Axonate eSign SDK

Python SDK for Indian eSign (Digital Signature) Integration

A comprehensive, production-ready Python SDK for integrating Indian Government's eSign service (Digital Signature) into your applications. Supports eSign API v2.1 and v3.3.

Features

✅ PDF Signing - Create placeholder signatures and embed PKCS7 signatures ✅ XML Request Builder - Generate eSign-compliant XML requests ✅ Easy Integration - Simple API, minimal configuration ✅ Type Hints - Full type annotations for better IDE support ✅ Production Ready - Used in production by multiple applications

Installation

pip install axonate-esign-sdk

For XML signing support:

pip install axonate-esign-sdk[xml-signing]

Quick Start

1. Create Placeholder PDF with Signature Field

from esign_sdk import ESignSDK

# Initialize SDK
sdk = ESignSDK()

# Create placeholder PDF with signature field
hash_value = sdk.create_placeholder(
    input_pdf="document.pdf",
    output_pdf="placeholder.pdf",
    signer_name="John Doe",
    reason="Document Approval",
    location="New Delhi",
    page_number=1,
    coordinates=(100, 700, 300, 750)  # (llx, lly, urx, ury)
)

print(f"Document Hash: {hash_value}")

2. Build eSign XML Request

# Build XML request for eSign gateway
xml_request = sdk.build_xml_request(
    asp_id="your_asp_id",
    transaction_id="unique_txn_id",
    document_hash=hash_value,
    document_info="Important Document",
    callback_url="https://your-server.com/callback",
    auth_mode="1"  # OTP-based authentication
)

print(xml_request)

3. Embed Signature After eSign Response

# After receiving eSign gateway response with PKCS7 signature
sdk.embed_signature(
    placeholder_pdf="placeholder.pdf",
    output_pdf="signed.pdf",
    pkcs7_signature="<base64_encoded_pkcs7>",
    field_name="signature_field_1"
)

print("PDF signed successfully!")

Complete Workflow Example

from esign_sdk import ESignSDK
import requests

# Initialize SDK
sdk = ESignSDK()

# Step 1: Create placeholder
hash_value = sdk.create_placeholder(
    input_pdf="contract.pdf",
    output_pdf="contract_placeholder.pdf",
    signer_name="Alice Johnson",
    reason="Contract Signing",
    location="Mumbai"
)

# Step 2: Build XML request
xml_request = sdk.build_xml_request(
    asp_id="mycompany_asp",
    transaction_id="TXN123456",
    document_hash=hash_value,
    document_info="Employment Contract",
    callback_url="https://myapp.com/esign/callback"
)

# Step 3: Post to eSign gateway
response = requests.post(
    "https://demo.esign.digital/esign/2.1/signdoc/",
    data={'esigndoc': xml_request}
)

# Step 4: User completes OTP on eSign portal
# Step 5: Receive callback with PKCS7 signature

# Step 6: Embed signature (in callback handler)
def handle_callback(request_data):
    pkcs7_sig = extract_signature_from_response(request_data)

    sdk.embed_signature(
        placeholder_pdf="contract_placeholder.pdf",
        output_pdf="contract_signed.pdf",
        pkcs7_signature=pkcs7_sig
    )

    return "Signature embedded successfully"

Configuration

ASP Configuration

from esign_sdk import ESignSDK, Config

config = Config(
    asp_id="your_asp_id",
    auth_mode="1",  # 1=OTP, 2=Biometric, 3=Both
    response_sig_type="PKCS7",
    gateway_url="https://demo.esign.digital/esign/2.1/signdoc/"
)

sdk = ESignSDK(config)

PDF Signature Appearance

# Customize signature appearance
hash_value = sdk.create_placeholder(
    input_pdf="document.pdf",
    output_pdf="placeholder.pdf",
    signer_name="Jane Smith",
    reason="Approval",
    location="Delhi",
    page_number=1,
    coordinates=(50, 50, 250, 150),  # Position and size
    lock_pdf=True,  # Lock PDF after signing
    visible=True    # Make signature visible
)

API Reference

ESignSDK Class

Main SDK class for eSign operations.

create_placeholder()

Creates PDF with empty signature field and returns document hash.

Parameters:

• input_pdf (str): Path to input PDF
• output_pdf (str): Path for output PDF
• signer_name (str): Name of signer
• reason (str): Reason for signing
• location (str): Location of signing
• page_number (int, optional): Page number (default: 1)
• coordinates (tuple, optional): (llx, lly, urx, ury)
• lock_pdf (bool, optional): Lock PDF after signing
• visible (bool, optional): Make signature visible

Returns: Document hash (str)

build_xml_request()

Builds eSign-compliant XML request.

Parameters:

• asp_id (str): ASP ID from eSign provider
• transaction_id (str): Unique transaction ID
• document_hash (str): Document hash from create_placeholder()
• document_info (str): Document description
• callback_url (str): Webhook URL for response
• auth_mode (str, optional): Authentication mode (default: "1")
• ekyc_id (str, optional): Aadhaar number (if required)

Returns: XML request string

embed_signature()

Embeds PKCS7 signature in placeholder PDF.

Parameters:

• placeholder_pdf (str): Path to placeholder PDF
• output_pdf (str): Path for signed PDF
• pkcs7_signature (str): Base64-encoded PKCS7 signature
• field_name (str, optional): Signature field name

Returns: None

Requirements

• Python 3.8+
• PyPDF2 >= 3.0.0
• reportlab >= 4.0.0
• lxml >= 4.9.0
• cryptography >= 41.0.0
• requests >= 2.31.0

License

MIT License

Copyright (c) 2025 Axonate Tech

Support

For support and queries:

• Email: info@axonatetech.com
• Website: https://axonatetech.com/

Contributing

Contributions are welcome! Please feel free to submit pull requests.

Changelog

v1.0.0 (2025-01-01)

• Initial release
• Support for eSign API v2.1 and v3.3
• Pure Python implementation
• PDF placeholder creation
• XML request building
• PKCS7 signature embedding