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lix/tests/restricted.sh

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Add tests for restricted eval mode
2016-04-14 15:24:06 +02:00
source common.sh
clearStore
Test: Replace --option with the corresponding flag
2017-11-20 17:50:49 +01:00
nix-instantiate --restrict-eval --eval -E '1 + 2'
Add pure evaluation mode In this mode, the following restrictions apply: * The builtins currentTime, currentSystem and storePath throw an error. * $NIX_PATH and -I are ignored. * fetchGit and fetchMercurial require a revision hash. * fetchurl and fetchTarball require a sha256 attribute. * No file system access is allowed outside of the paths returned by fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is not allowed. Thus, the evaluation result is completely reproducible from the command line arguments. E.g. nix build --pure-eval '( let nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; }; nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; }; in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux )' The goal is to enable completely reproducible and traceable evaluation. For example, a NixOS configuration could be fully described by a single Git commit hash. 'nixos-rebuild' would do something like nix build --pure-eval '( (import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system ') where the Git repository /my-nixos-config would use further fetchGit calls or Git externals to fetch Nixpkgs and whatever other dependencies it has. Either way, the commit hash would uniquely identify the NixOS configuration and allow it to reproduced.
2018-01-16 18:50:38 +01:00
(! nix-instantiate --restrict-eval ./restricted.nix)
(! nix-instantiate --eval --restrict-eval <(echo '1 + 2'))
Test: Replace --option with the corresponding flag
2017-11-20 17:50:49 +01:00
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
Add tests for restricted eval mode
2016-04-14 15:24:06 +02:00
Test: Replace --option with the corresponding flag
2017-11-20 17:50:49 +01:00
(! nix-instantiate --restrict-eval --eval -E 'builtins.readFile ./simple.nix')
nix-instantiate --restrict-eval --eval -E 'builtins.readFile ./simple.nix' -I src=..
Add tests for restricted eval mode
2016-04-14 15:24:06 +02:00
Use boost::format from the boost package Note that this only requires headers from boost so it doesn't add a runtime dependency. Also, use Nixpkgs 18.03.
2018-03-14 19:01:22 +01:00
(! nix-instantiate --restrict-eval --eval -E 'builtins.readDir ../src/nix-channel')
nix-instantiate --restrict-eval --eval -E 'builtins.readDir ../src/nix-channel' -I src=../src
Add tests for restricted eval mode
2016-04-14 15:24:06 +02:00
Test: Replace --option with the corresponding flag
2017-11-20 17:50:49 +01:00
(! nix-instantiate --restrict-eval --eval -E 'let __nixPath = [ { prefix = "foo"; path = ./.; } ]; in <foo>')
nix-instantiate --restrict-eval --eval -E 'let __nixPath = [ { prefix = "foo"; path = ./.; } ]; in <foo>' -I src=.
Add tests for restricted eval mode
2016-04-14 15:24:06 +02:00
nix: Add --expr flag This replaces the '(...)' installable syntax, which is not very discoverable. The downside is that you can't have multiple expressions or mix expressions and other installables.
2019-11-27 00:05:30 +01:00
p=$(nix eval --raw --expr "builtins.fetchurl file://$(pwd)/restricted.sh" --impure --restrict-eval --allowed-uris "file://$(pwd)")
Add option allowed-uris This allows network access in restricted eval mode.
2017-10-30 12:39:59 +01:00
cmp $p restricted.sh
nix: Add --expr flag This replaces the '(...)' installable syntax, which is not very discoverable. The downside is that you can't have multiple expressions or mix expressions and other installables.
2019-11-27 00:05:30 +01:00
(! nix eval --raw --expr "builtins.fetchurl file://$(pwd)/restricted.sh" --impure --restrict-eval)
Add option allowed-uris This allows network access in restricted eval mode.
2017-10-30 12:39:59 +01:00
nix: Add --expr flag This replaces the '(...)' installable syntax, which is not very discoverable. The downside is that you can't have multiple expressions or mix expressions and other installables.
2019-11-27 00:05:30 +01:00
(! nix eval --raw --expr "builtins.fetchurl file://$(pwd)/restricted.sh" --impure --restrict-eval --allowed-uris "file://$(pwd)/restricted.sh/")
Add option allowed-uris This allows network access in restricted eval mode.
2017-10-30 12:39:59 +01:00
nix: Add --expr flag This replaces the '(...)' installable syntax, which is not very discoverable. The downside is that you can't have multiple expressions or mix expressions and other installables.
2019-11-27 00:05:30 +01:00
nix eval --raw --expr "builtins.fetchurl file://$(pwd)/restricted.sh" --impure --restrict-eval --allowed-uris "file://$(pwd)/restricted.sh"
Add option allowed-uris This allows network access in restricted eval mode.
2017-10-30 12:39:59 +01:00
nix: Add --expr flag This replaces the '(...)' installable syntax, which is not very discoverable. The downside is that you can't have multiple expressions or mix expressions and other installables.
2019-11-27 00:05:30 +01:00
(! nix eval --raw --expr "builtins.fetchurl https://github.com/NixOS/patchelf/archive/master.tar.gz" --impure --restrict-eval)
(! nix eval --raw --expr "builtins.fetchTarball https://github.com/NixOS/patchelf/archive/master.tar.gz" --impure --restrict-eval)
(! nix eval --raw --expr "fetchGit git://github.com/NixOS/patchelf.git" --impure --restrict-eval)
Add pure evaluation mode In this mode, the following restrictions apply: * The builtins currentTime, currentSystem and storePath throw an error. * $NIX_PATH and -I are ignored. * fetchGit and fetchMercurial require a revision hash. * fetchurl and fetchTarball require a sha256 attribute. * No file system access is allowed outside of the paths returned by fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is not allowed. Thus, the evaluation result is completely reproducible from the command line arguments. E.g. nix build --pure-eval '( let nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; }; nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; }; in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux )' The goal is to enable completely reproducible and traceable evaluation. For example, a NixOS configuration could be fully described by a single Git commit hash. 'nixos-rebuild' would do something like nix build --pure-eval '( (import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system ') where the Git repository /my-nixos-config would use further fetchGit calls or Git externals to fetch Nixpkgs and whatever other dependencies it has. Either way, the commit hash would uniquely identify the NixOS configuration and allow it to reproduced.
2018-01-16 18:50:38 +01:00
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 .
realiseContext(): Add derivation outputs to the allowed paths This makes import-from-derivation work in restricted mode again.
2018-02-06 15:38:45 +01:00
nix: Add --expr flag This replaces the '(...)' installable syntax, which is not very discoverable. The downside is that you can't have multiple expressions or mix expressions and other installables.
2019-11-27 00:05:30 +01:00
[[ $(nix eval --raw --impure --restrict-eval -I . --expr 'builtins.readFile "${import ./simple.nix}/hello"') == 'Hello World!' ]]
Fix symlink leak in restricted eval mode In EvalState::checkSourcePath, the path is checked against the list of allowed paths first and later it's checked again *after* resolving symlinks. The resolving of the symlinks is done via canonPath, which also strips out "../" and "./". However after the canonicalisation the error message pointing out that the path is not allowed prints the symlink target in the error message. Even if we'd suppress the message, symlink targets could still be leaked if the symlink target doesn't exist (in this case the error is thrown in canonPath). So instead, we now do canonPath() without symlink resolving first before even checking against the list of allowed paths and then later do the symlink resolving and checking the allowed paths again. The first call to canonPath() should get rid of all the "../" and "./", so in theory the only way to leak a symlink if the attacker is able to put a symlink in one of the paths allowed by restricted evaluation mode. For the latter I don't think this is part of the threat model, because if the attacker can write to that path, the attack vector is even larger. Signed-off-by: aszlig <aszlig@nix.build>
2018-08-03 06:24:57 +02:00
# Check whether we can leak symlink information through directory traversal.
traverseDir="$(pwd)/restricted-traverse-me"
ln -sfn "$(pwd)/restricted-secret" "$(pwd)/restricted-innocent"
mkdir -p "$traverseDir"
goUp="..$(echo "$traverseDir" | sed -e 's,[^/]\+,..,g')"
output="$(nix eval --raw --restrict-eval -I "$traverseDir" \
nix: Add --expr flag This replaces the '(...)' installable syntax, which is not very discoverable. The downside is that you can't have multiple expressions or mix expressions and other installables.
2019-11-27 00:05:30 +01:00
--expr "builtins.readFile \"$traverseDir/$goUp$(pwd)/restricted-innocent\"" \
Fix symlink leak in restricted eval mode In EvalState::checkSourcePath, the path is checked against the list of allowed paths first and later it's checked again *after* resolving symlinks. The resolving of the symlinks is done via canonPath, which also strips out "../" and "./". However after the canonicalisation the error message pointing out that the path is not allowed prints the symlink target in the error message. Even if we'd suppress the message, symlink targets could still be leaked if the symlink target doesn't exist (in this case the error is thrown in canonPath). So instead, we now do canonPath() without symlink resolving first before even checking against the list of allowed paths and then later do the symlink resolving and checking the allowed paths again. The first call to canonPath() should get rid of all the "../" and "./", so in theory the only way to leak a symlink if the attacker is able to put a symlink in one of the paths allowed by restricted evaluation mode. For the latter I don't think this is part of the threat model, because if the attacker can write to that path, the attack vector is even larger. Signed-off-by: aszlig <aszlig@nix.build>
2018-08-03 06:24:57 +02:00
2>&1 || :)"
echo "$output" | grep "is forbidden"
! echo "$output" | grep -F restricted-secret
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