java.lang.Object
com.gitlab.pdftk_java.com.lowagie.text.pdf.PdfPKCS7

public class PdfPKCS7 extends Object
This class does all the processing related to signing and verifying a PKCS#7 signature.

It's based in code found at org.bouncycastle.

  • Field Details

  • Constructor Details

  • Method Details

    • update

      public void update(byte[] buf, int off, int len) throws SignatureException
      Update the digest with the specified bytes. This method is used both for signing and verifying
      Parameters:
      buf - the data buffer
      off - the offset in the data buffer
      len - the data length
      Throws:
      SignatureException - on error
    • verify

      public boolean verify() throws SignatureException
      Verify the digest.
      Returns:
      true if the signature checks out, false otherwise
      Throws:
      SignatureException - on error
    • getCertificates

      public Certificate[] getCertificates()
      Get the X.509 certificates associated with this PKCS#7 object
      Returns:
      the X.509 certificates associated with this PKCS#7 object
    • getCRLs

      public Collection getCRLs()
      Get the X.509 certificate revocation lists associated with this PKCS#7 object
      Returns:
      the X.509 certificate revocation lists associated with this PKCS#7 object
    • getSigningCertificate

      public X509Certificate getSigningCertificate()
      Get the X.509 certificate actually used to sign the digest.
      Returns:
      the X.509 certificate actually used to sign the digest
    • getVersion

      public int getVersion()
      Get the version of the PKCS#7 object. Always 1
      Returns:
      the version of the PKCS#7 object. Always 1
    • getSigningInfoVersion

      public int getSigningInfoVersion()
      Get the version of the PKCS#7 "SignerInfo" object. Always 1
      Returns:
      the version of the PKCS#7 "SignerInfo" object. Always 1
    • getDigestAlgorithm

      public String getDigestAlgorithm()
      Get the algorithm used to calculate the message digest
      Returns:
      the algorithm used to calculate the message digest
    • getHashAlgorithm

      public String getHashAlgorithm()
      Returns the algorithm.
      Returns:
      the digest algorithm
    • loadCacertsKeyStore

      public static KeyStore loadCacertsKeyStore()
      Loads the default root certificates at <java.home>/lib/security/cacerts with the default provider.
      Returns:
      a KeyStore
    • loadCacertsKeyStore

      public static KeyStore loadCacertsKeyStore(String provider)
      Loads the default root certificates at <java.home>/lib/security/cacerts.
      Parameters:
      provider - the provider or null for the default provider
      Returns:
      a KeyStore
    • verifyCertificate

      public static String verifyCertificate(X509Certificate cert, Collection crls, Calendar calendar)
      Verifies a single certificate.
      Parameters:
      cert - the certificate to verify
      crls - the certificate revocation list or null
      calendar - the date or null for the current date
      Returns:
      a String with the error description or null if no error
    • verifyCertificates

      public static Object[] verifyCertificates(Certificate[] certs, KeyStore keystore, Collection crls, Calendar calendar)
      Verifies a certificate chain against a KeyStore.
      Parameters:
      certs - the certificate chain
      keystore - the KeyStore
      crls - the certificate revocation list or null
      calendar - the date or null for the current date
      Returns:
      null if the certificate chain could be validade or a Object[]{cert,error} where cert is the failed certificate and error is the error message
    • getIssuer

      private static org.bouncycastle.asn1.ASN1Primitive getIssuer(byte[] enc)
      Get the "issuer" from the TBSCertificate bytes that are passed in
      Parameters:
      enc - a TBSCertificate in a byte array
      Returns:
      a ASN1Primitive
    • getSubject

      private static org.bouncycastle.asn1.ASN1Primitive getSubject(byte[] enc)
      Get the "subject" from the TBSCertificate bytes that are passed in
      Parameters:
      enc - A TBSCertificate in a byte array
      Returns:
      a ASN1Primitive
    • getIssuerFields

      public static PdfPKCS7.X500Name getIssuerFields(X509Certificate cert)
      Get the issuer fields from an X509 Certificate
      Parameters:
      cert - an X509Certificate
      Returns:
      an X500Name
    • getSubjectFields

      public static PdfPKCS7.X500Name getSubjectFields(X509Certificate cert)
      Get the subject fields from an X509 Certificate
      Parameters:
      cert - an X509Certificate
      Returns:
      an X500Name
    • getEncodedPKCS1

      public byte[] getEncodedPKCS1()
      Gets the bytes for the PKCS#1 object.
      Returns:
      a byte array
    • setExternalDigest

      public void setExternalDigest(byte[] digest, byte[] RSAdata, String digestEncryptionAlgorithm)
      Sets the digest/signature to an external calculated value.
      Parameters:
      digest - the digest. This is the actual signature
      RSAdata - the extra data that goes into the data tag in PKCS#7
      digestEncryptionAlgorithm - the encryption algorithm. It may must be null if the digest is also null. If the digest is not null then it may be "RSA" or "DSA"
    • getEncodedPKCS7

      public byte[] getEncodedPKCS7()
      Gets the bytes for the PKCS7SignedData object.
      Returns:
      the bytes for the PKCS7SignedData object
    • getEncodedPKCS7

      public byte[] getEncodedPKCS7(byte[] secondDigest, Calendar signingTime)
      Gets the bytes for the PKCS7SignedData object. Optionally the authenticatedAttributes in the signerInfo can also be set. If either of the parameters is null, none will be used.
      Parameters:
      secondDigest - the digest in the authenticatedAttributes
      signingTime - the signing time in the authenticatedAttributes
      Returns:
      the bytes for the PKCS7SignedData object
    • getAuthenticatedAttributeBytes

      public byte[] getAuthenticatedAttributeBytes(byte[] secondDigest, Calendar signingTime)
      When using authenticatedAttributes the authentication process is different. The document digest is generated and put inside the attribute. The signing is done over the DER encoded authenticatedAttributes. This method provides that encoding and the parameters must be exactly the same as in getEncodedPKCS7(byte[],Calendar).

      A simple example:

       Calendar cal = Calendar.getInstance();
       PdfPKCS7 pk7 = new PdfPKCS7(key, chain, null, "SHA1", null, false);
       MessageDigest messageDigest = MessageDigest.getInstance("SHA1");
       byte buf[] = new byte[8192];
       int n;
       InputStream inp = sap.getRangeStream();
       while ((n = inp.read(buf)) > 0) {
          messageDigest.update(buf, 0, n);
       }
       byte hash[] = messageDigest.digest();
       byte sh[] = pk7.getAuthenticatedAttributeBytes(hash, cal);
       pk7.update(sh, 0, sh.length);
       byte sg[] = pk7.getEncodedPKCS7(hash, cal);
       
      Parameters:
      secondDigest - the content digest
      signingTime - the signing time
      Returns:
      the byte array representation of the authenticatedAttributes ready to be signed
    • getReason

      public String getReason()
      Getter for property reason.
      Returns:
      Value of property reason.
    • setReason

      public void setReason(String reason)
      Setter for property reason.
      Parameters:
      reason - New value of property reason.
    • getLocation

      public String getLocation()
      Getter for property location.
      Returns:
      Value of property location.
    • setLocation

      public void setLocation(String location)
      Setter for property location.
      Parameters:
      location - New value of property location.
    • getSignDate

      public Calendar getSignDate()
      Getter for property signDate.
      Returns:
      Value of property signDate.
    • setSignDate

      public void setSignDate(Calendar signDate)
      Setter for property signDate.
      Parameters:
      signDate - New value of property signDate.
    • getSignName

      public String getSignName()
      Getter for property sigName.
      Returns:
      Value of property sigName.
    • setSignName

      public void setSignName(String signName)
      Setter for property sigName.
      Parameters:
      signName - New value of property sigName.