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#include "crypto.hh"
#include "util.hh"
#include "globals.hh"
#if HAVE_SODIUM
#include <sodium.h>
#endif
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 HAVE_SODIUM
if (key.size() != crypto_sign_SECRETKEYBYTES)
throw Error("secret key is not valid");
#endif
}
#if !HAVE_SODIUM
[[noreturn]] static void noSodium()
{
throw Error("Nix was not compiled with libsodium, required for signed binary cache support");
}
#endif
std::string SecretKey::signDetached(std::string_view data) const
{
#if HAVE_SODIUM
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));
#else
noSodium();
#endif
}
PublicKey SecretKey::toPublicKey() const
{
#if HAVE_SODIUM
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));
#else
noSodium();
#endif
}
SecretKey SecretKey::generate(std::string_view name)
{
#if HAVE_SODIUM
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));
#else
noSodium();
#endif
}
PublicKey::PublicKey(std::string_view s)
: Key(s)
{
#if HAVE_SODIUM
if (key.size() != crypto_sign_PUBLICKEYBYTES)
throw Error("public key is not valid");
#endif
}
bool verifyDetached(const std::string & data, const std::string & sig,
const PublicKeys & publicKeys)
{
#if HAVE_SODIUM
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;
#else
noSodium();
#endif
}
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;
}
}
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