Schemas need fast feedback
Catch module errors, type issues, and syntax problems before they become encoded data problems.
Native ASN.1 tools for Mac
ASN.1 schema and encoding tools for Mac
Validate schemas, check values, encode bytes, and decode payloads without leaving one focused native workspace.
Built for ASN.1 work that moves between specifications, values, and bytes.
- Schema validation
- Value checking
- Byte encoding
- Payload decoding
- Validate
- Encode
- Decode
The problem
ASN.1 work often gets split across specs, scripts, and byte viewers.
ASN.1 is precise, but the daily workflow can get scattered. You need to confirm the schema is valid, prove a value matches it, then check the encoded payload without losing the thread.
Values need proof
Check structured values against the schema before you hand them to another system or test fixture.
Bytes need context
Decode payloads beside the schema and value that explain what those bytes mean.
Workflow
Move from schema to value to bytes without switching tools.
ASN1 is built around the loop engineers repeat while implementing, testing, and inspecting ASN.1 data.
Validate the module
Open an ASN.1 schema, inspect diagnostics, and keep symbol context close while you iterate.
Check the value
Paste or write a value, then verify it against the selected type before encoding.
Encode or decode
Turn values into bytes, decode existing payloads, and compare the result in the same workspace.
Codecs
Work across the encodings you meet in protocols and test data.
DER, BER, GSER, OER, PER, UPER, XER
Binary interchange
Use DER and BER when inspecting certificate and protocol payloads with strict byte-level expectations.
Textual formats
Use GSER and XER when readable values help with review, tests, or comparisons.
Compact encodings
Use OER, PER, and UPER when the schema needs compact or rule-specific binary output.
Templates
Start from real protocol shapes instead of a blank editor.
Built-in templates help you explore X.509, OCSP, LDAP, SNMP, Kerberos, Time-Stamp Protocol, and related ASN.1 structures.
Certificates and trust
Inspect certificate, revocation, and timestamping structures from a known starting point.
Directory and management protocols
Review directory and management schemas while keeping value checks and byte output nearby.
Authentication payloads
Open security-oriented ASN.1 examples when you need to inspect tickets, tokens, and nested fields.
Workspace
A focused Mac workspace for the whole ASN.1 loop.
Keep the schema, value, encoder, decoder, and diagnostics visible as connected parts of the same task.
Schema
Validate modules with diagnostics in view.
Read schema issues beside the module instead of bouncing through separate parser output.
Values
Check structured values against the selected type.
Validate the value before encoding so type mismatches and missing fields are visible early.
Encoding
Inspect encoded bytes and decoded structure together.
Move between hex output, decoded payloads, and schema context without rebuilding the workspace.
Privacy
Your ASN.1 work stays local to the app unless you choose to send it.
The app itself does not collect data. ASN1 works with schemas, values, and encoded payloads on your Mac. Optional support forms are separate and ask only for what you decide to provide.
- No third-party advertising SDKs.
- No analytics SDKs in the app.
- Purchases are handled by Apple.
- Support contact goes to support@inyosystems.com.
FAQ
Questions before you open a schema.
What is ASN1 for?
ASN1 helps you validate ASN.1 schemas, check values, encode bytes, and decode payloads in a native Mac workspace.
Which encodings can I work with?
ASN1 includes DER, BER, GSER, OER, PER, UPER, and XER workflows for common schema and payload inspection tasks.
Do I need to start from scratch?
No. Templates provide useful starting points for certificate, directory, management, authentication, and timestamping structures.
Where can I ask for help?
Email support@inyosystems.com, send feedback, or report a bug from the links below.
Download
Download ASN1 on the Mac App Store
Install ASN1 for macOS and keep schema validation, value checks, encoding, and decoding in one native app.