java - can't verify pdf signatures. itext, pdf, GOST3410 -

i'am trying verify signatures in pdf file. there 3 of them. have signed file code i've found in internet , adopted needs, might encorrect too. here signed file pdf file

verifier code here:

package com.mycompany.verifysignature;  import java.io.bytearrayoutputstream; import java.io.fileinputstream; import java.io.ioexception; import java.io.inputstream; import java.util.arraylist; import java.util.hashmap; import java.util.map; import org.bouncycastle.crypto.digests.gost3411digest; import ru.cryptopro.cades.cadessignature; import ru.cryptopro.cades.cadestype;  public class main {  public static void main(string args[]) {      try {         arraylist<map<string, string>> reslist = new arraylist<map<string, string>>();                      inputstream pdfis = new fileinputstream("/home/user1/desktop/321-17.pdf");          com.itextpdf.text.pdf.pdfreader reader = new com.itextpdf.text.pdf.pdfreader(pdfis);         bytearrayoutputstream baos = new bytearrayoutputstream();         com.itextpdf.text.pdf.pdfstamper stamper = com.itextpdf.text.pdf.pdfstamper.createsignature(reader, baos, '\0');         com.itextpdf.text.pdf.pdfsignatureappearance sap = stamper.getsignatureappearance();          com.itextpdf.text.pdf.acrofields fields = reader.getacrofields();         (string signame : fields.getsignaturenames()) {             hashmap<string, string> m = new hashmap();             m.put("name", signame.tostring());                             system.out.println("name:"+signame);             com.itextpdf.text.pdf.pdfdictionary sig = fields.getsignaturedictionary(signame);             if (sig != null && sig.getasstring(com.itextpdf.text.pdf.pdfname.reason) != null) {                 m.put("reason", sig.getasstring(com.itextpdf.text.pdf.pdfname.reason).tostring()                     .replaceall("\"", "\\\""));                                     system.out.println("reason:"+sig.getasstring(com.itextpdf.text.pdf.pdfname.reason).tostring()                     .replaceall("\"", "\\\""));             } else {                 m.put("reason", "undefined");                                     system.out.println("reason:undefined");             }               byte signature[] = null;              if (sig != null && sig.getbytes() != null) {                 signature = sig.getbytes();             }              byte hash[] = calchash(sap.getrangestream());              if (hash != null) {                  cadessignature  cadessignature = new cadessignature(signature, hash, cadestype.cades_x_long_type_1);                  try {                     cadessignature.verify(null);                     m.put("valid", "true");                                             system.out.println("valid:true");                 } catch(exception ex) {                     m.put("valid", "false");                                             system.out.println("valid:false");                 }             } else {                 m.put("valid", "\"undefined\"");                                     system.out.println("valid:undefined");             }   //              com.itextpdf.text.pdf.security.pdfpkcs7 pk = fields.verifysignature(signame); //               //              m.put("valid", new boolean(pk.verify()).tostring()); //                                system.out.println("valid:"+new boolean(pk.verify()).tostring());              reslist.add(m);         }             } catch (exception ex) {                 ex.printstacktrace();             }  }    public static byte[] calchash(inputstream is) {     if (is == null) return null;     try {         gost3411digest digest = new gost3411digest();          byte node[] = readbytesfromstream(is);         digest.update(node, 0, node.length);          byte[] resbuf = new byte[digest.getdigestsize()];         digest.dofinal(resbuf, 0);          return resbuf;     } catch (throwable e) {         e.printstacktrace();         //throw new exception(e);     }     return null; }     private static byte[] readbytesfromstream(inputstream is) throws exception {     arraylist<object[]> c = new arraylist();     int n, size = 0;     byte b[] = null;     if (is == null) throw new exception("input stream null");     try {         while ((n = is.read(b = new byte[1024])) > 0) {             c.add(new object[] { n, b });             size += n;         }     } catch (ioexception e) {         e.printstacktrace();     }     byte rv[] = new byte[size];     int pos = 0;     (object[] bb : c) {         (int = 0; < (integer) bb[0]; i++) {             rv[pos++] = ((byte[]) bb[1])[i];         }     }     return rv; }    } 

i have signed file's digest, made gost3411, test certificate, generated on cryptopro site.

when open file pdf reader, says there 3 signatures. have realy signed 3 times. code above takes out pdf signature names not equal names wrote. signature1, signature2 etc. there should written "cn" in 3 cases. please help. have made wrong?

the file provided op, 321-174.pdf, signed using 1 signature, not three, , prime error contents of signature dictionary content not cms signature instead textually, base64 encoded. thus, decoding in-between in code seems necessary.

that been said cannot find gost3410 in table 257 – subfilter value algorithm support - of specification iso 32000-1- use in context wont accepted.