#!/usr/bin/env bash
# Default file provider.
set -euo pipefail
uri="$1"
path="${uri#file://}"
case "${path}" in
[A-Za-z]:/*)
drive="${path%%:*}"
rest="${path#*:}"
if [ -n "${BASH_VERSINFO:-}" ] && [ "${BASH_VERSINFO[0]}" -ge 4 ]; then
path="/${drive,,}${rest}"
else
case "${drive}" in
[A-Z])
lower_drive=$(printf '%s' "${drive}" | tr '[:upper:]' '[:lower:]')
path="/${lower_drive}${rest}"
;;
*)
path="/${drive}${rest}"
;;
esac
fi
;;
esac
path="${path//\\//}"
if [ -z "${MSYS2_ARG_CONV_EXCL:-}" ]; then
MSYS2_ARG_CONV_EXCL="*"
fi
normalize_path() {
local target="$1"
local normalized=""
if command -v realpath >/dev/null 2>&1; then
normalized="$(realpath "${target}" 2>/dev/null || true)"
fi
if [ -z "${normalized}" ]; then
normalized="$(
cd "$(dirname "${target}")" 2>/dev/null || exit 1
printf '%s/%s\n' "$(pwd -P)" "$(basename "${target}")"
)"
fi
# On Windows/MSYS, canonicalize via cygpath to expand 8.3 short names (e.g., RUNNER~1 -> runneradmin)
# and resolve MSYS virtual paths (e.g., /tmp -> /c/Users/.../Temp). The -l flag expands short names.
if [[ "${OSTYPE:-}" == msys* || "${OSTYPE:-}" == cygwin* ]] && command -v cygpath >/dev/null 2>&1; then
local win_path unix_path
win_path="$(cygpath -w -l "${normalized}" 2>/dev/null || true)"
if [ -n "${win_path}" ]; then
unix_path="$(cygpath -u "${win_path}" 2>/dev/null || true)"
[ -n "${unix_path}" ] && normalized="${unix_path}"
fi
fi
printf '%s' "${normalized}"
}
path="$(normalize_path "${path}" 2>/dev/null || true)"
if [ -z "${path}" ]; then
# Path could not be normalized (likely missing); treat as not found.
exit 3
fi
roots_input="${MCP_RESOURCES_ROOTS:-${MCPBASH_RESOURCES_DIR:-${MCPBASH_PROJECT_ROOT:-}}}"
check_allowed() {
local candidate="$1"
local allowed=false
local check_root=""
while IFS= read -r root; do
[ -z "${root}" ] && continue
check_root="$(normalize_path "${root}" 2>/dev/null || true)"
[ -z "${check_root}" ] && continue
# SECURITY: containment checks must be literal (not shell patterns).
# Paths can contain glob metacharacters like []?* which would turn a
# prefix check into a wildcard match and allow root bypasses.
if [ "${check_root}" != "/" ]; then
check_root="${check_root%/}"
fi
if [ "${candidate}" = "${check_root}" ]; then
allowed=true
break
fi
if [ "${check_root}" = "/" ]; then
allowed=true
break
fi
local prefix="${check_root}/"
if [ "${candidate:0:${#prefix}}" = "${prefix}" ]; then
allowed=true
break
fi
done <<<"$(printf '%s\n' "${roots_input}" | tr ':' '\n')"
if [ "${allowed}" != true ]; then
return 1
fi
return 0
}
if ! check_allowed "${path}"; then
# Fail closed if no roots were usable or path is outside allowed roots.
exit 2
fi
if [ ! -f "${path}" ]; then
exit 3
fi
# Reject symlinks up front; prevents swapping a validated path to an external target.
if [ -L "${path}" ]; then
exit 2
fi
if ! exec 3<"${path}"; then
exit 3
fi
if [ -L "${path}" ]; then
exec 3<&-
exit 2
fi
cat <&3
exec 3<&-
