Base64是常用的编码规范之一，如网络传输中应用广泛，之前列举过base64编码的原理：《base64举例》 以及java实现的base64编码工具类。
这里，贴出OC下的base64代码，在平台之间通信过程中保证编码能通用——中间出现一个编码问题，google官方提供的base64Util包默认用的Utf-8编码，而中文之前统一用的gbk编码，以下代码修正了这个问题：
关键点：将CommonFunc的
base64StringFromText 和 textFromBase64String中的UTF8encoding改成gbkEncoding:
NSData *data = [text dataUsingEncoding:NSUTF8StringEncoding];
改成
NSStringEncoding gbkEncoding =CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
NSData *data = [text dataUsingEncoding:gbkEncoding];
// // CommonFunc.h // Base64Proj // // Created by qslang on 14-6-12. // Copyright (c) 2014年 Dev. All rights reserved. #import <Foundation/Foundation.h> #define __BASE64( text ) [CommonFunc base64StringFromText:text] #define __TEXT( base64 ) [CommonFunc textFromBase64String:base64] @interface CommonFunc : NSObject /****************************************************************************** 函数名称 : + (NSString *)base64StringFromText:(NSString *)text 函数描述 : 将文本转换为base64格式字符串 输入参数 : (NSString *)text 文本 输出参数 : N/A 返回参数 : (NSString *) base64格式字符串 备注信息 : ******************************************************************************/ + (NSString *)base64StringFromText:(NSString *)text; /****************************************************************************** 函数名称 : + (NSString *)textFromBase64String:(NSString *)base64 函数描述 : 将base64格式字符串转换为文本 输入参数 : (NSString *)base64 base64格式字符串 输出参数 : N/A 返回参数 : (NSString *) 文本 备注信息 : ******************************************************************************/ + (NSString *)textFromBase64String:(NSString *)base64; @end
1 //
2 // CommonFunc.m
3 // Base64Proj
4 //
5 // Created by qslang on 14-6-12.
6 // Copyright (c) 2014年 Dev. All rights reserved.
7 //
8
9 #import "CommonFunc.h"
10
11 //引入IOS自带密码库
12 #import <CommonCrypto/CommonCryptor.h>
13
14 //空字符串
15 #define LocalStr_None @""
16
17 static const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
18
19 @implementation CommonFunc
20
21 + (NSString *)base64StringFromText:(NSString *)text
22 {
23 if (text && ![text isEqualToString:LocalStr_None]) {
24 NSStringEncoding gbkEncoding =CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
25
26 //取项目的bundleIdentifier作为KEY 改动了此处
27 //NSString *key = [[NSBundle mainBundle] bundleIdentifier];
28 NSData *data = [text dataUsingEncoding:gbkEncoding];//NSUTF8StringEncoding
29 //IOS 自带DES加密 Begin 改动了此处
30 //data = [self DESEncrypt:data WithKey:key];
31 //IOS 自带DES加密 End
32 return [self base64EncodedStringFrom:data];
33 }
34 else {
35 return LocalStr_None;
36 }
37 }
38
39 + (NSString *)textFromBase64String:(NSString *)base64
40 {
41 if (base64 && ![base64 isEqualToString:LocalStr_None]) {
42 //取项目的bundleIdentifier作为KEY 改动了此处
43 //NSString *key = [[NSBundle mainBundle] bundleIdentifier];
44 NSData *data = [self dataWithBase64EncodedString:base64];
45 //IOS 自带DES解密 Begin 改动了此处
46 //data = [self DESDecrypt:data WithKey:key];
47 //IOS 自带DES加密 End
48 NSStringEncoding gbkEncoding =CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
49
50 return [[NSString alloc] initWithData:data encoding:gbkEncoding];
51 }
52 else {
53 return LocalStr_None;
54 }
55 }
56
57 /******************************************************************************
58 函数名称 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
59 函数描述 : 文本数据进行DES加密
60 输入参数 : (NSData *)data
61 (NSString *)key
62 输出参数 : N/A
63 返回参数 : (NSData *)
64 备注信息 : 此函数不可用于过长文本
65 ******************************************************************************/
66 + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
67 {
68 char keyPtr[kCCKeySizeAES256+1];
69 bzero(keyPtr, sizeof(keyPtr));
70
71 [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
72
73 NSUInteger dataLength = [data length];
74
75 size_t bufferSize = dataLength + kCCBlockSizeAES128;
76 void *buffer = malloc(bufferSize);
77
78 size_t numBytesEncrypted = 0;
79 CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,
80 kCCOptionPKCS7Padding | kCCOptionECBMode,
81 keyPtr, kCCBlockSizeDES,
82 NULL,
83 [data bytes], dataLength,
84 buffer, bufferSize,
85 &numBytesEncrypted);
86 if (cryptStatus == kCCSuccess) {
87 return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
88 }
89
90 free(buffer);
91 return nil;
92 }
93
94 /******************************************************************************
95 函数名称 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
96 函数描述 : 文本数据进行DES解密
97 输入参数 : (NSData *)data
98 (NSString *)key
99 输出参数 : N/A
100 返回参数 : (NSData *)
101 备注信息 : 此函数不可用于过长文本
102 ******************************************************************************/
103 + (NSData *)DESDecrypt:(NSData *)data WithKey:(NSString *)key
104 {
105 char keyPtr[kCCKeySizeAES256+1];
106 bzero(keyPtr, sizeof(keyPtr));
107
108 [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
109
110 NSUInteger dataLength = [data length];
111
112 size_t bufferSize = dataLength + kCCBlockSizeAES128;
113 void *buffer = malloc(bufferSize);
114
115 size_t numBytesDecrypted = 0;
116 CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES,
117 kCCOptionPKCS7Padding | kCCOptionECBMode,
118 keyPtr, kCCBlockSizeDES,
119 NULL,
120 [data bytes], dataLength,
121 buffer, bufferSize,
122 &numBytesDecrypted);
123
124 if (cryptStatus == kCCSuccess) {
125 return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
126 }
127
128 free(buffer);
129 return nil;
130 }
131
132
133 /******************************************************************************
134 函数名称 : + (NSData *)dataWithBase64EncodedString:(NSString *)string
135 函数描述 : base64格式字符串转换为文本数据
136 输入参数 : (NSString *)string
137 输出参数 : N/A
138 返回参数 : (NSData *)
139 备注信息 :
140 ******************************************************************************/
141 + (NSData *)dataWithBase64EncodedString:(NSString *)string
142 {
143 if (string == nil)
144 [NSException raise:NSInvalidArgumentException format:nil];
145 if ([string length] == 0)
146 return [NSData data];
147
148 static char *decodingTable = NULL;
149 if (decodingTable == NULL)
150 {
151 decodingTable = malloc(256);
152 if (decodingTable == NULL)
153 return nil;
154 memset(decodingTable, CHAR_MAX, 256);
155 NSUInteger i;
156 for (i = 0; i < 64; i++)
157 decodingTable[(short)encodingTable[i]] = i;
158 }
159
160 const char *characters = [string cStringUsingEncoding:NSASCIIStringEncoding];
161 if (characters == NULL) // Not an ASCII string!
162 return nil;
163 char *bytes = malloc((([string length] + 3) / 4) * 3);
164 if (bytes == NULL)
165 return nil;
166 NSUInteger length = 0;
167
168 NSUInteger i = 0;
169 while (YES)
170 {
171 char buffer[4];
172 short bufferLength;
173 for (bufferLength = 0; bufferLength < 4; i++)
174 {
175 if (characters[i] == ‘\0‘)
176 break;
177 if (isspace(characters[i]) || characters[i] == ‘=‘)
178 continue;
179 buffer[bufferLength] = decodingTable[(short)characters[i]];
180 if (buffer[bufferLength++] == CHAR_MAX) // Illegal character!
181 {
182 free(bytes);
183 return nil;
184 }
185 }
186
187 if (bufferLength == 0)
188 break;
189 if (bufferLength == 1) // At least two characters are needed to produce one byte!
190 {
191 free(bytes);
192 return nil;
193 }
194
195 // Decode the characters in the buffer to bytes.
196 bytes[length++] = (buffer[0] << 2) | (buffer[1] >> 4);
197 if (bufferLength > 2)
198 bytes[length++] = (buffer[1] << 4) | (buffer[2] >> 2);
199 if (bufferLength > 3)
200 bytes[length++] = (buffer[2] << 6) | buffer[3];
201 }
202
203 bytes = realloc(bytes, length);
204 return [NSData dataWithBytesNoCopy:bytes length:length];
205 }
206
207 + (NSString *)stringWithBase64EncodedString:(NSString *)string withEncoding:(NSStringEncoding)encoding
208 {
209 NSData *data = [self dataWithBase64EncodedString:string];
210 if (data)
211 {
212 return [[self alloc] initWithData:data encoding:encoding];
213 }
214 return nil;
215
216 }
217
218 //+ (NSString *)base64DecodedString:(NSStringEncoding)encoding
219 //{
220 // // return [self stringWithBase64EncodedString: withEncoding:encoding];
221 // //data = [self DESEncrypt:data WithKey:key];
222 //
223 //}
224
225 /******************************************************************************
226 函数名称 : + (NSString *)base64EncodedStringFrom:(NSData *)data
227 函数描述 : 文本数据转换为base64格式字符串
228 输入参数 : (NSData *)data
229 输出参数 : N/A
230 返回参数 : (NSString *)
231 备注信息 :
232 ******************************************************************************/
233 + (NSString *)base64EncodedStringFrom:(NSData *)data
234 {
235 if ([data length] == 0)
236 return @"";
237
238 char *characters = malloc((([data length] + 2) / 3) * 4);
239 if (characters == NULL)
240 return nil;
241 NSUInteger length = 0;
242
243 NSUInteger i = 0;
244 while (i < [data length])
245 {
246 char buffer[3] = {0,0,0};
247 short bufferLength = 0;
248 while (bufferLength < 3 && i < [data length])
249 buffer[bufferLength++] = ((char *)[data bytes])[i++];
250
251 // Encode the bytes in the buffer to four characters, including padding "=" characters if necessary.
252 characters[length++] = encodingTable[(buffer[0] & 0xFC) >> 2];
253 characters[length++] = encodingTable[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];
254 if (bufferLength > 1)
255 characters[length++] = encodingTable[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];
256 else characters[length++] = ‘=‘;
257 if (bufferLength > 2)
258 characters[length++] = encodingTable[buffer[2] & 0x3F];
259 else characters[length++] = ‘=‘;
260 }
261
262 return [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES];
263 }
264
265
266
267 @end
CommonFunc.m
调用代码：
NSString *str1 = @"*&*我爱你中国";
NSLog(@"baseStr=======%@",str1);
NSString *encodes = [CommonFunc base64StringFromText:str1];
NSLog(@"encodeStr=========%@",[CommonFunc base64StringFromText:str1]);
NSLog(@"decodeStr========%@",[CommonFunc textFromBase64String:encodes]);
结果：
2014-06-17 16:04:19.275 Base64Proj[23496:303] baseStr=======*&*我爱你中国 2014-06-17 16:04:19.277 Base64Proj[23496:303] encodeStr=========KiYqztKwrsTj1tC5+g== 2014-06-17 16:04:19.278 Base64Proj[23496:303] decodeStr========*&*我爱你中国 Program ended with exit code: 0
OC下Base64编码的中文字符编码问题
时间： 2024-08-07 21:20:55