Fixed certificate policy bugs if DnsName is null. (#22646)

Author: BethanyZhou

src/KeyVault/KeyVault/ChangeLog.md

@@ -18,6 +18,7 @@
         - Additional information about change #1
 -->
 ## Upcoming Release
+* Fixed certificate policy bugs if DnsName is null. [#22642]
 * Supported multi-regions for Managed Hsm: Added `Add/Get/Remove-AzAzKeyVaultManagedHsmRegion`.
 * Added `Test-AzKeyVaultNameAvailability` and `Test-AzKeyVaultManagedHsmNameAvailability`.
 * Formatted the table view of `*-AzKeyVault`, `*-AzKeyVaultKey` and `*-AzKeyVaultSecret`

src/KeyVault/KeyVault/Models/Certificate/PSKeyVaultCertificatePolicy.cs

@@ -411,28 +411,27 @@ internal static PSKeyVaultCertificatePolicy FromCertificatePolicy(CertificatePol
         {
             return new PSKeyVaultCertificatePolicy
             {
-                SecretContentType = certificatePolicy.SecretProperties == null ? null : certificatePolicy.SecretProperties.ContentType,
-                Kty = certificatePolicy.KeyProperties == null ? null : certificatePolicy.KeyProperties.KeyType,
-                KeySize = certificatePolicy.KeyProperties == null ? null : certificatePolicy.KeyProperties.KeySize,
-                Curve = certificatePolicy.KeyProperties == null ? null : certificatePolicy.KeyProperties.Curve,
-                Exportable = certificatePolicy.KeyProperties == null ? null : certificatePolicy.KeyProperties.Exportable,
-                ReuseKeyOnRenewal = certificatePolicy.KeyProperties == null ? null : certificatePolicy.KeyProperties.ReuseKey,
-                SubjectName = certificatePolicy.X509CertificateProperties == null ? null : certificatePolicy.X509CertificateProperties.Subject,
-                DnsNames = certificatePolicy.X509CertificateProperties == null || certificatePolicy.X509CertificateProperties.SubjectAlternativeNames == null ?
-                    null : new List<string>(certificatePolicy.X509CertificateProperties.SubjectAlternativeNames.DnsNames),
-                KeyUsage = certificatePolicy.X509CertificateProperties == null ? null : certificatePolicy.X509CertificateProperties.KeyUsage == null ? null : new List<string>(certificatePolicy.X509CertificateProperties.KeyUsage),
-                Ekus = certificatePolicy.X509CertificateProperties == null ? null : certificatePolicy.X509CertificateProperties.Ekus == null ? null : new List<string>(certificatePolicy.X509CertificateProperties.Ekus),               
-                ValidityInMonths = certificatePolicy.X509CertificateProperties == null ? null : certificatePolicy.X509CertificateProperties.ValidityInMonths,
-                CertificateTransparency = certificatePolicy.IssuerParameters == null ? null : certificatePolicy.IssuerParameters.CertificateTransparency,
-                IssuerName = certificatePolicy.IssuerParameters == null ? null : certificatePolicy.IssuerParameters.Name,
-                CertificateType = certificatePolicy.IssuerParameters == null ? null : certificatePolicy.IssuerParameters.CertificateType,
+                SecretContentType = certificatePolicy?.SecretProperties?.ContentType,
+                Kty = certificatePolicy?.KeyProperties?.KeyType,
+                KeySize = certificatePolicy?.KeyProperties?.KeySize,
+                Curve = certificatePolicy?.KeyProperties?.Curve,
+                Exportable = certificatePolicy?.KeyProperties?.Exportable,
+                ReuseKeyOnRenewal = certificatePolicy?.KeyProperties?.ReuseKey,
+                SubjectName = certificatePolicy?.X509CertificateProperties?.Subject,
+                DnsNames = certificatePolicy?.X509CertificateProperties?.SubjectAlternativeNames?.DnsNames?.ToList(),
+                KeyUsage = certificatePolicy?.X509CertificateProperties?.KeyUsage?.ToList(),
+                Ekus = certificatePolicy?.X509CertificateProperties?.Ekus?.ToList(),               
+                ValidityInMonths = certificatePolicy?.X509CertificateProperties?.ValidityInMonths,
+                CertificateTransparency = certificatePolicy?.IssuerParameters?.CertificateTransparency,
+                IssuerName = certificatePolicy?.IssuerParameters?.Name,
+                CertificateType = certificatePolicy?.IssuerParameters?  .CertificateType,
                 RenewAtNumberOfDaysBeforeExpiry = certificatePolicy.LifetimeActions == null ? null : FindIntValueForAutoRenewAction(certificatePolicy.LifetimeActions, (trigger) => trigger.DaysBeforeExpiry),
                 RenewAtPercentageLifetime = certificatePolicy.LifetimeActions == null ? null : FindIntValueForAutoRenewAction(certificatePolicy.LifetimeActions, (trigger) => trigger.LifetimePercentage),
                 EmailAtNumberOfDaysBeforeExpiry = certificatePolicy.LifetimeActions == null ? null : FindIntValueForEmailAction(certificatePolicy.LifetimeActions, (trigger) => trigger.DaysBeforeExpiry),
                 EmailAtPercentageLifetime = certificatePolicy.LifetimeActions == null ? null : FindIntValueForEmailAction(certificatePolicy.LifetimeActions, (trigger) => trigger.LifetimePercentage),
-                Enabled = certificatePolicy.Attributes == null ? null : certificatePolicy.Attributes.Enabled,
-                Created = certificatePolicy.Attributes == null ? null : certificatePolicy.Attributes.Created,
-                Updated = certificatePolicy.Attributes == null ? null : certificatePolicy.Attributes.Updated,
+                Enabled = certificatePolicy?.Attributes?.Enabled,
+                Created = certificatePolicy?.Attributes?.Created,
+                Updated = certificatePolicy?.Attributes?.Updated,
             };
         }
 
@@ -450,8 +449,8 @@ internal static PSKeyVaultCertificatePolicy FromTrack2CertificatePolicy(Track2Ce
                 DnsNames = certificatePolicy.SubjectAlternativeNames?.DnsNames?.ToList(),
                 Emails = certificatePolicy.SubjectAlternativeNames?.Emails?.ToList(),
                 UserPrincipalNames = certificatePolicy.SubjectAlternativeNames?.UserPrincipalNames?.ToList(),
-                KeyUsage = certificatePolicy.KeyUsage == null ? null : certificatePolicy.KeyUsage == null ? null : certificatePolicy.KeyUsage.Select(keyUsage => keyUsage.ToString()).ToList(),
-                Ekus = certificatePolicy.EnhancedKeyUsage == null ? null : new List<string>(certificatePolicy.EnhancedKeyUsage),
+                KeyUsage =  certificatePolicy?.KeyUsage?.Select(keyUsage => keyUsage.ToString())?.ToList(),
+                Ekus = certificatePolicy?.EnhancedKeyUsage?.ToList(),
                 ValidityInMonths = certificatePolicy.ValidityInMonths,
                 CertificateTransparency = certificatePolicy.CertificateTransparency,
                 IssuerName = certificatePolicy.IssuerName,