Browse Source

Completely quote AppPath and CustomConf paths (#12955)

* Completely quote AppPath and CustomConf paths

Properly handle spaces in AppPath and CustomConf within hooks and
authorized_keys. Unfortunately here we don't seem to be able to get away
with using go-shellquote as it appears that Windows doesn't play too
well with singlequote quoting - therefore we will avoid singlequote
quoting unless we absolutely cannot get away without it, e.g. \n or !.

Fix #10813

Signed-off-by: Andrew Thornton <art27@cantab.net>

* missing change

Signed-off-by: Andrew Thornton <art27@cantab.net>

* fix Test_CmdKeys

Signed-off-by: Andrew Thornton <art27@cantab.net>
pull/1047/head
zeripath 1 month ago
committed by GitHub
parent
commit
4c6ac08182
No known key found for this signature in database GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 200 additions and 8 deletions
  1. +2
    -2
      integrations/cmd_keys_test.go
  2. +3
    -3
      models/ssh_key.go
  3. +3
    -3
      modules/repository/hooks.go
  4. +100
    -0
      modules/util/shellquote.go
  5. +92
    -0
      modules/util/shellquote_test.go

+ 2
- 2
integrations/cmd_keys_test.go View File

@@ -10,11 +10,11 @@ import (
"io"
"net/url"
"os"
"strconv"
"testing"

"code.gitea.io/gitea/cmd"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/util"

"github.com/urfave/cli"
)
@@ -32,7 +32,7 @@ func Test_CmdKeys(t *testing.T) {
{"with_key",
[]string{"keys", "-e", "git", "-u", "git", "-t", "ssh-rsa", "-k", "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"},
false,
"# gitea public key\ncommand=\"" + setting.AppPath + " --config=" + strconv.Quote(strconv.Quote(setting.CustomConf))[1:len(strconv.Quote(strconv.Quote(setting.CustomConf)))-1] + " serv key-1\",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty ssh-rsa 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 user2@localhost\n",
"# gitea public key\ncommand=\"" + setting.AppPath + " --config=" + util.ShellEscape(setting.CustomConf) + " serv key-1\",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty ssh-rsa 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 user2@localhost\n",
},
{"invalid", []string{"keys", "--not-a-flag=git"}, true, "Incorrect Usage: flag provided but not defined: -not-a-flag\n\n"},
}


+ 3
- 3
models/ssh_key.go View File

@@ -38,8 +38,8 @@ import (

const (
tplCommentPrefix = `# gitea public key`
tplCommand = "%s --config=%q serv key-%d"
tplPublicKey = tplCommentPrefix + "\n" + `command=%q,no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty %s` + "\n"
tplCommand = "%s --config=%s serv key-%d"
tplPublicKey = tplCommentPrefix + "\n" + `command=%s,no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty %s` + "\n"
)

var sshOpLocker sync.Mutex
@@ -84,7 +84,7 @@ func (key *PublicKey) OmitEmail() string {

// AuthorizedString returns formatted public key string for authorized_keys file.
func (key *PublicKey) AuthorizedString() string {
return fmt.Sprintf(tplPublicKey, fmt.Sprintf(tplCommand, setting.AppPath, setting.CustomConf, key.ID), key.Content)
return fmt.Sprintf(tplPublicKey, util.ShellEscape(fmt.Sprintf(tplCommand, util.ShellEscape(setting.AppPath), util.ShellEscape(setting.CustomConf), key.ID)), key.Content)
}

func extractTypeFromBase64Key(key string) (string, error) {


+ 3
- 3
modules/repository/hooks.go View File

@@ -28,9 +28,9 @@ func getHookTemplates() (hookNames, hookTpls, giteaHookTpls []string) {
fmt.Sprintf("#!/usr/bin/env %s\ndata=$(cat)\nexitcodes=\"\"\nhookname=$(basename $0)\nGIT_DIR=${GIT_DIR:-$(dirname $0)}\n\nfor hook in ${GIT_DIR}/hooks/${hookname}.d/*; do\ntest -x \"${hook}\" && test -f \"${hook}\" || continue\necho \"${data}\" | \"${hook}\"\nexitcodes=\"${exitcodes} $?\"\ndone\n\nfor i in ${exitcodes}; do\n[ ${i} -eq 0 ] || exit ${i}\ndone\n", setting.ScriptType),
}
giteaHookTpls = []string{
fmt.Sprintf("#!/usr/bin/env %s\n\"%s\" hook --config='%s' pre-receive\n", setting.ScriptType, setting.AppPath, setting.CustomConf),
fmt.Sprintf("#!/usr/bin/env %s\n\"%s\" hook --config='%s' update $1 $2 $3\n", setting.ScriptType, setting.AppPath, setting.CustomConf),
fmt.Sprintf("#!/usr/bin/env %s\n\"%s\" hook --config='%s' post-receive\n", setting.ScriptType, setting.AppPath, setting.CustomConf),
fmt.Sprintf("#!/usr/bin/env %s\n%s hook --config=%s pre-receive\n", setting.ScriptType, util.ShellEscape(setting.AppPath), util.ShellEscape(setting.CustomConf)),
fmt.Sprintf("#!/usr/bin/env %s\n%s hook --config=%s update $1 $2 $3\n", setting.ScriptType, util.ShellEscape(setting.AppPath), util.ShellEscape(setting.CustomConf)),
fmt.Sprintf("#!/usr/bin/env %s\n%s hook --config=%s post-receive\n", setting.ScriptType, util.ShellEscape(setting.AppPath), util.ShellEscape(setting.CustomConf)),
}
return
}


+ 100
- 0
modules/util/shellquote.go View File

@@ -0,0 +1,100 @@
// Copyright 2020 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package util

import "strings"

// Bash has the definition of a metacharacter:
// * A character that, when unquoted, separates words.
// A metacharacter is one of: " \t\n|&;()<>"
//
// The following characters also have addition special meaning when unescaped:
// * ‘${[*?!"'`\’
//
// Double Quotes preserve the literal value of all characters with then quotes
// excepting: ‘$’, ‘`’, ‘\’, and, when history expansion is enabled, ‘!’.
// The backslash retains its special meaning only when followed by one of the
// following characters: ‘$’, ‘`’, ‘"’, ‘\’, or newline.
// Backslashes preceding characters without a special meaning are left
// unmodified. A double quote may be quoted within double quotes by preceding
// it with a backslash. If enabled, history expansion will be performed unless
// an ‘!’ appearing in double quotes is escaped using a backslash. The
// backslash preceding the ‘!’ is not removed.
//
// -> This means that `!\n` cannot be safely expressed in `"`.
//
// Looking at the man page for Dash and ash the situation is similar.
//
// Now zsh requires that ‘}’, and ‘]’ are also enclosed in doublequotes or escaped
//
// Single quotes escape everything except a ‘'’
//
// There's one other gotcha - ‘~’ at the start of a string needs to be expanded
// because people always expect that - of course if there is a special character before '/'
// this is not going to work

const (
tildePrefix = '~'
needsEscape = " \t\n|&;()<>${}[]*?!\"'`\\"
needsSingleQuote = "!\n"
)

var doubleQuoteEscaper = strings.NewReplacer(`$`, `\$`, "`", "\\`", `"`, `\"`, `\`, `\\`)
var singleQuoteEscaper = strings.NewReplacer(`'`, `'\''`)
var singleQuoteCoalescer = strings.NewReplacer(`''\'`, `\'`, `\'''`, `\'`)

// ShellEscape will escape the provided string.
// We can't just use go-shellquote here because our preferences for escaping differ from those in that we want:
//
// * If the string doesn't require any escaping just leave it as it is.
// * If the string requires any escaping prefer double quote escaping
// * If we have ! or newlines then we need to use single quote escaping
func ShellEscape(toEscape string) string {
if len(toEscape) == 0 {
return toEscape
}

start := 0

if toEscape[0] == tildePrefix {
// We're in the forcibly non-escaped section...
idx := strings.IndexRune(toEscape, '/')
if idx < 0 {
idx = len(toEscape)
} else {
idx++
}
if !strings.ContainsAny(toEscape[:idx], needsEscape) {
// We'll assume that they intend ~ expansion to occur
start = idx
}
}

// Now for simplicity we'll look at the rest of the string
if !strings.ContainsAny(toEscape[start:], needsEscape) {
return toEscape
}

// OK we have to do some escaping
sb := &strings.Builder{}
_, _ = sb.WriteString(toEscape[:start])

// Do we have any characters which absolutely need to be within single quotes - that is simply ! or \n?
if strings.ContainsAny(toEscape[start:], needsSingleQuote) {
// We need to single quote escape.
sb2 := &strings.Builder{}
_, _ = sb2.WriteRune('\'')
_, _ = singleQuoteEscaper.WriteString(sb2, toEscape[start:])
_, _ = sb2.WriteRune('\'')
_, _ = singleQuoteCoalescer.WriteString(sb, sb2.String())
return sb.String()
}

// OK we can just use " just escape the things that need escaping
_, _ = sb.WriteRune('"')
_, _ = doubleQuoteEscaper.WriteString(sb, toEscape[start:])
_, _ = sb.WriteRune('"')
return sb.String()
}

+ 92
- 0
modules/util/shellquote_test.go View File

@@ -0,0 +1,92 @@
// Copyright 2020 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package util

import "testing"

func TestShellEscape(t *testing.T) {
tests := []struct {
name string
toEscape string
want string
}{
{
"Simplest case - nothing to escape",
"a/b/c/d",
"a/b/c/d",
}, {
"Prefixed tilde - with normal stuff - should not escape",
"~/src/go/gitea/gitea",
"~/src/go/gitea/gitea",
}, {
"Typical windows path with spaces - should get doublequote escaped",
`C:\Program Files\Gitea v1.13 - I like lots of spaces\gitea`,
`"C:\\Program Files\\Gitea v1.13 - I like lots of spaces\\gitea"`,
}, {
"Forward-slashed windows path with spaces - should get doublequote escaped",
"C:/Program Files/Gitea v1.13 - I like lots of spaces/gitea",
`"C:/Program Files/Gitea v1.13 - I like lots of spaces/gitea"`,
}, {
"Prefixed tilde - but then a space filled path",
"~git/Gitea v1.13/gitea",
`~git/"Gitea v1.13/gitea"`,
}, {
"Bangs are unforutunately not predictable so need to be singlequoted",
"C:/Program Files/Gitea!/gitea",
`'C:/Program Files/Gitea!/gitea'`,
}, {
"Newlines are just irritating",
"/home/git/Gitea\n\nWHY-WOULD-YOU-DO-THIS\n\nGitea/gitea",
"'/home/git/Gitea\n\nWHY-WOULD-YOU-DO-THIS\n\nGitea/gitea'",
}, {
"Similarly we should nicely handle mutiple single quotes if we have to single-quote",
"'!''!'''!''!'!'",
`\''!'\'\''!'\'\'\''!'\'\''!'\''!'\'`,
}, {
"Double quote < ...",
"~/<gitea",
"~/\"<gitea\"",
}, {
"Double quote > ...",
"~/gitea>",
"~/\"gitea>\"",
}, {
"Double quote and escape $ ...",
"~/$gitea",
"~/\"\\$gitea\"",
}, {
"Double quote {...",
"~/{gitea",
"~/\"{gitea\"",
}, {
"Double quote }...",
"~/gitea}",
"~/\"gitea}\"",
}, {
"Double quote ()...",
"~/(gitea)",
"~/\"(gitea)\"",
}, {
"Double quote and escape `...",
"~/gitea`",
"~/\"gitea\\`\"",
}, {
"Double quotes can handle a number of things without having to escape them but not everything ...",
"~/<gitea> ${gitea} `gitea` [gitea] (gitea) \"gitea\" \\gitea\\ 'gitea'",
"~/\"<gitea> \\${gitea} \\`gitea\\` [gitea] (gitea) \\\"gitea\\\" \\\\gitea\\\\ 'gitea'\"",
}, {
"Single quotes don't need to escape except for '...",
"~/<gitea> ${gitea} `gitea` (gitea) !gitea! \"gitea\" \\gitea\\ 'gitea'",
"~/'<gitea> ${gitea} `gitea` (gitea) !gitea! \"gitea\" \\gitea\\ '\\''gitea'\\'",
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
if got := ShellEscape(tt.toEscape); got != tt.want {
t.Errorf("ShellEscape(%q):\nGot: %s\nWanted: %s", tt.toEscape, got, tt.want)
}
})
}
}

Loading…
Cancel
Save