64 lines
1.8 KiB
Markdown
64 lines
1.8 KiB
Markdown
# pkcs7
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[](https://pkg.go.dev/github.com/smallstep/pkcs7)
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[](https://github.com/smallstep/pkcs7/actions/workflows/ci.yml?query=branch%3Amain+event%3Apush)
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pkcs7 implements parsing and creating signed and enveloped messages.
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```go
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package main
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import (
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"bytes"
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"crypto/rsa"
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"crypto/x509"
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"encoding/pem"
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"fmt"
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"os"
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"github.com/smallstep/pkcs7"
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)
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func SignAndDetach(content []byte, cert *x509.Certificate, privkey *rsa.PrivateKey) (signed []byte, err error) {
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toBeSigned, err := NewSignedData(content)
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if err != nil {
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return fmt.Errorf("Cannot initialize signed data: %w", err)
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}
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if err = toBeSigned.AddSigner(cert, privkey, SignerInfoConfig{}); err != nil {
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return fmt.Errorf("Cannot add signer: %w", err)
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}
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// Detach signature, omit if you want an embedded signature
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toBeSigned.Detach()
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signed, err = toBeSigned.Finish()
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if err != nil {
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return fmt.Errorf("Cannot finish signing data: %w", err)
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}
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// Verify the signature
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pem.Encode(os.Stdout, &pem.Block{Type: "PKCS7", Bytes: signed})
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p7, err := pkcs7.Parse(signed)
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if err != nil {
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return fmt.Errorf("Cannot parse our signed data: %w", err)
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}
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// since the signature was detached, reattach the content here
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p7.Content = content
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if bytes.Compare(content, p7.Content) != 0 {
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return fmt.Errorf("Our content was not in the parsed data:\n\tExpected: %s\n\tActual: %s", content, p7.Content)
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}
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if err = p7.Verify(); err != nil {
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return fmt.Errorf("Cannot verify our signed data: %w", err)
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}
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return signed, nil
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}
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```
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## Credits
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This is a fork of [mozilla-services/pkcs7](https://github.com/mozilla-services/pkcs7) which, itself, was a fork of [fullsailor/pkcs7](https://github.com/fullsailor/pkcs7).
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