# pdf-signatures > Sign PDFs with electronic signatures in Nodejs Latest version **0.1.0** (published 2021-04-23) · AGPL license · 0 weekly downloads ## Install ```sh npm install pdf-signatures pnpm add pdf-signatures yarn add pdf-signatures bun add pdf-signatures ``` ## Health **Score 15/100 (F)** — status: abandoned. Positive: no vulnerabilities. Warnings: low downloads; no types; no esm support; pre 1.0. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 0.1.0 | | Published | 2021-04-23 | | First published | 2019-10-10 | | Weekly downloads | 0 | | License | AGPL | | TypeScript types | none | | Module format | CommonJS | | Node | >=8.10.0 | | Dependencies | 1 | | Unpacked size | 7.2 MB | | Known vulnerabilities | 0 | | Install scripts | no | | GitHub stars | 17 | | Author | Advanon Team | | Maintainers | dbejan, advanon-root, pandomic | | Keywords | sign, pdf, nodejs | ## Links - npm: https://www.npmjs.com/package/pdf-signatures - Repository: https://github.com/Advanon/pdf-signatures - Homepage: https://github.com/Advanon/pdf-signatures#readme - Issues: https://github.com/Advanon/pdf-signatures/issues - npm.io page: https://npm.io/package/pdf-signatures ## Dependencies (1) - [get-installed-path](https://npm.io/package/get-installed-path.md) ^4.0.8 ## Alternatives - [@cantoo/pdf-lib](https://npm.io/package/@cantoo/pdf-lib.md) — 297.9K weekly downloads - [datatables.net-buttons](https://npm.io/package/datatables.net-buttons.md) — 200.1K weekly downloads - [@ckeditor/ckeditor5-export-pdf](https://npm.io/package/@ckeditor/ckeditor5-export-pdf.md) — 167.0K weekly downloads - [scanbot-web-sdk](https://npm.io/package/scanbot-web-sdk.md) — 15.0K weekly downloads - [@syncfusion/ej2-angular-pdfviewer](https://npm.io/package/@syncfusion/ej2-angular-pdfviewer.md) — 8.8K weekly downloads ## Recent versions - 0.1.0 (latest) — 2021-04-23 - 0.0.2 — 2019-10-10 - 0.0.1 — 2019-10-10 ## README [![Build Status](https://travis-ci.org/Advanon/pdf-signatures.svg?branch=master)](https://travis-ci.org/Advanon/pdf-signatures) # PDF-Signatures Sign PDFs with PKCS7 signatures like a boss! ## Dependencies * UNIX-like OS * Java runtime >= 1.8 * Nodejs >= 8.10 ## License This library is distributed under the AGPL license. However, some dependencies may be licenced under different licence types. See https://www.gnu.org/licenses/agpl-3.0.en.html. ## Testing * npm run lint * npm run test * ./gradlew checkstyleMain * ./gradlew test ## Building (Before publishing an npm package) * gradle build * gradle copyJarToLibs * gradle clean (optional) ## Usage (Nodejs) ### Add signature placeholder ```js const { addSignaturePlaceholderToPdf, CertificationLevels } = require('pdf-signatures'); const outputPath = await addSignaturePlaceholderToPdf({ file: '/path/to/file.pdf', // Path to file, Required out: '/path/to/out.pdf', // Output file path, Required estimatedsize: 30000, // Estimated signature size, Optional, Default is 30000 certlevel: CertificationLevels.NotCertified, // Certification level, Optional, Default is CertificationLevels.NotCertified password: '123456', // Document password, Optional reason: 'I want to sign the document', // Signing reason, Optional, Default is undefined location: 'Moon', // Signing location, Optional, Default is undefined contact: 'John Doe', // Signing contact, Optional, Default is undefined date: '2019-09-26T20:54:41.426Z', // Signing date in ISO-8601 format, Optional, Default is undefined }); ``` ### Calculate document digest ```js const { preparePdf, HashAlgorithms } = require('pdf-signatures'); const base64EncodedDigest = await pdfDigest({ file: '/path/to/file.pdf', // Path to file, Required password: '123456', // Document password, Optional algorithm: HashAlgorithms.Sha512, // Hash algorithm, Optional, Default is HashAlgorithms.Sha512 }); ``` ### Sign PDF with external signature ```js const outputPath = await signPdf({ file: '/path/to/file.pdf', // Path to file, Required out: '/path/to/out.pdf', // Output file path, Required signature: 'base64', // Base64-encoded external signature password: '123456', // Document password, Optional }); ``` ### Embed LTV (Long Time Validation) information ```js const outputPath = await addLtvToPdf({ file: '/path/to/file.pdf', // Path to file, Required out: '/path/to/out.pdf', // Output file path, Required crl: [ // Certificate revocation list (bbase64-encoded), Required 'base64', 'base64', '...' ], ocsp: [ // Online certificate status protocol responses list, (base64-encoded), Required 'base64', 'base64', '...' ], }); ``` ## Usage (Jar) General invokation format: ```bash $ java -jar ``` Where `` is one of the following: ```bash Advanon PKCS7 document signer Usage: help Show this help version Display current version number --version Display current version number -v Display current version number placeholder Add a signature placeholder --file Path to the document --out Path where to save a new document [--estimatedsize ] Estimated signature size, default is 30000 bytes [--certlevel ] Desired certification level, default is 0 * 0 Not certified * 1 Certified, no changes allowed * 2 Certified, form filling * 3 Certified, form filling and annotations [--password ] Document password [--reason ] Signing reason [--location ] Signing location [--contact ] Signing contact [--date ] Date of signing in ISO 8601 format digest Calculate document digest excluding signatures --file Path to the document [--password ] Document password [--algorithm ] Encryption algorithm, default is SHA-512 sign Sign the document with external signature --file Path to the document --out Path where to save a new document --signature Base64-encoded signature [--password ] Document password ltv Add LTV information to the document --file Path to the document --out Path where to save a new document --crl ... Base64-encoded CRL (each single CRL should be prepended with -crl) --ocsp ... Base64-encoded OCSP (each single OCSP should be prepended with -ocsp) [--password ] Document password Example placeholder --file file.pdf --out placeholdered.pdf Add signature placeholder digest --file placeholdered.pdf --algorithm sha512 Calculate document digest sign --file placeholdered.pdf --out signed.pdf --signature abb4rjfh= Sign the document with external signature ltv --file signed.pdf --out signedltv.pdf --crl abb4rjfh= --crl fgsllldj5kg= --oscp abb4rjfh= --ocsp fgsllldj5kg= Insert LTV information into signed document ``` ## Notes ### Pdf objects, their encoding, position and length You may notice in the source code a some "magic" conversions, like `(N + 2) / 2`, or `(X - 2 / 2)`, this is because PDF objects are HEX-encoded, which means that every two bytes of the PDF object you read is actually one HEX-digit. For example, if you are writing byte `255` into PDF, you should bare in mind that this will (or at least that should) be actually written as `FF` which is now `TWO!` bytes. Now you may wonder what does `+2` or `-2` mean. The answer is pretty straightforward - content of PDF objects begins with `<` and ends with `>`, and sometimes you simply don't need these markers taken into account. ### Signature byte range and document hash Every signature has a byte range information, which contains... a byte range of the signature and of the document content surrounding it. For instance, consider the next byte range: `[ 0, 200, 400, 250 ]`: ``` |----------------------------| 0 | /Content < | |----------------------------| 200 | signature HEX | |----------------------------| 400 | > | |----------------------------| 650 (400 + 250) ``` When calculating hash of a signed document, signature bytes are exluded from the calculation. From the example, these are 200 bytes `200 -> 400`. --- _Source: https://npm.io/package/pdf-signatures · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._