Signature Verification

From f0063afa71bc7e71f19d174acc2fde26f0c11850 Mon Sep 17 00:00:00 2001 From: Ben McGinnes Date: Tue, 15 May 2018 13:13:16 +1000 Subject: docs: python bindings HOWTO - DITA XML version * Due to the org-babel bug which breaks Python source code examples beyond the most simple snippets, ported the HOWTO to a source format which I *know* for sure won't break it. * Details of the org-mode bug is in https://dev.gnupg.org/T3977 * DITA project uses DITA-OT 2.x (2.4 or 2.5, IIRC) with support for DITA 1.3. * source files were written with oXygenXML Editor 20.0, hence the oXygenXML project file in the directory; however only the .ditamap and .dita files are required to generate any output with the DITA-OT. Signed-off-by: Ben McGinnes --- .../docs/dita/howto/part04/verification.dita | 150 +++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 lang/python/docs/dita/howto/part04/verification.dita (limited to 'lang/python/docs/dita/howto/part04/verification.dita') diff --git a/lang/python/docs/dita/howto/part04/verification.dita b/lang/python/docs/dita/howto/part04/verification.dita new file mode 100644 index 00000000..d50482a8 --- /dev/null +++ b/lang/python/docs/dita/howto/part04/verification.dita @@ -0,0 +1,150 @@ + + + + + Signature Verification + +

Essentially there are two principal methods of verification of a signature. The first + of these is for use with the normal or default signing method and for clear-signed messages. + The second is for use with files and data with detached signatures.

The following example is intended for use with the default signing method where the file + was not ASCII armoured:

+ import gpg +import time + +filename = "statement.txt" +gpg_file = "statement.txt.gpg" + +c = gpg.Context() + +try: + data, result = c.verify(open(gpg_file)) + verified = True +except gpg.errors.BadSignatures as e: + verified = False + print(e) + +if verified is True: + for i in range(len(result.signatures)): + sign = result.signatures[i] + print("""Good signature from: +{0} +with key {1} +made at {2} +""".format(c.get_key(sign.fpr).uids[0].uid, + sign.fpr, time.ctime(sign.timestamp))) +else: + pass + +

Whereas this next example, which is almost identical would work with normal ASCII armoured + files and with clear-signed files:

+ import gpg +import time + +filename = "statement.txt" +asc_file = "statement.txt.asc" + +c = gpg.Context() + +try: + data, result = c.verify(open(asc_file)) + verified = True +except gpg.errors.BadSignatures as e: + verified = False + print(e) + +if verified is True: + for i in range(len(result.signatures)): + sign = result.signatures[i] + print("""Good signature from: +{0} +with key {1} +made at {2} +""".format(c.get_key(sign.fpr).uids[0].uid, + sign.fpr, time.ctime(sign.timestamp))) +else: + pass + +

In both of the previous examples it is also possible to compare the original data that was + signed against the signed data in data to see if it matches with something + like this:

+ with open(filename, "rb") as afile: + text = afile.read() + +if text == data: + print("Good signature.") +else: + pass + +

The following two examples, however, deal with detached signatures. With his method of + verification the data that was signed does not get returned since it is already being + explicitly referenced in the first argument of c.verify. So + data is None and only the information in + result is available.

+ import gpg +import time + +filename = "statement.txt" +sig_file = "statement.txt.sig" + +c = gpg.Context() + +try: + data, result = c.verify(open(filename), open(sig_file)) + verified = True +except gpg.errors.BadSignatures as e: + verified = False + print(e) + +if verified is True: + for i in range(len(result.signatures)): + sign = result.signatures[i] + print("""Good signature from: +{0} +with key {1} +made at {2} +""".format(c.get_key(sign.fpr).uids[0].uid, + sign.fpr, time.ctime(sign.timestamp))) +else: + pass + +

+ import gpg +import time + +filename = "statement.txt" +asc_file = "statement.txt.asc" + +c = gpg.Context() + +try: + data, result = c.verify(open(filename), open(asc_file)) + verified = True +except gpg.errors.BadSignatures as e: + verified = False + print(e) + +if verified is not None: + for i in range(len(result.signatures)): + sign = result.signatures[i] + print("""Good signature from: +{0} +with key {1} +made at {2} +""".format(c.get_key(sign.fpr).uids[0].uid, + sign.fpr, time.ctime(sign.timestamp))) +else: + pass + +

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