Digital signature specification. -- 2

The project consists of consulting hours to solve a software solution to develop a digital signature component and an effort estimate (time and cost). Software solution: We have a document management software that is a web portal, which must digitally sign the documents using a browser, accessing the repository / certificate store of each client. The solution must be cross-platform. Current system: - Data Signing: xml, pdf, office, text - Support usb token, smartcard, keyfile - Reading user cerificate information in pc - Browser support: Google Chrome, Firefox, Edge, Safari, Opera. - Operation support: Windows, MacOS, Linux We need a component that meets the following functionalities: - Digitally sign a document. - Obtain the certificate to sign from the certificate store, or webservice, or local device (Smartcard). - Extract metadata from the certificate. - assemble pdf / A with associated metadata. The metadata consists of information about the document to be signed (for example: resolution, size, ect) + certificate tags (example: name - surname - title - ect). - The component must be cross-platform. - The component checks against a certificate revocation list (CRL). - We need to extract the tags from the certificate to associate with the metadata of the document to be signed in the case of PDF / A. By country the tags of the signing certificate may vary. It is necessary to configure the tags that I want to export to the metadata of the PDF/A created when signing. For example: I need to extract SERIALNUMBER information from the SUBJECT. Example of a certificate from Paraguay and another from Uruguay. We need the SerialNumber and CN. Uruguay: CN = PEPE ERNESTO RODRIGUEZ EICHIN SERIALNUMBER = DNI41322277 C = UY Paraguay: C = PY O = PERSONA FISICA OU = FIRMA F1 SERIALNUMBER = CI2555345 CN = ANGEL PEPE CILMEN SN = PEPE CILMEN G = ANGEL - The signature hash must be SHA-256 - What external library do you use for the signing process? for example itext or tell me which one. - We need TimeStamping and validation with a TimeStamp Server URL. This TimeStamp Server URL must be configurable. We have a list of servers available, it is necessary that if a url is down we can access the next in the list for TimeStamping. Example List: [login to view URL] [login to view URL] [login to view URL] - Show the document in the signing process, by selecting the certificate to sign, see the document that I am going to sign. - When signing, we need to add a mark to the document a text with a picture + the name of the signer. - The level of certification is applied to the document must be configurable. the option are: +FormFilling +FormFillingAndAnnotations +NoChanges +NotCertified. Expected deliverables: Specification document of solution for a software system that meets the stated requirements. - The document must specify: architecture of the solution, technology. - Advantages and disadvantages of alternative solutions. - The document must consider the security aspects of the system. - estimated effort hours to implement the solution provided. The effort estimate must be in time and cost.