Support Windows based ECDSA SignedCms

Supports SignedCms signatured with an ECDSA key created by the Windows API or .NET Framework. These signatures store an EC public key OID rather than a hash specific ECDSA OID used in newer versions of dotnet. Fixes dotnet#77377
jborean93 · Aug 27, 2023 · f6a9b2c · f6a9b2c
1 parent f5881e5
commit f6a9b2c
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Showing 4 changed files with 52 additions and 4 deletions.
diff --git a/...em.Security.Cryptography.Pkcs/src/System/Security/Cryptography/Pkcs/CmsSignature.ECDsa.cs b/...em.Security.Cryptography.Pkcs/src/System/Security/Cryptography/Pkcs/CmsSignature.ECDsa.cs
@@ -22,17 +22,17 @@ static partial void PrepareRegistrationECDsa(Dictionary<string, CmsSignature> lo
             lookup.Add(Oids.ECDsaWithSha3_384, new ECDsaCmsSignature(Oids.ECDsaWithSha3_384, HashAlgorithmName.SHA3_384));
             lookup.Add(Oids.ECDsaWithSha3_512, new ECDsaCmsSignature(Oids.ECDsaWithSha3_512, HashAlgorithmName.SHA3_512));
 #endif
-            lookup.Add(Oids.EcPublicKey, new ECDsaCmsSignature(null, default));
+            lookup.Add(Oids.EcPublicKey, new ECDsaCmsSignature(null, null));
         }
 
         private sealed partial class ECDsaCmsSignature : CmsSignature
         {
-            private readonly HashAlgorithmName _expectedDigest;
+            private readonly HashAlgorithmName? _expectedDigest;
             private readonly string? _signatureAlgorithm;
 
             internal override RSASignaturePadding? SignaturePadding => null;
 
-            internal ECDsaCmsSignature(string? signatureAlgorithm, HashAlgorithmName expectedDigest)
+            internal ECDsaCmsSignature(string? signatureAlgorithm, HashAlgorithmName? expectedDigest)
             {
                 _signatureAlgorithm = signatureAlgorithm;
                 _expectedDigest = expectedDigest;
@@ -56,7 +56,7 @@ internal override bool VerifySignature(
                 ReadOnlyMemory<byte>? signatureParameters,
                 X509Certificate2 certificate)
             {
-                if (_expectedDigest != digestAlgorithmName)
+                if (_expectedDigest != null && _expectedDigest != digestAlgorithmName)
                 {
                     throw new CryptographicException(
                         SR.Format(

diff --git a/src/libraries/System.Security.Cryptography.Pkcs/tests/Oids.cs b/src/libraries/System.Security.Cryptography.Pkcs/tests/Oids.cs
@@ -25,6 +25,7 @@ internal static class Oids
         public const string RsaPss = "1.2.840.113549.1.1.10";
         public const string Esdh = "1.2.840.113549.1.9.16.3.5";
         public const string Dh = "1.2.840.10046.2.1";
+        public const string EcPublicKey = "1.2.840.10045.2.1";
         public const string EcdsaSha256 = "1.2.840.10045.4.3.2";
 
         // Cryptographic Attribute Types

diff --git a/src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedCmsTests.netcoreapp.cs b/src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedCmsTests.netcoreapp.cs
@@ -823,6 +823,20 @@ public static void ExistingDocument_Rsa_Sha3_512()
             }
         }
 
+        [Fact]
+        public static void ExistingDocument_Ecdsa_Sha256_FromNetFX()
+        {
+            SignedCms cms = new SignedCms();
+            cms.Decode(SignedDocuments.Ecdsa_Sha256_FromNetFX_SignedDocument);
+
+            cms.CheckSignature(true); // Assert.NoThrow
+            Assert.Single(cms.SignerInfos);
+
+            SignerInfo signerInfo = cms.SignerInfos[0];
+            Assert.Equal(Oids.Sha256, signerInfo.DigestAlgorithm.Value);
+            Assert.Equal(Oids.EcPublicKey, signerInfo.SignatureAlgorithm.Value);
+        }
+
         private static void VerifyWithExplicitPrivateKey(X509Certificate2 cert, AsymmetricAlgorithm key)
         {
             using (var pubCert = new X509Certificate2(cert.RawData))

diff --git a/src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedDocuments.cs b/src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedDocuments.cs
@@ -1789,5 +1789,38 @@ internal static class SignedDocuments
             "F11C632B4F605A41821A3F15B4F537FD5F0EE3426A7A03732AC946C3B435" +
             "776A873A3DAE93FB8312C681144CF51F05CE37A0DB4C1544E178F88E421C" +
             "0B5456D18C13B335DA808CE60C4E35F507").HexToByteArray();
+
+        // produced with the below PowerShell code using the pfx Certificates.ECDsaP256Win
+        // $cert = [System.Security.Cryptography.X509Certificates.X509Certificate2]::new(
+        //     [System.Convert]::FromBase64String($Certificates_ECDsaP256Win),
+        //     'Test',
+        //     'EphemeralKeySet')
+        // $signer = [System.Security.Cryptography.Pkcs.CmsSigner]::new('IssuerAndSerialNumber', $cert)
+        // $signer.IncludeOption = 'ExcludeRoot'
+        // $signer.DigestAlgorithm = '2.16.840.1.101.3.4.2.1'
+        // $contentInfo = [System.Security.Cryptography.Pkcs.ContentInfo]::new([byte[]]@(0))
+        // $signedCms = [System.Security.Cryptography.Pkcs.SignedCms]::new($contentInfo, $false)
+        // $signedCms.ComputeSignature($signer, $true)
+        // $signedCms.Encode()
+        internal static readonly byte[] Ecdsa_Sha256_FromNetFX_SignedDocument = (
+            "3082023106092A864886F70D010702A08202223082021E020101310F300D" +
+            "06096086480165030402010500301006092A864886F70D010701A0030401" +
+            "00A082015C308201583081FFA003020102021035428F3B3C5107AD49E776" +
+            "D6E74C4DC8300A06082A8648CE3D04030230153113301106035504030C0A" +
+            "45434453412054657374301E170D3135303530313030333730335A170D31" +
+            "36303530313030353730335A30153113301106035504030C0A4543445341" +
+            "20546573743059301306072A8648CE3D020106082A8648CE3D0301070342" +
+            "00047590F69CA114E92927E034C997B7C882A8C992AC00CEFB4EB8319015" +
+            "36F291E1B515263BCD20E1EA32496FDAC84E2D8D1B703266A9088F6EAF65" +
+            "2549D9BB63D5A331302F300E0603551D0F0101FF040403020388301D0603" +
+            "551D0E0416041411218A92C5EB12273B3C5CCFB8220CCCFDF387DB300A06" +
+            "082A8648CE3D040302034800304502201AFE595E19F1AE4B6A4B231E8851" +
+            "926438C55B5DDE632E6ADF13C1023A65898E022100CBDF434FDD197D8B59" +
+            "4E8026E44263BADE773C2BEBD060CC4109484A498E7C7E31819530819202" +
+            "0101302930153113301106035504030C0A45434453412054657374021035" +
+            "428F3B3C5107AD49E776D6E74C4DC8300D06096086480165030402010500" +
+            "300B06072A8648CE3D020105000446304402203557687B26E650E4F86F4B" +
+            "77A5BF5851350C96F01142696CC1391632CB95C3370220017FD4D9329F00" +
+            "1EC74210CD34CAEE3878B2302602DB7930347E104679734291").HexToByteArray();
     }
 }