//用法 加密转base 64 NSString *str = [self base64StringFromText:@"qingjoin" withKey:@"key"]; //转base 64 解密 NSString *stred = [self textFromBase64String:str withKey:@"key"];
//文本先进行DES加密。然后再转成base64 + (NSString *)base64StringFromText:(NSString *)text withKey:(NSString*)key { if (text && ![text isEqualToString:@""]) { //取项目的bundleIdentifier作为KEY //NSString *key = [[NSBundle mainBundle] bundleIdentifier]; NSData *data = [text dataUsingEncoding:NSUTF8StringEncoding]; //IOS 自带DES加密 Begin data = [self DESEncrypt:data WithKey:key]; //IOS 自带DES加密 End return [self base64EncodedStringFrom:data]; } else { return @""; } } //先把base64转为文本。然后再DES解密 + (NSString *)textFromBase64String:(NSString *)base64 withKey:(NSString*)key { if (base64 && ![base64 isEqualToString:@""]) { //取项目的bundleIdentifier作为KEY //NSString *key = [[NSBundle mainBundle] bundleIdentifier]; NSData *data = [self dataWithBase64EncodedString:base64]; //IOS 自带DES解密 Begin data = [self DESDecrypt:data WithKey:key]; //IOS 自带DES加密 End return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]; } else { return @""; } } /****************************************************************************** 函数名称 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key 函数描述 : 文本数据进行DES加密 输入参数 : (NSData *)data (NSString *)key 输出参数 : N/A 返回参数 : (NSData *) 备注信息 : 此函数不可用于过长文本 ******************************************************************************/ + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key { char keyPtr[kCCKeySizeAES256+1]; bzero(keyPtr, sizeof(keyPtr)); [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [data length]; size_t bufferSize = dataLength + kCCBlockSizeAES128; void *buffer = malloc(bufferSize); size_t numBytesEncrypted = 0; CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES, kCCOptionPKCS7Padding | kCCOptionECBMode, keyPtr, kCCBlockSizeDES, NULL, [data bytes], dataLength, buffer, bufferSize, &numBytesEncrypted); if (cryptStatus == kCCSuccess) { return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted]; } free(buffer); return nil; } /****************************************************************************** 函数名称 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key 函数描述 : 文本数据进行DES解密 输入参数 : (NSData *)data (NSString *)key 输出参数 : N/A 返回参数 : (NSData *) 备注信息 : 此函数不可用于过长文本 ******************************************************************************/ + (NSData *)DESDecrypt:(NSData *)data WithKey:(NSString *)key { char keyPtr[kCCKeySizeAES256+1]; bzero(keyPtr, sizeof(keyPtr)); [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [data length]; size_t bufferSize = dataLength + kCCBlockSizeAES128; void *buffer = malloc(bufferSize); size_t numBytesDecrypted = 0; CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES, kCCOptionPKCS7Padding | kCCOptionECBMode, keyPtr, kCCBlockSizeDES, NULL, [data bytes], dataLength, buffer, bufferSize, &numBytesDecrypted); if (cryptStatus == kCCSuccess) { return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted]; } free(buffer); return nil; } /****************************************************************************** 函数名称 : + (NSData *)dataWithBase64EncodedString:(NSString *)string 函数描述 : base64格式字符串转换为文本数据 输入参数 : (NSString *)string 输出参数 : N/A 返回参数 : (NSData *) 备注信息 : ******************************************************************************/ static const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + (NSData *)dataWithBase64EncodedString:(NSString *)string { if (string == nil) [NSException raise:NSInvalidArgumentException format:nil]; if ([string length] == 0) return [NSData data]; static char *decodingTable = NULL; if (decodingTable == NULL) { decodingTable = malloc(256); if (decodingTable == NULL) return nil; memset(decodingTable, CHAR_MAX, 256); NSUInteger i; for (i = 0; i < 64; i++) decodingTable[(short)encodingTable[i]] = i; } const char *characters = [string cStringUsingEncoding:NSASCIIStringEncoding]; if (characters == NULL) // Not an ASCII string! return nil; char *bytes = malloc((([string length] + 3) / 4) * 3); if (bytes == NULL) return nil; NSUInteger length = 0; NSUInteger i = 0; while (YES) { char buffer[4]; short bufferLength; for (bufferLength = 0; bufferLength < 4; i++) { if (characters[i] == ' ') break; if (isspace(characters[i]) || characters[i] == '=') continue; buffer[bufferLength] = decodingTable[(short)characters[i]]; if (buffer[bufferLength++] == CHAR_MAX) // Illegal character! { free(bytes); return nil; } } if (bufferLength == 0) break; if (bufferLength == 1) // At least two characters are needed to produce one byte! { free(bytes); return nil; } // Decode the characters in the buffer to bytes. bytes[length++] = (buffer[0] << 2) | (buffer[1] >> 4); if (bufferLength > 2) bytes[length++] = (buffer[1] << 4) | (buffer[2] >> 2); if (bufferLength > 3) bytes[length++] = (buffer[2] << 6) | buffer[3]; } bytes = realloc(bytes, length); return [NSData dataWithBytesNoCopy:bytes length:length]; } /****************************************************************************** 函数名称 : + (NSString *)base64EncodedStringFrom:(NSData *)data 函数描述 : 文本数据转换为base64格式字符串 输入参数 : (NSData *)data 输出参数 : N/A 返回参数 : (NSString *) 备注信息 : ******************************************************************************/ + (NSString *)base64EncodedStringFrom:(NSData *)data { if ([data length] == 0) return @""; char *characters = malloc((([data length] + 2) / 3) * 4); if (characters == NULL) return nil; NSUInteger length = 0; NSUInteger i = 0; while (i < [data length]) { char buffer[3] = {0,0,0}; short bufferLength = 0; while (bufferLength < 3 && i < [data length]) buffer[bufferLength++] = ((char *)[data bytes])[i++]; // Encode the bytes in the buffer to four characters, including padding "=" characters if necessary. characters[length++] = encodingTable[(buffer[0] & 0xFC) >> 2]; characters[length++] = encodingTable[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)]; if (bufferLength > 1) characters[length++] = encodingTable[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)]; else characters[length++] = '='; if (bufferLength > 2) characters[length++] = encodingTable[buffer[2] & 0x3F]; else characters[length++] = '='; } return [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES]; }
原文地址： http://www.cnblogs.com/thefeelingofsimple/archive/2012/11/29/2794724.html