moved helpers separately

2026-10-13 16:21:24 +02:00
parent ba1e07744e
commit 9911f6d01d
33 changed files with 1489 additions and 1089 deletions
@@ -0,0 +1,74 @@
+#!/usr/bin/env bash
+# ------------------------------------------------------------------------------
+# Copyright (c) 2013-2026 Geoffray Levasseur <fatalerrors@geoffray-levasseur.org>
+# Protected by the BSD3 license. Please read bellow for details.
+#
+# * Redistribution and use in source and binary forms,
+# * with or without modification, are permitted provided
+# * that the following conditions are met:
+# *
+# *   Redistributions of source code must retain the above
+# *   copyright notice, this list of conditions and the
+# *   following disclaimer.
+# *
+# *   Redistributions in binary form must reproduce the above
+# *   copyright notice, this list of conditions and the following
+# *   disclaimer in the documentation and/or other materials
+# *   provided with the distribution.
+# *
+# *   Neither the name of the copyright holder nor the names
+# *   of any other contributors may be used to endorse or
+# *   promote products derived from this software without
+# *   specific prior written permission.
+# *
+# * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+# * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+# * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+# * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+# * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+# * OF SUCH DAMAGE.
+# ------------------------------------------------------------------------------
+
+# Private helpers of profile.d/pwd.sh, loaded by the module itself.
+
+# Pool of random words read from /dev/urandom, refilled by _pwd_rand.
+_PWD_POOL=()
+
+# Internal helper: put in _PWD_RAND an integer uniformly distributed in
+# [0, $1), for 1 <= $1 <= 2^32. $RANDOM is NOT usable for passwords: it only
+# has 15 bits, a state seeded from the time and the PID, and is predictable.
+# The source is $SRANDOM (bash >= 5.1, from the kernel's random generator), or
+# else /dev/urandom read through od, 256 words at a time to limit the number
+# of processes. Values above the largest multiple of $1 are rejected, so that
+# "% $1" introduces no bias.
+# Usage: _pwd_rand <max>
+_pwd_rand()
+{
+    local max="$1" limit r
+    limit=$(( 4294967296 - 4294967296 % max ))
+    while :; do
+        if [[ -n "${SRANDOM+x}" ]]; then
+            r="$SRANDOM"
+        else
+            if (( ${#_PWD_POOL[@]} == 0 )); then
+                # shellcheck disable=SC2207 # whitespace-separated numbers
+                _PWD_POOL=( $(od -An -v -N1024 -tu4 /dev/urandom 2>/dev/null) )
+                if (( ${#_PWD_POOL[@]} == 0 )); then
+                    disp E "No source of random numbers available (/dev/urandom)."
+                    return 1
+                fi
+            fi
+            r="${_PWD_POOL[-1]}"
+            unset '_PWD_POOL[-1]'
+        fi
+        if (( r < limit )); then
+            _PWD_RAND=$(( r % max ))
+            return 0
+        fi
+    done
+}