iOS开发之Objective-c的AES128加密和解密算法的实现

 

 1 #import <Foundation/Foundation.h>
 2 
 3 #import <CommonCrypto/CommonDigest.h>
 4 
 5 #import <CommonCrypto/CommonCryptor.h>
 6 
 7 #import "NSData+AES.h"
 8 
 9 @interface NSString (AES)
10 
11 //加密字符串
12 
13 - (NSString*)aes128Encrypt:(NSString *)aKey;
14 
15 //解密字符串
16 
17 - (NSString*)aes128Decrypt:(NSString *)aKey;
18 
19 @end

 

  1 #define gIv             @"0102030405060708" //自行修改16位 -->偏移量
  2 
  3 @implementation NSString (AES256)
  4 
  5  - (NSString *)aes128Encrypt:(NSString *)aKey
  6 
  7 {
  8 
  9     char keyPtr[kCCKeySizeAES128+1];
 10 
 11     memset(keyPtr, 0, sizeof(keyPtr));
 12 
 13     [aKey getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
 14 
 15     
 16 
 17     char ivPtr[kCCBlockSizeAES128+1];
 18 
 19     memset(ivPtr, 0, sizeof(ivPtr));
 20 
 21     [gIv getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];
 22 
 23     
 24 
 25     NSData* data = [self dataUsingEncoding:NSUTF8StringEncoding];
 26 
 27     NSUInteger dataLength = [data length];
 28 
 29     
 30 
 31     int diff = kCCKeySizeAES128 - (dataLength % kCCKeySizeAES128);
 32 
 33     int newSize = 0;
 34 
 35     
 36 
 37     if(diff > 0)
 38 
 39     {
 40 
 41         newSize = dataLength + diff;
 42 
 43     }
 44 
 45     
 46 
 47     char dataPtr[newSize];
 48 
 49     memcpy(dataPtr, [data bytes], [data length]);
 50 
 51     for(int i = 0; i < diff; i++)
 52 
 53     {
 54 
 55         dataPtr[i + dataLength] = 0x00;
 56 
 57     }
 58 
 59     
 60 
 61     size_t bufferSize = newSize + kCCBlockSizeAES128;
 62 
 63     void *buffer = malloc(bufferSize);
 64 
 65     memset(buffer, 0, bufferSize);
 66 
 67     
 68 
 69     size_t numBytesCrypted = 0;
 70 
 71     
 72 
 73     CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
 74 
 75                                           kCCAlgorithmAES128,
 76 
 77                                           kCCOptionPKCS7Padding,  // 补码方式
 78 
 79                                           keyPtr,
 80 
 81                                           kCCKeySizeAES128,
 82 
 83                                           ivPtr,
 84 
 85                                           dataPtr,
 86 
 87                                           sizeof(dataPtr),
 88 
 89                                           buffer,
 90 
 91                                           bufferSize,
 92 
 93                                           &numBytesCrypted);
 94 
 95     
 96 
 97     if (cryptStatus == kCCSuccess) {
 98 
 99         NSData *result = [NSData dataWithBytesNoCopy:buffer length:numBytesCrypted];
100 
101         if (result && result.length > 0) {
102 
103             
104 
105             Byte *datas = (Byte*)[result bytes];
106 
107             NSMutableString *output = [NSMutableString stringWithCapacity:result.length * 2];
108 
109             for(int i = 0; i < result.length; i++){
110 
111                 [output appendFormat:@"%02x", datas[i]];
112 
113             }
114 
115             return output;
116 
117         }
118 
119     }
120 
121     free(buffer);
122 
123     return nil;
124 
125 }
126 
127  
128 
129 - (NSString *)aes128Decrypt:(NSString *)aKey
130 
131 {
132 
133     char keyPtr[kCCKeySizeAES128 + 1];
134 
135     memset(keyPtr, 0, sizeof(keyPtr));
136 
137     [aKey getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
138 
139     
140 
141     char ivPtr[kCCBlockSizeAES128 + 1];
142 
143     memset(ivPtr, 0, sizeof(ivPtr));
144 
145     [gIv getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];
146 
147     
148 
149     NSMutableData *data = [NSMutableData dataWithCapacity:self.length / 2];
150 
151     unsigned char whole_byte;
152 
153     char byte_chars[3] = {'\0','\0','\0'};
154 
155     int i;
156 
157     for (i=0; i < [self length] / 2; i++) {
158 
159         byte_chars[0] = [self characterAtIndex:i*2];
160 
161         byte_chars[1] = [self characterAtIndex:i*2+1];
162 
163         whole_byte = strtol(byte_chars, NULL, 16);
164 
165         [data appendBytes:&whole_byte length:1];
166 
167     }
168 
169     
170 
171     NSUInteger dataLength = [data length];
172 
173     size_t bufferSize = dataLength + kCCBlockSizeAES128;
174 
175     void *buffer = malloc(bufferSize);
176 
177     
178 
179     size_t numBytesCrypted = 0;
180 
181     CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
182 
183                                           kCCAlgorithmAES128,
184 
185                                           kCCOptionPKCS7Padding,
186 
187                                           keyPtr,
188 
189                                           kCCBlockSizeAES128,
190 
191                                           ivPtr,
192 
193                                           [data bytes],
194 
195                                           dataLength,
196 
197                                           buffer,
198 
199                                           bufferSize,
200 
201                                           &numBytesCrypted);
202 
203     if (cryptStatus == kCCSuccess) {
204 
205         NSData *resultData = [NSData dataWithBytesNoCopy:buffer length:numBytesCrypted];
206 
207         return [[NSString alloc] initWithData:resultData encoding:NSUTF8StringEncoding];
208 
209     }
210 
211     free(buffer);
212 
213     return nil;
214 
215 }
216 
217 @end

 

iOS Objective c 16进制字符串转为二进制数组

原文：http://lizhuang.iteye.com/blog/2060143

 1 @implementation NSString (StringToHexData)
 2 
 3 //
 4 // Decodes an NSString containing hex encoded bytes into an NSData object
 5 //
 6 - (NSData *) stringToHexData
 7 {
 8     int len = [self length] / 2;    // Target length
 9     unsigned char *buf = malloc(len)
10     unsigned char *whole_byte = buf;
11     char byte_chars[3] = {'\0','\0','\0'};
12 
13     int i;
14     for (i=0; i < [self length] / 2; i++) {
15         byte_chars[0] = [self characterAtIndex:i*2];
16         byte_chars[1] = [self characterAtIndex:i*2+1];
17         *whole_byte = strtol(byte_chars, NULL, 16);
18         whole_byte++;
19     }
20 
21     NSData *data = [NSData dataWithBytes:buf length:len];
22     free( buf );
23     return data;
24 }
25 @end
26 @implementation NSData (DataToHexString)
27 
28 - (NSString *) dataToHexString
29 {
30     NSUInteger          len = [self length];
31     char *              chars = (char *)[self bytes];
32     NSMutableString *   hexString = [[NSMutableString alloc] init];
33 
34     for(NSUInteger i = 0; i < len; i++ )
35         [hexString appendString:[NSString stringWithFormat:@"%0.2hhx", chars[i]]];
36 
37     return hexString;
38 }
39 @end

16进制-View Code