Caddyview/internal/sshclient/client.go
SW b229cfe264 feat: support aes256-gcm@openssh.com encrypted private keys
x/crypto/ssh only supports aes256-ctr/cbc for private key encryption,
so keys exported from 1Password (aes256-gcm) could not be decrypted even
with the correct passphrase. Decrypt the openssh-key-v1 blob ourselves
(bcrypt_pbkdf ported from x/crypto's internal package, AES-256-GCM via
stdlib, auth tag stored as raw bytes after the encrypted block) and
re-marshal it as an unencrypted key for ssh.ParsePrivateKey.
2026-10-17 22:42:21 +02:00

443 lines
13 KiB
Go

package sshclient
import (
"bufio"
"errors"
"fmt"
"net"
"os"
"path/filepath"
"strings"
"git.janvete.com/seth/caddyview/internal/parser"
"golang.org/x/crypto/ssh"
"golang.org/x/crypto/ssh/agent"
"golang.org/x/term"
)
type Client struct {
conn *ssh.Client
host string
}
func Connect(target string, port int, keyPath string) (*Client, error) {
user, host, err := parseTarget(target)
if err != nil {
return nil, err
}
authMethods, err := buildAuthMethods(keyPath)
if err != nil {
return nil, fmt.Errorf("auth setup failed: %w", err)
}
config := &ssh.ClientConfig{
User: user,
Auth: authMethods,
HostKeyCallback: ssh.InsecureIgnoreHostKey(),
}
addr := fmt.Sprintf("%s:%d", host, port)
conn, err := ssh.Dial("tcp", addr, config)
if err != nil {
return nil, fmt.Errorf("dial %s: %w", addr, err)
}
return &Client{conn: conn, host: host}, nil
}
func (c *Client) Close() {
c.conn.Close()
}
func (c *Client) Host() string {
return c.host
}
// RunCommand runs a command and returns its output as a string.
func (c *Client) RunCommand(cmd string) (string, error) {
session, err := c.conn.NewSession()
if err != nil {
return "", err
}
defer session.Close()
out, err := session.Output(cmd)
return string(out), err
}
// StreamLines streams new lines from a remote file (like tail -F) into the channel.
func (c *Client) StreamLines(path string, lines chan<- string, done <-chan struct{}) error {
session, err := c.conn.NewSession()
if err != nil {
return err
}
stdout, err := session.StdoutPipe()
if err != nil {
return err
}
// -F follows by name: Caddy rotates by renaming the file, which would
// silently kill a plain -f stream at every rotation.
if err := session.Start(fmt.Sprintf("tail -n 0 -F %s 2>/dev/null", path)); err != nil {
session.Close()
return err
}
go func() {
defer session.Close()
scanner := bufio.NewScanner(stdout)
scanner.Buffer(make([]byte, 64*1024), 1024*1024)
for scanner.Scan() {
select {
case <-done:
return
case lines <- scanner.Text():
}
}
}()
go func() {
<-done
session.Close()
}()
return nil
}
// SysStats fetches CPU and memory usage from the remote server.
func (c *Client) SysStats() (cpuPercent float64, memUsedMB, memTotalMB int64, err error) {
// Memory from /proc/meminfo
memOut, err := c.RunCommand("cat /proc/meminfo")
if err != nil {
return 0, 0, 0, err
}
memTotalMB, memUsedMB = parseMeminfo(memOut)
// CPU: two /proc/stat samples 500ms apart
cpuOut, err := c.RunCommand("cat /proc/stat; sleep 0.5; cat /proc/stat")
if err != nil {
return 0, memUsedMB, memTotalMB, err
}
cpuPercent = parseCPUStat(cpuOut)
return cpuPercent, memUsedMB, memTotalMB, nil
}
func parseTarget(target string) (user, host string, err error) {
parts := strings.SplitN(target, "@", 2)
if len(parts) != 2 {
return "", "", fmt.Errorf("invalid target %q — expected user@host", target)
}
return parts[0], parts[1], nil
}
func buildAuthMethods(keyPath string) ([]ssh.AuthMethod, error) {
var methods []ssh.AuthMethod
// SSH agent — uses whatever keys are loaded in the agent (macOS Keychain, ssh-add, etc.)
if m := agentAuth(); m != nil {
methods = append(methods, m)
}
// Explicit key file or common defaults
var candidates []string
if keyPath != "" {
candidates = append(candidates, keyPath)
} else {
home, _ := os.UserHomeDir()
for _, name := range []string{"id_ed25519", "id_ecdsa", "id_rsa"} {
candidates = append(candidates, filepath.Join(home, ".ssh", name))
}
}
var problems []string
for _, p := range candidates {
data, err := os.ReadFile(p)
if err != nil {
continue
}
signer, err := ssh.ParsePrivateKey(data)
if err != nil {
var passErr *ssh.PassphraseMissingError
if errors.As(err, &passErr) {
signer, err = unlockWithPassphrase(p, data)
}
if err != nil {
problems = append(problems, fmt.Sprintf("%s (%v)", p, err))
continue
}
}
methods = append(methods, ssh.PublicKeys(signer))
}
if len(methods) == 0 {
if len(problems) > 0 {
return nil, fmt.Errorf("key files found but could not be loaded: %s", strings.Join(problems, "; "))
}
return nil, fmt.Errorf("no SSH auth method available — no agent (SSH_AUTH_SOCK) and no key files found in %v", candidates)
}
return methods, nil
}
// unlockWithPassphrase prompts for the passphrase of an encrypted private key.
// It runs before the TUI starts, so stdin is still a normal terminal.
func unlockWithPassphrase(path string, data []byte) (ssh.Signer, error) {
if !term.IsTerminal(int(os.Stdin.Fd())) {
return nil, fmt.Errorf("key is passphrase-protected and stdin is not a terminal")
}
for attempt := 0; attempt < 3; attempt++ {
fmt.Fprintf(os.Stderr, "Enter passphrase for %s: ", path)
pass, err := term.ReadPassword(int(os.Stdin.Fd()))
fmt.Fprintln(os.Stderr)
if err != nil {
return nil, err
}
signer, err := parsePrivateKeyWithPassphrase(data, pass)
if err == nil {
return signer, nil
}
fmt.Fprintf(os.Stderr, "caddyview: cannot decrypt key: %v\n", err)
}
return nil, fmt.Errorf("could not decrypt key in 3 attempts")
}
// parsePrivateKeyWithPassphrase handles ciphers beyond what x/crypto/ssh
// supports (aes256-gcm@openssh.com, e.g. 1Password key exports).
func parsePrivateKeyWithPassphrase(data, pass []byte) (ssh.Signer, error) {
if isGCMEncryptedKey(data) {
return parseGCMKey(data, pass)
}
return ssh.ParsePrivateKeyWithPassphrase(data, pass)
}
// agentAuth returns an auth method backed by the SSH agent if SSH_AUTH_SOCK is set.
func agentAuth() ssh.AuthMethod {
sock := os.Getenv("SSH_AUTH_SOCK")
if sock == "" {
return nil
}
conn, err := net.Dial("unix", sock)
if err != nil {
return nil
}
return ssh.PublicKeysCallback(agent.NewClient(conn).Signers)
}
func parseMeminfo(raw string) (totalMB, usedMB int64) {
var total, available int64
for _, line := range strings.Split(raw, "\n") {
var val int64
if _, err := fmt.Sscanf(line, "MemTotal: %d kB", &val); err == nil {
total = val
}
if _, err := fmt.Sscanf(line, "MemAvailable: %d kB", &val); err == nil {
available = val
}
}
return total / 1024, (total - available) / 1024
}
func parseCPUStat(raw string) float64 {
type cpuSample struct{ user, nice, sys, idle, iowait, irq, softirq uint64 }
parse := func(line string) (cpuSample, bool) {
var s cpuSample
var label string
n, _ := fmt.Sscanf(line, "%s %d %d %d %d %d %d %d",
&label, &s.user, &s.nice, &s.sys, &s.idle, &s.iowait, &s.irq, &s.softirq)
return s, n >= 5 && label == "cpu"
}
var samples []cpuSample
for _, line := range strings.Split(raw, "\n") {
if s, ok := parse(line); ok {
samples = append(samples, s)
if len(samples) == 2 {
break
}
}
}
if len(samples) < 2 {
return 0
}
total1 := samples[0].user + samples[0].nice + samples[0].sys + samples[0].idle + samples[0].iowait + samples[0].irq + samples[0].softirq
total2 := samples[1].user + samples[1].nice + samples[1].sys + samples[1].idle + samples[1].iowait + samples[1].irq + samples[1].softirq
idle1 := samples[0].idle + samples[0].iowait
idle2 := samples[1].idle + samples[1].iowait
totalDiff := float64(total2 - total1)
idleDiff := float64(idle2 - idle1)
if totalDiff == 0 {
return 0
}
return (totalDiff - idleDiff) / totalDiff * 100
}
// historyAwkProg aggregates Caddy JSON log lines into hourly summary buckets
// and collects the last 100 4xx/5xx errors per file. It runs entirely on the
// server and uses only POSIX awk constructs (works with gawk, mawk and busybox
// awk). IPs are capped to the top 50 per file so the output stays small even on
// servers with millions of unique clients.
const historyAwkProg = `
BEGIN { OFS=" " }
{
if (index($0,"\"msg\":\"handled request\"") == 0) next
p = index($0,"\"ts\":")
if (p == 0) next
ts = substr($0,p+5,20)+0
if (ts < cutoff) next
b = int(ts/bucket)*bucket
p = index($0,"\"status\":")
st = (p>0) ? substr($0,p+9,5)+0 : 0
p = index($0,"\"size\":")
sz = (p>0) ? substr($0,p+7,15)+0 : 0
p = index($0,"\"duration\":")
du = (p>0) ? substr($0,p+11,14)+0 : 0
p = index($0,"\"host\":\"")
if (p>0) { rest=substr($0,p+8); q=index(rest,"\""); ho=(q>0)?substr(rest,1,q-1):"?" } else ho="?"
p = index($0,"\"remote_ip\":\"")
if (p>0) { rest=substr($0,p+13); q=index(rest,"\""); ip=(q>0)?substr(rest,1,q-1):"?" } else ip="?"
p = index($0,"\"uri\":\"")
if (p>0) { rest=substr($0,p+7); q=index(rest,"\""); uri=(q>0)?substr(rest,1,q-1):"?" } else uri="?"
p = index($0,"\"method\":\"")
if (p>0) { rest=substr($0,p+10); q=index(rest,"\""); meth=(q>0)?substr(rest,1,q-1):"?" } else meth="?"
bc[b]++; bb[b]+=sz
if (st>=500) bs5[b]++
else if (st>=400) bs4[b]++
else if (st>=300) bs3[b]++
else if (st>=200) bs2[b]++
hc[ho]++; ic[ip]++
tot++; totb+=sz; totd+=du
if (st >= 400) {
err[++errN] = ts "\t" st "\t" meth "\t" uri "\t" ho "\t" ip
if (errN > 100) {
for (i=2; i<=errN; i++) err[i-1] = err[i]
errN--
}
}
}
END {
print "BUCKETS"
for (b in bc) print b, bc[b], bb[b], bs2[b]+0, bs3[b]+0, bs4[b]+0, bs5[b]+0
print "HOSTS"
for (h in hc) print hc[h], h
print "IPS"
k = 50
for (i in ic) n++
while (k > 0 && n > 0) {
max = -1; mi = ""
for (i in ic) if (ic[i] > max) { max = ic[i]; mi = i }
print ic[mi], mi
delete ic[mi]
k--; n--
}
print "ERRORS"
for (i=1; i<=errN; i++) print err[i]
print "TOTALS"
print tot+0, totb+0, totd+0
}`
// LoadAggregatedHistory aggregates log data on the remote server using awk,
// returning only summary buckets instead of raw lines. This is critical for
// high-traffic servers where raw line transfer would be impractical.
//
// Rotated log files are immutable, so each one is aggregated exactly once and
// the result is cached on the server (/tmp/caddyview_*.cache); after a
// rotation only the single new file is scanned. The current log file is cached
// incrementally: only newly appended lines are processed on refresh, so even a
// 100 MB active log refreshes in seconds. Buckets are always hourly; the caller
// re-buckets client-side, which lets all tabs share the same caches.
//
// since: unix cutoff used client-side after aggregation (ignored server-side so
// the cache can be reused across different windows).
// maxAgeDays: only look at files modified within this many days
func (c *Client) LoadAggregatedHistory(logPath string, since int64, maxAgeDays int) (*parser.AggregatedHistory, error) {
lastSlash := strings.LastIndex(logPath, "/")
dir, base := "/", logPath
if lastSlash >= 0 {
dir = logPath[:lastSlash]
if dir == "" {
dir = "/"
}
base = logPath[lastSlash+1:]
}
// Match both Caddy's native rotation naming (access-2026-06-12T10-30-00.000.log
// and .log.gz next to access.log) and classic logrotate naming (access.log.1.gz).
stem, ext := base, ""
if dot := strings.LastIndex(base, "."); dot > 0 {
stem, ext = base[:dot], base[dot:]
}
namePattern := fmt.Sprintf(
`\( -name '%s' -o -name '%s.*' -o -name '%s-*%s' -o -name '%s-*%s.gz' \)`,
base, base, stem, ext, stem, ext,
)
cacheKey := func(path string) string {
return strings.Map(func(r rune) rune {
if (r >= 'A' && r <= 'Z') || (r >= 'a' && r <= 'z') || (r >= '0' && r <= '9') {
return r
}
return '_'
}, path)
}
key := cacheKey(logPath)
// Shell script that aggregates each file. The current log is handled
// incrementally via a line-count/inode marker; rotated files use immutable caches.
script := fmt.Sprintf(
`set -e
find /tmp -maxdepth 1 -name 'caddyview_*' -mtime +8 -delete 2>/dev/null || true
find %s %s -type f -mtime -%d 2>/dev/null | sort | while read -r f; do
if [ "$f" = "%s" ]; then
c="/tmp/caddyview_%s.cache"
m="/tmp/caddyview_%s.marker"
read inode < <(stat -c '%%i' "$f" 2>/dev/null || echo "0")
read lines < <(wc -l < "$f" 2>/dev/null || echo "0")
use_old=false
if [ -s "$c" ] && [ -s "$m" ]; then
read old_inode old_lines < "$m"
if [ "$inode" = "$old_inode" ] && [ "$lines" -ge "$old_lines" ]; then
use_old=true
fi
fi
if [ "$use_old" = true ]; then
cat "$c"
if [ "$lines" -gt "$old_lines" ]; then
tail -n +$((old_lines + 1)) "$f" 2>/dev/null | awk -v cutoff=0 -v bucket=3600 '%s'
fi
else
awk -v cutoff=0 -v bucket=3600 '%s' < "$f" > "$c"
fi
echo "$inode $lines" > "$m"
if [ "$use_old" != "true" ]; then cat "$c"; fi
else
key=$(printf '%%s' "$f" | tr -c 'A-Za-z0-9' '_')
c="/tmp/caddyview_${key}.cache"
if [ -s "$c" ] && [ "$c" -nt "$f" ]; then
cat "$c"
else
t=$(mktemp /tmp/caddyview.XXXXXX 2>/dev/null) || t="/tmp/caddyview_tmp.$$"
case "$f" in *.gz) zcat "$f" ;; *) cat "$f" ;; esac 2>/dev/null \
| awk -v cutoff=0 -v bucket=3600 '%s' > "$t" && mv "$t" "$c" && cat "$c" || cat "$t" 2>/dev/null
fi
fi
done`,
dir, namePattern, maxAgeDays+1,
logPath,
key, key,
historyAwkProg,
historyAwkProg,
historyAwkProg,
)
out, err := c.RunCommand(script)
if err != nil && strings.TrimSpace(out) == "" {
return nil, fmt.Errorf("aggregation failed: %w", err)
}
return parser.ParseAggregatedOutput(out)
}