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#include "crypto.hh"
#include "globals.hh"
#include "util.hh"
#if HAVE_SODIUM
#include <sodium.h>
#endif
namespace nix {
static std::pair<std::string, std::string> split(const string& s) {
size_t colon = s.find(':');
if (colon == std::string::npos || colon == 0) {
return {"", ""};
}
return {std::string(s, 0, colon), std::string(s, colon + 1)};
}
Key::Key(const string& s) {
auto ss = split(s);
name = ss.first;
key = ss.second;
if (name.empty() || key.empty()) {
throw Error("secret key is corrupt");
}
key = base64Decode(key);
}
SecretKey::SecretKey(const string& 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(const std::string& 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
}
PublicKey::PublicKey(const string& 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(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;
}
} // namespace nix
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