diff options
-rw-r--r-- | mk/tests.mk | 2 | ||||
-rw-r--r-- | release.nix | 2 | ||||
-rw-r--r-- | src/libexpr/eval.cc | 65 | ||||
-rw-r--r-- | src/libexpr/eval.hh | 8 | ||||
-rw-r--r-- | src/libexpr/primops.cc | 44 | ||||
-rw-r--r-- | src/libexpr/primops/fetchGit.cc | 15 | ||||
-rw-r--r-- | src/libexpr/primops/fetchMercurial.cc | 6 | ||||
-rw-r--r-- | src/libstore/globals.hh | 3 | ||||
-rw-r--r-- | src/libutil/util.cc | 6 | ||||
-rw-r--r-- | src/libutil/util.hh | 6 | ||||
-rwxr-xr-x | src/nix-build/nix-build.cc | 4 | ||||
-rw-r--r-- | src/nix-instantiate/nix-instantiate.cc | 2 | ||||
-rw-r--r-- | tests/fetchGit.sh | 7 | ||||
-rw-r--r-- | tests/fetchMercurial.sh | 7 | ||||
-rw-r--r-- | tests/local.mk | 3 | ||||
-rw-r--r-- | tests/pure-eval.nix | 3 | ||||
-rw-r--r-- | tests/pure-eval.sh | 18 | ||||
-rw-r--r-- | tests/restricted.nix | 1 | ||||
-rw-r--r-- | tests/restricted.sh | 10 |
19 files changed, 159 insertions, 53 deletions
diff --git a/mk/tests.mk b/mk/tests.mk index e353d46a0..70c30661b 100644 --- a/mk/tests.mk +++ b/mk/tests.mk @@ -39,7 +39,7 @@ installcheck: echo "$${red}$$failed out of $$total tests failed $$normal"; \ exit 1; \ else \ - echo "$${green}All tests succeeded"; \ + echo "$${green}All tests succeeded$$normal"; \ fi .PHONY: check installcheck diff --git a/release.nix b/release.nix index 30bec2a6e..04f1f8367 100644 --- a/release.nix +++ b/release.nix @@ -6,7 +6,7 @@ let - pkgs = import nixpkgs {}; + pkgs = import nixpkgs { system = "x86_64-linux"; }; jobs = rec { diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 087a95dde..f8685e010 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -300,16 +300,25 @@ EvalState::EvalState(const Strings & _searchPath, ref<Store> store) { countCalls = getEnv("NIX_COUNT_CALLS", "0") != "0"; - restricted = settings.restrictEval; - assert(gcInitialised); /* Initialise the Nix expression search path. */ - Strings paths = parseNixPath(getEnv("NIX_PATH", "")); - for (auto & i : _searchPath) addToSearchPath(i); - for (auto & i : paths) addToSearchPath(i); + if (!settings.pureEval) { + Strings paths = parseNixPath(getEnv("NIX_PATH", "")); + for (auto & i : _searchPath) addToSearchPath(i); + for (auto & i : paths) addToSearchPath(i); + } addToSearchPath("nix=" + settings.nixDataDir + "/nix/corepkgs"); + if (settings.restrictEval || settings.pureEval) { + allowedPaths = PathSet(); + for (auto & i : searchPath) { + auto r = resolveSearchPathElem(i); + if (!r.first) continue; + allowedPaths->insert(r.second); + } + } + clearValue(vEmptySet); vEmptySet.type = tAttrs; vEmptySet.attrs = allocBindings(0); @@ -326,38 +335,39 @@ EvalState::~EvalState() Path EvalState::checkSourcePath(const Path & path_) { - if (!restricted) return path_; + if (!allowedPaths) return path_; + + auto doThrow = [&]() [[noreturn]] { + throw RestrictedPathError("access to path '%1%' is forbidden in restricted mode", path_); + }; + + bool found = false; + + for (auto & i : *allowedPaths) { + if (isDirOrInDir(path_, i)) { + found = true; + break; + } + } + + if (!found) doThrow(); /* Resolve symlinks. */ debug(format("checking access to '%s'") % path_); Path path = canonPath(path_, true); - for (auto & i : searchPath) { - auto r = resolveSearchPathElem(i); - if (!r.first) continue; - if (path == r.second || isInDir(path, r.second)) + for (auto & i : *allowedPaths) { + if (isDirOrInDir(path, i)) return path; } - /* To support import-from-derivation, allow access to anything in - the store. FIXME: only allow access to paths that have been - constructed by this evaluation. */ - if (store->isInStore(path)) return path; - -#if 0 - /* Hack to support the chroot dependencies of corepkgs (see - corepkgs/config.nix.in). */ - if (path == settings.nixPrefix && isStorePath(settings.nixPrefix)) - return path; -#endif - - throw RestrictedPathError(format("access to path '%1%' is forbidden in restricted mode") % path_); + doThrow(); } void EvalState::checkURI(const std::string & uri) { - if (!restricted) return; + if (!settings.restrictEval) return; /* 'uri' should be equal to a prefix, or in a subdirectory of a prefix. Thus, the prefix https://github.co does not permit @@ -396,7 +406,7 @@ void EvalState::addConstant(const string & name, Value & v) } -void EvalState::addPrimOp(const string & name, +Value * EvalState::addPrimOp(const string & name, unsigned int arity, PrimOpFun primOp) { Value * v = allocValue(); @@ -407,6 +417,7 @@ void EvalState::addPrimOp(const string & name, staticBaseEnv.vars[symbols.create(name)] = baseEnvDispl; baseEnv.values[baseEnvDispl++] = v; baseEnv.values[0]->attrs->push_back(Attr(sym, v)); + return v; } @@ -659,8 +670,10 @@ Value * ExprPath::maybeThunk(EvalState & state, Env & env) } -void EvalState::evalFile(const Path & path, Value & v) +void EvalState::evalFile(const Path & path_, Value & v) { + auto path = checkSourcePath(path_); + FileEvalCache::iterator i; if ((i = fileEvalCache.find(path)) != fileEvalCache.end()) { v = i->second; diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index cc971ae80..9e3d30d95 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -76,9 +76,9 @@ public: already exist there. */ RepairFlag repair; - /* If set, don't allow access to files outside of the Nix search - path or to environment variables. */ - bool restricted; + /* The allowed filesystem paths in restricted or pure evaluation + mode. */ + std::experimental::optional<PathSet> allowedPaths; Value vEmptySet; @@ -212,7 +212,7 @@ private: void addConstant(const string & name, Value & v); - void addPrimOp(const string & name, + Value * addPrimOp(const string & name, unsigned int arity, PrimOpFun primOp); public: diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 98fe2199e..0ec035b86 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -439,7 +439,7 @@ static void prim_tryEval(EvalState & state, const Pos & pos, Value * * args, Val static void prim_getEnv(EvalState & state, const Pos & pos, Value * * args, Value & v) { string name = state.forceStringNoCtx(*args[0], pos); - mkString(v, state.restricted ? "" : getEnv(name)); + mkString(v, settings.restrictEval || settings.pureEval ? "" : getEnv(name)); } @@ -1929,7 +1929,14 @@ void fetch(EvalState & state, const Pos & pos, Value * * args, Value & v, state.checkURI(url); + if (settings.pureEval && !expectedHash) + throw Error("in pure evaluation mode, '%s' requires a 'sha256' argument", who); + Path res = getDownloader()->downloadCached(state.store, url, unpack, name, expectedHash); + + if (state.allowedPaths) + state.allowedPaths->insert(res); + mkString(v, res, PathSet({res})); } @@ -1981,11 +1988,28 @@ void EvalState::createBaseEnv() mkNull(v); addConstant("null", v); - mkInt(v, time(0)); - addConstant("__currentTime", v); + auto vThrow = addPrimOp("throw", 1, prim_throw); - mkString(v, settings.thisSystem); - addConstant("__currentSystem", v); + auto addPurityError = [&](const std::string & name) { + Value * v2 = allocValue(); + mkString(*v2, fmt("'%s' is not allowed in pure evaluation mode", name)); + mkApp(v, *vThrow, *v2); + addConstant(name, v); + }; + + if (settings.pureEval) + addPurityError("__currentTime"); + else { + mkInt(v, time(0)); + addConstant("__currentTime", v); + } + + if (settings.pureEval) + addPurityError("__currentSystem"); + else { + mkString(v, settings.thisSystem); + addConstant("__currentSystem", v); + } mkString(v, nixVersion); addConstant("__nixVersion", v); @@ -2001,10 +2025,10 @@ void EvalState::createBaseEnv() addConstant("__langVersion", v); // Miscellaneous - addPrimOp("scopedImport", 2, prim_scopedImport); + auto vScopedImport = addPrimOp("scopedImport", 2, prim_scopedImport); Value * v2 = allocValue(); mkAttrs(*v2, 0); - mkApp(v, *baseEnv.values[baseEnvDispl - 1], *v2); + mkApp(v, *vScopedImport, *v2); forceValue(v); addConstant("import", v); if (settings.enableNativeCode) { @@ -2020,7 +2044,6 @@ void EvalState::createBaseEnv() addPrimOp("__isBool", 1, prim_isBool); addPrimOp("__genericClosure", 1, prim_genericClosure); addPrimOp("abort", 1, prim_abort); - addPrimOp("throw", 1, prim_throw); addPrimOp("__addErrorContext", 2, prim_addErrorContext); addPrimOp("__tryEval", 1, prim_tryEval); addPrimOp("__getEnv", 1, prim_getEnv); @@ -2035,7 +2058,10 @@ void EvalState::createBaseEnv() // Paths addPrimOp("__toPath", 1, prim_toPath); - addPrimOp("__storePath", 1, prim_storePath); + if (settings.pureEval) + addPurityError("__storePath"); + else + addPrimOp("__storePath", 1, prim_storePath); addPrimOp("__pathExists", 1, prim_pathExists); addPrimOp("baseNameOf", 1, prim_baseNameOf); addPrimOp("dirOf", 1, prim_dirOf); diff --git a/src/libexpr/primops/fetchGit.cc b/src/libexpr/primops/fetchGit.cc index fb664cffb..2e3e2634d 100644 --- a/src/libexpr/primops/fetchGit.cc +++ b/src/libexpr/primops/fetchGit.cc @@ -22,10 +22,15 @@ struct GitInfo uint64_t revCount = 0; }; +std::regex revRegex("^[0-9a-fA-F]{40}$"); + GitInfo exportGit(ref<Store> store, const std::string & uri, std::experimental::optional<std::string> ref, std::string rev, const std::string & name) { + if (settings.pureEval && rev == "") + throw Error("in pure evaluation mode, 'fetchGit' requires a Git revision"); + if (!ref && rev == "" && hasPrefix(uri, "/") && pathExists(uri + "/.git")) { bool clean = true; @@ -76,11 +81,8 @@ GitInfo exportGit(ref<Store> store, const std::string & uri, if (!ref) ref = "master"s; - if (rev != "") { - std::regex revRegex("^[0-9a-fA-F]{40}$"); - if (!std::regex_match(rev, revRegex)) - throw Error("invalid Git revision '%s'", rev); - } + if (rev != "" && !std::regex_match(rev, revRegex)) + throw Error("invalid Git revision '%s'", rev); Path cacheDir = getCacheDir() + "/nix/git"; @@ -231,6 +233,9 @@ static void prim_fetchGit(EvalState & state, const Pos & pos, Value * * args, Va mkString(*state.allocAttr(v, state.symbols.create("shortRev")), gitInfo.shortRev); mkInt(*state.allocAttr(v, state.symbols.create("revCount")), gitInfo.revCount); v.attrs->sort(); + + if (state.allowedPaths) + state.allowedPaths->insert(gitInfo.storePath); } static RegisterPrimOp r("fetchGit", 1, prim_fetchGit); diff --git a/src/libexpr/primops/fetchMercurial.cc b/src/libexpr/primops/fetchMercurial.cc index a317476c5..5517d83df 100644 --- a/src/libexpr/primops/fetchMercurial.cc +++ b/src/libexpr/primops/fetchMercurial.cc @@ -27,6 +27,9 @@ std::regex commitHashRegex("^[0-9a-fA-F]{40}$"); HgInfo exportMercurial(ref<Store> store, const std::string & uri, std::string rev, const std::string & name) { + if (settings.pureEval && rev == "") + throw Error("in pure evaluation mode, 'fetchMercurial' requires a Mercurial revision"); + if (rev == "" && hasPrefix(uri, "/") && pathExists(uri + "/.hg")) { bool clean = runProgram("hg", true, { "status", "-R", uri, "--modified", "--added", "--removed" }) == ""; @@ -196,6 +199,9 @@ static void prim_fetchMercurial(EvalState & state, const Pos & pos, Value * * ar mkString(*state.allocAttr(v, state.symbols.create("shortRev")), std::string(hgInfo.rev, 0, 12)); mkInt(*state.allocAttr(v, state.symbols.create("revCount")), hgInfo.revCount); v.attrs->sort(); + + if (state.allowedPaths) + state.allowedPaths->insert(hgInfo.storePath); } static RegisterPrimOp r("fetchMercurial", 1, prim_fetchMercurial); diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh index af72f7b1e..81bb24a4e 100644 --- a/src/libstore/globals.hh +++ b/src/libstore/globals.hh @@ -232,6 +232,9 @@ public: "Whether to restrict file system access to paths in $NIX_PATH, " "and network access to the URI prefixes listed in 'allowed-uris'."}; + Setting<bool> pureEval{this, false, "pure-eval", + "Whether to restrict file system and network access to files specified by cryptographic hash."}; + Setting<size_t> buildRepeat{this, 0, "repeat", "The number of times to repeat a build in order to verify determinism.", {"build-repeat"}}; diff --git a/src/libutil/util.cc b/src/libutil/util.cc index 197df0c44..272997397 100644 --- a/src/libutil/util.cc +++ b/src/libutil/util.cc @@ -192,6 +192,12 @@ bool isInDir(const Path & path, const Path & dir) } +bool isDirOrInDir(const Path & path, const Path & dir) +{ + return path == dir or isInDir(path, dir); +} + + struct stat lstat(const Path & path) { struct stat st; diff --git a/src/libutil/util.hh b/src/libutil/util.hh index a3494e09b..75eb97515 100644 --- a/src/libutil/util.hh +++ b/src/libutil/util.hh @@ -53,10 +53,12 @@ Path dirOf(const Path & path); following the final `/'. */ string baseNameOf(const Path & path); -/* Check whether a given path is a descendant of the given - directory. */ +/* Check whether 'path' is a descendant of 'dir'. */ bool isInDir(const Path & path, const Path & dir); +/* Check whether 'path' is equal to 'dir' or a descendant of 'dir'. */ +bool isDirOrInDir(const Path & path, const Path & dir); + /* Get status of `path'. */ struct stat lstat(const Path & path); diff --git a/src/nix-build/nix-build.cc b/src/nix-build/nix-build.cc index 58366daa6..1b2494275 100755 --- a/src/nix-build/nix-build.cc +++ b/src/nix-build/nix-build.cc @@ -279,8 +279,8 @@ void mainWrapped(int argc, char * * argv) else /* If we're in a #! script, interpret filenames relative to the script. */ - exprs.push_back(state.parseExprFromFile(resolveExprPath(lookupFileArg(state, - inShebang && !packages ? absPath(i, absPath(dirOf(script))) : i)))); + exprs.push_back(state.parseExprFromFile(resolveExprPath(state.checkSourcePath(lookupFileArg(state, + inShebang && !packages ? absPath(i, absPath(dirOf(script))) : i))))); } /* Evaluate them into derivations. */ diff --git a/src/nix-instantiate/nix-instantiate.cc b/src/nix-instantiate/nix-instantiate.cc index 55ac007e8..e05040a42 100644 --- a/src/nix-instantiate/nix-instantiate.cc +++ b/src/nix-instantiate/nix-instantiate.cc @@ -182,7 +182,7 @@ int main(int argc, char * * argv) for (auto & i : files) { Expr * e = fromArgs ? state.parseExprFromString(i, absPath(".")) - : state.parseExprFromFile(resolveExprPath(lookupFileArg(state, i))); + : state.parseExprFromFile(resolveExprPath(state.checkSourcePath(lookupFileArg(state, i)))); processExpr(state, attrPaths, parseOnly, strict, autoArgs, evalOnly, outputKind, xmlOutputSourceLocation, e); } diff --git a/tests/fetchGit.sh b/tests/fetchGit.sh index b556fe594..530ac7bb8 100644 --- a/tests/fetchGit.sh +++ b/tests/fetchGit.sh @@ -29,10 +29,17 @@ rev2=$(git -C $repo rev-parse HEAD) path=$(nix eval --raw "(builtins.fetchGit file://$repo).outPath") [[ $(cat $path/hello) = world ]] +# In pure eval mode, fetchGit without a revision should fail. +[[ $(nix eval --raw "(builtins.readFile (fetchGit file://$repo + \"/hello\"))") = world ]] +(! nix eval --pure-eval --raw "(builtins.readFile (fetchGit file://$repo + \"/hello\"))") + # Fetch using an explicit revision hash. path2=$(nix eval --raw "(builtins.fetchGit { url = file://$repo; rev = \"$rev2\"; }).outPath") [[ $path = $path2 ]] +# In pure eval mode, fetchGit with a revision should succeed. +[[ $(nix eval --pure-eval --raw "(builtins.readFile (fetchGit { url = file://$repo; rev = \"$rev2\"; } + \"/hello\"))") = world ]] + # Fetch again. This should be cached. mv $repo ${repo}-tmp path2=$(nix eval --raw "(builtins.fetchGit file://$repo).outPath") diff --git a/tests/fetchMercurial.sh b/tests/fetchMercurial.sh index 271350ecd..4088dbd39 100644 --- a/tests/fetchMercurial.sh +++ b/tests/fetchMercurial.sh @@ -29,10 +29,17 @@ rev2=$(hg log --cwd $repo -r tip --template '{node}') path=$(nix eval --raw "(builtins.fetchMercurial file://$repo).outPath") [[ $(cat $path/hello) = world ]] +# In pure eval mode, fetchGit without a revision should fail. +[[ $(nix eval --raw "(builtins.readFile (fetchMercurial file://$repo + \"/hello\"))") = world ]] +(! nix eval --pure-eval --raw "(builtins.readFile (fetchMercurial file://$repo + \"/hello\"))") + # Fetch using an explicit revision hash. path2=$(nix eval --raw "(builtins.fetchMercurial { url = file://$repo; rev = \"$rev2\"; }).outPath") [[ $path = $path2 ]] +# In pure eval mode, fetchGit with a revision should succeed. +[[ $(nix eval --pure-eval --raw "(builtins.readFile (fetchMercurial { url = file://$repo; rev = \"$rev2\"; } + \"/hello\"))") = world ]] + # Fetch again. This should be cached. mv $repo ${repo}-tmp path2=$(nix eval --raw "(builtins.fetchMercurial file://$repo).outPath") diff --git a/tests/local.mk b/tests/local.mk index 83154228e..82502a8e5 100644 --- a/tests/local.mk +++ b/tests/local.mk @@ -20,7 +20,8 @@ nix_tests = \ fetchMercurial.sh \ signing.sh \ run.sh \ - brotli.sh + brotli.sh \ + pure-eval.sh # parallel.sh install-tests += $(foreach x, $(nix_tests), tests/$(x)) diff --git a/tests/pure-eval.nix b/tests/pure-eval.nix new file mode 100644 index 000000000..ed25b3d45 --- /dev/null +++ b/tests/pure-eval.nix @@ -0,0 +1,3 @@ +{ + x = 123; +} diff --git a/tests/pure-eval.sh b/tests/pure-eval.sh new file mode 100644 index 000000000..49c856448 --- /dev/null +++ b/tests/pure-eval.sh @@ -0,0 +1,18 @@ +source common.sh + +clearStore + +nix eval --pure-eval '(assert 1 + 2 == 3; true)' + +[[ $(nix eval '(builtins.readFile ./pure-eval.sh)') =~ clearStore ]] + +(! nix eval --pure-eval '(builtins.readFile ./pure-eval.sh)') + +(! nix eval --pure-eval '(builtins.currentTime)') +(! nix eval --pure-eval '(builtins.currentSystem)') + +(! nix-instantiate --pure-eval ./simple.nix) + +[[ $(nix eval "((import (builtins.fetchurl { url = file://$(pwd)/pure-eval.nix; })).x)") == 123 ]] +(! nix eval --pure-eval "((import (builtins.fetchurl { url = file://$(pwd)/pure-eval.nix; })).x)") +nix eval --pure-eval "((import (builtins.fetchurl { url = file://$(pwd)/pure-eval.nix; sha256 = \"$(nix hash-file pure-eval.nix --type sha256)\"; })).x)" diff --git a/tests/restricted.nix b/tests/restricted.nix new file mode 100644 index 000000000..e0ef58402 --- /dev/null +++ b/tests/restricted.nix @@ -0,0 +1 @@ +1 + 2 diff --git a/tests/restricted.sh b/tests/restricted.sh index c063c8693..6c0392fac 100644 --- a/tests/restricted.sh +++ b/tests/restricted.sh @@ -3,7 +3,8 @@ source common.sh clearStore nix-instantiate --restrict-eval --eval -E '1 + 2' -(! nix-instantiate --restrict-eval ./simple.nix) +(! nix-instantiate --restrict-eval ./restricted.nix) +(! nix-instantiate --eval --restrict-eval <(echo '1 + 2')) nix-instantiate --restrict-eval ./simple.nix -I src=. nix-instantiate --restrict-eval ./simple.nix -I src1=simple.nix -I src2=config.nix -I src3=./simple.builder.sh @@ -28,3 +29,10 @@ nix eval --raw "(builtins.fetchurl file://$(pwd)/restricted.sh)" --restrict-eval (! nix eval --raw "(builtins.fetchurl https://github.com/NixOS/patchelf/archive/master.tar.gz)" --restrict-eval) (! nix eval --raw "(builtins.fetchTarball https://github.com/NixOS/patchelf/archive/master.tar.gz)" --restrict-eval) (! nix eval --raw "(fetchGit git://github.com/NixOS/patchelf.git)" --restrict-eval) + +ln -sfn $(pwd)/restricted.nix $TEST_ROOT/restricted.nix +[[ $(nix-instantiate --eval $TEST_ROOT/restricted.nix) == 3 ]] +(! nix-instantiate --eval --restrict-eval $TEST_ROOT/restricted.nix) +(! nix-instantiate --eval --restrict-eval $TEST_ROOT/restricted.nix -I $TEST_ROOT) +(! nix-instantiate --eval --restrict-eval $TEST_ROOT/restricted.nix -I .) +nix-instantiate --eval --restrict-eval $TEST_ROOT/restricted.nix -I $TEST_ROOT -I . |