Metadata-Version: 2.4
Name: pysapsso2
Version: 1.1.0
Summary: A pure python library for generating SAP Assertion/Logon tickets.
Author: BougeBouge Consulting
License: MIT License
        
        Copyright (c) 2019 BougeBouge Consulting
        
        Permission is hereby granted, free of charge, to any person obtaining a copy
        of this software and associated documentation files (the "Software"), to deal
        in the Software without restriction, including without limitation the rights
        to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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        The above copyright notice and this permission notice shall be included in all
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        THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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Project-URL: Homepage, https://github.com/bougebouge/pysapsso2
Project-URL: Repository, https://github.com/bougebouge/pysapsso2
Project-URL: Issues, https://github.com/bougebouge/pysapsso2/issues
Keywords: sap,sso,logon-ticket,assertion-ticket,netweaver
Classifier: Development Status :: 4 - Beta
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.10
Classifier: Programming Language :: Python :: 3.11
Classifier: Programming Language :: Python :: 3.12
Classifier: Programming Language :: Python :: 3.13
Classifier: Topic :: Security :: Cryptography
Classifier: Topic :: System :: Systems Administration :: Authentication/Directory
Requires-Python: >=3.10
Description-Content-Type: text/markdown
License-File: LICENSE
Requires-Dist: asn1crypto>=1.5.1
Requires-Dist: pycryptodome>=3.19.0
Dynamic: license-file

# pysapsso2
A pure python library for generating SAP Assertion/Logon tickets.

SAP Logon Tickets are authentication tokens accepted by :
 - SAP NetWeaver ABAP (SAP GUI, Webdynpro/Fiori, Web Services)
 - SAP NetWeaver Java (Web)


This library is an opensource alternative to SAPSSOEXT ([304450 - Single-Sign-On with SAP logon tickets in non-SAP systems](https://me.sap.com/notes/304450))

## Installation

```
pip install pysapsso2
```

## How to generate an SAP shortcut
cf. [examples/generate_shortcut.py](examples/generate_shortcut.py)

## How to parse an SAP Logon Ticket

```python
from pysapsso2 import SapTicket

ticket = SapTicket.from_b64(cookie_value)
print(ticket.user, ticket.source_sid, ticket.source_client, ticket.expires_at)
```

## How to verify an SAP Logon Ticket

```python
from pysapsso2 import SapTicket, SapTicketHandler

ticket = SapTicket.from_b64(cookie_value)
handler = SapTicketHandler("SSO", "000", certificate=trusted_cert_pem)
handler.verify(ticket)  # raises SignatureError / CertificateError
```

`verify()` checks, in order:

1. the payload digest against the `message_digest` signed attribute,
2. that the ticket names the supplied certificate as its signer,
3. that the certificate is within its validity period (`check_certificate_validity=False` to skip, `at_time=` to pin the moment),
4. the signature over the signed attributes.

**The certificate must come from the caller.** A ticket may embed a certificate,
but anybody can embed one they hold the key for, so it is never used as a trust
anchor. `pysapsso2.crypto.get_dsa_key()` exposes the embedded key for inspection
only.

## Signing algorithms

| Key | Key sizes | Digest |
|---|---|---|
| DSA | 1024 – 4096 | `sha1`, `sha256` |
| RSA (PKCS#1 v1.5) | 1024 – 4096 | `sha1`, `sha256` |
| ECDSA | P-256, P-384, P-521 | `sha1`, `sha256` |

Every combination in the table was accepted by a live SAP NetWeaver ABAP system.

DSA with `sha1` is the default, because that is what SAPSSOEXT emits. Use it if
you need a ticket that SAPSSOEXT can also read. Otherwise prefer RSA or ECDSA
with `sha256`.

Pick the algorithm on the handler:

```python
from Crypto.PublicKey import RSA
from pysapsso2 import SapTicketHandler

handler = SapTicketHandler(
    "SSO",
    "000",
    private_key=RSA.import_key(key_pem),
    certificate=cert_pem,
    digest_algorithm="sha256",
)
ticket = handler.new("DEMOUSER")
```

`digest_algorithm` defaults to `"sha1"`. The handler picks the signer from the
key type. You can also build the signer yourself with
`pysapsso2.DsaSigner`, `pysapsso2.RsaSigner` or `pysapsso2.signer_for_key()` and
pass it as `private_key`; the handler's `digest_algorithm` is then ignored,
because the signer carries its own.

Verification needs no configuration. `verify()` reads the digest algorithm from
the ticket and the key algorithm from the certificate.

## Development
This project uses [uv](https://docs.astral.sh/uv/).

```
# Create the virtualenv and install the project with its dev dependencies
uv sync

# Run the tests / linter
uv run pytest
uv run ruff check

# Run an example
uv run examples/generate_shortcut.py

# Build the sdist and wheel
uv build
```

`tests/keys/` holds throwaway self-signed keys, one pair per row of the
algorithm matrix. They are committed, so a clone runs the suite straight away.
To replace them, or to add a key size or curve, run
`pwsh tools/make_test_keys.ps1 -Force`. It needs `openssl`; on Windows it falls
back to the one shipped with Git.

`sapsso2.key` and `sapsso2.crt` are the exception: the script never touches
them. That key signed the SAPSSOEXT reference ticket pinned in
`tests/test_sapticket.py`, so a regenerated key would not verify that
signature.

## Further reading

- [docs/sapssoext.md](docs/sapssoext.md) — developer notes: signing a ticket
  with SAPSSOEXT itself, and running the interop suite
  (`uv run pytest -m oracle`) against it.
- [docs/interop.md](docs/interop.md) records what SAP actually does with a
  ticket, measured rather than quoted: which keys and digests each consumer
  signs and validates, the DSA subgroup rule, the error pairs, and the validity
  and base64 behaviour.
