Merge pull request #9688 from obsidiansystems/signature-generalization-prep

Signer infrastructure: Prep for #9076
This commit is contained in:
John Ericson 2024-01-03 17:25:37 -05:00 committed by GitHub
commit 65fad9b84c
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
24 changed files with 233 additions and 70 deletions

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@ -12,7 +12,6 @@
#include "realisation.hh"
#include "globals.hh"
#include "store-api.hh"
#include "crypto.hh"
#include "posix-source-accessor.hh"
#include <sodium.h>

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@ -28,7 +28,8 @@ BinaryCacheStore::BinaryCacheStore(const Params & params)
, Store(params)
{
if (secretKeyFile != "")
secretKey = std::unique_ptr<SecretKey>(new SecretKey(readFile(secretKeyFile)));
signer = std::make_unique<LocalSigner>(
SecretKey { readFile(secretKeyFile) });
StringSink sink;
sink << narVersionMagic1;
@ -274,7 +275,7 @@ ref<const ValidPathInfo> BinaryCacheStore::addToStoreCommon(
stats.narWriteCompressionTimeMs += duration;
/* Atomically write the NAR info file.*/
if (secretKey) narInfo->sign(*this, *secretKey);
if (signer) narInfo->sign(*this, *signer);
writeNarInfo(narInfo);

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@ -1,7 +1,7 @@
#pragma once
///@file
#include "crypto.hh"
#include "signature/local-keys.hh"
#include "store-api.hh"
#include "log-store.hh"
@ -57,8 +57,7 @@ class BinaryCacheStore : public virtual BinaryCacheStoreConfig,
{
private:
std::unique_ptr<SecretKey> secretKey;
std::unique_ptr<Signer> signer;
protected:

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@ -15,8 +15,6 @@
#include <nlohmann/json.hpp>
#include <sodium/core.h>
#ifdef __GLIBC__
# include <gnu/lib-names.h>
# include <nss.h>
@ -409,9 +407,6 @@ void initLibStore() {
initLibUtil();
if (sodium_init() == -1)
throw Error("could not initialise libsodium");
loadConfFile();
preloadNSS();

31
src/libstore/keys.cc Normal file
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@ -0,0 +1,31 @@
#include "file-system.hh"
#include "globals.hh"
#include "keys.hh"
namespace nix {
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;
}
}

10
src/libstore/keys.hh Normal file
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@ -0,0 +1,10 @@
#pragma once
///@file
#include "signature/local-keys.hh"
namespace nix {
PublicKeys getDefaultPublicKeys();
}

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@ -14,6 +14,7 @@
#include "signals.hh"
#include "posix-fs-canonicalise.hh"
#include "posix-source-accessor.hh"
#include "keys.hh"
#include <iostream>
#include <algorithm>
@ -1578,7 +1579,8 @@ void LocalStore::signRealisation(Realisation & realisation)
for (auto & secretKeyFile : secretKeyFiles.get()) {
SecretKey secretKey(readFile(secretKeyFile));
realisation.sign(secretKey);
LocalSigner signer(std::move(secretKey));
realisation.sign(signer);
}
}
@ -1590,7 +1592,8 @@ void LocalStore::signPathInfo(ValidPathInfo & info)
for (auto & secretKeyFile : secretKeyFiles.get()) {
SecretKey secretKey(readFile(secretKeyFile));
info.sign(*this, secretKey);
LocalSigner signer(std::move(secretKey));
info.sign(*this, signer);
}
}

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@ -8,7 +8,7 @@ libstore_SOURCES := $(wildcard $(d)/*.cc $(d)/builtins/*.cc $(d)/build/*.cc)
libstore_LIBS = libutil
libstore_LDFLAGS += $(SQLITE3_LIBS) $(LIBCURL_LIBS) $(SODIUM_LIBS) -pthread
libstore_LDFLAGS += $(SQLITE3_LIBS) $(LIBCURL_LIBS) -pthread
ifdef HOST_LINUX
libstore_LDFLAGS += -ldl
endif

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@ -38,9 +38,9 @@ std::string ValidPathInfo::fingerprint(const Store & store) const
}
void ValidPathInfo::sign(const Store & store, const SecretKey & secretKey)
void ValidPathInfo::sign(const Store & store, const Signer & signer)
{
sigs.insert(secretKey.signDetached(fingerprint(store)));
sigs.insert(signer.signDetached(fingerprint(store)));
}
std::optional<ContentAddressWithReferences> ValidPathInfo::contentAddressWithReferences() const

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@ -1,7 +1,7 @@
#pragma once
///@file
#include "crypto.hh"
#include "signature/signer.hh"
#include "path.hh"
#include "hash.hh"
#include "content-address.hh"
@ -107,7 +107,7 @@ struct ValidPathInfo : UnkeyedValidPathInfo {
*/
std::string fingerprint(const Store & store) const;
void sign(const Store & store, const SecretKey & secretKey);
void sign(const Store & store, const Signer & signer);
/**
* @return The `ContentAddressWithReferences` that determines the

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@ -1,7 +1,5 @@
#include "store-dir-config.hh"
#include <sodium.h>
namespace nix {
static void checkName(std::string_view path, std::string_view name)
@ -49,9 +47,7 @@ StorePath StorePath::dummy("ffffffffffffffffffffffffffffffff-x");
StorePath StorePath::random(std::string_view name)
{
Hash hash(HashAlgorithm::SHA1);
randombytes_buf(hash.hash, hash.hashSize);
return StorePath(hash, name);
return StorePath(Hash::random(HashAlgorithm::SHA1), name);
}
StorePath StoreDirConfig::parseStorePath(std::string_view path) const

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@ -1,6 +1,7 @@
#include "realisation.hh"
#include "store-api.hh"
#include "closure.hh"
#include "signature/local-keys.hh"
#include <nlohmann/json.hpp>
namespace nix {
@ -113,9 +114,9 @@ std::string Realisation::fingerprint() const
return serialized.dump();
}
void Realisation::sign(const SecretKey & secretKey)
void Realisation::sign(const Signer &signer)
{
signatures.insert(secretKey.signDetached(fingerprint()));
signatures.insert(signer.signDetached(fingerprint()));
}
bool Realisation::checkSignature(const PublicKeys & publicKeys, const std::string & sig) const

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@ -8,7 +8,7 @@
#include "derived-path.hh"
#include <nlohmann/json_fwd.hpp>
#include "comparator.hh"
#include "crypto.hh"
#include "signature/signer.hh"
namespace nix {
@ -64,7 +64,7 @@ struct Realisation {
static Realisation fromJSON(const nlohmann::json& json, const std::string& whence);
std::string fingerprint() const;
void sign(const SecretKey &);
void sign(const Signer &);
bool checkSignature(const PublicKeys & publicKeys, const std::string & sig) const;
size_t checkSignatures(const PublicKeys & publicKeys) const;

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@ -1,4 +1,4 @@
#include "crypto.hh"
#include "signature/local-keys.hh"
#include "source-accessor.hh"
#include "globals.hh"
#include "derived-path.hh"

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@ -14,6 +14,8 @@
#include <sys/stat.h>
#include <fcntl.h>
#include <sodium.h>
namespace nix {
static size_t regularHashSize(HashAlgorithm type) {
@ -261,6 +263,13 @@ Hash::Hash(std::string_view rest, HashAlgorithm algo, bool isSRI)
throw BadHash("hash '%s' has wrong length for hash algorithm '%s'", rest, printHashAlgo(this->algo));
}
Hash Hash::random(HashAlgorithm algo)
{
Hash hash(algo);
randombytes_buf(hash.hash, hash.hashSize);
return hash;
}
Hash newHashAllowEmpty(std::string_view hashStr, std::optional<HashAlgorithm> ha)
{
if (hashStr.empty()) {

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@ -5,7 +5,6 @@
#include "serialise.hh"
#include "file-system.hh"
namespace nix {
@ -143,6 +142,11 @@ public:
}
static Hash dummy;
/**
* @return a random hash with hash algorithm `algo`
*/
static Hash random(HashAlgorithm algo);
};
/**

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@ -4,14 +4,17 @@ libutil_NAME = libnixutil
libutil_DIR := $(d)
libutil_SOURCES := $(wildcard $(d)/*.cc)
libutil_SOURCES := $(wildcard $(d)/*.cc $(d)/signature/*.cc)
libutil_CXXFLAGS += -I src/libutil
libutil_LDFLAGS += -pthread $(OPENSSL_LIBS) $(LIBBROTLI_LIBS) $(LIBARCHIVE_LIBS) $(BOOST_LDFLAGS) -lboost_context
libutil_LDFLAGS += -pthread $(LIBCURL_LIBS) $(SODIUM_LIBS) $(OPENSSL_LIBS) $(LIBBROTLI_LIBS) $(LIBARCHIVE_LIBS) $(BOOST_LDFLAGS) -lboost_context
$(foreach i, $(wildcard $(d)/args/*.hh), \
$(eval $(call install-file-in, $(i), $(includedir)/nix/args, 0644)))
$(foreach i, $(wildcard $(d)/signature/*.hh), \
$(eval $(call install-file-in, $(i), $(includedir)/nix/signature, 0644)))
ifeq ($(HAVE_LIBCPUID), 1)
libutil_LDFLAGS += -lcpuid

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@ -1,13 +1,12 @@
#include "crypto.hh"
#include "signature/local-keys.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)
BorrowedCryptoValue BorrowedCryptoValue::parse(std::string_view s)
{
size_t colon = s.find(':');
if (colon == std::string::npos || colon == 0)
@ -17,10 +16,10 @@ static std::pair<std::string_view, std::string_view> split(std::string_view s)
Key::Key(std::string_view s)
{
auto ss = split(s);
auto ss = BorrowedCryptoValue::parse(s);
name = ss.first;
key = ss.second;
name = ss.name;
key = ss.payload;
if (name == "" || key == "")
throw Error("secret key is corrupt");
@ -73,45 +72,34 @@ PublicKey::PublicKey(std::string_view s)
throw Error("public key is not valid");
}
bool verifyDetached(const std::string & data, const std::string & sig,
const PublicKeys & publicKeys)
bool PublicKey::verifyDetached(std::string_view data, std::string_view sig) const
{
auto ss = split(sig);
auto ss = BorrowedCryptoValue::parse(sig);
auto key = publicKeys.find(std::string(ss.first));
if (key == publicKeys.end()) return false;
if (ss.name != std::string_view { name }) return false;
auto sig2 = base64Decode(ss.second);
return verifyDetachedAnon(data, ss.payload);
}
bool PublicKey::verifyDetachedAnon(std::string_view data, std::string_view sig) const
{
auto sig2 = base64Decode(sig);
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;
(unsigned char *) key.data()) == 0;
}
PublicKeys getDefaultPublicKeys()
bool verifyDetached(std::string_view data, std::string_view sig, const PublicKeys & publicKeys)
{
PublicKeys publicKeys;
auto ss = BorrowedCryptoValue::parse(sig);
// FIXME: filter duplicates
auto key = publicKeys.find(std::string(ss.name));
if (key == publicKeys.end()) return false;
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;
return key->second.verifyDetachedAnon(data, ss.payload);
}
}

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@ -7,6 +7,25 @@
namespace nix {
/**
* Except where otherwise noted, Nix serializes keys and signatures in
* the form:
*
* ```
* <name>:<key/signature-in-Base64>
* ```
*/
struct BorrowedCryptoValue {
std::string_view name;
std::string_view payload;
/**
* This splits on the colon, the user can then separated decode the
* Base64 payload separately.
*/
static BorrowedCryptoValue parse(std::string_view);
};
struct Key
{
std::string name;
@ -49,21 +68,36 @@ struct PublicKey : Key
{
PublicKey(std::string_view data);
/**
* @return true iff `sig` and this key's names match, and `sig` is a
* correct signature over `data` using the given public key.
*/
bool verifyDetached(std::string_view data, std::string_view sigs) const;
/**
* @return true iff `sig` is a correct signature over `data` using the
* given public key.
*
* @param just the Base64 signature itself, not a colon-separated pair of a
* public key name and signature.
*/
bool verifyDetachedAnon(std::string_view data, std::string_view sigs) const;
private:
PublicKey(std::string_view name, std::string && key)
: Key(name, std::move(key)) { }
friend struct SecretKey;
};
/**
* Map from key names to public keys
*/
typedef std::map<std::string, PublicKey> PublicKeys;
/**
* @return true iff sig is a correct signature over data using one
* of the given public keys.
*/
bool verifyDetached(const std::string & data, const std::string & sig,
const PublicKeys & publicKeys);
PublicKeys getDefaultPublicKeys();
bool verifyDetached(std::string_view data, std::string_view sig, const PublicKeys & publicKeys);
}

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@ -0,0 +1,23 @@
#include "signature/signer.hh"
#include "error.hh"
#include <sodium.h>
namespace nix {
LocalSigner::LocalSigner(SecretKey && privateKey)
: privateKey(privateKey)
, publicKey(privateKey.toPublicKey())
{ }
std::string LocalSigner::signDetached(std::string_view s) const
{
return privateKey.signDetached(s);
}
const PublicKey & LocalSigner::getPublicKey()
{
return publicKey;
}
}

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@ -0,0 +1,61 @@
#pragma once
#include "types.hh"
#include "signature/local-keys.hh"
#include <map>
#include <optional>
namespace nix {
/**
* An abstract signer
*
* Derive from this class to implement a custom signature scheme.
*
* It is only necessary to implement signature of bytes and provide a
* public key.
*/
struct Signer
{
virtual ~Signer() = default;
/**
* Sign the given data, creating a (detached) signature.
*
* @param data data to be signed.
*
* @return the [detached
* signature](https://en.wikipedia.org/wiki/Detached_signature),
* i.e. just the signature itself without a copy of the signed data.
*/
virtual std::string signDetached(std::string_view data) const = 0;
/**
* View the public key associated with this `Signer`.
*/
virtual const PublicKey & getPublicKey() = 0;
};
using Signers = std::map<std::string, Signer*>;
/**
* Local signer
*
* The private key is held in this machine's RAM
*/
struct LocalSigner : Signer
{
LocalSigner(SecretKey && privateKey);
std::string signDetached(std::string_view s) const override;
const PublicKey & getPublicKey() override;
private:
SecretKey privateKey;
PublicKey publicKey;
};
}

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@ -7,6 +7,7 @@
#include <grp.h>
#include <regex>
#include <sodium.h>
namespace nix {
@ -28,6 +29,9 @@ void initLibUtil() {
}
// This is not actually the main point of this check, but let's make sure anyway:
assert(caught);
if (sodium_init() == -1)
throw Error("could not initialise libsodium");
}
//////////////////////////////////////////////////////////////////////

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@ -112,7 +112,7 @@ struct CmdSign : StorePathsCommand
std::string description() override
{
return "sign store paths";
return "sign store paths with a local key";
}
void run(ref<Store> store, StorePaths && storePaths) override
@ -121,6 +121,7 @@ struct CmdSign : StorePathsCommand
throw UsageError("you must specify a secret key file using '-k'");
SecretKey secretKey(readFile(secretKeyFile));
LocalSigner signer(std::move(secretKey));
size_t added{0};
@ -129,7 +130,7 @@ struct CmdSign : StorePathsCommand
auto info2(*info);
info2.sigs.clear();
info2.sign(*store, secretKey);
info2.sign(*store, signer);
assert(!info2.sigs.empty());
if (!info->sigs.count(*info2.sigs.begin())) {

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@ -5,6 +5,7 @@
#include "thread-pool.hh"
#include "references.hh"
#include "signals.hh"
#include "keys.hh"
#include <atomic>