diff --git a/host/lib/cros_archive.sh b/host/lib/cros_archive.sh
new file mode 100644
index 0000000..1a9078b
--- /dev/null
+++ b/host/lib/cros_archive.sh
@@ -0,0 +1,380 @@
+#!/bin/bash
+#
+# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# Shared library for searching and choosing CrOS images from a large collection
+# of archived versions.
+#
+# This library deals with CrOS versions in four forms:
+#
+# version string: e.g. "R12-3456.7.8"
+#   Completely specifies a CrOS version as release, major, minor and revision
+#   numbers. The revision number may be followed by a '-' or '.' and arbitrary
+#   characters, which will be ignored (e.g. "R12-3456.7.8-a9-b123").
+#
+# version pattern: e.g. "R12-3456", "3456.7", etc.
+#   Specifies a partial CrOS version by omitting some of the numbers. For
+#   example, all of the following patterns would match "R12-3456.7.8":
+#     '', R12, R12-3456, R12-3456.7, R12-3456.7.8, 3456, 3456.7, 3456.7.8
+#
+# numeric version: e.g. "12 3456 7 8"
+#   A version written as four space-separated integers corresponding to the
+#   release, major, minor and revision numbers. The last integer may be
+#   followed by another space and arbitrary characters, which will be ignored.
+#
+# numeric pattern: e.g. "12 3456 -1 -1"
+#   A version pattern written as four space-separated integers corresponding to
+#   the release, major, minor and revision numbers. Unrestricted fields are
+#   indicated by negative values. The last integer may be followed by another
+#   space and arbitrary characters, which will be ignored.
+
+### GENERIC FUNCTIONS
+
+# Usage: cros_archive_get_numeric_version version
+# Generates a numeric version for the specified version string.
+#
+# Writes the numeric version to stdout and returns success. If the version
+# string is malformed, will produce no output and return failure.
+cros_archive_get_numeric_version() {
+  local arg_{rel,ver,maj,min,rev,tail}
+
+  # BUG(cwolfe):
+  #     For some reason, attaching the next IFS to its read results in the IFS
+  #     being ignored during cros_archive_filter_url_version_newest. This only
+  #     occurs when run in the chroot (bash 4.2.20) and not on my workstation
+  #     (bash 4.1.5). Hacking it to work for the moment, and need to figure out
+  #     whether I've discovered a weird feature or a bash bug.
+  #
+  # Absent the bug, the next four lines should be:
+  #   IFS='-' read -r arg_{rel,ver,tail} <<<"$1"
+  local old_ifs="${IFS}"
+  IFS='-'
+  read -r arg_{rel,ver,tail} <<<"$1"
+  IFS="${old_ifs}"
+
+  IFS='.' read -r arg_{maj,min,rev,tail} <<<"${arg_ver}"
+  arg_rel=${arg_rel#R}
+  if [[ -z ${arg_rel} || -z ${arg_maj} ||
+        -z ${arg_min} || -z ${arg_rev} ]]; then
+    return 1  # Malformed version
+  fi
+
+  printf '%d %d %d %d\n' "${arg_rel}" "${arg_maj}" "${arg_min}" "${arg_rev}"
+}
+
+# Usage: cros_archive_get_numeric_pattern version
+# Generates a numeric pattern corresponding to the specified version pattern.
+#
+# Writes the numeric pattern to stdout and returns success. If the version
+# pattern is malformed or contains extra characters, will produce no output and
+# return failure.
+cros_archive_get_numeric_pattern() {
+  local arg_{rel,ver,maj,min,rev,tail}
+
+  IFS='-' read -r arg_{rel,ver,tail} <<<"$1"
+  if [[ -n ${arg_tail} ]]; then
+    return 1  # Malformed pattern: extra characters
+  fi
+  if [[ ${arg_rel:0:1} == 'R' ]]; then
+    arg_rel=${arg_rel#R}  # Strip the 'R' prefix
+  elif [[ -n ${arg_rel} ]]; then
+    arg_ver=${arg_rel}  # Actually got a version with no release.
+    arg_rel=
+  fi
+  if [[ -n ${arg_ver} ]]; then
+    IFS='.' read -r arg_{maj,min,rev,tail} <<<"${arg_ver}"
+    if [[ -n ${arg_tail} ]]; then
+      return 1  # Malformed pattern: extra characters
+    fi
+  fi
+
+  printf '%d %d %d %d\n' \
+         "${arg_rel:--1}" "${arg_maj:--1}" "${arg_min:--1}" "${arg_rev:--1}"
+}
+
+# Usage: cros_archive_get_wildcard_pattern version
+# Generates a wildcard pattern that will match the specified numeric version.
+#
+# Writes the wildcard pattern to stdout and returns success. If the numeric
+# version is malformed, will produce no output and return failure.
+cros_archive_get_wildcard_pattern() {
+  local arg_{rel,maj,min,rev}
+  read -r arg_{rel,maj,min,rev} <<<"$1"
+
+  # Replace any negative fields with '*'.
+  [[ ${arg_rel} -ge 0 ]] || arg_rel='*'
+  [[ ${arg_maj} -ge 0 ]] || arg_maj='*'
+  [[ ${arg_min} -ge 0 ]] || arg_min='*'
+  [[ ${arg_rev} -ge 0 ]] || arg_rev='*'
+
+  printf "R%s-%s.%s.%s\n" "${arg_rel}" "${arg_maj}" "${arg_min}" "${arg_rev}"
+}
+
+# Usage: cros_archive_test_numeric_version_matches pattern version
+# Tests whether a numeric pattern matches a numeric version.
+#
+# Returns success if the pattern matches the version and failure otherwise.
+cros_archive_test_numeric_version_matches() {
+  local -a pattern version
+  read -ra pattern <<<"$1"
+  read -ra version <<<"$2"
+  if [[ ${#pattern[@]} -lt 4 || ${#version[@]} -lt 4 ]]; then
+    return 1  # Malformed pattern or version
+  fi
+
+  local i
+  for i in {0..3}; do
+    if [[ ${pattern[$i]} -ge 0 && ${pattern[$i]} -ne ${version[$i]} ]]; then
+      return 1  # Version does not match pattern
+    fi
+  done
+  return 0  # Version matches pattern
+}
+
+# Usage: cros_archive_test_numeric_version_newer first second
+# Tests whether the first numeric version is newer than the second.
+#
+# Returns success if the first numeric version is newer than the second,
+# and failure otherwise.
+cros_archive_test_numeric_version_newer() {
+  local -a first second
+  read -ra first <<<"$1"
+  read -ra second <<<"$2"
+  if [[ ${#first[@]} -lt 4 || ${#second[@]} -lt 4 ]]; then
+    return 1  # Malformed version
+  fi
+
+  local i
+  for i in {0..3}; do
+    if [[ ${first[$i]} -ne ${second[$i]} ]]; then
+      if [[ ${first[$i]} -gt ${second[$i]} ]]; then
+        return 0  # First is indeed newer then second.
+      else
+        return 1  # First is older than second.
+      fi
+    fi
+  done
+  return 1  # First and second are equal.
+}
+
+# Usage: cros_archive_filter_numeric_version_matches pattern
+# Filters a stream of numeric versions, keeping those which match the specified
+# numeric pattern.
+#
+# Reads lines from stdin. Each line must be a numeric version. If a line
+# matches the pattern it will be written to stdout in its entirety, otherwise
+# the line will be discarded.
+#
+# Returns success at the end if input.
+cros_archive_filter_numeric_version_matches() {
+  local pattern="$1"
+  local version
+  while read -r version; do
+    if cros_archive_test_numeric_version_matches "${pattern}" "${version}"; then
+      printf '%s\n' "${version}"
+    fi
+  done
+}
+
+# Usage: cros_archive_filter_numeric_version_newest
+# Filters a stream of numeric versions to choose the newest.
+#
+# Reads lines from stdin. Each line must be a numeric version. Once the end of
+# input has been reached, the line containing the newest numeric version will
+# be written to stdout in its entirety. Will not produce any output if no
+# versions have been read.
+#
+# Returns success unless an error was encountered, even if no versions were
+# processed.
+cros_archive_filter_numeric_version_newest() {
+  local best
+  local curr
+  while read -r curr; do
+    if [[ -z ${best} ]] ||
+       cros_archive_test_numeric_version_newer "${curr}" "${best}"; then
+      best="${curr}"
+    fi
+  done
+  if [[ -n ${best} ]]; then
+    printf '%s\n' "${best}"
+  fi
+}
+
+# Usage: cros_archive_filter_url_version_newest regexp [pattern]
+# Filters a stream of URLs to choose the one containing the newest version
+# string. Optionally discards versions which do not match the specified numeric
+# pattern.
+#
+# The regexp must contain a single parenthesized subexpression that selects the
+# version string from a URL. Any URL which does not match this regexp or does
+# not record a parenthesized subexpression will be discarded.
+#
+# Reads lines from stdin, each of which must consist of a single URL. Once the
+# end of input has been reached, the URL containing the newest version string
+# will be written to stdout.
+#
+# Returns success unless an error was encountered, even if no URLs were found.
+cros_archive_filter_url_version_newest() {
+  local regexp="$1"
+  local pattern="${2:--1 -1 -1 -1}"
+
+  get_numeric_result() {
+    local input
+    while read -r input; do
+      if [[ ! ( ${input} =~ ^${regexp}$ ) || ${#BASH_REMATCH[@]} -lt 1 ]]; then
+        continue
+      fi
+      local version=$(cros_archive_get_numeric_version "${BASH_REMATCH[1]}")
+      printf '%s %s\n' "${version}" "${input}"
+    done |
+    cros_archive_filter_numeric_version_matches "${pattern}" |
+    cros_archive_filter_numeric_version_newest
+  }
+
+  local -a result
+  if ! read -a result < <(get_numeric_result); then
+    return 0  # No URL available
+  fi
+
+  # Drop the first four elements in the result array, as they contain the
+  # numeric version.
+  printf '%s\n' "${result[*]:4}"
+}
+
+### GOOGLE STORAGE SPECIFIC FUNCTIONS
+#
+# This code addresses the problem of getting images from a GS archive in two
+# stages: it generates a set of wildcards passed to "gsutil ls", and then uses
+# a regexp to parse the version numbers out of the list. These two steps are
+# necessary because gsutil supports only simple glob-style wildcards and can
+# not do version-number ordering of the results. Fortunately the processing
+# can be run in parallel to the "gsutil ls", so the overhead is small.
+#
+
+# Usage: cros_archive_gs_get_url_wildcards channel board [pattern]
+# Gets one or more URL wildcard for a specified channel and board which will
+# include at least the archives corresponding to the specified numeric pattern.
+#
+# The 'archive' virtual channel is loaded from gs://chromeos-image-archive.
+# All other channels will be requested from gs://chromeos-releases.
+cros_archive_gs_get_url_wildcards() {
+  local channel="$1"
+  local board="$2"
+  local pattern=$(cros_archive_get_wildcard_pattern "${3:--1 -1 -1 -1}")
+
+  # Add a '*' after the pattern, as some of the uploaded paths (but not all)
+  # contain additional numbers for attempt and build like "-a0-b1234". To
+  # avoid doubling '*'s, also remove any trailing '*' from the pattern.
+  pattern="${pattern%\*}*"
+
+  if [[ ${channel} == 'archive' ]]; then
+    # Most boards use a -release builder, so output that URL first.
+    local suffix
+    for suffix in release full; do
+      printf 'gs://chromeos-image-archive/%s-%s/%s/image.zip\n' \
+             "${board}" "${suffix}" "${pattern}"
+    done
+  else
+    printf 'gs://chromeos-releases/%s/%s/%s/ChromeOS-%s-%s.zip\n' \
+           "${channel}-channel" "${board}" "${pattern#R*-}" "${pattern}" \
+           "${board}"
+  fi
+}
+
+# Usage: cros_archive_gs_get_url_regexp channel board
+# Gets a regexp which can be used to extract the version from URLs associated
+# with the specified channel and board.
+#
+# The 'archive' virtual channel is loaded from gs://chromeos-image-archive.
+# All other channels will be requested from gs://chromeos-releases.
+cros_archive_gs_get_url_regexp() {
+  local channel="$1"
+  local board="$2"
+  local pattern=$(cros_archive_get_wildcard_pattern "${3:--1 -1 -1 -1}")
+
+  # The version_regexp picks out and records two dash-separated components that
+  # look like a CrOS version. In some cases it will be followed by another dash
+  # and additional information, so we need to be a little careful about what it
+  # matches.
+  local version_regexp='(R[^/-]*-[^/-]*)'
+  if [[ ${channel} == 'archive' ]]; then
+    printf 'gs://chromeos-image-archive/%s[^/]*/%s[^/]*/image.zip\n' \
+           "${board}" "${version_regexp}"
+  else
+    printf 'gs://chromeos-releases/%s/%s/[^/]*/ChromeOS-%s[^/]*-%s.zip\n' \
+           "${channel}-channel" "${board}" "${version_regexp}" "${board}"
+  fi
+}
+
+# Usage: cros_archive_gsutil_ls_filter
+# Gets multiple directory listings from gsutil ls.
+#
+# Reads lines from stdin. Each line must be a gs:// URL, possibly containing
+# wildcards. Will write zero or more lines to stdout containing the URLs which
+# were returned from the server.
+#
+# Errors from gsutil related to there being no matching URLs will be ignored.
+# Returns success unless an error was encountered, even if no URLs were found.
+#
+# Environment:
+#   GSUTIL: name of gsutil program (default is 'gsutil')
+cros_archive_gsutil_ls_filter() {
+  local url
+  while read -r url; do
+    # Run gsutil with its stdout passed through and its stderr recorded.
+    local rc=0
+    exec 3>&1
+    local error=$( ${GSUTIL:-gsutil} ls "${url}" 2>&1 1>&3 3>&- ) || rc=$?
+    exec 3>&-
+
+    # Ignore errors that only indicate no matches were found. This behavior
+    # may vary between different versions of gsutil, so we should not assume
+    # an empty result sets non-zero rc.
+    if [[ ${rc} -ne 0 && ${error} != 'No matches for'* ]]; then
+      printf 'gsutil: %s\n' "${error}" >&2
+      return 1
+    fi
+  done
+}
+
+# Usage: cros_archive_gs_list channel board [pattern]
+# Gets the list of URLs matching the specified channel and board which will
+# satisfy the specified numeric pattern.
+#
+# This command calls the Google Storage backend to get a list of available
+# files.
+#
+# Returns success unless an error was encountered, even if no URLs were found.
+cros_archive_gs_list() {
+  local channel="$1"
+  local board="$2"
+  local pattern=$(cros_archive_get_numeric_pattern "$3")
+
+  local regexp=$(cros_archive_gs_get_url_regexp "${channel}" "${board}")
+
+  cros_archive_gs_get_url_wildcards "${channel}" "${board}" "${pattern}" |
+  cros_archive_gsutil_ls_filter |
+  cros_archive_filter_url_version_newest "${regexp}" "${pattern}"
+}
+
+# Usage: cros_archive_gs_get_url_version channel board url
+# Gets the version string contained in the image URL for a particular channel
+# and board.
+#
+# Writes the version string to stdout and returns success. If the URL does not
+# match the pattern expected for the channel and board will produce no output
+# and return failure.
+cros_archive_gs_get_url_version() {
+  local channel="$1"
+  local board="$2"
+  local url="$3"
+
+  local regexp=$(cros_archive_gs_get_url_regexp "${channel}" "${board}")
+
+  if [[ ! ( ${url} =~ ^${regexp}$ ) || ${#BASH_REMATCH[@]} -lt 1 ]]; then
+    return 1
+  fi
+  echo "${BASH_REMATCH[1]}"
+}
diff --git a/host/lib/cros_archive_unittest.sh b/host/lib/cros_archive_unittest.sh
new file mode 100755
index 0000000..961c660
--- /dev/null
+++ b/host/lib/cros_archive_unittest.sh
@@ -0,0 +1,379 @@
+#!/bin/bash
+#
+# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+
+set -o errexit
+set -o pipefail
+
+. "$(dirname "$(readlink -f "$0")")"/cros_archive.sh
+
+### TESTING FUNCTIONS
+
+total_passed=0
+total_failed=0
+
+expect() {
+  local caller_line="${BASH_SOURCE[1]}:${BASH_LINENO[0]}"
+  local output='*'
+  local status='0'
+  unset OPTIND
+  while getopts ':o:s:' OPTOPT; do
+    case ${OPTOPT} in
+      'o') output=${OPTARG} ;;
+      's') status=${OPTARG} ;;
+      '?') echo "expect: error processing option ${OPTARG}" \
+                "(called from ${caller_line})"
+           exit 2
+      ;;
+    esac
+  done
+  shift $(( OPTIND - 1 ))
+  local cmd=( "$@" )
+
+  local actual_output
+  local actual_status=0
+  actual_output=$( "${cmd[@]}" ) || actual_status=$?
+
+  local wrong_status
+  local wrong_output
+  if [[ ${status} != '*' && ${actual_status} -ne ${status} ]]; then
+    wrong_status='yes'
+  fi
+  if [[ ${output} != '*' && ${actual_output} != "${output}" ]]; then
+    wrong_output='yes'
+  fi
+
+  if [[ -n ${wrong_status} || -n ${wrong_output} ]]; then
+    echo "FAIL at ${caller_line}: ${cmd[@]}"
+    if [[ -n ${wrong_status} ]]; then
+      echo "  exit status was ${actual_status}, expected ${status}"
+    fi
+    if [[ -n ${wrong_output} ]]; then
+      echo "  the command produced unexpected content on stdout"
+      echo "  expected: '${output}'"
+      echo "  received: '${actual_output}'"
+    fi
+    echo
+    : $(( ++total_failed ))
+  else
+    : $(( ++total_passed ))
+  fi
+}
+
+### TESTS
+
+### cros_archive_get_numeric_version
+
+expect -o '12 3456 7 8' \
+    cros_archive_get_numeric_version 'R12-3456.7.8'
+
+expect -o '12 3456 7 8' \
+    cros_archive_get_numeric_version 'R12-3456.7.8-a9-b123'
+
+### cros_archive_get_numeric_pattern
+
+expect -o '-1 -1 -1 -1' \
+    cros_archive_get_numeric_pattern ''
+
+expect -o '12 -1 -1 -1' \
+    cros_archive_get_numeric_pattern 'R12'
+
+expect -o '12 3456 -1 -1' \
+    cros_archive_get_numeric_pattern 'R12-3456'
+
+expect -o '12 3456 7 -1' \
+    cros_archive_get_numeric_pattern 'R12-3456.7'
+
+expect -o '12 3456 7 8' \
+    cros_archive_get_numeric_pattern 'R12-3456.7.8'
+
+expect -o '-1 3456 -1 -1' \
+    cros_archive_get_numeric_pattern '3456'
+
+expect -o '-1 3456 7 -1' \
+    cros_archive_get_numeric_pattern '3456.7'
+
+expect -o '-1 3456 7 8' \
+    cros_archive_get_numeric_pattern '3456.7.8'
+
+### cros_archive_get_wildcard_pattern
+
+expect -o 'R*-*.*.*' \
+    cros_archive_get_wildcard_pattern '-1 -1 -1 -1'
+
+expect -o 'R12-*.*.*' \
+    cros_archive_get_wildcard_pattern '12 -1 -1 -1'
+
+expect -o 'R12-3456.*.*' \
+    cros_archive_get_wildcard_pattern '12 3456 -1 -1'
+
+expect -o 'R12-3456.7.*' \
+    cros_archive_get_wildcard_pattern '12 3456 7 -1'
+
+expect -o 'R12-3456.7.8' \
+    cros_archive_get_wildcard_pattern '12 3456 7 8'
+
+expect -o 'R*-3456.*.*' \
+    cros_archive_get_wildcard_pattern '-1 3456 -1 -1'
+
+expect -o 'R*-3456.7.*' \
+    cros_archive_get_wildcard_pattern '-1 3456 7 -1'
+
+expect -o 'R*-3456.7.8' \
+    cros_archive_get_wildcard_pattern '-1 3456 7 8'
+
+### cros_archive_test_numeric_version_matches
+
+expect cros_archive_test_numeric_version_matches \
+    '-1 -1 -1 -1' '12 3456 7 8'
+
+expect cros_archive_test_numeric_version_matches \
+    '12 -1 -1 -1' '12 3456 7 8'
+
+expect cros_archive_test_numeric_version_matches \
+    '12 3456 -1 -1' '12 3456 7 8'
+
+expect cros_archive_test_numeric_version_matches \
+    '12 3456 7 -1' '12 3456 7 8'
+
+expect cros_archive_test_numeric_version_matches \
+    '12 3456 7 8' '12 3456 7 8'
+
+expect cros_archive_test_numeric_version_matches \
+    '-1 3456 -1 -1' '12 3456 7 8'
+
+expect cros_archive_test_numeric_version_matches \
+    '-1 3456 7 -1' '12 3456 7 8'
+
+expect cros_archive_test_numeric_version_matches \
+    '-1 3456 7 8' '12 3456 7 8'
+
+expect -s 1 cros_archive_test_numeric_version_matches \
+    '12 -1 -1 -1' '99 3456 7 8'
+
+expect -s 1 cros_archive_test_numeric_version_matches \
+    '12 3456 -1 -1' '12 9999 7 8'
+
+expect -s 1 cros_archive_test_numeric_version_matches \
+    '12 3456 7 -1' '12 3456 9 8'
+
+expect -s 1 cros_archive_test_numeric_version_matches \
+    '12 3456 7 8' '12 3456 7 9'
+
+expect -s 1 cros_archive_test_numeric_version_matches \
+    '-1 3456 -1 -1' '12 9999 7 8'
+
+expect -s 1 cros_archive_test_numeric_version_matches \
+    '-1 3456 7 -1' '12 3456 9 8'
+
+expect -s 1 cros_archive_test_numeric_version_matches \
+    '-1 3456 7 8' '12 3456 7 9'
+
+### cros_archive_test_numeric_version_newer
+
+expect cros_archive_test_numeric_version_newer \
+    '12 3456 7 8' '11 3456 7 8'
+
+expect cros_archive_test_numeric_version_newer \
+    '12 3456 7 8' '12 3455 7 8'
+
+expect cros_archive_test_numeric_version_newer \
+    '12 3456 7 8' '12 3456 6 8'
+
+expect cros_archive_test_numeric_version_newer \
+    '12 3456 7 8' '12 3456 7 7'
+
+expect -s 1 cros_archive_test_numeric_version_newer \
+    '12 3456 7 8' '12 3456 7 8'
+
+expect -s 1 cros_archive_test_numeric_version_newer \
+    '12 3456 7 8' '13 1 1 1'
+
+expect -s 1 cros_archive_test_numeric_version_newer \
+    '12 3456 7 8' '12 3457 1 1'
+
+expect -s 1 cros_archive_test_numeric_version_newer \
+    '12 3456 7 8' '12 3456 8 1'
+
+expect -s 1 cros_archive_test_numeric_version_newer \
+    '12 3456 7 8' '12 3456 7 9'
+
+### cros_archive_filter_numeric_version_matches
+
+numeric_version_list="\
+12 3456 7 8
+11 3456 7 8
+13 3456 7 8
+12 3455 7 8
+12 3457 7 8
+12 3456 6 8
+12 3456 8 8
+12 3456 7 7
+12 3456 7 9
+"
+
+expect -o $'12 3456 7 8' \
+    cros_archive_filter_numeric_version_matches '12 3456 7 8' \
+    <<<"${numeric_version_list}"
+
+expect -o $'12 3456 7 8\n11 3456 7 8\n13 3456 7 8' \
+    cros_archive_filter_numeric_version_matches '-1 3456 7 8' \
+    <<<"${numeric_version_list}"
+
+expect -o $'12 3456 7 8\n12 3455 7 8\n12 3457 7 8' \
+    cros_archive_filter_numeric_version_matches '12 -1 7 8' \
+    <<<"${numeric_version_list}"
+
+expect -o $'12 3456 7 8\n12 3456 6 8\n12 3456 8 8' \
+    cros_archive_filter_numeric_version_matches '12 3456 -1 8' \
+    <<<"${numeric_version_list}"
+
+expect -o $'12 3456 7 8\n12 3456 7 7\n12 3456 7 9' \
+    cros_archive_filter_numeric_version_matches '12 3456 7 -1' \
+    <<<"${numeric_version_list}"
+
+### cros_archive_filter_numeric_version_newest
+
+expect -o '13 3456 7 8' \
+    cros_archive_filter_numeric_version_newest \
+    <<<"${numeric_version_list}"
+
+numeric_version_list="\
+1 1 1 1
+1 1 1 0
+1 1 0 0
+1 0 0 0
+0 0 0 0
+"
+
+expect -o '1 1 1 1' \
+    cros_archive_filter_numeric_version_newest \
+    <<<"${numeric_version_list}"
+
+### cros_archive_filter_url_version_newest
+
+url_regexp='http://example.net/(.*)/image.zip'
+
+expect -o '' \
+    cros_archive_filter_url_version_newest "${url_regexp}" \
+    <<<""
+
+url_list="\
+http://example.net/R12-3456.7.8/image.zip
+http://example.net/R11-3456.7.8/image.zip
+http://example.net/R13-3456.7.8/image.zip
+http://example.net/R12-3455.7.8/image.zip
+http://example.net/R12-3457.7.8/image.zip
+http://example.net/R12-3456.6.8/image.zip
+http://example.net/R12-3456.8.8/image.zip
+http://example.net/R12-3456.7.7/image.zip
+http://example.net/R12-3456.7.9/image.zip"
+
+expect -o "\
+http://example.net/R13-3456.7.8/image.zip" \
+    cros_archive_filter_url_version_newest "${url_regexp}" \
+    <<<"${url_list}"
+
+url_list="\
+http://example.net/R1-1.1.1/image.zip
+http://example.net/R1-1.1.0/image.zip
+http://example.net/R1-1.0.0/image.zip
+http://example.net/R1-0.0.0/image.zip
+http://example.net/R0-0.0.0/image.zip"
+
+expect -o 'http://example.net/R1-1.1.1/image.zip' \
+    cros_archive_filter_url_version_newest "${url_regexp}" \
+    <<<"${url_list}"
+
+### cros_archive_gs_get_url_wildcards
+
+expect -o "\
+gs://chromeos-image-archive/x86-generic-release/R*-*.*.*/image.zip
+gs://chromeos-image-archive/x86-generic-full/R*-*.*.*/image.zip" \
+    cros_archive_gs_get_url_wildcards 'archive' 'x86-generic'
+
+expect_base='gs://chromeos-releases/canary-channel/x86-alex'
+expect -o "${expect_base}/*.*.*/ChromeOS-R*-*.*.*-x86-alex.zip" \
+    cros_archive_gs_get_url_wildcards 'canary' 'x86-alex'
+
+### cros_archive_gs_get_url_regexp
+
+url_list="\
+gs://chromeos-image-archive/x86-generic-full/R18-1660.0.0-a1-b1626/image.zip
+gs://chromeos-image-archive/x86-generic-full/R20-2223.0.0-a1-b3069/image.zip"
+regexp=$(cros_archive_gs_get_url_regexp 'archive' 'x86-generic')
+expect -o "${url_list}" grep -E "${regexp}" <<<"${url_list}"
+
+expect_base='gs://chromeos-releases/canary-channel'
+url_list="\
+${expect_base}/x86-alex/1590.2.0/ChromeOS-R18-1590.2.0-a1-b18-x86-alex.zip
+${expect_base}/x86-alex/2223.0.0/ChromeOS-R20-2223.0.0-x86-alex.zip"
+regexp=$(cros_archive_gs_get_url_regexp 'canary' 'x86-alex')
+expect -o "${url_list}" grep -E "${regexp}" <<<"${url_list}"
+
+### cros_archive_gs_list
+
+archive_base='gs://chromeos-image-archive/x86-generic-full'
+canary_base='gs://chromeos-releases/canary-channel/x86-alex'
+url_list="\
+${archive_base}/R18-1659.0.0-a1-b1625/image.zip
+${archive_base}/R18-1660.0.0-a1-b1626/image.zip
+${archive_base}/R20-2223.0.0-a1-b3069/image.zip
+${canary_base}/1589.0.0/ChromeOS-R18-1589.0.0-a1-b17-x86-alex.zip
+${canary_base}/1590.2.0/ChromeOS-R18-1590.2.0-a1-b18-x86-alex.zip
+${canary_base}/2223.0.0/ChromeOS-R20-2223.0.0-x86-alex.zip"
+
+mock_gsutil() {
+  if [[ $# -ne 2 || $1 != 'ls' ]]; then
+    echo 'Mock expected usage to be "ls URL"' >&2
+    return 1
+  fi
+  local pattern="$2"
+  local found
+  local url
+  while read -r url; do
+    if [[ ${url} == ${pattern} ]]; then
+      echo ${url}
+      found='yes'
+    fi
+  done <<<"${url_list}"
+  if [[ -z ${found} ]]; then
+    echo "No matches for ${pattern}" >&2
+    return 1
+  fi
+}
+
+GSUTIL=mock_gsutil
+expect -o '' \
+    cros_archive_gs_list archive x86-generic R17
+expect -o "${archive_base}/R18-1660.0.0-a1-b1626/image.zip" \
+    cros_archive_gs_list archive x86-generic R18
+expect -o "${archive_base}/R20-2223.0.0-a1-b3069/image.zip" \
+    cros_archive_gs_list archive x86-generic
+expect -o '' \
+    cros_archive_gs_list canary x86-alex R17
+expect -o "${canary_base}/1590.2.0/ChromeOS-R18-1590.2.0-a1-b18-x86-alex.zip" \
+    cros_archive_gs_list canary x86-alex R18
+expect -o "${canary_base}/2223.0.0/ChromeOS-R20-2223.0.0-x86-alex.zip" \
+    cros_archive_gs_list canary x86-alex
+
+expect -o 'R18-1660.0.0' \
+    cros_archive_gs_get_url_version archive x86-generic \
+    "${archive_base}/R18-1660.0.0-a1-b1626/image.zip"
+expect -o 'R20-2223.0.0' \
+    cros_archive_gs_get_url_version archive x86-generic \
+    "${archive_base}/R20-2223.0.0-a1-b3069/image.zip"
+
+expect -o 'R18-1590.2.0' \
+    cros_archive_gs_get_url_version canary x86-alex \
+    "${canary_base}/1590.2.0/ChromeOS-R18-1590.2.0-a1-b18-x86-alex.zip"
+expect -o 'R20-2223.0.0' \
+    cros_archive_gs_get_url_version canary x86-alex \
+    "${canary_base}/2223.0.0/ChromeOS-R20-2223.0.0-x86-alex.zip"
+
+if [[ ${total_failed} -gt 0 ]]; then
+  exit 1
+fi