sign_pdf: Digitally sign a PDF document

In pdfsigner: Digitally Sign and Verify PDF Documents

Digitally sign a PDF document

Description

Signs pdf_file using an RSA key + certificate stored in a PKCS#12 (.p12/.pfx) keystore, writing the signed document to output_file. The signature is a detached adbe.pkcs7.detached CMS over the whole document and is added as an incremental update, so any pre-existing signatures stay valid.

Usage

sign_pdf(
  pdf_file,
  output_file,
  keystore_path = Sys.getenv("KEYSTORE_PATH"),
  keystore_password = Sys.getenv("KEY_PASSWORD"),
  signtext = NULL,
  validate_link = NULL,
  reason = NULL,
  signer_name = NULL,
  page = 1,
  x = 36,
  y = 36,
  width = 320,
  height = 64,
  font_size = 8,
  font = NULL,
  image = NULL,
  border = TRUE,
  translate = FALSE,
  tsa_url = NULL,
  pades_level = c("bb", "bt", "blt", "blta")
)

Arguments

pdf_file	Path to the input PDF.
output_file	Path where the signed PDF is written.
keystore_path	Path to the .p12/.pfx keystore. Defaults to the KEYSTORE_PATH environment variable.
keystore_password	Password for the keystore. Defaults to the KEY_PASSWORD environment variable.
signtext	Optional text for a visible signature box. When NULL or empty the signature is invisible.
validate_link	Optional validation URL appended to the visible box.
reason, signer_name	Optional ⁠/Reason⁠ and ⁠/Name⁠ for the signature dictionary.
page	1-based page number for the visible box.
x, y, width, height	Visible box geometry, in PDF points (origin at the page's bottom-left).
font_size	Font size for the visible box, in points.
font	Optional path to a TrueType/OpenType font file (.ttf/.otf) to embed in the visible box. When NULL, the standard Helvetica is used. Only the WinAnsi (Latin-1) glyph range is embedded. Ignored for invisible signatures.
image	Optional path to a PNG or JPEG logo drawn in the visible box. Ignored for invisible signatures.
border	Draw a border around the visible box.
translate	If TRUE, the date label in the visible box is in Portuguese; otherwise English.
tsa_url	Optional RFC 3161 Time-Stamping Authority ⁠http://⁠ URL. Required for pades_level "bt" and above. Requires network access.
pades_level	PAdES conformance level: "bb" (baseline, default), "bt" (+ signature timestamp), "blt" (+ DSS with certificates and CRLs), or "blta" (+ a document timestamp over the whole file). Levels "bt" and above need tsa_url.

Value

Invisibly, the path to the signed PDF. Raises an error on failure.

Examples

## Not run: 
sign_pdf(
  pdf_file = "input.pdf",
  output_file = "signed.pdf",
  keystore_path = "keystore.p12",
  keystore_password = "password",
  signtext = "Document digitally signed by CastLab",
  validate_link = "https://castlab.org/validate",
  translate = TRUE
)

## End(Not run)

pdfsigner documentation built on Sept. 25, 2026, 5:09 p.m.