ssh bug fix

README.md

@@ -138,14 +138,14 @@ A bar-style prompt showing current time, execution time of the last command
 | `pwdscore` | pwd | Calculate the strength score of a given password |
 | `rain` | rain | Console screensaver with falling-rain effect (multiple color themes) |
 | `rainbow` | rain | Full-screen rainbow screensaver using only background colors, with horizontal color shifting |
-| `rmhost` | ssh | Remove host(s) (name and IP) from SSH known_hosts; supports `--all-users` as root |
+| `rmhost` | ssh | Remove host(s) from SSH known_hosts: a name is removed with every IP address it resolves to, `[host]:port` entries and glob patterns are supported; `--all-users` (root) handles every local user's file and keeps its owner and mode |
 | `rmspc` | filefct | Replace spaces in filenames with underscores (or a custom character, attached: `-c-` / `--subst-char=-`); never overwrites an existing file and does not follow symlinked directories |
 | `setc` | lang | Set locale to standard C (POSIX) |
 | `setlocale` | lang | Set console locale to any installed locale (codeset spelling tolerant, UTF-8 preferred when none is given); clears `LC_ALL` and the other per-category variables so the change always applies |
 | `set_theme` | prompt | Switch the prompt colour theme for the session (`--list`, `--preview`, `--save`) |
 | `settrace` | debug | Activate (`--on`), deactivate (`--off`) or query (`--status`) an ERR trap that prints the exit status and a call stack (on stderr) for each failing command; `--force` replaces/removes an ERR trap set by something else; active at startup when `SETTRACE_DEFAULT_ENABLED=1` |
 | `showinfo` | info | Display welcome banner and system information (figlet + fastfetch/neofetch) |
-| `ssr` | ssh | SSH into a server as root, forwarding extra ssh options |
+| `ssr` | ssh | SSH into a server as root (the server comes first, then extra ssh options); default options from `SSH_DEFAULT_OPT` |
 | `taz` | compress | Compress files and directories into a chosen archive format |
 | `term_set` | conf | Set `TERM` to the best available terminal capability |
 | `urlencode` | net | URL-encode a string |
@@ -261,7 +261,7 @@ change the default without having to pass flags every time.
 
 | Key | Default | Description |
 | --- | --- | --- |
-| `SSH_DEFAULT_OPT` | _(empty)_ | Extra options passed to `ssr` (e.g. `-Y` for X forwarding) |
+| `SSH_DEFAULT_OPT` | `-Y` when unset | Options passed to `ssr` before the server (e.g. `-Y -o StrictHostKeyChecking=accept-new`); set it empty for none |
 
 **`[pwd]`** — password tools
 

doc/CHANGELOG.md

@@ -152,6 +152,15 @@ Versions follow `MAJOR.MINOR.PATCH-REVISION_STAGE_N` (e.g. `3.99.1-4_rc_1`).
   silent white, a null speed no longer spins the CPU, a non-terminal stdin or
   stdout is refused instead of looping, and the usage mentions `q` to quit;
   README defaults of the `[rain]` keys corrected.
+- `ssh.sh`: `rmhost` with a wildcard that matched nothing tried to remove an
+  empty host name; it removed only the first IP of a name (all addresses are
+  now handled); `[host]:port` arguments were taken for glob patterns; each
+  match was removed from every file with warnings for the others (now per
+  file); with `--all-users`, `ssh-keygen` left other users' files owned by
+  root (owner and mode are restored) and a shared home directory was
+  processed twice; `@cert-authority` lines are never touched. `ssr` ignored an
+  empty `SSH_DEFAULT_OPT` (documented as "no option") and now rejects an
+  option given in place of the server.
 - `compress.sh`: option flags and loop variables no longer leak into the
   interactive shell.
 

profile.d/ssh.sh

@@ -36,6 +36,35 @@
 
 load_conf "ssh"
 
+# ------------------------------------------------------------------------------
+# Internal helper: remove <key> (a name or an IP, in known_hosts notation, so
+# also "[host]:port") from the known_hosts file <file> with ssh-keygen -R.
+# ssh-keygen writes a new file: run by root on another user's file (--all-users)
+# it would leave it owned by root with mode 0644, which keeps that user's ssh
+# from adding host keys, or exposes a private file. The owner and mode of the
+# file, and of its ".old" backup, are therefore put back.
+# Returns ssh-keygen's status (non-zero when the key was not found).
+# Usage: _rmhost_remove <key> <file>
+_rmhost_remove()
+{
+    local key="$1" file="$2" owner="" mode="" rc=0
+    if [[ ${EUID:-$(id -u)} -eq 0 ]]; then
+        owner=$(stat -c '%u:%g' -- "$file" 2>/dev/null)
+        mode=$(stat -c '%a' -- "$file" 2>/dev/null)
+    fi
+
+    ssh-keygen -R "$key" -f "$file" </dev/null >/dev/null 2>&1 || rc=$?
+
+    if [[ -n $owner && -n $mode ]]; then
+        chown "$owner" -- "$file" "${file}.old" 2>/dev/null
+        chmod "$mode" -- "$file" "${file}.old" 2>/dev/null
+    fi
+    return "$rc"
+}
+export -f _rmhost_remove
+# ------------------------------------------------------------------------------
+
+
 # ------------------------------------------------------------------------------
 # Remove host entries (name and IP) from ~/.ssh/known_hosts for the active user
 # Usage: rmhost <hostname|ip> [hostname2|ip2 [...]]
@@ -47,10 +76,12 @@ rmhost()
 
     PARSED=$(getopt -o ha --long help,all-users -n 'rmhost' -- "$@")
     # shellcheck disable=SC2181 # getopt return code is checked immediately after
-    if [[ $? -ne 0 ]]; then return 1; fi
+    if [[ $? -ne 0 ]]; then
-    local -a _pargs=()
+        disp E "Invalid options, use \"rmhost --help\" to display usage."
-    readarray -td '' _pargs < <(printf '%s' "$PARSED" | xargs printf '%s\0')
+        return 1
-    set -- "${_pargs[@]}"
+    fi
+    # Restore the getopt-normalised (shell-quoted) argument list
+    eval set -- "$PARSED"
 
     while true; do
         case "$1" in
@@ -60,6 +91,7 @@ rmhost()
                 printf "Options:\n"
                 printf "  -a, --all-users   Remove entries from all local users when run as root\n"
                 printf "  -h, --help        Display this help screen\n\n"
+                printf "A host name is removed together with all the IP addresses it resolves to.\n"
                 printf "Wildcards:\n"
                 printf "  Glob patterns (*, ?, [...]) are expanded against unhashed known_hosts entries.\n"
                 printf "  Hashed entries (prefixed with |1|) are never matched by wildcards.\n"
@@ -90,14 +122,27 @@ rmhost()
         return 127
     }
 
+    # A name starting with "-" would be read as an option by the tools below
+    local target
+    for target in "$@"; do
+        if [[ "$target" == -* ]]; then
+            disp E "Invalid host '$target'."
+            return 1
+        fi
+    done
+
     if (( all_users )); then
         [[ ${EUID:-$(id -u)} -eq 0 ]] || {
             disp E "Option --all-users is only available when run as root."
             return 1
         }
 
+        # Users may share a home directory: each file is listed once
+        local -A _seen_homes=()
+        local home
         while IFS=: read -r _ _ _ _ _ home _; do
-            [[ -n $home && -f $home/.ssh/known_hosts ]] || continue
+            [[ -n $home && -f $home/.ssh/known_hosts && -z ${_seen_homes[$home]+x} ]] || continue
+            _seen_homes[$home]=1
             known_hosts_files+=("$home/.ssh/known_hosts")
         done < /etc/passwd
 
@@ -109,19 +154,27 @@ rmhost()
             return 0
         }
     else
+        if [[ ! -f "${HOME}/.ssh/known_hosts" ]]; then
+            disp W "No known_hosts file found (${HOME}/.ssh/known_hosts)."
+            return 0
+        fi
         known_hosts_files=("${HOME}/.ssh/known_hosts")
     fi
 
     for target in "$@"; do
-        # Wildcard: expand glob pattern against unhashed known_hosts entries
+        # Wildcard: expand the glob pattern against the unhashed entries of
-        if [[ "$target" == *['*?[']* ]]; then
+        # each file, and remove the matches from that file only. A "[host]:port"
-            local -a _matched=()
+        # entry is not a pattern: its brackets are known_hosts notation.
-            local _wf _wl _wfield _whost _wmatch
+        if [[ "$target" == *['*?']* ]] || \
-            local -a _wentries
+           [[ "$target" == *'['* && ! "$target" =~ ^\[[^][]+\]:[0-9]+$ ]]; then
+            local -a _matched=() _wentries=()
+            local _wf _wl _wfield _whost _wmatch _key _found=0
             for _wf in "${known_hosts_files[@]}"; do
-                [[ -f "$_wf" ]] || continue
+                _matched=()
                 while IFS= read -r _wl; do
-                    [[ -z "$_wl" || "$_wl" == '#'* || "$_wl" == '|'* ]] && continue
+                    # Comments, hashed entries and @cert-authority/@revoked
+                    # marker lines are left alone
+                    [[ -z "$_wl" || "$_wl" == '#'* || "$_wl" == '|'* || "$_wl" == '@'* ]] && continue
                     _wfield="${_wl%% *}"
                     IFS=',' read -ra _wentries <<< "$_wfield"
                     for _whost in "${_wentries[@]}"; do
@@ -132,55 +185,50 @@ rmhost()
                         else
                             _wmatch="$_whost"
                         fi
-                        # shellcheck disable=SC2053
+                        # shellcheck disable=SC2053 # unquoted on purpose: glob match
                         [[ "$_wmatch" == $target ]] && _matched+=("$_whost")
                     done
                 done < "$_wf"
-            done
 
-            mapfile -t _matched < <(printf '%s\n' "${_matched[@]}" | sort -u)
+                [[ ${#_matched[@]} -gt 0 ]] || continue
-
+                _found=1
-            if [[ ${#_matched[@]} -eq 0 ]]; then
+                while IFS= read -r _key; do
-                disp W "No known_hosts entries match pattern '$target'."
+                    disp I "Removing '$_key' from $_wf..."
-                continue
+                    if ! _rmhost_remove "$_key" "$_wf"; then
-            fi
+                        disp W "No known_hosts entry found for '$_key' in '$_wf'."
-
-            local _key _known_hosts_file
-            for _key in "${_matched[@]}"; do
-                for _known_hosts_file in "${known_hosts_files[@]}"; do
-                    disp I "Removing '$_key' from $_known_hosts_file..."
-                    if ! ssh-keygen -R "$_key" -f "$_known_hosts_file" >/dev/null 2>&1; then
-                        disp W "No known_hosts entry found for '$_key' in '$_known_hosts_file'."
                     fi
-                done
+                done < <(printf '%s\n' "${_matched[@]}" | sort -u)
             done
+
+            (( _found )) || disp W "No known_hosts entries match pattern '$target'."
             continue
         fi
 
         local hst="$target"
-        local ip=""
+        local ip
-        local v4=1
+        local -a ips=()
-        local v6=1
 
-        isipv4 "$hst" >/dev/null 2>&1; v4=$?
+        if isipv4 "$hst" >/dev/null 2>&1 || isipv6 "$hst" >/dev/null 2>&1; then
-        isipv6 "$hst" >/dev/null 2>&1; v6=$?
+            ips=("$hst")
-
-        if [[ $v4 -eq 0 || $v6 -eq 0 ]]; then
-            ip="$hst"
             hst=""
-        fi
+        elif [[ "$hst" == '['*']:'* ]]; then
-
+            # Explicit [host]:port entry: removed exactly as given
-        if [[ -z ${ip:-} && -n ${hst:-} ]]; then
+            :
+        else
+            # All the addresses of the name: ssh records the one it connected
+            # to, which may be any of them (IPv4 and IPv6, several A records)
             if command -v host >/dev/null 2>&1; then
-                ip=$(host "$hst" 2>/dev/null |
+                mapfile -t ips < <(host "$hst" 2>/dev/null |
-                    awk '/has address|has IPv6 address/ {print $NF; exit}')
+                    awk '/has address|has IPv6 address/ {print $NF}' | sort -u)
             elif command -v getent >/dev/null 2>&1; then
-                ip=$(getent ahosts "$hst" 2>/dev/null | awk 'NR == 1 {print $1; exit}')
+                # ahosts lists every address once per socket type
+                mapfile -t ips < <(getent ahosts "$hst" 2>/dev/null |
+                    awk '{print $1}' | sort -u)
             else
                 disp W "No resolver tool found; removing hostname only for '$hst'."
             fi
 
-            [[ -z ${ip:-} ]] && \
+            [[ ${#ips[@]} -eq 0 ]] && \
                 disp W "Could not resolve IP for '$hst'; removing hostname only."
         fi
 
@@ -188,16 +236,16 @@ rmhost()
         for known_hosts_file in "${known_hosts_files[@]}"; do
             if [[ -n ${hst:-} ]]; then
                 disp I "Removing host $hst from $known_hosts_file..."
-                if ! ssh-keygen -R "$hst" -f "$known_hosts_file" >/dev/null 2>&1; then
+                if ! _rmhost_remove "$hst" "$known_hosts_file"; then
                     disp W "No known_hosts entry found for '$hst' in '$known_hosts_file'."
                 fi
             fi
-            if [[ -n ${ip:-} ]]; then
+            for ip in "${ips[@]}"; do
                 disp I "Removing IP $ip from $known_hosts_file..."
-                if ! ssh-keygen -R "$ip" -f "$known_hosts_file" >/dev/null 2>&1; then
+                if ! _rmhost_remove "$ip" "$known_hosts_file"; then
                     disp W "No known_hosts entry found for '$ip' in '$known_hosts_file'."
                 fi
-            fi
+            done
         done
     done
 }
@@ -238,9 +286,18 @@ ssr()
     local srv=$1
     shift
 
-    # Build default options array from config, falling back to -Y (X11 forwarding)
+    # The first argument is the server: an option here ("ssr -p 22 host")
+    # would end up in the root@... destination
+    if [[ $srv == -* ]]; then
+        disp E "'$srv' is not a server name: the server comes first, then the ssh options."
+        return 1
+    fi
+
+    # Build the default options array from the configuration. An unset
+    # SSH_DEFAULT_OPT means -Y (X11 forwarding); an empty one means no default
+    # option at all, as the example configuration documents.
     local -a ssh_default_opts=()
-    if [[ -n "${SSH_DEFAULT_OPT:-}" ]]; then
+    if [[ -n "${SSH_DEFAULT_OPT+x}" ]]; then
         read -ra ssh_default_opts <<< "${SSH_DEFAULT_OPT}"
     else
         ssh_default_opts=(-Y)