我尝试使用 SecretSharing在 Crypto++ 中上课,但我无法让它工作。
这是我的代码:
using namespace CryptoPP;
void secretSharing(){
AutoSeededRandomPool rng;
SecretSharing shamir(rng, 4, 6);
byte test[] = {'a', 'b', 'c', 'd'};
shamir.Put(test, 4);
//shamir.MessageEnd();
//cout << shamir.TotalBytesRetrievable() <<endl;
}
编译运行后得到:
./main
terminate called after throwing an instance of 'CryptoPP::BufferedTransformation::NoChannelSupport'
what(): unknown: this object doesn't support multiple channels
[1] 3597 abort (core dumped) ./main
SecretSharing::SecretSharing()
的声明是:
SecretSharing(RandomNumberGenerator &rng,int threshold,int nShares,BufferedTransformation *attachment=NULL,bool addPadding=true)
我应该给它一个BufferedTransformation*
,但我到底应该使用哪个类?
Crypto++ 中是否有 secret 共享示例代码?
最佳答案
基于 Fraser 的回答,这是代码。
void SecretShareFile(int threshold, int nShares, const char *filename, const char *seed)
{
RandomPool rng;
rng.IncorporateEntropy((byte *)seed, strlen(seed));
ChannelSwitch *channelSwitch;
FileSource source(filename, false, new SecretSharing(rng,
threshold, nShares, channelSwitch = new ChannelSwitch));
vector_member_ptrs<FileSink> fileSinks(nShares);
string channel;
for (int i=0; i<nShares; i++)
{
char extension[5] = ".000";
extension[1]='0'+byte(i/100);
extension[2]='0'+byte((i/10)%10);
extension[3]='0'+byte(i%10);
fileSinks[i].reset(new FileSink((string(filename)+extension).c_str()));
channel = WordToString<word32>(i);
fileSinks[i]->Put((byte *)channel.data(), 4);
channelSwitch->AddRoute(channel, *fileSinks[i], DEFAULT_CHANNEL);
}
source.PumpAll();
}
在上面的代码中,有一个使用 new
创建的命名 ChannelSwitch
变量。 FileSource
source
拥有它并将删除它。但他需要一个命名变量(而不是匿名变量或临时变量),因为他后来调用了 channelSwitch->AddRoute
Wei 可以使用 Redirector
来完成它,以允许堆栈分配(远离内存管理器)并确保 FileSource
过滤器不会删除它:
ChannelSwitch channelSwitch;
FileSource source(filename, false, new SecretSharing(rng,
threshold, nShares, new Redirector(channelSwitch));
...
channelSwitch.AddRoute(channel, *fileSinks[i], DEFAULT_CHANNEL);
恢复代码:
void SecretRecoverFile(int threshold, const char *outFilename, char *const *inFilenames)
{
SecretRecovery recovery(threshold, new FileSink(outFilename));
vector_member_ptrs<FileSource> fileSources(threshold);
SecByteBlock channel(4);
int i;
for (i=0; i<threshold; i++)
{
fileSources[i].reset(new FileSource(inFilenames[i], false));
fileSources[i]->Pump(4);
fileSources[i]->Get(channel, 4);
fileSources[i]->Attach(new ChannelSwitch(recovery, string((char *)channel.begin(), 4)));
}
while (fileSources[0]->Pump(256))
for (i=1; i<threshold; i++)
fileSources[i]->Pump(256);
for (i=0; i<threshold; i++)
fileSources[i]->PumpAll();
}
关于c++ - 如何在 Crypto++ 中使用 Shamir secret 共享类,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20917558/