ASN.1: Use GetTagged with cursor methods

- Add GetTagged method for all CHOICE types
- Make most Asn1Utilities methods public

6 files changed, 32 insertions, 16 deletions

diff --git a/crypto/src/asn1/pkcs/CertificationRequestInfo.cs b/crypto/src/asn1/pkcs/CertificationRequestInfo.cs
index 53bdffdaa..38d2d39dd 100644
--- a/crypto/src/asn1/pkcs/CertificationRequestInfo.cs
+++ b/crypto/src/asn1/pkcs/CertificationRequestInfo.cs
@@ -63,7 +63,7 @@ namespace Org.BouncyCastle.Asn1.Pkcs
             m_subjectPKInfo = SubjectPublicKeyInfo.GetInstance(seq[pos++]);
 
             // NOTE: some CertificationRequestInfo objects seem to treat this field as optional.
-            m_attributes = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, false, Asn1Set.GetInstance);
+            m_attributes = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, false, Asn1Set.GetTagged);
 
             if (pos != count)
                 throw new ArgumentException("Unexpected elements in sequence", nameof(seq));
diff --git a/crypto/src/asn1/pkcs/PrivateKeyInfo.cs b/crypto/src/asn1/pkcs/PrivateKeyInfo.cs
index 7397b7061..1185cf2f8 100644
--- a/crypto/src/asn1/pkcs/PrivateKeyInfo.cs
+++ b/crypto/src/asn1/pkcs/PrivateKeyInfo.cs
@@ -53,11 +53,27 @@ namespace Org.BouncyCastle.Asn1.Pkcs
             return new PrivateKeyInfo(Asn1Sequence.GetInstance(obj));
         }
 
-        public static PrivateKeyInfo GetInstance(Asn1TaggedObject obj, bool explicitly)
+        public static PrivateKeyInfo GetInstance(Asn1TaggedObject obj, bool explicitly) =>
+            new PrivateKeyInfo(Asn1Sequence.GetInstance(obj, explicitly));
+
+        public static PrivateKeyInfo GetOptional(Asn1Encodable element)
         {
-            return new PrivateKeyInfo(Asn1Sequence.GetInstance(obj, explicitly));
+            if (element == null)
+                throw new ArgumentNullException(nameof(element));
+
+            if (element is PrivateKeyInfo privateKeyInfo)
+                return privateKeyInfo;
+
+            Asn1Sequence asn1Sequence = Asn1Sequence.GetOptional(element);
+            if (asn1Sequence != null)
+                return new PrivateKeyInfo(asn1Sequence);
+
+            return null;
         }
 
+        public static PrivateKeyInfo GetTagged(Asn1TaggedObject taggedObject, bool declaredExplicit) =>
+            new PrivateKeyInfo(Asn1Sequence.GetTagged(taggedObject, declaredExplicit));
+
         private readonly DerInteger m_version;
         private readonly AlgorithmIdentifier m_privateKeyAlgorithm;
         private readonly Asn1OctetString m_privateKey;
@@ -73,8 +89,8 @@ namespace Org.BouncyCastle.Asn1.Pkcs
             m_version = DerInteger.GetInstance(seq[pos++]);
             m_privateKeyAlgorithm = AlgorithmIdentifier.GetInstance(seq[pos++]);
             m_privateKey = Asn1OctetString.GetInstance(seq[pos++]);
-            m_attributes = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, false, Asn1Set.GetInstance);
-            m_publicKey = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 1, false, DerBitString.GetInstance);
+            m_attributes = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, false, Asn1Set.GetTagged);
+            m_publicKey = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 1, false, DerBitString.GetTagged);
 
             if (pos != count)
                 throw new ArgumentException("Unexpected elements in sequence", nameof(seq));
diff --git a/crypto/src/asn1/pkcs/RSAESOAEPparams.cs b/crypto/src/asn1/pkcs/RSAESOAEPparams.cs
index 3490509e7..1ce8c7daf 100644
--- a/crypto/src/asn1/pkcs/RSAESOAEPparams.cs
+++ b/crypto/src/asn1/pkcs/RSAESOAEPparams.cs
@@ -43,13 +43,13 @@ namespace Org.BouncyCastle.Asn1.Pkcs
             if (count < 0 || count > 3)
                 throw new ArgumentException("Bad sequence size: " + count, nameof(seq));
 
-			m_hashAlgorithm = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, true, AlgorithmIdentifier.GetInstance)
+			m_hashAlgorithm = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, true, AlgorithmIdentifier.GetTagged)
 				?? DefaultHashAlgorithm;
 
-            m_maskGenAlgorithm = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 1, true, AlgorithmIdentifier.GetInstance)
+            m_maskGenAlgorithm = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 1, true, AlgorithmIdentifier.GetTagged)
                 ?? DefaultMaskGenAlgorithm;
 
-            m_pSourceAlgorithm = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 2, true, AlgorithmIdentifier.GetInstance)
+            m_pSourceAlgorithm = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 2, true, AlgorithmIdentifier.GetTagged)
                 ?? DefaultPSourceAlgorithm;
 
             if (pos != count)
diff --git a/crypto/src/asn1/pkcs/RSASSAPSSparams.cs b/crypto/src/asn1/pkcs/RSASSAPSSparams.cs
index f7a9d6956..7f38cd73f 100644
--- a/crypto/src/asn1/pkcs/RSASSAPSSparams.cs
+++ b/crypto/src/asn1/pkcs/RSASSAPSSparams.cs
@@ -45,16 +45,16 @@ namespace Org.BouncyCastle.Asn1.Pkcs
             if (count < 0 || count > 4)
                 throw new ArgumentException("Bad sequence size: " + count, nameof(seq));
 
-            m_hashAlgorithm = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, true, AlgorithmIdentifier.GetInstance)
+            m_hashAlgorithm = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, true, AlgorithmIdentifier.GetTagged)
                 ?? DefaultHashAlgorithm;
 
-            m_maskGenAlgorithm = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 1, true, AlgorithmIdentifier.GetInstance)
+            m_maskGenAlgorithm = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 1, true, AlgorithmIdentifier.GetTagged)
                 ?? DefaultMaskGenAlgorithm;
 
-            m_saltLength = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 2, true, DerInteger.GetInstance)
+            m_saltLength = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 2, true, DerInteger.GetTagged)
                 ?? DefaultSaltLength;
 
-            m_trailerField = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 3, true, DerInteger.GetInstance)
+            m_trailerField = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 3, true, DerInteger.GetTagged)
                 ?? DefaultTrailerField;
 
             if (pos != count)
diff --git a/crypto/src/asn1/pkcs/SignedData.cs b/crypto/src/asn1/pkcs/SignedData.cs
index de9c758fb..77f9d00dc 100644
--- a/crypto/src/asn1/pkcs/SignedData.cs
+++ b/crypto/src/asn1/pkcs/SignedData.cs
@@ -38,8 +38,8 @@ namespace Org.BouncyCastle.Asn1.Pkcs
             m_version = DerInteger.GetInstance(seq[pos++]);
             m_digestAlgorithms = Asn1Set.GetInstance(seq[pos++]);
             m_contentInfo = ContentInfo.GetInstance(seq[pos++]);
-            m_certificates = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, false, Asn1Set.GetInstance);
-            m_crls = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 1, false, Asn1Set.GetInstance);
+            m_certificates = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, false, Asn1Set.GetTagged);
+            m_crls = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 1, false, Asn1Set.GetTagged);
             m_signerInfos = Asn1Set.GetInstance(seq[pos++]);
 
             if (pos != count)
diff --git a/crypto/src/asn1/pkcs/SignerInfo.cs b/crypto/src/asn1/pkcs/SignerInfo.cs
index 01d9de98e..8f2e94983 100644
--- a/crypto/src/asn1/pkcs/SignerInfo.cs
+++ b/crypto/src/asn1/pkcs/SignerInfo.cs
@@ -46,10 +46,10 @@ namespace Org.BouncyCastle.Asn1.Pkcs
             m_version = DerInteger.GetInstance(seq[pos++]);
             m_issuerAndSerialNumber = IssuerAndSerialNumber.GetInstance(seq[pos++]);
             m_digAlgorithm = AlgorithmIdentifier.GetInstance(seq[pos++]);
-            m_authenticatedAttributes = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, false, Asn1Set.GetInstance);
+            m_authenticatedAttributes = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 0, false, Asn1Set.GetTagged);
             m_digEncryptionAlgorithm = AlgorithmIdentifier.GetInstance(seq[pos++]);
             m_encryptedDigest = Asn1OctetString.GetInstance(seq[pos++]);
-            m_unauthenticatedAttributes = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 1, false, Asn1Set.GetInstance);
+            m_unauthenticatedAttributes = Asn1Utilities.ReadOptionalContextTagged(seq, ref pos, 1, false, Asn1Set.GetTagged);
 
             if (pos != count)
                 throw new ArgumentException("Unexpected elements in sequence", nameof(seq));