v2.5.0

Highlights

This release introduces EMV TLV (Tag-Length-Value) support for chip card data, enabling first-class parsing, building, and integration of BER-TLV encoded data -- commonly carried in ISO 8583 field 55. The implementation follows the EMV v4.3 Specification and ISO/IEC 8825-1 BER encoding rules.

New Features

• TlvParser -- Parses BER-TLV encoded byte arrays into structured TlvTag records. Handles single-byte tags, multi-byte tags (2-3+ bytes), short-form and long-form lengths, constructed (nested) tags, and inter-TLV padding bytes (0x00, 0xFF).

• TlvBuilder -- Fluent API for constructing BER-TLV byte sequences:

  byte[] data = new TlvBuilder()
      .AddTag("9F26", cryptogramValue)
      .AddTag("9F27", cidValue)
      .Build();

• TlvTag -- Immutable record type representing a single TLV data object with Tag (hex string), Length, Value (byte array), and optional Description. Supports IsConstructed detection and GetNestedTags() for constructed data objects.

• EmvTags -- Built-in FrozenDictionary of 38 common EMV tag descriptions sourced from EMV v4.3 Book 3 (Annex A) and ISO/IEC 7816-4, with case-insensitive lookup. Spec version exposed via EmvTags.SpecVersion.

• TlvField -- ICustomBinaryField implementation that allows field 55 (or any field) to be registered as a TLV-aware composite field in both XML and programmatic (MessageFactoryBuilder) configurations.

• IsoMessage TLV extension methods -- Convenience helpers for field 55 access:

  • GetTlvTags() -- retrieve parsed TLV tags
  • SetTlvTags() -- set TLV tags on the message
  • GetTlvBytes() -- retrieve raw TLV bytes
  • FindTlvTag(string tag) -- find a specific tag by hex identifier

Improvements

• Expanded test coverage: Added new test classes with comprehensive unit tests covering single-byte tags, multi-byte tags, nested constructed tags, round-trip encode/decode, TlvField integration, IsoMessage extension methods, and EmvTags dictionary validation.
• MIT license headers Added to all C# source files across the entire solution.
• Documentation: Comprehensive README section covering BER-TLV encoding rules, standalone usage, XML and programmatic configuration, and IsoMessage extension methods, with a full EMV tag reference table.

Bug Fixes

• Fixed date/time related test failures.

Supported Frameworks

• .NET 8.0
• .NET 9.0
• .NET 10.0

Pull Requests

• test: add tests to validate a bug reported sometime ago by @Tochemey in #45
• feat: ✨ add emv v4.3 field 55 parser support by @Tochemey in #47

Full Changelog: 2.4.0...v2.5.0

2.4.0

🚀 What's Changed

✨ Fluent Message Factory Builder API

• Code-first configuration without XML — a new MessageFactoryBuilder<T> provides a fluent, type-safe API for constructing fully-configured MessageFactory instances entirely in code.
• 🧩 Supports all configuration options previously available only through XML: headers, templates, parse maps, custom fields, composite fields, and all factory properties.
• 🔗 Template and parse-map inheritance via Extends(), with field-level override and exclusion support.
• 🏗️ New builder classes: MessageFactoryBuilder<T>, TemplateBuilder, ParseMapBuilder, and CompositeFieldBuilder.

var factory = new MessageFactoryBuilder<IsoMessage>()
    .WithEncoding(Encoding.UTF8)
    .WithHeader(0x0200, "ISO")
    .WithTemplate(0x0200, t => t
        .Field(3, IsoType.NUMERIC, "000000", 6)
        .Field(11, IsoType.NUMERIC, "000001", 6)
        .Field(41, IsoType.ALPHA, "TERMINAL", 8))
    .WithTemplate(0x0210, t => t
        .Extends(0x0200)
        .Field(39, IsoType.ALPHA, "00", 2))
    .WithParseMap(0x0200, p => p
        .Field(3, IsoType.NUMERIC, 6)
        .Field(11, IsoType.NUMERIC, 6)
        .Field(41, IsoType.ALPHA, 8))
    .WithParseMap(0x0210, p => p
        .Extends(0x0200)
        .Field(39, IsoType.ALPHA, 2))
    .Build();

📎 PR: #42

⚡ Performance: Zero-Copy Parsing, Span<T>, Bitmap128 & Allocation Reductions

• 🧮 Bitmap128 struct backed by UInt128 replaces BitArray for field-presence tracking — significantly faster bit operations with zero heap allocations.
• 🔬 Span<T> and ReadOnlySpan<T> used throughout parsing and encoding, enabling zero-copy byte/string conversions and eliminating intermediate array allocations.
• 🔄 Zero-copy byte utilities (Bytes extensions) using MemoryMarshal.Cast for reinterpreting between byte[] and sbyte[] without copying.
• 🧵 Stringx extensions with GetSignedBytes() overloads that encode directly into destination buffers, plus ArrayPool<T> pooled variants for hot paths.
• 💾 EncodingCache to avoid repeated encoding lookups.
• 📦 Reorganised internal utilities from NetCore8583.Util → NetCore8583.Extensions namespace for clearer separation.
• 🔧 All field parsers, IsoMessage, IsoValue, MessageFactory, and codec classes updated to use the new span-based APIs.

📎 PR: #41

⚠️ Breaking Changes

• The NetCore8583.Util namespace has been reorganised into NetCore8583.Extensions. If you reference types like HexCodec, Bcd, Arrays, OsUtil, Enumm, DictionaryExtensions, or ParseException directly, update your using statements accordingly.
• 🗑️ Removed: ByteUtil, DateUtil, StringUtil, DictionaryExtensions, Enumm, and ParseException from NetCore8583.Util (replaced by equivalents in NetCore8583.Extensions).

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Full Changelog: 2.3.0...2.4.0

2.3.0

🚀 What’s Changed

✨ Features

• Add support for .NET 10
  Includes test fixes to ensure compatibility and stability.
  Thanks to @fernandoareias 🙌
  → #37

🧹 Maintenance

• Upgrade dependencies & sunset legacy frameworks
  • Updated project dependencies to their latest compatible versions
  • Dropped support for .NET 6 and .NET 7 (now end-of-life / nearing EOL)
    → #39

---

⚠️ Breaking Changes

• Support for .NET 6 and .NET 7 has been removed.
  Please upgrade to a supported .NET version before updating.

---

👋 New Contributors

• 🎉 @fernandoareias made their first contribution!
  Thanks for helping move the project forward 💙
  → #37

Full Changelog: 2.2.2...2.3.0

2.2.2

What's Changed

• chore: add net9 support by @TadijaB in #32

Full Changelog: 2.2.1...2.2.2

2.2.1

What's Changed

• feat: add ILogger interface that can be implemented by @Tochemey in #27
• fix: create unconfigured response message by @TadijaB in #29

New Contributors

• @TadijaB made their first contribution in #29

Full Changelog: 2.2.0...2.2.1

2.2.0

What's Changed

• Added .Net 8 support by @amammes in #23

New Contributors

• @amammes made their first contribution in #23

Full Changelog: 2.1.0...2.2.0

2.1.0

What's Changed

• chore: add net7 support by @Tochemey in #21

Full Changelog: 2.0.0...2.1.0

2.0.0

What's Changed

• Upgrade to Net 6.0

1.0.3

Noteworthy

• CopyFieldsFrom added to IsoMessage to copy specific fields from one message to another
• RemoveFields added to IsoMessage remove specific fields from message
• ToUnsignedBytes has been renamed to ToUint8
• ToSignedBytes has been renamed to ToInt8

1.0.2

Noteworthy

• Upgraded to NET 5.0
• Bug fixing in LLLBinParseInfo
• Bug fix: 128th field in referenced template is missing when using extends in template element
• Bug fix: LLLLBIN length calculation when element is more than 1000 bytes
• Configurable radix for integer parsing.
• New behavior for MessageFactory.createResponse(): The new behavior for the createResponse method within the MessageFactory class (while preserving the existing one), in order to be able to create a response with only the fields in the template, overriding the values with the contents of the request only for those fields.