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https://github.com/zboris12/zgapdfsigner
A javascript tool to sign a pdf in web browser, google apps script and nodejs.
https://github.com/zboris12/zgapdfsigner
google-apps-script javascript ltv pdf-encryption pdf-sign pdf-signature tsa
Last synced: 3 months ago
JSON representation
A javascript tool to sign a pdf in web browser, google apps script and nodejs.
- Host: GitHub
- URL: https://github.com/zboris12/zgapdfsigner
- Owner: zboris12
- License: mit
- Created: 2022-09-17T12:48:13.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2024-08-10T11:50:51.000Z (3 months ago)
- Last Synced: 2024-08-10T12:34:30.776Z (3 months ago)
- Topics: google-apps-script, javascript, ltv, pdf-encryption, pdf-sign, pdf-signature, tsa
- Language: JavaScript
- Homepage:
- Size: 204 KB
- Stars: 22
- Watchers: 2
- Forks: 5
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- jimsghstars - zboris12/zgapdfsigner - A javascript tool to sign a pdf in web browser, google apps script and nodejs. (JavaScript)
README
# ZgaPdfSigner
A javascript tool to sign a pdf or set protection of a pdf in web browser.
And it is more powerful when used in [Google Apps Script](https://developers.google.com/apps-script) or [nodejs](https://nodejs.org/).
PS: __ZGA__ is the abbreviation of my father's name.
And I use this name to hope the merits from this application will be dedicated to my parents.
## Main features
* Sign a pdf with an invisible pkcs#7 signature.
* Sign a pdf with a visible pkcs#7 signature by drawing an image or a text or both.
* A visible signature can be placed on multiple pages. (In the same position)
* Sign a pdf and set [DocMDP](https://github.com/zboris12/zgapdfsigner/wiki/API#note).
* Add a new signature to a pdf if it has been signed already. (An incremental update)
* Add a document timestamp from [TSA](https://github.com/zboris12/zgapdfsigner/wiki/API#note). ( :no_entry_sign:__Not__ available in web browser)
* Sign a pdf with a timestamp from [TSA](https://github.com/zboris12/zgapdfsigner/wiki/API#note). ( :no_entry_sign:__Not__ available in web browser)
* Enable signature's [LTV](https://github.com/zboris12/zgapdfsigner/wiki/API#note). ( :no_entry_sign:__Not__ available in web browser)
* Set password protection to a pdf. Supported algorithms:
* 40bit RC4 Encryption
* 128bit RC4 Encryption
* 128bit AES Encryption
* 256bit AES Encryption
* Set public-key certificate protection to a pdf.
Supported algorithms are as same as the password protection.
## About signing with [TSA](https://github.com/zboris12/zgapdfsigner/wiki/API#note) and [LTV](https://github.com/zboris12/zgapdfsigner/wiki/API#note)
Because of the [CORS](https://github.com/zboris12/zgapdfsigner/wiki/API#note) security restrictions in web browser,
signing with a timestamp from [TSA](https://github.com/zboris12/zgapdfsigner/wiki/API#note) or enabling [LTV](https://github.com/zboris12/zgapdfsigner/wiki/API#note) can only be used in [Google Apps Script](https://developers.google.com/apps-script) or [nodejs](https://nodejs.org/).
## The Dependencies
* [pdf-lib](https://pdf-lib.js.org/)
* [node-forge](https://github.com/digitalbazaar/forge)
* [follow-redirects](https://github.com/follow-redirects/follow-redirects)
## How to use this tool
:question: For more details please see the [wiki](https://github.com/zboris12/zgapdfsigner/wiki/API).
### Web Browser
Just import the dependencies and this tool.
```html
```
When drawing text by non-standard font, importing the fontkit library is necessary.
```html
```
### [Google Apps Script](https://developers.google.com/apps-script)
Load the dependencies and this tool.
```js
// Simulate setTimeout function for pdf-lib
function setTimeout(func, sleep){
Utilities.sleep(sleep);
func();
}
// Simulate window for node-forge
var window = globalThis;
// Load pdf-lib
eval(UrlFetchApp.fetch("https://unpkg.com/[email protected]/dist/pdf-lib.min.js").getContentText());
// It is necessary for drawing text by non-standard font.
eval(UrlFetchApp.fetch("https://unpkg.com/@pdf-lib/fontkit/dist/fontkit.umd.min.js").getContentText());
// Load node-forge
eval(UrlFetchApp.fetch("https://unpkg.com/[email protected]/dist/forge.min.js").getContentText());
// Load ZgaPdfSigner
eval(UrlFetchApp.fetch("https://cdn.jsdelivr.net/npm/zgapdfsigner/dist/zgapdfsigner.min.js").getContentText());
```
Or simply import the library of [ZgaPdfToolkit](https://script.google.com/macros/library/d/1T0UPf50gGp2fJ4dR1rZfEFgKYC5VpCwUVooCRNySiL7klvIUVsFBCZ9m/7)
1. Add the library of ZgaPdfToolkit to your project, and suppose the id of library you defined is "pdfkit".
Script id: `1T0UPf50gGp2fJ4dR1rZfEFgKYC5VpCwUVooCRNySiL7klvIUVsFBCZ9m`
2. Load the library.
```js
pdfkit.loadZga(globalThis);
```
### [nodejs](https://nodejs.org/)
1. Install
```
npm install zgapdfsigner
```
2. Import
```js
const Zga = require("zgapdfsigner");
```
## Let's sign
Sign with an invisible signature.
```js
/**
* @param {ArrayBuffer} pdf
* @param {ArrayBuffer} cert
* @param {string} pwd
* @return {Promise}
*/
async function sign1(pdf, cert, pwd){
/** @type {SignOption} */
var sopt = {
p12cert: cert,
pwd: pwd,
permission: 1,
};
var signer = new Zga.PdfSigner(sopt);
var u8arr = await signer.sign(pdf);
return new Blob([u8arr], {"type" : "application/pdf"});
}
```
Sign with a visible signature of an image.
```js
/**
* @param {ArrayBuffer} pdf
* @param {ArrayBuffer} cert
* @param {string} pwd
* @param {ArrayBuffer} imgdat
* @param {string} imgtyp
* @return {Promise}
*/
async function sign2(pdf, cert, pwd, imgdat, imgtyp){
/** @type {SignOption} */
var sopt = {
p12cert: cert,
pwd: pwd,
drawinf: {
area: {
x: 25, // left
y: 150, // top
w: 60, // width
h: 60, // height
},
imgInfo: {
imgData: imgdat,
imgType: imgtyp,
},
},
};
var signer = new Zga.PdfSigner(sopt);
var u8arr = await signer.sign(pdf);
return new Blob([u8arr], {"type" : "application/pdf"});
}
```
Sign with a visible signature by drawing a text.
```js
/**
* @param {ArrayBuffer} pdf
* @param {ArrayBuffer} cert
* @param {string} pwd
* @param {string} txt
* @param {ArrayBuffer} fontdat
* @return {Promise}
*/
async function sign3(pdf, cert, pwd, txt, fontdat){
/** @type {SignOption} */
var sopt = {
p12cert: cert,
pwd: pwd,
drawinf: {
area: {
x: 25, // left
y: 150, // top
w: 60, // width
h: 60, // height
},
textInfo: {
text: txt,
fontData: fontdat,
color: "#00f0f1",
size: 16,
},
},
};
var signer = new Zga.PdfSigner(sopt);
var u8arr = await signer.sign(pdf);
return new Blob([u8arr], {"type" : "application/pdf"});
}
```
Use it in [Google Apps Script](https://developers.google.com/apps-script)
```js
/**
* @param {string} pwd Passphrase of certificate
* @return {Promise}
*/
async function createPdf(pwd){
// Load pdf, certificate
var pdfBlob = DriveApp.getFilesByName("_test.pdf").next().getBlob();
var certBlob = DriveApp.getFilesByName("_test.pfx").next().getBlob();
// Sign the pdf
/** @type {SignOption} */
var sopt = {
p12cert: certBlob.getBytes(),
pwd,
signdate: "1",
ltv: 1,
};
var signer = new Zga.PdfSigner(sopt);
var u8arr = await signer.sign(pdfBlob.getBytes());
// Save the result pdf to some folder
var fld = DriveApp.getFolderById("a folder's id");
fld.createFile(Utilities.newBlob(u8arr, "application/pdf").setName("signed_test.pdf"));
}
```
Use queryPassword function in [ZgaPdfToolkit](https://script.google.com/macros/library/d/1T0UPf50gGp2fJ4dR1rZfEFgKYC5VpCwUVooCRNySiL7klvIUVsFBCZ9m/5).
```js
function myfunction(){
var spd = SpreadsheetApp.getActiveSpreadsheet();
pdfkit.queryPassword("createPdf", "Please input the passphrase", spd.getName());
}
```
Use it in [nodejs](https://nodejs.org/)
```js
const m_fs = require("fs");
const m_path = require("path");
async function main(){
/** @type {string} */
var pdfPath = m_path.join(__dirname, "_test.pdf");
/** @type {string} */
var pfxPath = m_path.join(__dirname, "_test.pfx");
/** @type {string} */
var ps = "";
/** @type {string} */
var imgPath = m_path.join(__dirname, "_test.png");
/** @type {string} */
var txt = "I am a test string!";
/** @type {string} */
var fontPath = m_path.join(__dirname, "_test.ttf");
if(process.argv.length > 3){
pfxPath = process.argv[2];
ps = process.argv[3];
}else if(process.argv[2]){
ps = process.argv[2];
}
if(!ps){
// throw new Error("The passphrase is not specified.");
pfxPath = "";
}
/** @type {Buffer} */
var pdf = m_fs.readFileSync(pdfPath);
/** @type {Buffer} */
var pfx = null;
if(pfxPath){
pfx = m_fs.readFileSync(pfxPath);
}
/** @type {Buffer} */
var img = null;
/** @type {string} */
var imgType = "";
if(imgPath){
img = m_fs.readFileSync(imgPath);
imgType = m_path.extname(imgPath).slice(1);
}
/** @type {Buffer} */
var font = null;
if(fontPath){
font = m_fs.readFileSync(fontPath);
}
/** @type {SignOption} */
var sopt = {
p12cert: pfx,
pwd: ps,
permission: pfx ? 2 : 0,
signdate: "1",
reason: "I have a test reason.",
location: "I am on the earth.",
contact: "[email protected]",
ltv: 1,
debug: true,
};
if(img || txt){
sopt.drawinf = {
area: {
x: 25, // left
y: 50, // top
w: txt ? undefined : 60,
h: txt ? undefined : 100,
},
pageidx: "2-3", // Placed the signature on the 3rd page and the 4th page. (Indexes of pages start from 0)
imgInfo: img ? {
imgData: img,
imgType: imgType,
} : undefined,
textInfo: txt ? {
text: txt,
fontData: font,
size: 16,
} : undefined,
};
}
/** @type {Zga.PdfSigner} */
var ser = new Zga.PdfSigner(sopt);
/** @type {Uint8Array} */
var u8dat = await ser.sign(pdf);
if(u8dat){
/** @type {string} */
var outPath = m_path.join(__dirname, "test_signed.pdf");
m_fs.writeFileSync(outPath, u8dat);
console.log("Output file: " + outPath);
}
console.log("Done");
}
```
## Let's protect the pdf
Set password protection to the pdf.
```js
/**
* @param {ArrayBuffer} pdf
* @param {string} upwd
* @param {string} opwd
* @return {Promise}
*/
async function protect1(pdf, upwd, opwd){
/** @type {EncryptOption} */
var eopt = {
mode: Zga.Crypto.Mode.RC4_40,
permissions: ["modify", "annot-forms", "fill-forms", "extract", "assemble"],
userpwd: upwd,
ownerpwd: opwd,
};
var cyptor = new Zga.PdfCryptor(eopt);
var pdfdoc = await cyptor.encryptPdf(pdf);
u8arr = await pdfdoc.save({"useObjectStreams": false});
return new Blob([u8arr], {"type" : "application/pdf"});
}
```
Set public-key certificate protection to the pdf.
```js
/**
* @param {ArrayBuffer} pdf
* @param {ArrayBuffer} cert
* @return {Promise}
*/
async function protect2(pdf, cert){
/** @type {EncryptOption} */
var eopt = {
mode: Zga.Crypto.Mode.AES_128,
pubkeys: [{
c: cert,
p: ["copy", "modify", "copy-extract", "annot-forms", "fill-forms", "extract", "assemble"],
}],
};
var cyptor = new Zga.PdfCryptor(eopt);
var pdfdoc = await cyptor.encryptPdf(pdf);
u8arr = await pdfdoc.save({"useObjectStreams": false});
return new Blob([u8arr], {"type" : "application/pdf"});
}
```
Sign and set protection.
```js
/**
* @param {ArrayBuffer} pdf
* @param {ArrayBuffer} cert
* @param {string} pwd
* @param {string} opwd
* @return {Promise}
*/
async function signAndProtect1(pdf, cert, pwd, opwd){
/** @type {SignOption} */
var sopt = {
p12cert: cert,
pwd: pwd,
};
/** @type {EncryptOption} */
var eopt = {
mode: Zga.Crypto.Mode.RC4_128,
permissions: ["modify", "annot-forms", "fill-forms", "extract", "assemble"],
ownerpwd: opwd,
};
var signer = new Zga.PdfSigner(sopt);
var u8arr = await signer.sign(pdf, eopt);
return new Blob([u8arr], {"type" : "application/pdf"});
}
```
Sign and set protection by the same certificate.
```js
/**
* @param {ArrayBuffer} pdf
* @param {ArrayBuffer} cert
* @param {string} pwd
* @return {Promise}
*/
async function signAndProtect2(pdf, cert, pwd){
/** @type {SignOption} */
var sopt = {
p12cert: cert,
pwd: pwd,
};
/** @type {EncryptOption} */
var eopt = {
mode: Zga.Crypto.Mode.AES_256,
permissions: ["modify", "annot-forms", "fill-forms", "extract", "assemble"],
pubkeys: [],
};
var signer = new Zga.PdfSigner(sopt);
var u8arr = await signer.sign(pdf, eopt);
return new Blob([u8arr], {"type" : "application/pdf"});
}
```
## Thanks
* The module of setting protection was almost migrated from [TCPDF](http://www.tcpdf.org).
## License
This tool is available under the
[MIT license](https://opensource.org/licenses/MIT).