Signing a file available by a permanent link

Start the Python shell and configure its session.

The following variables should be available now:

>>> base_url  # the base URL of the API
'https://eu2-cloud.acronis.com/api/notary/v2'
>>> auth  # the 'Authorization' header value with the access token
{'Authorization': 'Bearer 8770b34b74f9e4d9424eff50c38182bb4ae7f5596582ae61900b1b6a23e3ec58'}

Define a variable named file_path, and then assign the path to your file to this variable:
```
>>> file_path = '<path to file>'
```
Important

If the path contains backslashes, remember to escape them with an additional backslash.
Define a variable named file_link, and then assign the permanent link to the file to this variable:
```
>>> file_link = 'https://www.example.com/loremipsum'
```
Open the file for reading in binary mode:
```
>>> file = open(file_path, 'rb')
```
Calculate the hash value of the file contents by using the SHA-256 algorithm:
```
>>> sha256 = hashlib.sha256()
>>> chunk = file.read(128 * sha256.block_size)
>>> while chunk:
...     sha256.update(chunk)
...     chunk = file.read(128 * sha256.block_size)
>>> file_hash
'2c7c3d5f244f1a40069a32224215e0cf9b42485c99d80f357d76f006359c7a18'
```
A correctly calculated hash value of the file contents may help signees to prove, via the API, that the file they see in an email message with the signature request is indeed being signed by using the notary service.
Close the file:
```
>>> file.close()
```

Fetch the size of the file:

>>> file_size = os.path.getsize(file_path)
>>> file_size
446

Fetch the file name from the file path:

>>> file_name = os.path.basename(file_path)

Define a variable named file_info, and then assign the information about the file to this variable:

>>> file_info = {
...     'link': file_link,
...     'name': file_name,
...     'size': file_size,
...     'hash': file_hash
... }

Define a variable named file_owner, and then assign the information about the signing initiator who is considered to be the file owner to this variable:
```
>>> file_owner = {
...     'email': 'john.doe@example.com',
...     'full_name': 'John Doe'
... }
```
Define a variable named file_data, and then assign an object with the following JSON parameters to this variable:
```
>>> file_data = {
...     'file': file_info,
...     'owner': file_owner,
...     'exclude_me': False,
...     'lang': 'en'
... }
```
The exclude_me key defines whether to exclude the signing initiator from the list of signees.

The lang key defines the language that will be used in email messages sent by the notary service during the signing and in the generated signature certificate file.

Available values:
- da - Danish
- de - German
- en - English
- es - Spanish
- fr - French
- hu - Hungarian
- it - Italian
- ja - Japanese
- ru - Russian
- tr - Turkish
[Optional] To sign the file with embedded signatures of the signees, add the embedded key and set its value to true:
```
>>> file_data['embedded'] = True
```
Note

In order to sign the file with embedded signature, it must comply with the following requirements:
1. The file must be either in PDF or in one of the following file types that will be converted to PDF by the notary service:
  - .doc/.docx
  - .xls/.xlsx
  - .ppt/.pptx
  - .txt
2. Maximum file size limit is 32 MB.
3. The file must not be protected by password.
4. If the uploaded file is in PDF, “Changing the Document” and “Commenting” permissions must be set to “Allowed”.
5. The link must be publicly accessible in order to be downloaded by the notary service.

Convert the file_data object to a JSON text:

>>> file_data = json.dumps(file_data, indent=4)

Send a POST request with the JSON text to the /documents endpoint:

>>> response = requests.post(
...     f'{base_url}/documents',
...     headers={'Content-Type': 'application/json', **auth},
...     data=file_data,
... )

Check the status code of the response:
```
>>> response.status_code
200
```
Status code 200 means that the notary service has received the object and created an e-sign document for it.

A different status code means that an error has occurred. For the details, refer to “Status and error codes”.

Also, the response body contains an object containing the ID of the document formatted as a JSON text. When converted to an object, it will look as follows:
```
>>> pprint.pprint(response.json())
{
    "document_id": "8592b052a9979f8d651618092bb3ac8472beebc66d52ab980deb4d320e26b0cb"
}
```

Convert the JSON text that the response body contains to an object, and then fetch the ID of the e-sign document:

>>> doc_id = response.json()['document_id']
>>> doc_id
'8592b052a9979f8d651618092bb3ac8472beebc66d52ab980deb4d320e26b0cb'

Define a variable named signees, and then assign an object containing the list of signees’ email addresses in the emails key to this variable:
```
>>> signees = {
...     'emails': ['john.smith@example.com', 'john.doe@example.com']
... }
```
If you want to sign this file, include your email address in this list.

Warning

It will not be possible to change the list of signees after sending the initial list to the notary service.
[Optional] If you chose to embed the signee signatures in the file:
1. Follow the Generating PDF annotations procedure to fetch the list of PDF annotations.
2. Add the annotations key and assign it with the list of PDF annotations:
  >>> signees['annotations'] = [ ... "{\"bbox\":[129.81423950195312,216.01904296875,200,50], ...}", ... "{\"bbox\":[186.60797119140625,409.7261962890625,200,50], ...}" ... ]

Convert the signees object to a JSON text:

>>> signees = json.dumps(signees, indent=4)
>>> print(signees)
{
    "emails": [
        "john.smith@example.com",
        "john.doe@example.com"
    ]
}

Send a POST request with the JSON text to the /documents/{doc_id}/signees endpoint:

>>> response = requests.post(
...     f'{base_url}/documents/{doc_id}/signees',
...     headers={'Content-Type': 'application/json', **auth},
...     data=signees,
... )

Check the status code of the response:
```
>>> response.status_code
200
```
Status code 200 means that the notary service has initiated the signing and sent email messages with the signature request to the signees. To check the signing status, refer to Checking the status of signing process.

A different status code means that an error has occurred. For the details, refer to “Status and error codes”.

Full code example

#!/usr/bin/env python3

import requests  # Will be used for sending requests to the API.
import hashlib   # Will be used for calculating hash values.
import os.path   # Will be used for path-related operations.
import pprint    # Will be used for formatting the output of JSON objects received in API responses.
import json      # Will be used for converting dictionaries into JSON text

# Define variables named "LOGIN" and "PASSWORD" and then assign them with your account credentials
LOGIN = '<your login>'        # Change login here
PASSWORD = '<your password>'  # Change password here

# Define a variable named "cloud_url" and then assign it with the URL of the cloud platform
cloud_url = 'https://cloud.acronis.com'

# Fetch the URL of the data center where your account is located by sending a GET request to the "/api/1/accounts" endpoint
response = requests.get(
    f'{cloud_url}/api/1/accounts',
    params={'login': LOGIN}
)
response.raise_for_status()

# Convert the JSON text that the response body contains to a dictionary and store the data center URL
# in a variable that will be used in further requests
server_url = response.json()['server_url']

# Define a variable named "account_creds", and then assign the username and password to this variable
account_creds = {
    'username': LOGIN,
    'password': PASSWORD
}

# Generate a token by sending a POST request to the "/api/2/idp/token" with your account credentials to the cloud platform
response = requests.post(
    f'{server_url}/api/2/idp/token',
    headers={'Content-Type': 'application/x-www-form-urlencoded'},
    data={'grant_type': 'password', **account_creds}
)
response.raise_for_status()

# Convert the JSON text that the response body contains to a dictionary and then assign it to a variable named "token_info"
token_info = response.json()

# Define a variable named "auth" and then assign it with a dictionary with "Authorization" key containing
# token string formatted as "Bearer <access_token>"
auth = {
    'Authorization': 'Bearer ' + token_info['access_token']
}

# Define a variable named "base_url", and then assign the API base URL using the data center URL
# to this variable
base_url = f'{server_url}/api/notary/v2'

# Define a variable named "file_id" and then assign it with the ID of the file
file_path = '<path to file>'  # Change path to file here

# Define a variable named "file_link" and then assign it with the link to the file
file_link = 'https://www.example.com/loremipsum'

# Open the file for reading in binary mode
file = open(file_path, 'rb')

# Calculate the SHA-256 hash of the file
sha256 = hashlib.sha256()
chunk = file.read(128 * sha256.block_size)
while chunk:
    sha256.update(chunk)
    chunk = file.read(128 * sha256.block_size)
file_hash = sha256.hexdigest()

# Close the file
file.close()

# Fetch the size of the file and then assign its value to the "file_size" variable
file_size = os.path.getsize(file_path)

# Fetch the name of the file and then assign its value to the "file_name" variable
file_name = os.path.basename(file_path)

# Define a variable named "file_info", and then assign the information about the file to this variable
file_info = {
    'link': file_link,
    'name': file_name,
    'size': file_size,
    'hash': file_hash
}

# Define a variable named "file_owner", and then assign the information about the signing initiator who is
# considered to be the file owner to this variable
file_owner = {
    'email': 'john.doe@example.com',
    'full_name': 'John Doe'
}

# Define a variable named file_data, and then assign a dictionary with the following JSON parameters to this variable
file_data = {
    'file': file_info,
    'owner': file_owner,
    'exclude_me': False,
    'lang': 'en'
}

# Convert the "file_data" dictionary to a JSON text
file_data = json.dumps(file_data, indent=4)

# Send the file for signing by sending a POST request to the "/documents" endpoint
response = requests.post(
    f'{base_url}/documents',
    headers={'Content-Type': 'application/json', **auth},
    data=file_data,
)
response.raise_for_status()

# Convert the JSON text that the response body contains to a dictionary and fetch the ID of the created document
doc_id = response.json()['document_id']

# Define a variable named "signees"
# and then assign it with a dictionary with "emails" key containing an array of the emails of the signees
signees = {
    'emails': ['john.smith@example.com', 'john.doe@example.com']
}

# Convert the "signees" dictionary to a JSON text
signees = json.dumps(signees, indent=4)

# Send the list of signees to the notary service by sending a POST request to the "/documents/{doc_id}/signees" endpoint
response = requests.post(
    f'{base_url}/documents/{doc_id}/signees',
    headers={'Content-Type': 'application/json', **auth},
    data=signees,
)
response.raise_for_status()