iOS开发:用DES对字符串加解密

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. @interface Base64 : NSObject
3. +(int)char2Int:(char)c;
4. +(NSData *)decode:(NSString *)data;
5. +(NSString *)encode:(NSData *)data;
6. @end

Base64.m

1. #import "Base64.h"
2. static const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
3. @interface Base64()
4. +(int)char2Int:(char)c;
5. @end
6. @implementation Base64
7. +(NSString *)encode:(NSData *)data
8. {
9. if (data.length == 0)
10. return nil;
11. char *characters = malloc(data.length * 3 / 2);
12. if (characters == NULL)
13. return nil;
14. int end = data.length - 3;
15. int index = 0;
16. int charCount = 0;
17. int n = 0;
18. while (index <= end) {
19. int d = (((int)(((char *)[data bytes])[index]) & 0x0ff) << 16)
20. | (((int)(((char *)[data bytes])[index + 1]) & 0x0ff) << 8)
21. | ((int)(((char *)[data bytes])[index + 2]) & 0x0ff);
22. characters[charCount++] = encodingTable[(d >> 18) & 63];
23. characters[charCount++] = encodingTable[(d >> 12) & 63];
24. characters[charCount++] = encodingTable[(d >> 6) & 63];
25. characters[charCount++] = encodingTable[d & 63];
26. index += 3;
27. if(n++ >= 14)
28. {
29. n = 0;
30. characters[charCount++] = ' ';
31. }
32. }
33. if(index == data.length - 2)
34. {
35. int d = (((int)(((char *)[data bytes])[index]) & 0x0ff) << 16)
36. | (((int)(((char *)[data bytes])[index + 1]) & 255) << 8);
37. characters[charCount++] = encodingTable[(d >> 18) & 63];
38. characters[charCount++] = encodingTable[(d >> 12) & 63];
39. characters[charCount++] = encodingTable[(d >> 6) & 63];
40. characters[charCount++] = '=';
41. }
42. else if(index == data.length - 1)
43. {
44. int d = ((int)(((char *)[data bytes])[index]) & 0x0ff) << 16;
45. characters[charCount++] = encodingTable[(d >> 18) & 63];
46. characters[charCount++] = encodingTable[(d >> 12) & 63];
47. characters[charCount++] = '=';
48. characters[charCount++] = '=';
49. }
50. NSString * rtnStr = [[NSString alloc] initWithBytesNoCopy:characters length:charCount encoding:NSUTF8StringEncoding freeWhenDone:YES];
51. return rtnStr;
52. }
53. +(NSData *)decode:(NSString *)data
54. {
55. if(data == nil || data.length <= 0) {
56. return nil;
57. }
58. NSMutableData *rtnData = [[NSMutableData alloc]init];
59. int slen = data.length;
60. int index = 0;
61. while (true) {
62. while (index < slen && [data characterAtIndex:index] <= ' ') {
63. index++;
64. }
65. if (index >= slen || index + 3 >= slen) {
66. break;
67. }
68. 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]];
69. Byte temp1 = (byte >> 16) & 255;
70. [rtnData appendBytes:&temp1 length:1];
71. if([data characterAtIndex:index + 2] == '=') {
72. break;
73. }
74. Byte temp2 = (byte >> 8) & 255;
75. [rtnData appendBytes:&temp2 length:1];
76. if([data characterAtIndex:index + 3] == '=') {
77. break;
78. }
79. Byte temp3 = byte & 255;
80. [rtnData appendBytes:&temp3 length:1];
81. index += 4;
82. }
83. return rtnData;
84. }
85. +(int)char2Int:(char)c
86. {
87. if (c >= 'A' && c <= 'Z') {
88. return c - 65;
89. } else if (c >= 'a' && c <= 'z') {
90. return c - 97 + 26;
91. } else if (c >= '0' && c <= '9') {
92. return c - 48 + 26 + 26;
93. } else {
94. switch(c) {
95. case '+':
96. return 62;
97. case '/':
98. return 63;
99. case '=':
100. return 0;
101. default:
102. return -1;
103. }
104. }
105. }
106. @end

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

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