#124 - verification of signatures of a multiple-signed file

m32 · Aug 29, 2022 · b26145d · b26145d
1 parent 482b00a
commit b26145d
Show file tree

Hide file tree

Showing 2 changed files with 23 additions and 14 deletions.
diff --git a/endesive/pdf/verify.py b/endesive/pdf/verify.py
@@ -3,15 +3,20 @@
 
 
 def verify(pdfdata, certs=None):
+    results = []
     n = pdfdata.find(b"/ByteRange")
-    start = pdfdata.find(b"[", n)
-    stop = pdfdata.find(b"]", start)
-    assert n != -1 and start != -1 and stop != -1
-    br = [int(i, 10) for i in pdfdata[start + 1 : stop].split()]
-    contents = pdfdata[br[0] + br[1] + 1 : br[2] - 1]
-    bcontents = bytes.fromhex(contents.decode("utf8"))
-    data1 = pdfdata[br[0] : br[0] + br[1]]
-    data2 = pdfdata[br[2] : br[2] + br[3]]
-    signedData = data1 + data2
+    while n != -1:
+        start = pdfdata.find(b"[", n)
+        stop = pdfdata.find(b"]", start)
+        assert n != -1 and start != -1 and stop != -1
+        br = [int(i, 10) for i in pdfdata[start + 1 : stop].split()]
+        contents = pdfdata[br[0] + br[1] + 1 : br[2] - 1]
+        bcontents = bytes.fromhex(contents.decode("utf8"))
+        data1 = pdfdata[br[0] : br[0] + br[1]]
+        data2 = pdfdata[br[2] : br[2] + br[3]]
+        signedData = data1 + data2
 
-    return verifier.verify(bcontents, signedData, certs)
+        result = verifier.verify(bcontents, signedData, certs)
+        results.append(result)
+        n = pdfdata.find(b"/ByteRange", br[2] + br[3])
+    return results
diff --git a/examples/pdf-verify-hsm.py b/examples/pdf-verify-hsm.py
@@ -43,16 +43,20 @@ def main(self):
         trusted_cert_pems = (ca_cert_pem,)
         for fname in (
             'pdf-signed-cms-hsm.pdf',
+            'pdf-signed-cms-hsm-signed-cms-hsm.pdf',
         ):
             print('*' * 20, fname)
             try:
                 data = open(fname, 'rb').read()
             except:
                 continue
-            (hashok, signatureok, certok) = pdf.verify(data, trusted_cert_pems)
-            print('signature ok?', signatureok)
-            print('hash ok?', hashok)
-            print('cert ok?', certok)
+            results = pdf.verify(data, trusted_cert_pems)
+            for i in range(len(results)):
+                print('*'*10, 'signature #{}'.format(i+1))
+                (hashok, signatureok, certok) = results[i]
+                print('signature ok?', signatureok)
+                print('hash ok?', hashok)
+                print('cert ok?', certok)
 
 def main():
     cls = HSM(dllpath)