Sorry, my mistake. RSAdata is ok and present in the PKCS7 signature.

Original question still stands: Why Adobe does not verify ?

Anyone ?





pchronos wrote:
> 
> UPDATE:
> 
> I noticed that RSAdata is not being set ( and therefore NOT output as part
> of the PKCS7 signature ) if the PDFPKCS7 object is created in this way. In
> addition the SUBFILTER is set as ADBE_PKCS7_SHA1 when using WINCER_SIGNED.
> Without the Hash included the PKCS7 signature is essentially a detached
> one ?
> 
> I suspect this is the problem. Can anyone confirm this ?
> Also, why is RSAdata not being set in GetEncodedPKCS7() if
> SetExternalDigest() provides the hash ?
> 
> Thanks
> 
> 
> 
> pchronos wrote:
>> 
>> Hi,
>> 
>> I can only generate PKCS1 signed hashes externally and I am able to sign
>> and verify PKCS1 signed PDFs using Adobe Acrobat 8.  However changing the
>> code to use PKCS7 signatures instread by using the PDFPKCS7 class to
>> create the PKCS7 signature does not work. Ie. Adobe does not verify
>> anymore.
>> 
>> I only changed 2 lines in the working code:
>> 
>>             sap.SetCrypto(null, chain, null,
>> PdfSignatureAppearance.SELF_SIGNED);
>> to 
>>             sap.SetCrypto(null, chain, null,
>> PdfSignatureAppearance.WINCER_SIGNED);
>> 
>> and 
>>             byte[] tSsig = tSigner.GetEncodedPKCS1();
>> to
>>             byte[] tSsig = tSigner.GetEncodedPKCS7();
>> 
>> What am I doing wrong or missing ?
>> 
>> Thanks in advance
>> 
>> Here is the c# working PKCS1 code:
>> 
>>             PdfReader reader = new PdfReader(PDFfile);
>>             AcroFields af = reader.AcroFields;
>>             ArrayList signames = af.GetBlankSignatureNames();
>>             PdfStamper stp = PdfStamper.CreateSignature(reader, new
>> FileStream(SignedPDFfile, FileMode.Create), '\0');
>> 
>>             PdfSignatureAppearance sap = stp.SignatureAppearance;
>>             sap.SetVisibleSignature(signames[0].ToString());
>>             sap.SignDate = DateTime.Now;
>>             sap.SetCrypto(null, chain, null,
>> PdfSignatureAppearance.SELF_SIGNED);
>>             sap.Reason = "No Reason";
>>             sap.Location = "Planet Earth";
>>             sap.Acro6Layers = true;
>> 
>>             sap.SetExternalDigest(new byte[128], new byte[20], "RSA");  
>>             sap.PreClose();
>> 
>>             HashAlgorithm sha = new SHA1CryptoServiceProvider();
>>             Stream s = sap.RangeStream;
>>             int read = 0;
>>             byte[] buff = new byte[8192];
>>             while ((read = s.Read(buff, 0, 8192)) > 0)
>> sha.TransformBlock(buff, 0, read, buff, 0);
>>             sha.TransformFinalBlock(buff, 0, 0);
>> 
>>             //Get external signature of hash (PKCS1)
>>             byte[] pk = externalSignHash(sha.Hash);
>> 
>>             PdfSigGenericPKCS tSig = sap.SigStandard; 
>>             PdfLiteral tPDFLiteral =
>> (PdfLiteral)tSig.Get(PdfName.CONTENTS); 
>>             byte[] tOutBytes = new byte[(tPDFLiteral.PosLength - 2) / 2]; 
>> 
>>             PdfPKCS7 tSigner = tSig.Signer; 
>>             tSigner.SetExternalDigest(pk, sha.Hash, "RSA");
>> 
>>             byte[] tSsig = tSigner.GetEncodedPKCS1();
>> 
>>             System.Array.Copy(tSsig, 0, tOutBytes, 0, tSsig.Length);
>>             PdfDictionary tPDFDic = new PdfDictionary();
>>             tPDFDic.Put(PdfName.CONTENTS, new
>> PdfString(tOutBytes).SetHexWriting(true)); 
>>             sap.Close(tPDFDic);
>> 
>> 
>> 
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> 
> 

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