Signing multiple hashes in Postman with one SAD
This guide uses the Client Credential flow authentication method. It explains which API calls must be run and the number of times execution is required to sign several hashes with one SAD (Signature Activation Data).
Note
In this method, you’re required to precalculate the number of hashes you want with "3 - Content Signing Service: Register Document" and "4 – Content Signing Service Create Hash" API calls before running "6 - DTM: extendTransaction" and "7 - DTM: CSC Signatures SignHash."
The signature in the "7 - DTM: CSC Signatures SignHash" response corresponds to the order of the hashes sent in its API call request.
You can run "8 - Content Signing Service: Embed Signature" API call repeatedly up to 200 times per cycle to embed signatures in the documents.
To sign a hash, run the individual API calls:
Note
The access token is valid for one hour but DigiCert® can extend it up to 24 hours.
In the Postman window, select Collections (left menu) > Content Signing Service > DTM CSC Credential List.
In the right window, switch to the Authorization tab.
Select Get New Access Token.
In the new popup window, select Proceed.
To apply access token, select Use Token.
To get a list of credentials (certificates) stored in your DigiCert ONE account:
Open the collection Content Signing Service-SealSign CADES - API-Token Flow - Visible Signature works.
Select 1 - DTM CSC Credential List > Send.
Your DigiCert ONE CredentialIDs (certificates) used appear in the body.
To get an overview of the functions used in DigiCert ONE:
Select 2 - DTM CSC Credential Info > Send.
You can see the functions used in DigiCert ONE.
To register a document:
Select 3 - Content Signing Service: Register Document.
Configure "tsa_url" variable value by entering the URL of the timestamp authority you use to sign documents.
Select Send.
To change signature appearance, use the following configurations:
Configuration | Description |
|---|---|
type (optional) | Depending on the type, you’re able to create a certified MDP (document modification detection and prevention) document. Default isn’t certified and shows a green tick. Certified shows a ribbon with a seal. Examples: NOT_CERTIFIED CERTIFIED_NO_CHANGES_ALLOWED CERTIFIED_FORM_FILLING CERTIFIED_FORM_FILLING_AND_ANNOTATIONS |
preservation_size (optional) | Enter preservation size of the space for embedding the signature in bytes. Value should be a multiple of 1024. (Format: int32). |
signature_rectangle (optional) | Set the position and size of the digital signature annotation. The default is an invisible signature. The position is defined by four values for the lower-left corner (x, y) and dimensions (w, h) of the rectangle. The units are document points (1 point = 1/72 inch, A4 = 595 x 842 points, letter = 612 x 792 points, 1cm = 28.3465 points) measured from the lower left corner of the page. If either the width or height is zero or negative, an invisible signature is created, that is, no visible appearance is created for the signature. (Format: int32). page: Enter page on which the signature is added. x: Enter x value of lower-left corner. y: Enter y value of lower-left corner. w: Enter width dimension of rectangle. h: Enter height dimension of rectangle. |
signature_text1 (optional) | Enter specific signature text instead of standard. (Example: signer's name). |
reason (optional) | Enter reason. |
contact (optional) | Enter contact. |
font_text1 (optional) | Enter name of the font. |
font_size_text1 (optional) | Enter font size of signature text 1. If attribute isn’t present default of 16pt is used. (Format: int32). |
signature_text2 (optional) | Enter specific signature text instead of standard. (Example: signer’s name, reason and/or signing time). |
font_text2 (optional) | Enter name of the font. |
font_size_text2 (optional) | Enter font size of signature text 2. If attribute isn’t present default of 8pt is used. (Format: int32). |
signature_fill_color (optional) | Enter background color in RGB. The default is 16761024 (red = 192, green = 192, blue = 255). Color value is calculated as follows: color red + green * 256 + blue * 256 * 256. To keep the rectangle transparent, set the value to -1. (Format: int32). |
signature_stroke_color (optional) | Enter the color of the signature’s border line as RGB value. The default is 8405056 (red = 64, green = 64, blue = 128). Color value is calculated as follows: color red + green * 256 + blue * 256 * 256. To keep it transparent, set the value to -1. (Format: int32). |
signature_line_width (optional) | Enter the thickness of the line surrounding the visual signature in points. (Format: int32). |
background_image (optional) | Insert the image to be embedded in the signature field. (Base64 encoded). (Example: "dGVzdA==”). |
To create a hash:
Attach document.
Select 4 - Content Signing Service: Create Hash > Send.
Repeat Step 3. Register document and Step 4. Create hash consecutively until you reach the number of hashes you want to calculate.
You receive DocumentIDs and their corresponding hashes.
Tip
Upload different documents after each execution of "Step 3. Register document" to calculate hashes and test with different documents.
To generate a SAD (Signature Activation Data) and start authorization via the Go>Sign Mobile application:
Select 5 - DTM: CSC Credential Authorize > Send.
Navigate to Go>Sign Mobile application > Authorization request > Authorize.
You receive a valid SAD required for signing the hash. This is required in "Embed signature step."
Note
In the DigiCert ONE demo environment, default values for reauthorization via Go>Sign Mobile application are set to "250,000 hashes or 30 days."
In the DigiCert ONE production environment, default values for reauthorization via Go>Sign Mobile application are to "1 million hashes or 95 days."
To sign the hash:
Select 7 - DTM: CSC Signatures SignHash > Send.
You receive one signature per hash sent.
To sign a new hash:
Select 8 - Content Signing Service: Embed Signature.
The SAD created in Authorize credential step is updated automatically.
Select Send.
Repeat this step for each signature individually in the order in which you received them in "4 - Content Signing Service: Create Hash."
To download the document and check the validity of the signature:
Select Save as example (bottom right) > Save response to file.