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Check signatures/checksums to ensure authenticity
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Please refer to [Verifying Node.js Binaries](https://blog.continuation.io/verifying-node-js-binaries/)
for why this is important.

Related to: asdf-vm/asdf#158
Mitigates: nodejs/node#9859
Mitigates: nodejs/node#6821

Implementing this feature required some rework of the `install` script
which is included in this PR. The following other PR are
superseded/included in this one:

Closes: asdf-vm#15
Closes: asdf-vm#16
Closes: asdf-vm#19

Note that this PR also updates the base download URL from
"http://nodejs.org/dist" to "https://nodejs.org/dist" meaning that
before this PR (or asdf-vm#16 which is not merged), binaries where downloaded
over plain legacy HTTP! (those binaries where later executed by the
user). This is really bad and is fairly easy to exploit!

Related to: nvm-sh/nvm#736
Related to: nvm-sh/nvm#793
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ypid committed Feb 20, 2017
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24 changes: 24 additions & 0 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,30 @@ Node.js plugin for [asdf](https://github.com/asdf-vm/asdf) version manager
asdf plugin-add nodejs https://github.com/asdf-vm/asdf-nodejs.git
```

## Bootstrap trust for signature validation

The plugin properly valides OpenPGP signatures, which is not yet done in any
other NodeJS version manager as of 2017-02. All you have to do is to bootstrap
the trust once as follows.

You can either import the OpenPGP public keys in your main OpenPGP keyring or use a dedicated keyring (recommended).
If you decided to do the later, prepare the dedicated keyring and make it temporarily the default one in your current shell:

```Shell
export GNUPGHOME="$HOME/.asdf/keyrings/nodejs" && mkdir -p "$GNUPGHOME" && chmod 0700 "$GNUPGHOME"
```

Then import the OpenPGP public keys of the [Release Team](https://github.com/nodejs/node/#release-team).

For more details, refer to [Verifying Node.js Binaries](https://blog.continuation.io/verifying-node-js-binaries/).
Note that only versions greater or equal to 0.10.0 are checked. Before that version, signatures for SHA2-256 hashes might not be provided.

This behavior can be influenced by the `NODEJS_CHECK_SIGNATURES` variable which supports the following options:

`no`: Do not check signatures/checksums.
`yes`: Check signatures/checksums if they should be present (enforced for >= 0.10.0).
`strict` (default): Check signatures/checksums and don’t operate on package versions which did not provide signatures/checksums properly (>= 0.10.0).

## Use

Check [asdf](https://github.com/asdf-vm/asdf) readme for instructions on how to install & manage versions of Node.js.
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213 changes: 147 additions & 66 deletions bin/install
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@@ -1,136 +1,217 @@
#!/usr/bin/env bash

set -o nounset -o pipefail -o errexit

NODEJS_CHECK_SIGNATURES="${NODEJS_CHECK_SIGNATURES:-strict}"

install_nodejs() {
local install_type=$1
local version=$2
local install_path=$3

if [ "$TMPDIR" = "" ]; then
local tmp_download_dir=$(mktemp -d)
else
local tmp_download_dir=$TMPDIR
fi
local tmp_download_dir="$(mktemp --directory -t 'asdf_nodejs_XXXXXX')"

local source_path=$(get_download_file_path $install_type $version $tmp_download_dir)
download_source_file $install_type $version $source_path
## Do this first as it is fast but could fail.
download_and_verify_checksums "$install_type" "$version" "$tmp_download_dir"

local archive_path="${tmp_download_dir}/$(get_archive_file_name "$install_type" "$version")"
download_file "$(get_download_url "$install_type" "$version")" "${archive_path}"

verify_archive "$tmp_download_dir"

# running this in a subshell
# we don't want to disturb current working dir
(
if [ "$install_type" != "version" ]; then
tar zxf $source_path -C $install_path --strip-components=1 || exit 1
cd $install_path
tar zxf "$archive_path" -C "$install_path" --strip-components=1 || exit 1
cd "$install_path" || exit 1

local configure_options="$(construct_configure_options $install_path)"
local configure_options="$(construct_configure_options "$install_path")"

# shellcheck disable=SC2086
./configure $configure_options || exit 1
make
make install

if [ $? -ne 0 ]; then
rm -rf $install_path
rm -rf "$install_path"
exit 1
fi
else
tar zxf $source_path -C $install_path --strip-components=1 || exit 1
tar zxf "$archive_path" -C "$install_path" --strip-components=1 || exit 1
fi

mkdir -p $install_path/.npm/lib/node_modules/.hooks
cp $(dirname $(dirname $0))/npm-hooks/* $install_path/.npm/lib/node_modules/.hooks/
chmod +x $install_path/.npm/lib/node_modules/.hooks/*
mkdir -p "$install_path/.npm/lib/node_modules/.hooks"
cp "$(dirname "$(dirname "$0")")"/npm-hooks/* "$install_path/.npm/lib/node_modules/.hooks/"
chmod +x "$install_path"/.npm/lib/node_modules/.hooks/*
)
}


construct_configure_options() {
local install_path=$1

if [ "$NODEJS_CONFIGURE_OPTIONS" = "" ]; then
local configure_options="$(os_based_configure_options) --prefix=$install_path"
if [ -z "${NODEJS_CONFIGURE_OPTIONS:-}" ]; then
local configure_options="--dest-cpu=$(get_nodejs_machine_hardware_name)"

if [ "$NODEJS_EXTRA_CONFIGURE_OPTIONS" != "" ]; then
configure_options="$configure_options $NODEJS_EXTRA_CONFIGURE_OPTIONS"
if [ "${NODEJS_EXTRA_CONFIGURE_OPTIONS:-}" != "" ]; then
configure_options="$configure_options ${NODEJS_EXTRA_CONFIGURE_OPTIONS:-}"
fi
else
local configure_options="$NODEJS_CONFIGURE_OPTIONS --prefix=$install_path"
local configure_options="${NODEJS_CONFIGURE_OPTIONS:-}"
fi

configure_options="$configure_options --prefix=$install_path"

echo "$configure_options"
}


os_based_configure_options() {
local operating_system=$(uname -a)
local configure_options=""
get_nodejs_machine_hardware_name() {
local machine_hardware_name=$(uname --machine)

if [[ "$operating_system" =~ "x86_64" ]]; then
local cpu_type="x64"
else
local cpu_type="x86"
fi
case "$machine_hardware_name" in
'x86_64') local cpu_type="x64";;
'i686') local cpu_type="x86";;
*) local cpu_type="$machine_hardware_name";;
esac

configure_options="$configure_options --dest-cpu=$cpu_type"
echo $configure_options
echo "$cpu_type"
}


download_source_file() {
local install_type=$1
local version=$2
local download_path=$3
local download_url=$(get_download_url $install_type $version)
download_file() {
local download_url="$1"
local download_path="$2"

curl -Lo $download_path -C - $download_url
curl -Lo "$download_path" -C - "$download_url"
}


get_download_file_path() {
local install_type=$1
local version=$2
local tmp_download_dir=$3

get_archive_file_name() {
local install_type="$1"
local version="$2"

if [ "$install_type" = "version" ]; then
if [[ "$operating_system" =~ "x86_64" ]]; then
local cpu_type="x64"
else
local cpu_type="x86"
fi

if [[ "$operating_system" =~ "Darwin" ]]; then
local pkg_name="node-v${version}-darwin-${cpu_type}"
else # we'll assume it is linux
local pkg_name="node-v${version}-linux-${cpu_type}"
fi
local pkg_name="node-v${version}-$(uname --kernel-name | tr '[:upper:]' '[:lower:]')-$(get_nodejs_machine_hardware_name)"
else
local pkg_name="${version}.tar.gz"
local pkg_name="${version}"
fi

echo "$tmp_download_dir/$pkg_name"
echo "${pkg_name}.tar.gz"
}


get_download_url() {
local install_type="$1"
local version="$2"

if [ "$install_type" = "version" ]; then
local download_url_base="https://nodejs.org/dist/v${version}"
else
local download_url_base="https://github.com/nodejs/node/archive"
fi

echo "${download_url_base}/$(get_archive_file_name "$install_type" "$version")"
}


get_signed_checksum_download_url() {
local install_type=$1
local version=$2
local operating_system=$(uname -a)

if [ "$install_type" = "version" ]; then
if [[ "$operating_system" =~ "x86_64" ]]; then
local cpu_type="x64"
else
local cpu_type="x86"
echo "https://nodejs.org/dist/v${version}/SHASUMS256.txt.asc"
else
# Not implemented.
exit 1
fi
}


download_and_verify_checksums() {
local install_type="$1"
local version="$2"
local tmp_download_dir="$3"

if [ "${NODEJS_CHECK_SIGNATURES}" == "no" ]; then
return 0
fi

## Seems nodejs.org started with around 0.10.0 to release properly signed SHA2-256 checksum files.
if verlte "0.10.0" "$version"
then
echo "$tmp_download_dir"
local signed_checksum_file="$tmp_download_dir/SHASUMS256.txt.asc"
local signed_checksum_download_url="$(get_signed_checksum_download_url "$install_type" "$version")"
if [ -z "${signed_checksum_download_url}" ]; then
if [ "${NODEJS_CHECK_SIGNATURES}" == "strict" ]; then
echo "$version did not provide signed checksums or support for them has not been implemented and NODEJS_CHECK_SIGNATURES=strict is set. Exiting." >&2
exit 1
else
echo "$version did not provide signed checksums or support for them has not been implemented. Continue without signature checking." >&2
return 0
fi
fi
download_file "${signed_checksum_download_url}" "$signed_checksum_file"

if [[ "$operating_system" =~ "Darwin" ]]; then
echo "https://nodejs.org/dist/v${version}/node-v${version}-darwin-${cpu_type}.tar.gz"
else # we'll assume it is linux
echo "https://nodejs.org/dist/v${version}/node-v${version}-linux-${cpu_type}.tar.gz"
local gnugp_verify_command_name="$(command -v gpg gpg2 | head -n 1)"
if [ -z "${gnugp_verify_command_name}" ]; then
echo "You should install GnuPG to verify the authenticity of the downloaded archives: https://www.gnupg.org/" >&2
exit 1
fi
else
echo "https://github.com/nodejs/node/archive/${version}.tar.gz"

(
if [ -z "${GNUPGHOME:-}" ] && [ -d "$HOME/.asdf/keyrings/nodejs" ]; then
export GNUPGHOME="$HOME/.asdf/keyrings/nodejs"
fi

local authentic_checksum_file="$tmp_download_dir/authentic_SHASUMS256.txt"
if ! $gnugp_verify_command_name --verify "$signed_checksum_file"; then
echo "Authenticity of checksum file can not be assured. Exiting." >&2
exit 1
fi
$gnugp_verify_command_name --output "${authentic_checksum_file}" --decrypt "$signed_checksum_file" 2>/dev/null
)
elif [ "${NODEJS_CHECK_SIGNATURES}" == "strict" ]; then
echo "$version did not provide signed checksums or support for them has not been implemented and NODEJS_CHECK_SIGNATURES=strict is set. Exiting." >&2
exit 1
fi
}


install_nodejs $ASDF_INSTALL_TYPE $ASDF_INSTALL_VERSION $ASDF_INSTALL_PATH
verify_archive() {
local tmp_download_dir="$1"

local authentic_checksum_file="$tmp_download_dir/authentic_SHASUMS256.txt"

if [ "${NODEJS_CHECK_SIGNATURES}" == "no" ]; then
return 0
fi

if [ "${NODEJS_CHECK_SIGNATURES}" == "yes" ] && [ ! -e "${authentic_checksum_file}" ]; then
return 0
fi

if verlte "0.10.0" "$version"
then
local archive_file_name="$(basename "$(get_download_url "$install_type" "$version")")"

(
cd "${tmp_download_dir}"
if ! sha256sum --check <(grep "\s$archive_file_name$" "${authentic_checksum_file}"); then
echo "Authenticity package archive can not be assured. Exiting." >&2
exit 1
fi
)
fi
}


## https://stackoverflow.com/questions/4023830/how-compare-two-strings-in-dot-separated-version-format-in-bash/4024263#4024263
verlte() {
[ "$1" = "$(echo -e "$1\n$2" | sort -V | head -n1)" ]
}


install_nodejs "$ASDF_INSTALL_TYPE" "$ASDF_INSTALL_VERSION" "$ASDF_INSTALL_PATH"

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