Related to Digital signiature

Question

Something related to Digital signature

if we have a doc in sales-force and needs to be digitally signed, which involves digital certificates.. and how we can use crypto class of apex in this. also how to verify that Digital signature in other peer for authenticity and integrity of the message.

If its come to digital signature, We use private and public key certificate for encrypt and decrypt the message. then how i can generate a public and private certificate in salesforce certificate key management.

Needed very solution very badly for this, Any help can be appreciated.

Answer 1

Apex class for capturing the sign

public class signAccountExtension {
    Id accountId;

    public string fileData { get; set; }

    public signAccountExtension(ApexPages.StandardController controller) {
        accountId = controller.getId();
    }
    public void saveImage() {
        insert new Attachment(
            ContentType='image/jpeg',
            Body=EncodingUtil.base64Decode(fileData),
            Name='Signature',
            ParentId = accountId
        );
    }
}

Visual Force Page:

<apex:page standardController="Account" extensions="signAccountExtension">
    <style>
        #signature {
        border: 1px solid black;
        }
    </style>
    <apex:form id="form">
        <apex:actionFunction action="{!saveImage}" name="saveImageToServer" reRender="">
            <apex:param assignTo="{!fileData}" name="data" value="" />
        </apex:actionFunction>
        <canvas id="signature" width="400" height="100" />
        <button id="save">
            Save
        </button>
    </apex:form>
    <script>
    !function() {
        var canvas, lastX, lastY;
        function start(event) {
            lastX = event.offsetX;
            lastY = event.offsetY;
            document.body.addEventListener("mousemove", draw);
            document.body.addEventListener("mouseup", end);
        }
        function draw(event) {
            var context = canvas.getContext("2d");

            if(event.target === canvas) {
                context.fillStyle = "black";
                context.strokeStyle = "black";
                context.beginPath();
                context.moveTo(lastX, lastY);
                context.lineTo(event.offsetX, event.offsetY, 3);
                context.stroke();
                lastX = event.offsetX;
                lastY = event.offsetY;
            }
            event.preventDefault();
        }
        function end(event) {
            document.body.removeEventListener("mousemove", draw);
            document.body.removeEventListener("mouseup", end);
            canvas.removeEventListener("mouseenter", mouseenter);
            event.preventDefault();
        }
        function save(event) {
            event.preventDefault();
            saveImageToServer(canvas.toDataURL("image/jpeg").split(/;base64,/)[1]);
        }
        function init() {
            var context;
            canvas = document.getElementById("signature");
            canvas.addEventListener("mousedown", start);


            context = canvas.getContext("2d");
            context.fillStyle = "white";
            context.fillRect(0, 0, canvas.width, canvas.height);

            document.getElementById("save").addEventListener("click", save);
        }
        window.addEventListener('DOMContentLoaded', init);
    }()
    </script>
</apex:page>