在目标C中创建B64，其中NSData是二进制值解码的HMAC，而key是非二进制值

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // 准备待编码的二进制数据
        unsigned char binaryData[] = {0x01, 0x02, 0x03, 0x04};
        NSUInteger length = sizeof(binaryData);
        NSData *data = [NSData dataWithBytes:binaryData length:length];
        
        // 进行Base64编码
        NSData *base64Data = [data base64EncodedDataWithOptions:0];
        
        // 解码HMAC密钥
        NSString *keyString = @"myKey";
        NSData *keyData = [keyString dataUsingEncoding:NSUTF8StringEncoding];
        
        // 解码二进制值
        NSData *decodedData = [[NSData alloc] initWithBase64EncodedData:base64Data options:0];
        
        // 输出结果
        NSLog(@"Base64编码结果：%@", [[NSString alloc] initWithData:base64Data encoding:NSUTF8StringEncoding]);
        NSLog(@"HMAC解码结果：%@", [[NSString alloc] initWithData:decodedData encoding:NSUTF8StringEncoding]);
    }
    return 0;
}