我写了一个函数来散列一个字符串,并得到十六进制格式的结果。我得到的输出看起来几乎与预期相同,但由于缺少零,它更短:
64: ae6a9df8bdf4545392e6b1354252af8546282b49033a9118b12e9511892197c6
64: ae6a9df8bdf4545392e6b1354252af8546282b4933a9118b12e9511892197c6
下面是我的代码:
#include <openssl/evp.h>
#include <cstdint>
#include <array>
#include <string_view>
#include <charconv>
#include <iostream>
int main(){
std::string oceanic = "oceanic 815";
EVP_MD_CTX *context = EVP_MD_CTX_new();
EVP_DigestInit(context, EVP_sha256());
EVP_DigestUpdate(context, oceanic.data(), oceanic.size());
std::array<uint8_t, EVP_MAX_MD_SIZE> hash{};
unsigned int written = 0;
EVP_DigestFinal(context, hash.data(), &written);
std::cout << written << '/' << EVP_MAX_MD_SIZE << '\n';
// from https://emn178.github.io/online-tools/sha256.html
std::string_view expected = "ae6a9df8bdf4545392e6b1354252af8546282b49033a9118b12e9511892197c6";
std::cout << expected.size() << ": " << expected << '\n';
std::array<char, 64> hex{};
for (size_t iHash = 0, iHex = 0; iHash < written; ++iHash)
{
std::to_chars(&hex[iHex], &hex[iHex + 2], hash[iHash], 16);
iHex += 2;
// This also produces invalid result
// const char hexMap[] = "0123456789ABCDEF";
// const char ch = hash[iHash];
// hex[iHash] = hexMap[(ch & 0xF0) >> 4];
// hex[iHash + 1] = hexMap[ch & 0xF];
// iHash += 2;
}
std::cout << hex.size() << ": " << std::string_view(hex.data(), hex.size()) << '\n';
return 0;
}
https://godbolt.org/z/hq9onW49z
我不想使用std::stringstream
,因为我不需要动态分配。
我的代码基于以下答案:https://stackoverflow.com/a/72132640/9363996
我做错了什么?
1条答案
按热度按时间kse8i1jr1#
对于使用十六进制表的第二个解决方案(已被注解掉),我发现了错误。我对
hex[]
使用了无效的迭代器。正确版本:
https://godbolt.org/z/vYcn4Geos