Add sign functionality

sign.go

@@ -0,0 +1,117 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"os"
+	"time"
+
+	"crypto"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"io/ioutil"
+
+	"bitbucket.org/digitorus/pdfsign/sign"
+	"bitbucket.org/digitorus/pdfsign/verify"
+)
+
+func usage() {
+	log.Fatal("Usage: sign input.pdf output.pdf certificate.crt private_key.key OR verify input.pdf")
+}
+
+func main() {
+	flag.Parse()
+
+	if len(flag.Args()) < 2 {
+		usage()
+	}
+
+	method := flag.Arg(0)
+	if method != "sign" && method != "verify" {
+		usage()
+	}
+
+	input := flag.Arg(1)
+	if len(input) == 0 {
+		usage()
+	}
+
+	if method == "verify" {
+		input_file, err := os.Open(input)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer input_file.Close()
+
+		resp, err := verify.Verify(input_file)
+		log.Println(resp)
+		if err != nil {
+			log.Println(err)
+		}
+	}
+
+	if method == "sign" {
+		if len(flag.Args()) < 5 {
+			usage()
+		}
+
+		output := flag.Arg(2)
+		if len(output) == 0 {
+			usage()
+		}
+
+		certificate_data, err := ioutil.ReadFile(flag.Arg(3))
+		if err != nil {
+			log.Fatal(err)
+
+		}
+		certificate_data_block, _ := pem.Decode(certificate_data)
+		if certificate_data_block == nil {
+			log.Fatal(errors.New("failed to parse PEM block containing the certificate"))
+		}
+
+		cert, err := x509.ParseCertificate(certificate_data_block.Bytes)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		key_data, err := ioutil.ReadFile(flag.Arg(4))
+		if err != nil {
+			log.Fatal(err)
+		}
+		key_data_block, _ := pem.Decode(key_data)
+		if key_data_block == nil {
+			log.Fatal(errors.New("failed to parse PEM block containing the private key"))
+		}
+
+		pkey, err := x509.ParsePKCS8PrivateKey(key_data_block.Bytes)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		key, ok := pkey.(crypto.Signer)
+		if !ok {
+			log.Fatal(errors.New("private key does not implement crypto.Signer"))
+		}
+
+		err = sign.SignFile(input, output, sign.SignData{
+			Signature: sign.SignDataSignature{
+				Info: sign.SignDataSignatureInfo{
+					Name:        "Jeroen Bobbeldijk",
+					Location:    "Rotterdam",
+					Reason:      "Test",
+					ContactInfo: "Geen",
+					Date:        time.Now().Local(),
+				},
+			},
+			Signer:      key,
+			Certificate: cert,
+		})
+		if err != nil {
+			log.Println(err)
+		} else {
+			log.Println("Signed PDF written to " + output)
+		}
+	}
+}