Handle IdLinkage X509 chain building status.

src/libraries/Native/Unix/System.Security.Cryptography.Native.Apple/pal_x509chain.c

@@ -190,14 +190,34 @@ static void MergeStatusCodes(CFTypeRef key, CFTypeRef value, void* context)
         // just ignore it for now.
     }
     else if (CFEqual(keyString, CFSTR("NonEmptySubject")) || CFEqual(keyString, CFSTR("GrayListedKey")) ||
-             CFEqual(keyString, CFSTR("CTRequired")) || CFEqual(keyString, CFSTR("GrayListedLeaf")))
+             CFEqual(keyString, CFSTR("CTRequired")) || CFEqual(keyString, CFSTR("GrayListedLeaf")) ||
+             CFEqual(keyString, CFSTR("IdLinkage")))
     {
         // Not a "problem" that we report.
     }
     else
     {
 #if defined DEBUG || defined DEBUGGING_UNKNOWN_VALUE
-        printf("Unknown Chain Status: %s\n", CFStringGetCStringPtr(keyString, CFStringGetSystemEncoding()));
+        CFIndex keyStringLength = CFStringGetLength(keyString);
+        CFIndex maxEncodedLength = CFStringGetMaximumSizeForEncoding(keyStringLength, kCFStringEncodingUTF8) + 1;
+        char* keyStringBuffer = malloc(maxEncodedLength);
+
+        if (keyStringBuffer)
+        {
+            if (CFStringGetCString(keyString, keyStringBuffer, maxEncodedLength, kCFStringEncodingUTF8))
+            {
+                printf("Unknown Chain Status: %s\n", keyStringBuffer);
+            }
+            else
+            {
+                printf("Unknown Chain Status. Could not get string.");
+            }
+            free(keyStringBuffer);
+        }
+        else
+        {
+            printf("Unknown Chain Status. Could not allocate string.");
+        }
 #endif
         *pStatus |= PAL_X509ChainErrorUnknownValue;
     }

src/libraries/System.Security.Cryptography.X509Certificates/tests/DynamicChainTests.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Linq;
+using System.Runtime.InteropServices;
 using Test.Cryptography;
 using Xunit;
 
@@ -450,6 +451,65 @@ public static void CustomTrustModeWithNoCustomTrustCerts()
             }
         }
 
+        [Fact]
+        public static void MismatchKeyIdentifiers()
+        {
+            X509Extension[] intermediateExtensions = new [] {
+                new X509BasicConstraintsExtension(
+                    certificateAuthority: true,
+                    hasPathLengthConstraint: false,
+                    pathLengthConstraint: 0,
+                    critical: true),
+                new X509Extension(
+                    "2.5.29.14",
+                    "0414C7AC28EFB300F46F9406ED155628A123633E556F".HexToByteArray(),
+                    critical: false)
+            };
+
+            X509Extension[] endEntityExtensions = new [] {
+                new X509BasicConstraintsExtension(
+                    certificateAuthority: false,
+                    hasPathLengthConstraint: false,
+                    pathLengthConstraint: 0,
+                    critical: true),
+                new X509Extension(
+                    "2.5.29.35",
+                    "30168014A84A6A63047DDDBAE6D139B7A64565EFF3A8ECA1".HexToByteArray(),
+                    critical: false)
+            };
+
+            TestDataGenerator.MakeTestChain3(
+                out X509Certificate2 endEntityCert,
+                out X509Certificate2 intermediateCert,
+                out X509Certificate2 rootCert,
+                intermediateExtensions: intermediateExtensions,
+                endEntityExtensions: endEntityExtensions);
+
+            using (endEntityCert)
+            using (intermediateCert)
+            using (rootCert)
+            using (ChainHolder chainHolder = new ChainHolder())
+            {
+                X509Chain chain = chainHolder.Chain;
+                chain.ChainPolicy.RevocationMode = X509RevocationMode.NoCheck;
+                chain.ChainPolicy.VerificationTime = endEntityCert.NotBefore.AddSeconds(1);
+                chain.ChainPolicy.TrustMode = X509ChainTrustMode.CustomRootTrust;
+                chain.ChainPolicy.CustomTrustStore.Add(rootCert);
+                chain.ChainPolicy.ExtraStore.Add(intermediateCert);
+
+                if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+                {
+                    Assert.False(chain.Build(endEntityCert), "chain.Build");
+                    Assert.Equal(X509ChainStatusFlags.PartialChain, chain.AllStatusFlags());
+                }
+                else
+                {
+                    Assert.True(chain.Build(endEntityCert), "chain.Build");
+                    Assert.Equal(3, chain.ChainElements.Count);
+                }
+            }
+        }
+
         private static X509Certificate2 TamperSignature(X509Certificate2 input)
         {
             byte[] cert = input.RawData;