#pdfcrypt

#Overview

• Encryption methods (AES, RC4)
• Permission flags for document restrictions
• Decryption of encrypted documents
• Encryption of output documents

#Encryption Methods

///|
pub(all) enum EncryptionMethod {
  AES256 // AES 256-bit (recommended, PDF 2.0)
  AES128 // AES 128-bit (PDF 1.6+)
  ARC4(Int) // RC4 with key length (legacy)
}

#Permissions

///|
pub(all) enum Permission {
  Print // Allow printing
  Edit // Allow editing
  Copy // Allow copying text
  Annot // Allow annotations
  Forms // Allow form filling
  Extract // Allow accessibility extraction
  Assemble // Allow page assembly
  Hqprint // Allow high-quality printing
}

#Getting Permissions

let perms = @pdfread.PdfRead::new().permissions(pdf)
for perm in perms {
  match perm {
    @pdfcrypt.Permission::Print => println("Print allowed")
    @pdfcrypt.Permission::Copy => println("Copy allowed")
    _ => ()
  }
}

#Permission Conversion

// Convert permission flags to/from integer

///|
let banlist = @pdfcrypt.PdfCrypt::new().banlist_of_p(flags)

#Encrypting Documents

let encryption = @pdfwrite.Encryption::new(
  @pdfcrypt.EncryptionMethod::AES256,
  user_password="user123",
  owner_password="owner456",
  permissions=[
    @pdfcrypt.Permission::Print,
    @pdfcrypt.Permission::Copy,
  ],
)

@pdfwritefs.PdfWriteFs::new().pdf_to_file_options(
  encryption=Some(encryption),
  build_new_id=true,
  pdf~,
  filename="encrypted.pdf",
)

#Decrypting Documents

// With user password

///|
let pdf = @pdfreadfs.PdfReadFs::new().pdf_of_file(
  user_password=Some("user123"),
  owner_password=None,
  filename="encrypted.pdf",
)

// With owner password (full access)

///|
let pdf = @pdfreadfs.PdfReadFs::new().pdf_of_file(
  user_password=None,
  owner_password=Some("owner456"),
  filename="encrypted.pdf",
)

#Checking Encryption

let method = @pdfread.PdfRead::new().what_encryption(pdf)
match method {
  None => println("Not encrypted")
  Some(@pdfcrypt.EncryptionMethod::AES256) => println("AES 256-bit")
  Some(@pdfcrypt.EncryptionMethod::AES128) => println("AES 128-bit")
  Some(@pdfcrypt.EncryptionMethod::ARC4(40)) => println("RC4 40-bit")
  Some(@pdfcrypt.EncryptionMethod::ARC4(128)) => println("RC4 128-bit")
  _ => println("Other encryption")
}

#Security Notes

• AES256 is recommended for new documents
• ARC4 is considered legacy and less secure
• User password allows restricted access based on permissions
• Owner password allows full access regardless of permissions