97 lines
3.2 KiB
Markdown
97 lines
3.2 KiB
Markdown
# Signing PDF files with Go
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[](https://github.com/digitorus/pdfsign/actions?query=workflow%3Abuild-and-test)
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[](https://github.com/digitorus/pdfsign/actions?query=workflow%3Agolangci-lint)
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[](https://goreportcard.com/report/github.com/digitorus/pdfsign)
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[](https://codecov.io/gh/)
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[](https://pkg.go.dev/github.com/digitorus/pdfsign)
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This PDF signing library is written in [Go](https://go.dev). The library is in development, might not work for all PDF files and the API might change, bug reports, contributions and suggestions are welcome.
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**See also our [PDFSigner](https://github.com/digitorus/pdfsigner/), a more advanced digital signature server that is using this project.**
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## From the command line
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```
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Usage of ./pdfsign:
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-contact string
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Contact information for signatory
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-location string
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Location of the signatory
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-name string
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Name of the signatory
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-reason string
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Reason for signig
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-tsa string
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URL for Time-Stamp Authority (default "https://freetsa.org/tsr")
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Example usage:
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./pdfsign -name "Jon Doe" sign input.pdf output.pdf certificate.crt private_key.key [chain.crt]
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./pdfsignverify input.pdf
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```
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## As library
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```go
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import "github.com/digitorus/pdf"
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input_file, err := os.Open(input)
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if err != nil {
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return err
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}
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defer input_file.Close()
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output_file, err := os.Create(output)
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if err != nil {
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return err
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}
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defer output_file.Close()
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finfo, err := input_file.Stat()
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if err != nil {
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return err
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}
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size := finfo.Size()
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rdr, err := pdf.NewReader(input_file, size)
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if err != nil {
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return err
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}
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err = sign.Sign(input_file, output_file, rdr, size, sign.SignData{
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Signature: sign.SignDataSignature{
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Info: sign.SignDataSignatureInfo{
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Name: "John Doe",
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Location: "Somewhere on the globe",
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Reason: "My season for siging this document",
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ContactInfo: "How you like",
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Date: time.Now().Local(),
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},
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CertType: sign.CertificationSignature,
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DocMDPPerm: sign.AllowFillingExistingFormFieldsAndSignaturesPerms,
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},
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Signer: privateKey, // crypto.Signer
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DigestAlgorithm: crypto.SHA256, // hash algorithm for the digest creation
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Certificate: certificate, // x509.Certificate
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CertificateChains: certificate_chains, // x509.Certificate.Verify()
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TSA: sign.TSA{
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URL: "https://freetsa.org/tsr",
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Username: "",
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Password: "",
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},
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// The follow options are likely to change in a future release
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//
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// cache revocation data when bulk signing
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RevocationData: revocation.InfoArchival{},
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// custom revocation lookup
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RevocationFunction: sign.DefaultEmbedRevocationStatusFunction,
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})
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if err != nil {
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log.Println(err)
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} else {
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log.Println("Signed PDF written to " + output)
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}
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```
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