From f16113d6d2dd7f6bccc4bf10a4f87af1615acea1 Mon Sep 17 00:00:00 2001 From: "Neal H. Walfield" Date: Tue, 8 Jun 2021 13:42:59 +0200 Subject: [PATCH 1/2] Show information about a PGP key only if we have a strong match. - OpenPGP is a packet-based format with little information at fixed offsets. - Currently, we print out interesting fields as we encounter them. Unfortunately, the certificate type (public or secret) is the first field. Thus, we've matched less than a byte of data before we print something, which results in false positives. - Delay printing this information until we've matched on the packet's type, sanity checked its size, its version field, and its creation time. - Note: because we use functions ('use' and 'name') we are not able to access the first byte of the file, and thus can no longer indicate whether the key is a public or a private key. - See: https://bugs.astron.com/view.php?id=266 --- magic/Magdir/pgp-binary-keys | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/magic/Magdir/pgp-binary-keys b/magic/Magdir/pgp-binary-keys index 1ce76d90..20e10aaa 100644 --- a/magic/Magdir/pgp-binary-keys +++ b/magic/Magdir/pgp-binary-keys @@ -160,16 +160,16 @@ # The first packet has to be a public key or a secret key. # # New-Style Public Key -0 ubyte =0xC6 OpenPGP Public Key +0 ubyte =0xC6 >&0 use primary_key_length_new # New-Style Secret Key -0 ubyte =0xC5 OpenPGP Secret Key +0 ubyte =0xC5 >&0 use primary_key_length_new # Old-Style Public Key -0 ubyte&0xFC =0x98 OpenPGP Public Key +0 ubyte&0xFC =0x98 >&-1 use primary_key_length_old # Old-Style Secret Key -0 ubyte&0xFC =0x94 OpenPGP Secret Key +0 ubyte&0xFC =0x94 >&-1 use primary_key_length_old # Parse the length, check the packet's body and finally advance to the @@ -228,10 +228,12 @@ # key format in a decade or so :D. >&0 ubyte >1 >>&-1 ubyte <8 ->>>&-1 byte x Version %d # Check that keys were created after 1990. # (1990 - 1970) * 365.2524 * 24 * 60 * 60 = 631156147 ->>>&0 bedate >631156147 \b, Created %s +>>>&0 bedate >631156147 +>>>>0 ubyte x OpenPGP Key +>>>>&-5 byte x Version %d +>>>>&-4 bedate x \b, Created %s >>>>&-5 ubyte >3 >>>>>&4 use pgp_binary_key_algo >>>>&-5 ubyte <4 -- 2.20.1