rublon-ssh/PAM/ssh/include/rublon/sign.hpp
2025-05-30 11:39:19 +02:00

64 lines
1.8 KiB
C++
Executable File

#pragma once
#include <memory>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/sha.h>
#include <rublon/utils.hpp>
namespace rublon {
struct EVP_MD_CTX_deleter{
void operator()(EVP_MD_CTX *ctx)const{
EVP_MD_CTX_free(ctx);
}
};
inline StaticString< SHA256_DIGEST_LENGTH * 2 > fileSHA256(const char * const path) {
std::string fileContent;
readFile(path, fileContent);
StaticString< SHA256_DIGEST_LENGTH * 2 > xRublon{};
std::array< unsigned char, SHA256_DIGEST_LENGTH + 1 > hash{};
auto ctx = std::unique_ptr<EVP_MD_CTX, EVP_MD_CTX_deleter>{EVP_MD_CTX_new()};
if(not ctx)
goto out;
// EVP_X methods return 1 on success, so does this function
// Any values other than 1 denote error
if(not EVP_DigestInit(ctx.get(), EVP_sha256()))
goto out;
if(not EVP_DigestUpdate(ctx.get(), fileContent.data(), fileContent.size()))
goto out;
// Provide uint* instead of NULL to get nBytes written, 32 for SHA256
if(not EVP_DigestFinal(ctx.get(), hash.data(), NULL))
goto out;
out:
for(unsigned int i = 0; i < SHA256_DIGEST_LENGTH; i++)
sprintf(&xRublon[i * 2], "%02x", ( unsigned int ) hash[i]);
return xRublon;
}
// +1 for \0
inline StaticString< SHA256_DIGEST_LENGTH * 2 > signData(std::string_view data, std::string_view secretKey) {
StaticString< SHA256_DIGEST_LENGTH * 2 > xRublon;
std::array< unsigned char, EVP_MAX_MD_SIZE > md{};
unsigned int md_len{};
HMAC(EVP_sha256(), secretKey.data(), secretKey.size(), ( unsigned const char * ) data.data(), data.size(), md.data(), &md_len);
for(unsigned int i = 0; i < md_len; i++)
sprintf(&xRublon[i * 2], "%02x", ( unsigned int ) md[i]);
return xRublon;
}
} // namespace rublon