sign_test.go

package pkcs7

import (
	"bytes"
	"crypto/x509"
	"encoding/asn1"
	"encoding/pem"
	"fmt"
	"io/ioutil"
	"log"
	"math/big"
	"os"
	"os/exec"
	"testing"
)

func TestSign(t *testing.T) {
	content := []byte("Hello World")
	sigalgs := []x509.SignatureAlgorithm{
		x509.SHA1WithRSA,
		x509.SHA256WithRSA,
		x509.SHA512WithRSA,
		x509.ECDSAWithSHA1,
		x509.ECDSAWithSHA256,
		x509.ECDSAWithSHA384,
		x509.ECDSAWithSHA512,
	}
	for _, sigalgroot := range sigalgs {
		rootCert, err := createTestCertificateByIssuer("PKCS7 Test Root CA", nil, sigalgroot, true)
		if err != nil {
			t.Fatalf("test %s: cannot generate root cert: %s", sigalgroot, err)
		}
		truststore := x509.NewCertPool()
		truststore.AddCert(rootCert.Certificate)
		for _, sigalginter := range sigalgs {
			interCert, err := createTestCertificateByIssuer("PKCS7 Test Intermediate Cert", rootCert, sigalginter, true)
			if err != nil {
				t.Fatalf("test %s/%s: cannot generate intermediate cert: %s", sigalgroot, sigalginter, err)
			}
			var parents []*x509.Certificate
			parents = append(parents, interCert.Certificate)
			for _, sigalgsigner := range sigalgs {
				signerCert, err := createTestCertificateByIssuer("PKCS7 Test Signer Cert", interCert, sigalgsigner, false)
				if err != nil {
					t.Fatalf("test %s/%s/%s: cannot generate signer cert: %s", sigalgroot, sigalginter, sigalgsigner, err)
				}
				log.Printf("test %s/%s/%s detached %t\n", sigalgroot, sigalginter, sigalgsigner, true)
				toBeSigned, err := NewSignedData()
				if err != nil {
					t.Fatalf("test %s/%s/%s: cannot initialize signed data: %s", sigalgroot, sigalginter, sigalgsigner, err)
				}

				// Set the digest to match the end entity cert
				signerDigest, _ := DigestOIDForSignatureAlgorithm(signerCert.Certificate.SignatureAlgorithm)
				//toBeSigned.SetDigestAlgorithm(signerDigest)

				if err := toBeSigned.AddSignerChain(signerCert.Certificate, *signerCert.PrivateKey, nil, nil, parents, SignerInfoConfig{}); err != nil {
					t.Fatalf("test %s/%s/%s: cannot add signer: %s", sigalgroot, sigalginter, sigalgsigner, err)
				}
				signed, err := toBeSigned.Finish()
				if err != nil {
					t.Fatalf("test %s/%s/%s: cannot finish signing data: %s", sigalgroot, sigalginter, sigalgsigner, err)
				}
				pem.Encode(os.Stdout, &pem.Block{Type: "PKCS7", Bytes: signed})
				p7, err := Parse(signed)
				if err != nil {
					t.Fatalf("test %s/%s/%s: cannot parse signed data: %s", sigalgroot, sigalginter, sigalgsigner, err)
				}
				p7.Content = content
				if !bytes.Equal(content, p7.Content) {
					t.Errorf("test %s/%s/%s: content was not found in the parsed data:\n\tExpected: %s\n\tActual: %s", sigalgroot, sigalginter, sigalgsigner, content, p7.Content)
				}
				if err := p7.VerifyWithChain(truststore); err != nil {
					t.Errorf("test %s/%s/%s: cannot verify signed data: %s", sigalgroot, sigalginter, sigalgsigner, err)
				}
				if !signerDigest.Equal(p7.Signers[0].DigestAlgorithm.Algorithm) {
					t.Errorf("test %s/%s/%s: expected digest algorithm %q but got %q",
						sigalgroot, sigalginter, sigalgsigner, signerDigest, p7.Signers[0].DigestAlgorithm.Algorithm)
				}
			}
		}
	}
}

func ExampleSignedData() {
	// generate a signing cert or load a key pair
	cert, err := createTestCertificate(x509.SHA256WithRSA)
	if err != nil {
		fmt.Printf("Cannot create test certificates: %s", err)
	}

	// Initialize a SignedData struct with content to be signed
	signedData, err := NewSignedData()
	//signedData, err := NewSignedData([]byte("Example data to be signed"))
	if err != nil {
		fmt.Printf("Cannot initialize signed data: %s", err)
	}

	// Add the signing cert and private key
	if err := signedData.AddSigner(cert.Certificate, cert.PrivateKey, nil, nil, SignerInfoConfig{}); err != nil {
		fmt.Printf("Cannot add signer: %s", err)
	}

	// Call Detach() is you want to remove content from the signature
	// and generate an S/MIME detached signature
	//signedData.Detach()

	// Finish() to obtain the signature bytes
	detachedSignature, err := signedData.Finish()
	if err != nil {
		fmt.Printf("Cannot finish signing data: %s", err)
	}
	pem.Encode(os.Stdout, &pem.Block{Type: "PKCS7", Bytes: detachedSignature})
}

func TestUnmarshalSignedAttribute(t *testing.T) {
	cert, err := createTestCertificate(x509.SHA512WithRSA)
	if err != nil {
		t.Fatal(err)
	}
	// content := []byte("Hello World")
	// toBeSigned, err := NewSignedData(content)
	toBeSigned, err := NewSignedData()
	if err != nil {
		t.Fatalf("Cannot initialize signed data: %s", err)
	}
	oidTest := asn1.ObjectIdentifier{2, 3, 4, 5, 6, 7}
	testValue := "TestValue"
	if err := toBeSigned.AddSigner(cert.Certificate, *cert.PrivateKey, nil, nil, SignerInfoConfig{
		ExtraSignedAttributes: []Attribute{Attribute{Type: oidTest, Value: testValue}},
	}); err != nil {
		t.Fatalf("Cannot add signer: %s", err)
	}
	signed, err := toBeSigned.Finish()
	if err != nil {
		t.Fatalf("Cannot finish signing data: %s", err)
	}
	p7, err := Parse(signed)
	if err != nil {
		t.Fatalf("Cannot parse signed data: %v", err)
	}
	var actual string
	err = p7.UnmarshalSignedAttribute(oidTest, &actual)
	if err != nil {
		t.Fatalf("Cannot unmarshal test value: %s", err)
	}
	if testValue != actual {
		t.Errorf("Attribute does not match test value\n\tExpected: %s\n\tActual: %s", testValue, actual)
	}
}

func TestDegenerateCertificate(t *testing.T) {
	cert, err := createTestCertificate(x509.SHA1WithRSA)
	if err != nil {
		t.Fatal(err)
	}
	deg, err := DegenerateCertificate(cert.Certificate.Raw)
	if err != nil {
		t.Fatal(err)
	}
	testOpenSSLParse(t, deg)
	pem.Encode(os.Stdout, &pem.Block{Type: "PKCS7", Bytes: deg})
}

// writes the cert to a temporary file and tests that openssl can read it.
func testOpenSSLParse(t *testing.T, certBytes []byte) {
	tmpCertFile, err := ioutil.TempFile("", "testCertificate")
	if err != nil {
		t.Fatal(err)
	}
	defer os.Remove(tmpCertFile.Name()) // clean up

	if _, err := tmpCertFile.Write(certBytes); err != nil {
		t.Fatal(err)
	}

	opensslCMD := exec.Command("openssl", "pkcs7", "-inform", "der", "-in", tmpCertFile.Name())
	_, err = opensslCMD.Output()
	if err != nil {
		t.Fatal(err)
	}

	if err := tmpCertFile.Close(); err != nil {
		t.Fatal(err)
	}

}

func fromHex(s string) *big.Int {
	result, ok := new(big.Int).SetString(s, 16)
	if !ok {
		panic(s)
	}
	return result
}