Fix signature padding, return verify error in validator

sign/pdfsignature.go

@@ -81,7 +81,7 @@ func (context *SignContext) createSignature() ([]byte, error) {
 	file_content = file_content[:len(file_content)-1]
 
 	// Collect the parts to sign.
-	sign_content := make([]byte, context.ByteRangeValues[1]+context.ByteRangeValues[3])
+	sign_content := make([]byte, 0)
 	sign_content = append(sign_content, file_content[context.ByteRangeValues[0]:(context.ByteRangeValues[0]+context.ByteRangeValues[1])]...)
 	sign_content = append(sign_content, file_content[context.ByteRangeValues[2]:(context.ByteRangeValues[2]+context.ByteRangeValues[3])]...)
 

verify/verify.go

@@ -123,10 +123,12 @@ func Verify(file *os.File) (apiResp *Response, err error) {
 			// Read the byte range from the raw file and add it to the contents.
 			// This content will be hashed with the corresponding algorithm to
 			// verify the signature.
+
 			content, err := ioutil.ReadAll(io.NewSectionReader(file, v.Key("ByteRange").Index(i-1).Int64(), v.Key("ByteRange").Index(i).Int64()))
 			if err != nil {
 				apiResp.Error = fmt.Sprintln("Failed to get ByteRange:", i, err)
 			}
+
 			p7.Content = append(p7.Content, content...)
 		}
 
@@ -178,7 +180,7 @@ func Verify(file *os.File) (apiResp *Response, err error) {
 				signer.ValidSignature = true
 				signer.TrustedIssuer = false
 			}
-			//apiResp.Error = fmt.Sprintln("Failed to verify signature:", err)
+			apiResp.Error = fmt.Sprintln("Failed to verify signature:", err)
 		} else {
 			signer.ValidSignature = true
 			signer.TrustedIssuer = true