iOS开发:用DES对字符串加解密

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参考http://www.cnblogs.com/janken/archive/2012/04/05/2432930.html，做了个小修改，实现PHP,JAVA,Objective-c加解密结果相同。
原先Android版的客户端与服务端(PHP)通讯部分内容用DES加密，加密方法：http://www.pocketdigi.com/20121112/940.html
直接拷贝原文的源码，发现结果不同，原因在于，我在java和php里用的IvParameterSpec是动态的，就是key转成byte[],但原文是静态写死的。
上修改后的源码:
先是Base64:
Base64.h:

1. #import <Foundation/Foundation.h>
2.  
3. @interface Base64 : NSObject
4. +(int)char2Int:(char)c;
5. +(NSData *)decode:(NSString *)data;
6. +(NSString *)encode:(NSData *)data;
7. @end
8.  

Base64.m

1. #import "Base64.h"
2.  
3. static const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
4.  
5. @interface Base64()
6. +(int)char2Int:(char)c;
7. @end
8.  
9. @implementation Base64
10.  
11. +(NSString *)encode:(NSData *)data
12. {
13. if (data.length == 0)
14. return nil;
16. char *characters = malloc(data.length * 3 / 2);
18. if (characters == NULL)
19. return nil;
21. int end = data.length - 3;
22. int index = 0;
23. int charCount = 0;
24. int n = 0;
26. while (index <= end) {
27. int d = (((int)(((char *)[data bytes])[index]) & 0x0ff) << 16)
28. | (((int)(((char *)[data bytes])[index + 1]) & 0x0ff) << 8)
29. | ((int)(((char *)[data bytes])[index + 2]) & 0x0ff);
31. characters[charCount++] = encodingTable[(d >> 18) & 63];
32. characters[charCount++] = encodingTable[(d >> 12) & 63];
33. characters[charCount++] = encodingTable[(d >> 6) & 63];
34. characters[charCount++] = encodingTable[d & 63];
36. index += 3;
38. if(n++ >= 14)
39. {
40. n = 0;
41. characters[charCount++] = ‘ ‘;
42. }
43. }
45. if(index == data.length - 2)
46. {
47. int d = (((int)(((char *)[data bytes])[index]) & 0x0ff) << 16)
48. | (((int)(((char *)[data bytes])[index + 1]) & 255) << 8);
49. characters[charCount++] = encodingTable[(d >> 18) & 63];
50. characters[charCount++] = encodingTable[(d >> 12) & 63];
51. characters[charCount++] = encodingTable[(d >> 6) & 63];
52. characters[charCount++] = ‘=‘;
53. }
54. else if(index == data.length - 1)
55. {
56. int d = ((int)(((char *)[data bytes])[index]) & 0x0ff) << 16;
57. characters[charCount++] = encodingTable[(d >> 18) & 63];
58. characters[charCount++] = encodingTable[(d >> 12) & 63];
59. characters[charCount++] = ‘=‘;
60. characters[charCount++] = ‘=‘;
61. }
62. NSString * rtnStr = [[NSString alloc] initWithBytesNoCopy:characters length:charCount encoding:NSUTF8StringEncoding freeWhenDone:YES];
63. return rtnStr;
65. }
66.  
67. +(NSData *)decode:(NSString *)data
68. {
69. if(data == nil || data.length <= 0) {
70. return nil;
71. }
72. NSMutableData *rtnData = [[NSMutableData alloc]init];
73. int slen = data.length;
74. int index = 0;
75. while (true) {
76. while (index < slen && [data characterAtIndex:index] <= ‘ ‘) {
77. index++;
78. }
79. if (index >= slen || index + 3 >= slen) {
80. break;
81. }
83. int byte = ([self char2Int:[data characterAtIndex:index]] << 18) + ([self char2Int:[data characterAtIndex:index + 1]] << 12) + ([self char2Int:[data characterAtIndex:index + 2]] << 6) + [self char2Int:[data characterAtIndex:index + 3]];
84. Byte temp1 = (byte >> 16) & 255;
85. [rtnData appendBytes:&temp1 length:1];
86. if([data characterAtIndex:index + 2] == ‘=‘) {
87. break;
88. }
89. Byte temp2 = (byte >> 8) & 255;
90. [rtnData appendBytes:&temp2 length:1];
91. if([data characterAtIndex:index + 3] == ‘=‘) {
92. break;
93. }
94. Byte temp3 = byte & 255;
95. [rtnData appendBytes:&temp3 length:1];
96. index += 4;
98. }
99. return rtnData;
100. }
101.  
102. +(int)char2Int:(char)c
103. {
104. if (c >= ‘A‘ && c <= ‘Z‘) {
105. return c - 65;
106. } else if (c >= ‘a‘ && c <= ‘z‘) {
107. return c - 97 + 26;
108. } else if (c >= ‘0‘ && c <= ‘9‘) {
109. return c - 48 + 26 + 26;
110. } else {
111. switch(c) {
112. case ‘+‘:
113. return 62;
114. case ‘/‘:
115. return 63;
116. case ‘=‘:
117. return 0;
118. default:
119. return -1;
120. }
121. }
122. }
123.  
124. @end
125.  

DESUtils.h:

1. #import <Foundation/Foundation.h>
2. #import <CommonCrypto/CommonCrypto.h>
3. #import "Base64.h"
4. @interface DESUtils : NSObject
5. +(NSString *)decryptUseDES:(NSString *)cipherText key:(NSString *)key;
6. +(NSString *) encryptUseDES:(NSString *)plainText key:(NSString *)key;
7. @end

DESUtils.m:

1.  
2. #import "DESUtils.h"
3.  
4. @implementation DESUtils
5. +(NSString *)decryptUseDES:(NSString *)cipherText key:(NSString *)key
6. {
7. NSString *plaintext = nil;
9. NSData *cipherdata = [Base64 decode:cipherText];
10.  
11. unsigned char buffer[1024];
12. memset(buffer, 0, sizeof(char));
13. size_t numBytesDecrypted = 0;
14. CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES,
15. kCCOptionPKCS7Padding,
16. [key UTF8String], kCCKeySizeDES,
17. (Byte *)[[key dataUsingEncoding:NSUTF8StringEncoding] bytes],
18. [cipherdata bytes], [cipherdata length],
19. buffer, 1024,
20. &numBytesDecrypted);
21. if(cryptStatus == kCCSuccess) {
22. NSData *plaindata = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesDecrypted];
23. plaintext = [[NSString alloc]initWithData:plaindata encoding:NSUTF8StringEncoding];
24. }
25. return plaintext;
26. }
27. +(NSString *) encryptUseDES:(NSString *)plainText key:(NSString *)key
28. {
29.  
30. NSString *ciphertext = nil;
31. NSData *textData = [plainText dataUsingEncoding:NSUTF8StringEncoding];
32. NSUInteger dataLength = [textData length];
33. unsigned char buffer[1024];
34. memset(buffer, 0, sizeof(char));
35. size_t numBytesEncrypted = 0;
36. CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,
37. kCCOptionPKCS7Padding,
38. [key UTF8String], kCCKeySizeDES,
39. (Byte *)[[key dataUsingEncoding:NSUTF8StringEncoding] bytes],
40. [textData bytes], dataLength,
41. buffer, 1024,
42. &numBytesEncrypted);
43. if (cryptStatus == kCCSuccess) {
44. NSData *data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];
45. ciphertext = [Base64 encode:data];
46. }
47. return ciphertext;
48. }
49. @end
50.  

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iOS开发:用DES对字符串加解密

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原文地址：http://www.cnblogs.com/kenshinobiy/p/4415479.html