lix/src/libstore/crypto.cc
John Ericson ac89bb064a Split up util.{hh,cc}
All OS and IO operations should be moved out, leaving only some misc
portable pure functions.

This is useful to avoid copious CPP when doing things like Windows and
Emscripten ports.

Newly exposed functions to break cycles:

 - `restoreSignals`
 - `updateWindowSize`
2023-11-05 12:20:02 -05:00

118 lines
3 KiB
C++

#include "crypto.hh"
#include "file-system.hh"
#include "util.hh"
#include "globals.hh"
#include <sodium.h>
namespace nix {
static std::pair<std::string_view, std::string_view> split(std::string_view s)
{
size_t colon = s.find(':');
if (colon == std::string::npos || colon == 0)
return {"", ""};
return {s.substr(0, colon), s.substr(colon + 1)};
}
Key::Key(std::string_view s)
{
auto ss = split(s);
name = ss.first;
key = ss.second;
if (name == "" || key == "")
throw Error("secret key is corrupt");
key = base64Decode(key);
}
std::string Key::to_string() const
{
return name + ":" + base64Encode(key);
}
SecretKey::SecretKey(std::string_view s)
: Key(s)
{
if (key.size() != crypto_sign_SECRETKEYBYTES)
throw Error("secret key is not valid");
}
std::string SecretKey::signDetached(std::string_view data) const
{
unsigned char sig[crypto_sign_BYTES];
unsigned long long sigLen;
crypto_sign_detached(sig, &sigLen, (unsigned char *) data.data(), data.size(),
(unsigned char *) key.data());
return name + ":" + base64Encode(std::string((char *) sig, sigLen));
}
PublicKey SecretKey::toPublicKey() const
{
unsigned char pk[crypto_sign_PUBLICKEYBYTES];
crypto_sign_ed25519_sk_to_pk(pk, (unsigned char *) key.data());
return PublicKey(name, std::string((char *) pk, crypto_sign_PUBLICKEYBYTES));
}
SecretKey SecretKey::generate(std::string_view name)
{
unsigned char pk[crypto_sign_PUBLICKEYBYTES];
unsigned char sk[crypto_sign_SECRETKEYBYTES];
if (crypto_sign_keypair(pk, sk) != 0)
throw Error("key generation failed");
return SecretKey(name, std::string((char *) sk, crypto_sign_SECRETKEYBYTES));
}
PublicKey::PublicKey(std::string_view s)
: Key(s)
{
if (key.size() != crypto_sign_PUBLICKEYBYTES)
throw Error("public key is not valid");
}
bool verifyDetached(const std::string & data, const std::string & sig,
const PublicKeys & publicKeys)
{
auto ss = split(sig);
auto key = publicKeys.find(std::string(ss.first));
if (key == publicKeys.end()) return false;
auto sig2 = base64Decode(ss.second);
if (sig2.size() != crypto_sign_BYTES)
throw Error("signature is not valid");
return crypto_sign_verify_detached((unsigned char *) sig2.data(),
(unsigned char *) data.data(), data.size(),
(unsigned char *) key->second.key.data()) == 0;
}
PublicKeys getDefaultPublicKeys()
{
PublicKeys publicKeys;
// FIXME: filter duplicates
for (auto s : settings.trustedPublicKeys.get()) {
PublicKey key(s);
publicKeys.emplace(key.name, key);
}
for (auto secretKeyFile : settings.secretKeyFiles.get()) {
try {
SecretKey secretKey(readFile(secretKeyFile));
publicKeys.emplace(secretKey.name, secretKey.toPublicKey());
} catch (SysError & e) {
/* Ignore unreadable key files. That's normal in a
multi-user installation. */
}
}
return publicKeys;
}
}