Use shorter SSH control path (gopasspw#1899)

Fixes gopasspw#1896

RELEASE_NOTES=[BUGFIX] Fix SSH control path

Signed-off-by: Dominik Schulz <dominik.schulz@gauner.org>

docs/faq.md

@@ -11,6 +11,7 @@
 * *gopass fails with 'gpg failed to sign the data fatal: failed to write commit object'* - If git is not able to interface with GPG, commits will fail because gopass configures git to sign commits by default. Have a look a [this question](https://stackoverflow.com/questions/39494631/gpg-failed-to-sign-the-data-fatal-failed-to-write-commit-object-git-2-10-0) for more information.
 * *Can gopass be used with Terraform?* - Yes, there is a gopass-based [Terraform provider](https://github.com/camptocamp/terraform-provider-pass) available.
 * *How can I fix ´"gpg: decryption failed: No secret key"` errors?* - Set the ´auto-expand-secmem` option in your gpg-agent.conf, if your version of GnuPG supports it.
+* *I'm getting `Path too long for Unix domain socket` errors, usually on MacOS*. This can be fixed by setting `export TMPDIR=/tmp` (or any other suiteable location with a path shorter than 80 characters).
 
 ## API Stability
 

internal/backend/crypto/gpg/cli/gpg.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/gopasspw/gopass/internal/backend/crypto/gpg"
 	"github.com/gopasspw/gopass/pkg/debug"
-	"github.com/gopasspw/gopass/pkg/fsutil"
 	lru "github.com/hashicorp/golang-lru"
 )
 
@@ -51,10 +50,16 @@ func New(ctx context.Context, cfg Config) (*GPG, error) {
 		}
 	}
 
+	gcfg, err := gpgConfig()
+	if err != nil {
+		debug.Log("failed to read GPG config: %s", err)
+	}
+	_, throwKids := gcfg["throw-keyids"]
+
 	g := &GPG{
 		binary:    "gpg",
 		args:      append(defaultArgs, cfg.Args...),
-		throwKids: fsutil.FileContains(gpgConfigLoc(), "throw-keyids"),
+		throwKids: throwKids,
 	}
 
 	debug.Log("initializing LRU cache")

internal/backend/crypto/gpg/cli/utils.go

@@ -1,6 +1,8 @@
 package cli
 
 import (
+	"bufio"
+	"io"
 	"os"
 	"path/filepath"
 	"strings"
@@ -29,6 +31,39 @@ func gpgConfigLoc() string {
 	return filepath.Join(uhd, ".gnupg", "gpg.conf")
 }
 
+func gpgConfig() (map[string]string, error) {
+	fh, err := os.Open(gpgConfigLoc())
+	if err != nil {
+		return nil, err
+	}
+	defer fh.Close()
+
+	return parseGpgConfig(fh)
+}
+
+func parseGpgConfig(fh io.Reader) (map[string]string, error) {
+	val := make(map[string]string, 20)
+	scanner := bufio.NewScanner(fh)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		// ignore comments
+		if strings.HasPrefix(line, "#") {
+			continue
+		}
+		p := strings.SplitN(line, " ", 2)
+		if len(p) < 1 {
+			continue
+		}
+		val[p[0]] = ""
+		if len(p) < 2 {
+			continue
+		}
+		val[p[0]] = strings.TrimSpace(p[1])
+	}
+
+	return val, nil
+}
+
 // GPGOpts parses extra GPG options from the environment
 func GPGOpts() []string {
 	for _, en := range []string{"GOPASS_GPG_OPTS", "PASSWORD_STORE_GPG_OPTS"} {

internal/backend/crypto/gpg/cli/utils_test.go

@@ -1,10 +1,12 @@
 package cli
 
 import (
+	"bytes"
 	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestGpgOpts(t *testing.T) {
@@ -33,3 +35,88 @@ func TestSplitPacket(t *testing.T) {
 		assert.Equal(t, out, splitPacket(in))
 	}
 }
+
+func TestGPGConfig(t *testing.T) {
+	in := `
+#-----------------------------
+# default key
+#-----------------------------
+# The default key to sign with. If this option is not used, the default key is
+# the first key found in the secret keyring
+#default-key 0xD8692123C4065DEA5E0F3AB5249B39D24F25E3F6
+#-----------------------------
+# behavior
+#-----------------------------
+# Disable inclusion of the version string in ASCII armored output
+no-emit-version
+# Disable comment string in clear text signatures and ASCII armored messages
+no-comments
+# Display long key IDs
+keyid-format 0xlong
+# List all keys (or the specified ones) along with their fingerprints
+with-fingerprint
+# Display the calculated validity of user IDs during key listings
+list-options show-uid-validity
+verify-options show-uid-validity
+# Try to use the GnuPG-Agent. With this option, GnuPG first tries to connect to
+# the agent before it asks for a passphrase.
+use-agent
+#-----------------------------
+# keyserver
+#-----------------------------
+# This is the server that --recv-keys, --send-keys, and --search-keys will
+# communicate with to receive keys from, send keys to, and search for keys on
+keyserver hkps://hkps.pool.sks-keyservers.net
+# Provide a certificate store to override the system default
+# Get this from https://sks-keyservers.net/sks-keyservers.netCA.pem
+#keyserver-options ca-cert-file=/usr/local/etc/ssl/certs/hkps.pool.sks-keyservers.net.pem
+# Set the proxy to use for HTTP and HKP keyservers - default to the standard
+# local Tor socks proxy
+# It is encouraged to use Tor for improved anonymity. Preferably use either a
+# dedicated SOCKSPort for GnuPG and/or enable IsolateDestPort and
+# IsolateDestAddr
+#keyserver-options http-proxy=socks5-hostname://127.0.0.1:9050
+# Don't leak DNS, see https://trac.torproject.org/projects/tor/ticket/2846
+#keyserver-options no-try-dns-srv
+# When using --refresh-keys, if the key in question has a preferred keyserver
+# URL, then disable use of that preferred keyserver to refresh the key from
+keyserver-options no-honor-keyserver-url
+# When searching for a key with --search-keys, include keys that are marked on
+# the keyserver as revoked
+keyserver-options include-revoked
+#-----------------------------
+# algorithm and ciphers
+#-----------------------------
+# list of personal digest preferences. When multiple digests are supported by
+# all recipients, choose the strongest one
+personal-cipher-preferences AES256 AES192 AES CAST5
+# list of personal digest preferences. When multiple ciphers are supported by
+# all recipients, choose the strongest one
+personal-digest-preferences SHA512 SHA384 SHA256 SHA224
+# message digest algorithm used when signing a key
+cert-digest-algo SHA512
+# This preference list is used for new keys and becomes the default for
+# "setpref" in the edit menu
+default-preference-list SHA512 SHA384 SHA256 SHA224 AES256 AES192 AES CAST5 ZLIB BZIP2 ZIP Uncompressed
+
+default-recipient-self
+# GPGConf disabled this option here at Di 26 Aug 2008 14:22:45 CEST
+# keyserver pgpkeys.pca.dfn.de
+default-cert-check-level 3
+no-mangle-dos-filenames
+no-secmem-warning
+use-agent
+
+#throw-keyids
+
+default-key  FEEDBEEF
+utf8-strings
+encrypt-to   DEADBEEF
+`
+	cfg, err := parseGpgConfig(bytes.NewReader([]byte(in)))
+	require.NoError(t, err)
+	assert.Equal(t, "SHA512", cfg["cert-digest-algo"])
+	_, found := cfg["throw-keyids"]
+	assert.False(t, found)
+	assert.Equal(t, "DEADBEEF", cfg["encrypt-to"])
+}

internal/backend/storage/fs/fsck.go

@@ -12,6 +12,7 @@ import (
 	"github.com/gopasspw/gopass/pkg/ctxutil"
 	"github.com/gopasspw/gopass/pkg/debug"
 	"github.com/gopasspw/gopass/pkg/fsutil"
+	"github.com/gopasspw/gopass/pkg/termio"
 )
 
 // Fsck checks the storage integrity
@@ -47,7 +48,12 @@ func (s *Store) Fsck(ctx context.Context) error {
 	}
 
 	debug.Log("checking root dir %q", s.path)
-	return s.fsckCheckDir(ctx, s.path)
+	if err := s.fsckCheckDir(ctx, s.path); err != nil {
+		return err
+	}
+
+	debug.Log("checking git config")
+	return s.InitConfig(ctx, termio.DetectName(ctx, nil), termio.DetectEmail(ctx, nil))
 }
 
 func (s *Store) fsckCheckFile(ctx context.Context, filename string) error {

internal/backend/storage/gitfs/ssh_others.go

@@ -11,6 +11,9 @@ import "os"
 //
 // Note: Setting GIT_SSH_COMMAND, possibly to an empty string, will take
 // precedence over this setting.
+//
+// %C is a hash of %l%h%p%r and should avoid "path too long for unix domain socket"
+// errors. If you still encounter this error set TMPDIR to a short path, e.g. /tmp.
 func gitSSHCommand() string {
-	return "ssh -oControlMaster=auto -oControlPersist=600 -oControlPath=" + os.TempDir() + "/.gopass-ssh-${USER}-%r@%h:%p"
+	return "ssh -oControlMaster=auto -oControlPersist=600 -oControlPath=" + os.TempDir() + "/.ssh-%C"
 }

internal/store/leaf/fsck.go

@@ -101,6 +101,9 @@ func (s *Store) fsckCheckEntry(ctx context.Context, name string) error {
 	}
 
 	// check itemRecps matches storeRecps
+	// TODO we need to noramlize both slices before we can compare them,
+	// otherwise one might contain a short key id or a name while the other has
+	// the full key id
 	missing, extra := compareStringSlices(perItemStoreRecps, itemRecps)
 	if len(missing) > 0 {
 		out.Errorf(ctx, "Missing recipients on %s: %+v\nRun fsck with the --decrypt flag to re-encrypt it automatically, or edit this secret yourself.", name, missing)