Restaurer les autorisations révoquées accordées aux applications

Cet article décrit comment restaurer des autorisations accordées à une application qui ont révoquées. Vous pouvez restaurer des autorisations accordées à une application afin d’accéder aux données de votre organisation. Vous pouvez également restaurer les autorisations accordées à une application afin d’agir en tant qu’utilisateur.

Actuellement, seuls les appels du PowerShell et de l’API Microsoft Graph permettent de restaurer des autorisations. Vous ne pouvez pas restaurer des autorisations par le biais du Centre d’administration Microsoft Entra. Cet article décrit comment restaurer des autorisations avec le PowerShell Microsoft Graph.

Prérequis

Pour restaurer des autorisations accordées à une application qui ont été révoquées, vous avez besoin des éléments suivants :

• Compte Azure avec un abonnement actif. Créez un compte gratuitement.
• Un des rôles suivants : Administrateur d’application cloud, Administrateur d’application.
• Un propriétaire de principal de service qui n’est pas administrateur peut invalider des jetons d’actualisation.

Restaurer les autorisations accordées à une application qui ont été révoquées

Différentes méthodes permettent de restaurer des autorisations :

• Utilisez le bouton Accorder le consentement administrateur dans la page Autorisations pour que l’application applique à nouveau le consentement. Ce consentement applique l’ensemble d’autorisations que le développeur de l’application a initialement demandé dans le manifeste de l’application.

• Si vous connaissez l’autorisation qui a été spécifiquement révoquée, vous pouvez l’accorder manuellement à l’aide du PowerShell ou de l’API Microsoft Graph.
• Si vous ne connaissez pas les autorisations révoquées, vous pouvez utiliser les scripts fournis dans cet article pour les détecter et les restaurer.

Tout d’abord, définissez la valeur service PrincipalId dans le script sur l’ID de l’application d’entreprise dont vous souhaitez restaurer les autorisations. Cet ID est également appelé object ID dans la page Applications d’entreprise du Centre d’administration Microsoft Entra.

Ensuite, exécutez chaque script avec $ForceGrantUpdate = $false pour afficher la liste des autorisations déléguées ou des autorisations d’application uniquement qui peuvent avoir été supprimées. Même si les autorisations ont déjà été restaurées, les événements de révocation des journaux d’audit peuvent encore apparaître dans les résultats du script.

Si vous souhaitez que le script tente de restaurer les autorisations révoquées qu’il détecte, laissez $ForceGrantUpdate défini sur $true. Même s’ils demandent une confirmation, les scripts n’exigent pas d’approbation individuelle pour chaque autorisation restaurée.

Soyez prudent lorsque vous accordez des autorisations aux applications. Pour en savoir plus sur l’évaluation des autorisations, consultez la section Évaluer les autorisations.

# WARNING: Setting $ForceGrantUpdate to true will modify permission grants without
# prompting for confirmation. This can result in unintended changes to your
# application's security settings. Use with caution!
$ForceGrantUpdate = $false

# Set the start and end dates for the audit log search
# If setting date use yyyy-MM-dd format
# endDate is set to tomorrow to include today's audit logs
$startDate = (Get-Date).AddDays(-7).ToString('yyyy-MM-dd')
$endDate = (Get-Date).AddDays(1).ToString('yyyy-MM-dd')

# Set the service principal ID
$servicePrincipalId = "aaaaaaaa-bbbb-cccc-1111-222222222222"

Write-Host "Searching for audit logs between $startDate and $endDate" -ForegroundColor Green
Write-Host "Searching for audit logs for service principal $servicePrincipalId" -ForegroundColor Green

if ($ForceGrantUpdate -eq $true) {
    Write-Host "WARNING: ForceGrantUpdate is set to true. This will modify permission grants without prompting for confirmation. This can result in unintended changes to your application's security settings. Use with caution!" -ForegroundColor Red
    $continue = Read-Host "Do you want to continue? (Y/N)"
    if ($continue -eq "Y" -or $continue -eq "y") {
        Write-Host "Continuing..."
    } else {
        Write-Host "Exiting..."
        exit
    }
}

# Connect to MS Graph
Connect-MgGraph -Scopes "AuditLog.Read.All","DelegatedPermissionGrant.ReadWrite.All" -ErrorAction Stop | Out-Null

# Create a hashtable to store the OAuth2PermissionGrants
$oAuth2PermissionGrants = @{}

function Merge-Scopes($oldScopes, $newScopes) {
    $oldScopes = $oldScopes.Trim() -split '\s+'
    $newScopes = $newScopes.Trim() -split '\s+'
    $mergedScopesArray = $oldScopes + $newScopes | Select-Object -Unique
    $mergedScopes = $mergedScopesArray -join ' '
    return $mergedScopes.Trim()
}

# Function to merge scopes if multiple OAuth2PermissionGrants are found in the audit logs
function Add-Scopes($resourceId, $newScopes) {
    if($oAuth2PermissionGrants.ContainsKey($resourceId)) {
        $oldScopes = $oAuth2PermissionGrants[$resourceId]
        $oAuth2PermissionGrants[$resourceId] = Merge-Scopes $oldScopes $newScopes
    }
    else {
        $oAuth2PermissionGrants[$resourceId] = $newScopes
    }
}

function Get-ScopeDifference ($generatedScope, $currentScope) {
    $generatedScopeArray = $generatedScope.Trim() -split '\s+'
    $currentScopeArray = $currentScope.Trim() -split '\s+'
    $difference = $generatedScopeArray | Where-Object { $_ -notin $currentScopeArray }
    $difference = $difference -join ' '
    return $difference.Trim()
}

# Set the filter for the audit log search
$filterOAuth2PermissionGrant = "activityDateTime ge $startDate and activityDateTime le $endDate" +
    " and Result eq 'success'" +
    " and ActivityDisplayName eq 'Remove delegated permission grant'" +
    " and targetResources/any(x: x/id eq '$servicePrincipalId')"
try {
    # Retrieve the audit logs for removed OAuth2PermissionGrants
    $oAuth2PermissionGrantsAuditLogs = Get-MgAuditLogDirectoryAudit -Filter $filterOAuth2PermissionGrant -All -ErrorAction Stop
}
catch {
    Disconnect-MgGraph | Out-Null
    throw $_
}

# Remove User Delegated Permission Grants
$oAuth2PermissionGrantsAuditLogs = $oAuth2PermissionGrantsAuditLogs | Where-Object {
    -not ($_.TargetResources.ModifiedProperties.OldValue -eq '"Principal"')
}

# Merge duplicate OAuth2PermissionGrants from AuditLogs using Add-Scopes
foreach ($auditLog in $oAuth2PermissionGrantsAuditLogs) {
    $resourceId = $auditLog.TargetResources[0].Id
    # We only want to process OAuth2PermissionGrant Audit Logs where $servicePrincipalId is the clientId not the resourceId
    if ($resourceId -eq $servicePrincipalId) {
        continue
    }
    $oldScope = $auditLog.TargetResources[0].ModifiedProperties | Where-Object { $_.DisplayName -eq "DelegatedPermissionGrant.Scope" } | Select-Object -ExpandProperty OldValue
    if ($oldScope -eq $null) {
        $oldScope = ""
    }
    $oldScope = $oldScope.Replace('"', '')
    $newScope = $auditLog.TargetResources[0].ModifiedProperties | Where-Object { $_.DisplayName -eq "DelegatedPermissionGrant.Scope" } | Select-Object -ExpandProperty NewValue
    if ($newScope -eq $null) {
        $newScope = ""
    }
    $newScope = $newScope.Replace('"', '')
    $scope = Merge-Scopes $oldScope $newScope
    Add-Scopes $resourceId $scope
}

$permissionCount = 0
foreach ($resourceId in $oAuth2PermissionGrants.keys) {
    $scope = $oAuth2PermissionGrants[$resourceId]
    $params = @{
        clientId = $servicePrincipalId
        consentType = "AllPrincipals"
        resourceId = $resourceId
        scope = $scope
    }

    try {
        $currentOAuth2PermissionGrant = Get-MgOauth2PermissionGrant -Filter "clientId eq '$servicePrincipalId' and consentType eq 'AllPrincipals' and resourceId eq '$resourceId'" -ErrorAction Stop
        $action = "Creating"
        if ($currentOAuth2PermissionGrant -ne $null) {
            $action = "Updating"
        }
        Write-Host "--------------------------"
        if ($ForceGrantUpdate -eq $true) {
            Write-Host "$action OAuth2PermissionGrant with the following parameters:"
        } else {
            Write-Host "Potentially removed OAuth2PermissionGrant scopes with the following parameters:"
        }
        Write-Host "    clientId: $($params.clientId)"
        Write-Host "    consentType: $($params.consentType)"
        Write-Host "    resourceId: $($params.resourceId)"
        if ($currentOAuth2PermissionGrant -ne $null) {
            $scopeDifference = Get-ScopeDifference $scope $currentOAuth2PermissionGrant.Scope
            if ($scopeDifference -eq "") {
                Write-Host "OAuth2PermissionGrant already exists with the same scope" -ForegroundColor Yellow
                if ($ForceGrantUpdate -eq $true) {
                    Write-Host "Skipping Update" -ForegroundColor Yellow
                }
                continue
            }
            else {
                Write-Host "    scope diff: '$scopeDifference'"
            }
        }
        else {
            Write-Host "    scope: '$($params.scope)'"
        }
        if ($ForceGrantUpdate -eq $true -and $currentOAuth2PermissionGrant -eq $null) {
            New-MgOauth2PermissionGrant -BodyParameter $params -ErrorAction Stop | Out-Null
            Write-Host "OAuth2PermissionGrant was created successfully" -ForegroundColor Green
        }
        if ($ForceGrantUpdate -eq $true -and $currentOAuth2PermissionGrant -ne $null) {
            Write-Host "    Current Scope: '$($currentOAuth2PermissionGrant.scope)'" -ForegroundColor Yellow
            Write-Host "    Merging with scopes from audit logs" -ForegroundColor Yellow
            $params.scope = Merge-Scopes $currentOAuth2PermissionGrant.scope $params.scope
            Write-Host "    New Scope: '$($params.scope)'" -ForegroundColor Yellow
            Update-MgOauth2PermissionGrant -OAuth2PermissionGrantId $currentOAuth2PermissionGrant.id -BodyParameter $params -ErrorAction Stop | Out-Null
            Write-Host "OAuth2PermissionGrant was updated successfully" -ForegroundColor Green
        }
        $permissionCount++
    }
    catch {
        Disconnect-MgGraph | Out-Null
        throw $_
    }
}

Disconnect-MgGraph | Out-Null

if ($ForceGrantUpdate -eq $true) {
    Write-Host "--------------------------"
    Write-Host "$permissionCount OAuth2PermissionGrants were created/updated successfully" -ForegroundColor Green
} else {
    Write-Host "--------------------------"
    Write-Host "$permissionCount OAuth2PermissionGrants were found" -ForegroundColor Green
}

# WARNING: Setting $ForceGrantUpdate to true will modify permission grants without
# prompting for confirmation. This can result in unintended changes to your
# application's security settings. Use with caution!
$ForceGrantUpdate = $false

# Set the start and end dates for the audit log search
# If setting date use yyyy-MM-dd format
# endDate is set to tomorrow to include today's audit logs
$startDate = (Get-Date).AddDays(-7).ToString('yyyy-MM-dd')
$endDate = (Get-Date).AddDays(1).ToString('yyyy-MM-dd')

# Set the service principal ID
$servicePrincipalId = "aaaaaaaa-bbbb-cccc-1111-222222222222"

Write-Host "Searching for audit logs between $startDate and $endDate" -ForegroundColor Green
Write-Host "Searching for audit logs for service principal $servicePrincipalId" -ForegroundColor Green

if ($ForceGrantUpdate -eq $true) {
    Write-Host "WARNING: ForceGrantUpdate is set to true. This will modify permission grants without prompting for confirmation. This can result in unintended changes to your application's security settings. Use with caution!" -ForegroundColor Red
    $continue = Read-Host "Do you want to continue? (Y/N)"
    if ($continue -eq "Y" -or $continue -eq "y") {
        Write-Host "Continuing..."
    } else {
        Write-Host "Exiting..."
        exit
    }
}

# Connect to MS Graph
Connect-MgGraph -Scopes "AuditLog.Read.All","Application.Read.All","AppRoleAssignment.ReadWrite.All" -ErrorAction Stop | Out-Null

# Set the filter for the audit log search
$filterAppRoleAssignment = "activityDateTime ge $startDate and activityDateTime le $endDate" + 
    " and Result eq 'success'" +
    " and ActivityDisplayName eq 'Remove app role assignment from service principal'" +
    " and targetResources/any(x: x/id eq '$servicePrincipalId')"

try {
    # Retrieve the audit logs for removed AppRoleAssignments
    $appRoleAssignmentsAuditLogs = Get-MgAuditLogDirectoryAudit -Filter $filterAppRoleAssignment -All -ErrorAction Stop
}
catch {
    Disconnect-MgGraph | Out-Null
    throw $_
}

$permissionCount = 0
foreach ($auditLog in $appRoleAssignmentsAuditLogs) {
    $resourceId = $auditLog.TargetResources[0].Id
    # We only want to process AppRoleAssignments Audit Logs where $servicePrincipalId is the principalId not the resourceId
    if ($resourceId -eq $servicePrincipalId) {
        continue
    }
    $appRoleId = $auditLog.TargetResources[0].ModifiedProperties | Where-Object { $_.DisplayName -eq "AppRole.Id" } | Select-Object -ExpandProperty OldValue
    $appRoleId = $appRoleId.Replace('"', '')
    $params = @{
        principalId = $servicePrincipalId
        resourceId = $resourceId
        appRoleId = $appRoleId
    }

    try {
        $sp = Get-MgServicePrincipal -ServicePrincipalId $resourceId
        $appRole = $sp.AppRoles | Where-Object { $_.Id -eq $appRoleId }

        Write-Host "--------------------------"
        if ($ForceGrantUpdate -eq $true) {
            Write-Host "Creating AppRoleAssignment with the following parameters:"
        } else {
            Write-Host "Potentially removed AppRoleAssignment with the following parameters:"
        }
        Write-Host "    principalId: $($params.principalId)"
        Write-Host "    resourceId: $($params.resourceId)"
        Write-Host "    appRoleId: $($params.appRoleId)"
        Write-Host "    appRoleValue: $($appRole.Value)"
        Write-Host "    appRoleDisplayName: $($appRole.DisplayName)"
        if ($ForceGrantUpdate -eq $true) {
            New-MgServicePrincipalAppRoleAssignment -ServicePrincipalId $servicePrincipalId -BodyParameter $params -ErrorAction Stop | Out-Null
            Write-Host "AppRoleAssignment was created successfully" -ForegroundColor Green
        }
        $permissionCount++
    }
    catch {
        if ($_.Exception.Message -like "*Permission being assigned already exists on the object*") {
            Write-Host "AppRoleAssignment already exists skipping creation" -ForegroundColor Yellow
        }
        else {
            Disconnect-MgGraph | Out-Null
            throw $_
        }
    }
}

Disconnect-MgGraph | Out-Null

if ($ForceGrantUpdate -eq $true) {
    Write-Host "--------------------------"
    Write-Host "$permissionCount AppRoleAssignments were created successfully" -ForegroundColor Green
} else {
    Write-Host "--------------------------"
    Write-Host "$permissionCount AppRoleAssignments were found" -ForegroundColor Green
}