@li0ard/tsemrtd/dist/dg7.js

simple library for eMRTD. supports browsers, node, bun and more!

import { TLV } from "@li0ard/tinytlv";
import { TAGS, ISO7816Tags } from "./consts/enums.js";
import { validateDataGroupTag } from "./utils.js";
/**
 * Class for working with DG7 (Signature)
*/
export class DG7 {
    /**
     * Get image of signature
     * @param data Data of EF.DG7 file
     */
    static load(data) {
        const tlv = TLV.parse(data);
        validateDataGroupTag(tlv, TAGS.DG7);
        const bict = tlv.childs[0];
        if (parseInt(bict.tag, 16) != ISO7816Tags.BIOMETRIC_INFO_COUNT)
            throw new Error(`Invalid object tag "0x${bict.tag}", expected 0x02`);
        const results = [];
        for (let i = 0; i < parseInt(bict.value, 16); i++) {
            const record = tlv.childs[i + 1];
            if (parseInt(record.tag, 16) != 0x5f43)
                throw new Error(`Invalid object tag "0x${tlv.tag}", expected 0x5f43`);
            results.push(record.byteValue);
        }
        return results;
    }
}