) inputData
46 {
47 NSMutableData *outData = [[NSMutableData alloc]init];
48 int loopCount = [inputData length];
49 const unsigned char * inputChar = [inputData bytes];
50 const unsigned char *cipherHash = [[[MD5 encode: [self getCipher]] dataUsingEncoding:NSASCIIStringEncoding] bytes];
51
52 int i = 0;
53 while (i < loopCount)
54 {
55 Byte b = (Byte)( inputChar[i] ^ cipherHash[i%32]);
56 [outData appendBytes:&b length:sizeof(char)];
57 i++;
58 }
59 return outData;
60 }
61
62
63 -(NSString*) encode:(NSString*) input
64 {
65 NSData *inputData = [input dataUsingEncoding:NSUTF8StringEncoding];
66 NSMutableData *outData = [[NSMutableData alloc]init];
67 int loopCount = [inputData length];
68 const unsigned char *inputChar = [inputData bytes];
69 const unsigned char *noiseChar = [[[MD5 encode:[NSString stringWithFormat:@"%@",[NSDate date]]]
70 dataUsingEncoding:NSASCIIStringEncoding] bytes];
71
72 int i = 0;
73 while (i < loopCount)
74 {
75 [outData appendBytes:&noiseChar[i%32] length:sizeof(char)];
76 Byte b = (Byte)(inputChar[i] ^ noiseChar[i%32]);
77 [outData appendBytes:&b length:sizeof(char)];
78 i++;
79 }
80 return [QSStrings encodeBase64WithData:[self cipherCrypt:outData]];
81 }
82
83 -(NSString*) decode:(NSString*) input
84 {
85 NSData* inputData = [self cipherCrypt:[QSStrings decodeBase64WithString:input]];
86 NSMutableData *outData = [[NSMutableData alloc] init];
87 int loopCount = [inputData length];
88 const unsigned char * inputChar = [inputData bytes];
89
90 int i = 0;
91 while (i < loopCount)
92 {
93 Byte b = (Byte)( inputChar[i] ^ inputChar[i+1]);
94 [outData appendBytes:&b length:sizeof(char)];
95 i = i + 2;
96 }
97 return [[NSString alloc] initWithData:outData encoding:NSUTF8StringEncoding];
98 }
99
100 @end
