feat: add bash cybersecurity audit and hardening functions

12 funciones Bash del dominio cybersecurity: auditoria de red y servicios
(analyze_dns, audit_http_headers, inspect_ssl_cert, list_active_connections,
enumerate_subdomains, geolocate_ip), auditoria de sistema (audit_ssh_config,
check_firewall, detect_suspicious_users), y utilidades crypto (encrypt_file,
generate_password, verify_file_hash). Dominio nuevo en bash/functions/.

bash/functions/cybersecurity/generate_password.sh

@@ -0,0 +1,143 @@
+#!/usr/bin/env bash
+# generate_password
+# -----------------
+# Genera contraseñas seguras en varios modos: completo (alfanumérico + símbolos),
+# solo alfanumérico, passphrase de palabras o PIN numérico.
+# Calcula la entropía en bits para cada contraseña generada.
+#
+# USO (directo):
+#   generate_password [full|alpha|passphrase|pin] [longitud] [cantidad]
+#
+# Depende de: /dev/urandom, python3 (para entropía), shuf (para passphrases)
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/../shell/bash_colors.sh"
+source "$SCRIPT_DIR/../shell/bash_log.sh"
+bash_colors
+bash_log_init
+
+# ─── Constantes ───────────────────────────────────────────────────────────────
+
+_GENPW_DEFAULT_LENGTH=16
+_GENPW_DEFAULT_COUNT=1
+_GENPW_WORDLIST_PATHS=("/usr/share/dict/words" "/usr/dict/words" "/usr/share/dict/american-english")
+
+# ─── Funciones puras ──────────────────────────────────────────────────────────
+
+_genpw_find_wordlist() {
+    for path in "${_GENPW_WORDLIST_PATHS[@]}"; do
+        [[ -f "$path" ]] && echo "$path" && return
+    done
+    echo ""
+}
+
+_genpw_calc_entropy() {
+    local charset_size="$1"
+    local length="$2"
+    python3 -c "import math; print(f'{math.log2(${charset_size}**${length}):.1f}')" 2>/dev/null || echo "?"
+}
+
+# ─── Funciones de generación ──────────────────────────────────────────────────
+
+_genpw_gen_full() {
+    local length="$1"
+    # Alfanumérico + símbolos (excluye ambiguos: 0OlI1)
+    tr -dc 'A-HJ-NP-Za-km-z2-9!@#$%^&*()_+-=[]{}|;:,.<>?' \
+        < /dev/urandom | head -c "$length"
+    echo
+}
+
+_genpw_gen_alpha() {
+    local length="$1"
+    tr -dc 'A-HJ-NP-Za-km-z2-9' \
+        < /dev/urandom | head -c "$length"
+    echo
+}
+
+_genpw_gen_passphrase() {
+    local words="$1"
+    local wordlist
+    wordlist="$(_genpw_find_wordlist)"
+
+    if [[ -z "$wordlist" ]]; then
+        error "generate_password: no se encontró diccionario (sudo apt install wamerican)" >&2
+        return 1
+    fi
+
+    local phrase=""
+    for ((i=0; i<words; i++)); do
+        local word
+        word="$(shuf -n1 "$wordlist" | tr -dc 'a-z' | head -c 20)"
+        [[ ${#word} -lt 3 ]] && { i=$((i-1)); continue; }
+        phrase="${phrase}${word}-"
+    done
+    echo "${phrase%-}"
+}
+
+_genpw_gen_pin() {
+    local length="$1"
+    tr -dc '0-9' < /dev/urandom | head -c "$length"
+    echo
+}
+
+# ─── Punto de entrada ─────────────────────────────────────────────────────────
+
+generate_password() {
+    local mode="${1:-full}"
+    local length="${2:-$_GENPW_DEFAULT_LENGTH}"
+    local count="${3:-$_GENPW_DEFAULT_COUNT}"
+
+    # Validar que length y count son numéricos
+    if ! [[ "$length" =~ ^[0-9]+$ ]] || ! [[ "$count" =~ ^[0-9]+$ ]]; then
+        error "generate_password: longitud y cantidad deben ser números enteros positivos" >&2
+        return 1
+    fi
+
+    local charset_size entropy
+
+    case "$mode" in
+        full)
+            charset_size=78
+            entropy="$(_genpw_calc_entropy $charset_size "$length")"
+            info "Contraseñas alfanuméricas + símbolos (longitud: ${length}, entropía: ~${entropy} bits)"
+            echo ""
+            for ((i=1; i<=count; i++)); do
+                _genpw_gen_full "$length"
+            done
+            ;;
+        alpha)
+            charset_size=56
+            entropy="$(_genpw_calc_entropy $charset_size "$length")"
+            info "Contraseñas alfanuméricas (longitud: ${length}, entropía: ~${entropy} bits)"
+            echo ""
+            for ((i=1; i<=count; i++)); do
+                _genpw_gen_alpha "$length"
+            done
+            ;;
+        passphrase)
+            info "Passphrases (${length} palabras)"
+            echo ""
+            for ((i=1; i<=count; i++)); do
+                _genpw_gen_passphrase "$length" || return 1
+            done
+            ;;
+        pin)
+            charset_size=10
+            entropy="$(_genpw_calc_entropy $charset_size "$length")"
+            info "PINs numéricos (longitud: ${length}, entropía: ~${entropy} bits)"
+            echo ""
+            for ((i=1; i<=count; i++)); do
+                _genpw_gen_pin "$length"
+            done
+            ;;
+        *)
+            error "generate_password: modo no válido '$mode'. Use: full|alpha|passphrase|pin" >&2
+            return 1
+            ;;
+    esac
+}
+
+# Ejecutar si se llama directamente
+if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
+    generate_password "$@"
+fi