/**
  * Add a store of precalculated signers to the generator.
  *
  * @param signerStore store of signers
  */
 public void AddSigners(
     SignerInformationStore signerStore)
 {
     foreach (SignerInformation o in signerStore.GetSigners())
     {
         _signers.Add(o);
         AddSignerCallback(o);
     }
 }
        /**
         * Replace the signerinformation store associated with this
         * CmsSignedData object with the new one passed in. You would
         * probably only want to do this if you wanted to change the unsigned
         * attributes associated with a signer, or perhaps delete one.
         *
         * @param signedData the signed data object to be used as a base.
         * @param signerInformationStore the new signer information store to use.
         * @return a new signed data object.
         */
        public static CmsSignedData ReplaceSigners(
            CmsSignedData signedData,
            SignerInformationStore signerInformationStore)
        {
            //
            // copy
            //
            CmsSignedData cms = new CmsSignedData(signedData);

            //
            // replace the store
            //
            cms.signerInfoStore = signerInformationStore;

            //
            // replace the signers in the SignedData object
            //
            Asn1EncodableVector digestAlgs = new Asn1EncodableVector();
            Asn1EncodableVector vec        = new Asn1EncodableVector();

            foreach (SignerInformation signer in signerInformationStore.GetSigners())
            {
                digestAlgs.Add(Helper.FixAlgID(signer.DigestAlgorithmID));
                vec.Add(signer.ToSignerInfo());
            }

            Asn1Set      digests = new DerSet(digestAlgs);
            Asn1Set      signers = new DerSet(vec);
            Asn1Sequence sD      = (Asn1Sequence)signedData.signedData.ToAsn1Object();

            //
            // signers are the last item in the sequence.
            //
            vec = new Asn1EncodableVector(
                sD[0],                 // version
                digests);

            for (int i = 2; i != sD.Count - 1; i++)
            {
                vec.Add(sD[i]);
            }

            vec.Add(signers);

            cms.signedData = SignedData.GetInstance(new BerSequence(vec));

            //
            // replace the contentInfo with the new one
            //
            cms.contentInfo = new ContentInfo(cms.contentInfo.ContentType, cms.signedData);

            return(cms);
        }
        /**
         * Return a signer information object with passed in SignerInformationStore representing counter
         * signatures attached as an unsigned attribute.
         *
         * @param signerInformation the signerInfo to be used as the basis.
         * @param counterSigners signer info objects carrying counter signature.
         * @return a copy of the original SignerInformationObject with the changed attributes.
         */
        public static SignerInformation AddCounterSigners(
            SignerInformation signerInformation,
            SignerInformationStore counterSigners)
        {
            // TODO Perform checks from RFC 3852 11.4

            SignerInfo sInfo = signerInformation.info;

            Asn1.Cms.AttributeTable unsignedAttr = signerInformation.UnsignedAttributes;
            Asn1EncodableVector     v;

            if (unsignedAttr != null)
            {
                v = unsignedAttr.ToAsn1EncodableVector();
            }
            else
            {
                v = new Asn1EncodableVector();
            }

            Asn1EncodableVector sigs = new Asn1EncodableVector();

            foreach (SignerInformation sigInf in counterSigners.GetSigners())
            {
                sigs.Add(sigInf.ToSignerInfo());
            }

            v.Add(new Asn1.Cms.Attribute(CmsAttributes.CounterSignature, new DerSet(sigs)));

            return(new SignerInformation(
                       new SignerInfo(
                           sInfo.SignerID,
                           sInfo.DigestAlgorithm,
                           sInfo.AuthenticatedAttributes,
                           sInfo.DigestEncryptionAlgorithm,
                           sInfo.EncryptedDigest,
                           new DerSet(v)),
                       signerInformation.contentType,
                       signerInformation.content,
                       null));
        }