up

src/__Libraries/StellaOps.Cryptography/CryptoProvider.cs

@@ -11,7 +11,8 @@ public enum CryptoCapability
     Signing,
     Verification,
     SymmetricEncryption,
-    KeyDerivation
+    KeyDerivation,
+    ContentHashing
 }
 
 /// <summary>
@@ -30,6 +31,13 @@ public interface ICryptoProvider
 
     IPasswordHasher GetPasswordHasher(string algorithmId);
 
+    /// <summary>
+    /// Retrieves a content hasher for the supplied algorithm.
+    /// </summary>
+    /// <param name="algorithmId">Hash algorithm identifier (e.g., SHA-256, GOST-R-34.11-2012-256).</param>
+    /// <returns>Hasher instance.</returns>
+    ICryptoHasher GetHasher(string algorithmId);
+
     /// <summary>
     /// Retrieves a signer for the supplied algorithm and key reference.
     /// </summary>
@@ -81,6 +89,37 @@ public interface ICryptoProviderRegistry
         string algorithmId,
         CryptoKeyReference keyReference,
         string? preferredProvider = null);
+
+    /// <summary>
+    /// Resolves a content hasher for the supplied algorithm using registry policy.
+    /// </summary>
+    /// <param name="algorithmId">Hash algorithm identifier (e.g., SHA-256, GOST-R-34.11-2012-256).</param>
+    /// <param name="preferredProvider">Optional provider hint.</param>
+    /// <returns>Resolved hasher with provider name.</returns>
+    CryptoHasherResolution ResolveHasher(string algorithmId, string? preferredProvider = null);
 }
 
 public sealed record CryptoSignerResolution(ICryptoSigner Signer, string ProviderName);
+
+public sealed record CryptoHasherResolution(ICryptoHasher Hasher, string ProviderName);
+
+/// <summary>
+/// Content hasher for computing cryptographic digests.
+/// </summary>
+public interface ICryptoHasher
+{
+    /// <summary>
+    /// Algorithm identifier (e.g., SHA-256, GOST-R-34.11-2012-256).
+    /// </summary>
+    string AlgorithmId { get; }
+
+    /// <summary>
+    /// Computes the hash of the given data.
+    /// </summary>
+    byte[] ComputeHash(ReadOnlySpan<byte> data);
+
+    /// <summary>
+    /// Computes the hash and returns it as a lowercase hex string.
+    /// </summary>
+    string ComputeHashHex(ReadOnlySpan<byte> data);
+}