Reference has no DigestMethod

[oh-mycode]

Hi! I have a PDF file that was signed before, and when I try to sign it I get KeyError exception about DigestMethod. I did some research and found out that for some reason /Reference has no /DigestMethod.

for k in ("/Root", "/Perms", "/DocMDP", "/Reference"):
    if k in obj:
        obj = obj[k]
        if isinstance(obj, po.ArrayObject):
            obj = obj[0]
        obj = obj.getObject()
    else:
        obj = None
        break
if obj is not None:
    algomd = obj["/DigestMethod"][1:].lower()

Probably the previous signature is wrong. What do you think if I expend the condition and check if the key /DigestMethodexists? I already tried it and got a successfully signed document. There is a small effect - Adobe shows that the previous signature is invalid, but I also tried to sign with JSignPdf util and got the same result, so it is fine by me. Please tell me WDYT?

[oh-mycode]

https://github.com/m32/endesive/pull/135 - my suggestion

[m32]

In my opinion, signing incorrect documents sooner or later will end in a catastrophe. Acrobat ignores this error, but there are some that it does not ignore and if you sign such a document, the problem will come back to you, not to the one who generated the incorrect document.

[oh-mycode]

@m32 what if do it optionally?

[m32]

I still do not like it :) - optionally, you can press it all, but I do not want to explain why the previous signature is incorrect, and somehow I feel that this is how it will be done