Fix KeyNotFoundException in CryptographyProvider.Verify

When a password hash is missing the 'iterations' parameter, Verify now
throws a descriptive FormatException instead of KeyNotFoundException.

- Extract GetIterationsParameter() helper method to avoid code duplication
- Provide distinct error messages for missing vs invalid parameters
- Add comprehensive unit tests for CryptographyProvider

1 files changed, 102 insertions, 0 deletions

diff --git a/tests/Jellyfin.Server.Implementations.Tests/Cryptography/CryptographyProviderTests.cs b/tests/Jellyfin.Server.Implementations.Tests/Cryptography/CryptographyProviderTests.cs
new file mode 100644
index 000000000..052bdf740
--- /dev/null
+++ b/tests/Jellyfin.Server.Implementations.Tests/Cryptography/CryptographyProviderTests.cs
@@ -0,0 +1,102 @@
+using System;
+using Emby.Server.Implementations.Cryptography;
+using MediaBrowser.Model.Cryptography;
+using Xunit;
+
+namespace Jellyfin.Server.Implementations.Tests.Cryptography;
+
+public class CryptographyProviderTests
+{
+    private readonly CryptographyProvider _sut = new();
+
+    [Fact]
+    public void CreatePasswordHash_WithPassword_ReturnsHashWithIterations()
+    {
+        var hash = _sut.CreatePasswordHash("testpassword");
+
+        Assert.Equal("PBKDF2-SHA512", hash.Id);
+        Assert.True(hash.Parameters.ContainsKey("iterations"));
+        Assert.NotEmpty(hash.Salt.ToArray());
+        Assert.NotEmpty(hash.Hash.ToArray());
+    }
+
+    [Fact]
+    public void Verify_WithValidPassword_ReturnsTrue()
+    {
+        const string password = "testpassword";
+        var hash = _sut.CreatePasswordHash(password);
+
+        Assert.True(_sut.Verify(hash, password));
+    }
+
+    [Fact]
+    public void Verify_WithWrongPassword_ReturnsFalse()
+    {
+        var hash = _sut.CreatePasswordHash("correctpassword");
+
+        Assert.False(_sut.Verify(hash, "wrongpassword"));
+    }
+
+    [Fact]
+    public void Verify_PBKDF2_MissingIterations_ThrowsFormatException()
+    {
+        var hash = PasswordHash.Parse("$PBKDF2$69F420$62FBA410AFCA5B4475F35137AB2E8596B127E4D927BA23F6CC05C067E897042D");
+
+        var exception = Assert.Throws<FormatException>(() => _sut.Verify(hash, "password"));
+        Assert.Contains("missing required 'iterations' parameter", exception.Message, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void Verify_PBKDF2SHA512_MissingIterations_ThrowsFormatException()
+    {
+        var hash = PasswordHash.Parse("$PBKDF2-SHA512$69F420$62FBA410AFCA5B4475F35137AB2E8596B127E4D927BA23F6CC05C067E897042D");
+
+        var exception = Assert.Throws<FormatException>(() => _sut.Verify(hash, "password"));
+        Assert.Contains("missing required 'iterations' parameter", exception.Message, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void Verify_PBKDF2_InvalidIterationsFormat_ThrowsFormatException()
+    {
+        var hash = PasswordHash.Parse("$PBKDF2$iterations=abc$69F420$62FBA410AFCA5B4475F35137AB2E8596B127E4D927BA23F6CC05C067E897042D");
+
+        var exception = Assert.Throws<FormatException>(() => _sut.Verify(hash, "password"));
+        Assert.Contains("invalid 'iterations' parameter", exception.Message, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void Verify_PBKDF2SHA512_InvalidIterationsFormat_ThrowsFormatException()
+    {
+        var hash = PasswordHash.Parse("$PBKDF2-SHA512$iterations=notanumber$69F420$62FBA410AFCA5B4475F35137AB2E8596B127E4D927BA23F6CC05C067E897042D");
+
+        var exception = Assert.Throws<FormatException>(() => _sut.Verify(hash, "password"));
+        Assert.Contains("invalid 'iterations' parameter", exception.Message, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void Verify_UnsupportedHashId_ThrowsNotSupportedException()
+    {
+        var hash = PasswordHash.Parse("$UNKNOWN$69F420$62FBA410AFCA5B4475F35137AB2E8596B127E4D927BA23F6CC05C067E897042D");
+
+        Assert.Throws<NotSupportedException>(() => _sut.Verify(hash, "password"));
+    }
+
+    [Fact]
+    public void GenerateSalt_ReturnsNonEmptyArray()
+    {
+        var salt = _sut.GenerateSalt();
+
+        Assert.NotEmpty(salt);
+    }
+
+    [Theory]
+    [InlineData(16)]
+    [InlineData(32)]
+    [InlineData(64)]
+    public void GenerateSalt_WithLength_ReturnsArrayOfSpecifiedLength(int length)
+    {
+        var salt = _sut.GenerateSalt(length);
+
+        Assert.Equal(length, salt.Length);
+    }
+}