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 # pypr
-pypr is a Python tool for parsing and working with PlayReady (PRD) device files, PSSH data, and DRM-related cryptographic structures.
+
+**pypr** is a Python toolkit for parsing, analyzing, and interacting with **Microsoft PlayReady (PRD) device files**, PlayReady headers, PSSH data, and license acquisition workflows.
+
+It provides structured, low-level access to PlayReady internals, enabling controlled inspection of device credentials, WRMHEADER data, SOAP-based license exchanges, and content key extraction.
+
+---
+
+## Overview
+
+`pypr` offers a standalone and modular implementation of PlayReady workflows, inspired by established projects such as **pyplayready** and **Bento4**. The project emphasizes clarity, extensibility, and direct control over DRM-related structures.
+
+It is intended for research, interoperability testing, and technical analysis of PlayReady-protected content.
+
+---
+
+## Features
+
+* Parsing and loading of **PlayReady Device (PRD) files**
+* Device initialization from:
+
+  * PRD files
+  * Exported certificate (`bgroupcert.dat`)
+  * Private key (`zgpriv.dat`)
+* Parsing and decoding of **PlayReady PSSH** containers
+* Extraction and processing of **WRMHEADER** data
+* Generation of **license acquisition challenges** (SOAP/XML)
+* Parsing of **license responses**
+* Extraction of **content keys (KID / KEY pairs)**
+* Support for **Revocation Lists** in license requests
+* Creation and customization of **PlayReady headers**
+* Integration with required cryptographic primitives
+
+---
+
+## Requirements
+
+* Python 3.9 or higher
+* `pycryptodome`
+* `construct==2.8.8`
+* `lxml`
+* `requests`
+
+Install dependencies:
+
+```bash
+pip install pycryptodome construct==2.8.8 lxml requests
+```
+
+> **Note:** This project is specifically tested with `construct==2.8.8`. Newer versions may introduce breaking changes.
+
+---
+
+## Usage
+
+```bash
+python pypr.py [options]
+```
+
+---
+
+## Examples
+
+### Using Exported Device Files
+
+```python
+import requests
+from pypr import PSSH, Device, Cdm, RevocationList
+
+device = Device.from_files(
+    certificate="bgroupcert.dat",
+    key="zgpriv.dat",
+)
+
+cdm = Cdm.from_device(device)
+session_id = cdm.open()
+
+pssh = PSSH("AAADfHBzc2gAAAAAmgTweZhAQoarkuZb4IhflQAAA1xcAwAAAQABAFIDPABXAFIATQBIAEUAQQBEAEUAUgAgAHgAbQBsAG4AcwA9"
+            "ACIAaAB0AHQAcAA6AC8ALwBzAGMAaABlAG0AYQBzAC4AbQBpAGMAcgBvAHMAbwBmAHQALgBjAG8AbQAvAEQAUgBNAC8AMgAwADAA"
+            "NwAvADAAMwAvAFAAbABhAHkAUgBlAGEAZAB5AEgAZQBhAGQAZQByACIAIAB2AGUAcgBzAGkAbwBuAD0AIgA0AC4AMAAuADAALgAw"
+            "ACIAPgA8AEQAQQBUAEEAPgA8AFAAUgBPAFQARQBDAFQASQBOAEYATwA+ADwASwBFAFkATABFAE4APgAxADYAPAAvAEsARQBZAEwA"
+            "RQBOAD4APABBAEwARwBJAEQAPgBBAEUAUwBDAFQAUgA8AC8AQQBMAEcASQBEAD4APAAvAFAAUgBPAFQARQBDAFQASQBOAEYATwA+"
+            "ADwASwBJAEQAPgA0AFIAcABsAGIAKwBUAGIATgBFAFMAOAB0AEcAawBOAEYAVwBUAEUASABBAD0APQA8AC8ASwBJAEQAPgA8AEMA"
+            "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")
+
+try:
+    request = cdm.get_license_challenge(
+        session_id,
+        pssh.wrm_headers[0],
+        rev_lists=RevocationList.SupportedListIds,
+    )
+
+    response = requests.post(
+        url="https://test.playready.microsoft.com/service/rightsmanager.asmx?cfg=(persist:false,sl:2000)",
+        headers={"Content-Type": "text/xml; charset=UTF-8"},
+        data=request,
+    )
+
+    response.raise_for_status()
+
+    cdm.parse_license(session_id, response.text)
+
+    for key in cdm.get_keys(session_id):
+        print(f"{key.key_id.hex}:{key.key.hex()}")
+
+finally:
+    cdm.close(session_id)
+```
+
+---
+
+### Using a PRD Device File
+
+```python
+import requests
+from pypr import PSSH, Device, Cdm, RevocationList
+
+device = Device.load("funai_electric_tv_43pfl4901f8_sl2000.prd")
+
+cdm = Cdm.from_device(device)
+session_id = cdm.open()
+
+pssh = PSSH("AAADfHBzc2gAAAAAmgTweZhAQoarkuZb4IhflQAAA1xcAwAAAQABAFIDPABXAFIATQBIAEUAQQBEAEUAUgAgAHgAbQBsAG4AcwA9"
+            "ACIAaAB0AHQAcAA6AC8ALwBzAGMAaABlAG0AYQBzAC4AbQBpAGMAcgBvAHMAbwBmAHQALgBjAG8AbQAvAEQAUgBNAC8AMgAwADAA"
+            "NwAvADAAMwAvAFAAbABhAHkAUgBlAGEAZAB5AEgAZQBhAGQAZQByACIAIAB2AGUAcgBzAGkAbwBuAD0AIgA0AC4AMAAuADAALgAw"
+            "ACIAPgA8AEQAQQBUAEEAPgA8AFAAUgBPAFQARQBDAFQASQBOAEYATwA+ADwASwBFAFkATABFAE4APgAxADYAPAAvAEsARQBZAEwA"
+            "RQBOAD4APABBAEwARwBJAEQAPgBBAEUAUwBDAFQAUgA8AC8AQQBMAEcASQBEAD4APAAvAFAAUgBPAFQARQBDAFQASQBOAEYATwA+"
+            "ADwASwBJAEQAPgA0AFIAcABsAGIAKwBUAGIATgBFAFMAOAB0AEcAawBOAEYAVwBUAEUASABBAD0APQA8AC8ASwBJAEQAPgA8AEMA"
+            "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")
+
+try:
+    request = cdm.get_license_challenge(
+        session_id,
+        pssh.wrm_headers[0],
+        rev_lists=RevocationList.SupportedListIds,
+    )
+
+    response = requests.post(
+        url="https://test.playready.microsoft.com/service/rightsmanager.asmx?cfg=(persist:false,sl:2000)",
+        headers={"Content-Type": "text/xml; charset=UTF-8"},
+        data=request,
+    )
+
+    response.raise_for_status()
+
+    cdm.parse_license(session_id, response.text)
+
+    for key in cdm.get_keys(session_id):
+        print(f"{key.key_id.hex}:{key.key.hex()}")
+
+finally:
+    cdm.close(session_id)
+```
+
+---
+
+### Building a PlayReady Header
+
+```python
+import base64
+from pypr import PlayReadyHeaderBuilder
+
+kid = "00000000000000000000000000000000"
+
+builder = PlayReadyHeaderBuilder(kid)
+
+header = builder.build_header(
+    version="4.0",
+    header_spec=None,
+    encryption_scheme="cenc",
+    key_specs=[(kid, kid)],
+)
+
+print("PlayReady Header:", base64.b64encode(header).decode())
+```
+
+---
+
+### Creating a PlayReady Header from KID
+
+```python
+from pypr import create_playready_header_from_kid
+
+kid = "00000000000000000000000000000000"
+
+header = create_playready_header_from_kid(
+    kid=kid,
+    key=kid,
+    version="4.0",
+    encryption_scheme="cenc",
+)
+
+print("PlayReady Header:", header)
+```
+
+---
+
+## Architecture
+
+The project is structured into distinct layers:
+
+* **Device Layer**
+  Handles PRD parsing and credential loading (certificate chain and private key)
+
+* **CDM Layer**
+  Manages session lifecycle, challenge generation, and license parsing
+
+* **PSSH Layer**
+  Extracts WRMHEADER and initialization data
+
+* **License Workflow**
+
+  1. Parse PSSH and extract WRMHEADER
+  2. Generate license challenge (SOAP/XML)
+  3. Send request to license server
+  4. Parse license response
+  5. Extract content keys
+
+---
+
+## Disclaimer
+
+This tool is intended strictly for **educational, research, and interoperability purposes**.
+The author does not support or encourage the misuse of DRM systems or unauthorized access to protected content.
+
+---
+
+## Issues and Support
+
+For bug reports, feature requests, or general inquiries, please open an issue in the repository.
+
+Support and updates are provided as availability permits.
+
+---
+
+## Acknowledgements
+
+This project is based on **pyplayready** and **Bento4**, drawing inspiration from their implementations and design approaches.