Add the ability to load a PKCS10 into CertificateRequest

src/libraries/Common/src/System/Security/Cryptography/Asn1/PssParamsAsn.manual.cs

@@ -0,0 +1,64 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Formats.Asn1;
+using Internal.Cryptography;
+
+namespace System.Security.Cryptography.Asn1
+{
+    internal partial struct PssParamsAsn
+    {
+        internal RSASignaturePadding GetSignaturePadding(
+            int? digestValueLength = null)
+        {
+            if (TrailerField != 1)
+            {
+                throw new CryptographicException(SR.Cryptography_Pkcs_InvalidSignatureParameters);
+            }
+
+            if (MaskGenAlgorithm.Algorithm != Oids.Mgf1)
+            {
+                throw new CryptographicException(
+                    SR.Cryptography_Pkcs_PssParametersMgfNotSupported,
+                    MaskGenAlgorithm.Algorithm);
+            }
+
+            if (MaskGenAlgorithm.Parameters == null)
+            {
+                throw new CryptographicException(SR.Cryptography_Pkcs_InvalidSignatureParameters);
+            }
+
+            AlgorithmIdentifierAsn mgfParams = AlgorithmIdentifierAsn.Decode(
+                MaskGenAlgorithm.Parameters.Value,
+                AsnEncodingRules.DER);
+
+            if (mgfParams.Algorithm != HashAlgorithm.Algorithm)
+            {
+                throw new CryptographicException(
+                    SR.Format(
+                        SR.Cryptography_Pkcs_PssParametersMgfHashMismatch,
+                        mgfParams.Algorithm,
+                        HashAlgorithm.Algorithm));
+            }
+
+            int saltSize = digestValueLength.GetValueOrDefault();
+
+            if (!digestValueLength.HasValue)
+            {
+                saltSize = Helpers.HashOidToByteLength(HashAlgorithm.Algorithm);
+            }
+
+            if (SaltLength != saltSize)
+            {
+                throw new CryptographicException(
+                    SR.Format(
+                        SR.Cryptography_Pkcs_PssParametersSaltMismatch,
+                        SaltLength,
+                        HashAlgorithm.Algorithm));
+            }
+
+            // When RSASignaturePadding supports custom salt sizes this return will look different.
+            return RSASignaturePadding.Pss;
+        }
+    }
+}

src/libraries/Common/src/System/Security/Cryptography/Helpers.cs

@@ -64,5 +64,19 @@ internal static bool TryCopyToDestination(this ReadOnlySpan<byte> source, Span<b
             bytesWritten = 0;
             return false;
         }
+
+        internal static int HashOidToByteLength(string hashOid)
+        {
+            // This file is compiled in netstandard2.0, can't use the HashSizeInBytes consts.
+            return hashOid switch
+            {
+                Oids.Sha256 => 256 >> 3,
+                Oids.Sha384 => 384 >> 3,
+                Oids.Sha512 => 512 >> 3,
+                Oids.Sha1 => 160 >> 3,
+                Oids.Md5 => 128 >> 3,
+                _ => throw new CryptographicException(SR.Format(SR.Cryptography_UnknownHashAlgorithm, hashOid)),
+            };
+        }
     }
 }

src/libraries/Common/src/System/Security/Cryptography/PemLabels.cs

@@ -14,5 +14,6 @@ internal static class PemLabels
         internal const string X509Certificate = "CERTIFICATE";
         internal const string Pkcs7Certificate = "PKCS7";
         internal const string X509CertificateRevocationList = "X509 CRL";
+        internal const string Pkcs10CertificateRequest = "CERTIFICATE REQUEST";
     }
 }

src/libraries/System.Security.Cryptography.Pkcs/src/System.Security.Cryptography.Pkcs.csproj

@@ -415,6 +415,10 @@ System.Security.Cryptography.Pkcs.EnvelopedCms</PackageDescription>
     <AsnXml Include="$(CommonPath)System\Security\Cryptography\Asn1\PssParamsAsn.xml">
       <Link>Common\System\Security\Cryptography\Asn1\PssParamsAsn.xml</Link>
     </AsnXml>
+    <Compile Include="$(CommonPath)System\Security\Cryptography\Asn1\PssParamsAsn.manual.cs">
+      <Link>Common\System\Security\Cryptography\Asn1\PssParamsAsn.manual.cs</Link>
+      <DependentUpon>Common\System\Security\Cryptography\Asn1\PssParamsAsn.xml</DependentUpon>
+    </Compile>
     <Compile Include="$(CommonPath)System\Security\Cryptography\Asn1\PssParamsAsn.xml.cs">
       <Link>Common\System\Security\Cryptography\Asn1\PssParamsAsn.xml.cs</Link>
       <DependentUpon>Common\System\Security\Cryptography\Asn1\PssParamsAsn.xml</DependentUpon>

src/libraries/System.Security.Cryptography.Pkcs/src/System/Security/Cryptography/Pkcs/CmsSignature.RSA.cs

@@ -309,47 +309,8 @@ protected override RSASignaturePadding GetSignaturePadding(
                             digestAlgorithmOid));
                 }
 
-                if (pssParams.TrailerField != 1)
-                {
-                    throw new CryptographicException(SR.Cryptography_Pkcs_InvalidSignatureParameters);
-                }
-
-                if (pssParams.SaltLength != digestValueLength)
-                {
-                    throw new CryptographicException(
-                        SR.Format(
-                            SR.Cryptography_Pkcs_PssParametersSaltMismatch,
-                            pssParams.SaltLength,
-                            digestAlgorithmName.Name));
-                }
-
-                if (pssParams.MaskGenAlgorithm.Algorithm != Oids.Mgf1)
-                {
-                    throw new CryptographicException(
-                        SR.Cryptography_Pkcs_PssParametersMgfNotSupported,
-                        pssParams.MaskGenAlgorithm.Algorithm);
-                }
-
-                if (pssParams.MaskGenAlgorithm.Parameters == null)
-                {
-                    throw new CryptographicException(SR.Cryptography_Pkcs_InvalidSignatureParameters);
-                }
-
-                AlgorithmIdentifierAsn mgfParams = AlgorithmIdentifierAsn.Decode(
-                    pssParams.MaskGenAlgorithm.Parameters.Value,
-                    AsnEncodingRules.DER);
-
-                if (mgfParams.Algorithm != digestAlgorithmOid)
-                {
-                    throw new CryptographicException(
-                        SR.Format(
-                            SR.Cryptography_Pkcs_PssParametersMgfHashMismatch,
-                            mgfParams.Algorithm,
-                            digestAlgorithmOid));
-                }
-
-                // When RSASignaturePadding supports custom salt sizes this return will look different.
-                return RSASignaturePadding.Pss;
+                RSASignaturePadding padding = pssParams.GetSignaturePadding(digestValueLength);
+                return padding;
             }
 
             protected override bool Sign(