我已经创建了一个 key ，并创建了一个子 key 。使用子 key ，我签署了一个文件。验证有效。撤销 key ，验证不成立。这是预期的行为。
但是，如果我尝试使用相同的子 key 进行签名并验证它是否仍然有效。我究竟做错了什么？这是我正在做的全部事情:
$ gpg --gen-key
$ gpg -k
/Users/mustafa/.gnupg/pubring.kbx
---------------------------------
pub rsa2048 2019-02-03 [SC] [expires: 2021-02-02]
5DD923FBCF6392A5CB366167D4C0627A07510C6C
uid [ultimate] Mustafa <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="88e5fdfbfce9eee9b1b9c8efe5e9e1e4a6ebe7e5" rel="noreferrer noopener nofollow">[email protected]</a>>
sub rsa2048 2019-02-03 [E] [expires: 2021-02-02]
使用编辑键添加子项。
$ gpg --edit-key 5DD923FBCF6392A5CB366167D4C0627A07510C6C
sec rsa2048/D4C0627A07510C6C
created: 2019-02-03 expires: 2021-02-02 usage: SC
trust: ultimate validity: ultimate
ssb rsa2048/E058B91696C43666
created: 2019-02-03 expires: 2021-02-02 usage: E
gpg> addkey
sec rsa2048/D4C0627A07510C6C
created: 2019-02-03 expires: 2021-02-02 usage: SC
trust: ultimate validity: ultimate
ssb rsa2048/E058B91696C43666
created: 2019-02-03 expires: 2021-02-02 usage: E
ssb rsa2048/38616BDAE66E418C
created: 2019-02-03 expires: 2019-02-13 usage: S
[ultimate] (1). Mustafa <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="7e130b0d0a1f181f474f3e19131f1712501d1113" rel="noreferrer noopener nofollow">[email protected]</a>>
gpg> q
Save changes? (y/N) y
签署文件并验证它。
$ gpg --armor --detach-sign --default-key 38616BDAE66E418C test.txt
gpg: using "38616BDAE66E418C" as default secret key for signing
$ gpg --verify test.txt.asc test.txt
gpg: Signature made Sun Feb 3 21:49:43 2019 +03
gpg: using RSA key 485FC77FC73DA3B800C7F41538616BDAE66E418C
gpg: Good signature from "Mustafa <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="066b7375726760673f3746616b676f6a2865696b" rel="noreferrer noopener nofollow">[email protected]</a>>" [ultimate]
撤销 key 并显示消息“该 key 现在在敌人手中。”
$ gpg --edit-key 5DD923FBCF6392A5CB366167D4C0627A07510C6C
gpg> key 2
sec rsa2048/D4C0627A07510C6C
created: 2019-02-03 expires: 2021-02-02 usage: SC
trust: ultimate validity: ultimate
ssb rsa2048/E058B91696C43666
created: 2019-02-03 expires: 2021-02-02 usage: E
ssb* rsa2048/38616BDAE66E418C
created: 2019-02-03 expires: 2019-02-13 usage: S
gpg> revkey
sec rsa2048/D4C0627A07510C6C
created: 2019-02-03 expires: 2021-02-02 usage: SC
trust: ultimate validity: ultimate
ssb rsa2048/E058B91696C43666
created: 2019-02-03 expires: 2021-02-02 usage: E
The following key was revoked on 2019-02-03 by RSA key D4C0627A07510C6C Mustafa <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="86ebf3f5f2e7e0e7bfb7c6e1ebe7efeaa8e5e9eb" rel="noreferrer noopener nofollow">[email protected]</a>>
ssb rsa2048/38616BDAE66E418C
created: 2019-02-03 revoked: 2019-02-03 usage: S
[ultimate] (1). Mustafa <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="deb3abadaabfb8bfe7ef9eb9b3bfb7b2f0bdb1b3" rel="noreferrer noopener nofollow">[email protected]</a>>
尝试验证旧签名并查看失败。
$ gpg --verify test.txt.asc test.txt
gpg: Signature made Sun Feb 3 21:49:43 2019 +03
gpg: using RSA key 485FC77FC73DA3B800C7F41538616BDAE66E418C
gpg: Good signature from "Mustafa <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="e588909691848384dcd4a58288848c89cb868a88" rel="noreferrer noopener nofollow">[email protected]</a>>" [ultimate]
gpg: WARNING: This subkey has been revoked by its owner!
gpg: reason for revocation: Key has been compromised
gpg: revocation comment: This key is now in the hands of the enemy.
但是，尝试使用已撤销的 key 进行签名。
$ rm test.key.asc
$ gpg --armor --detach-sign --default-key 38616BDAE66E418C test.txt
gpg: using "38616BDAE66E418C" as default secret key for signing
为什么没有失败？如何验证？
$ gpg --verify test.txt.asc test.txt
gpg: Signature made Sun Feb 3 21:53:11 2019 +03
gpg: using RSA key 5DD923FBCF6392A5CB366167D4C0627A07510C6C
gpg: Good signature from "Mustafa <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="c4a9b1b7b0a5a2a5fdf584a3a9a5ada8eaa7aba9" rel="noreferrer noopener nofollow">[email protected]</a>>" [ultimate]
最佳答案
看看你的最后两段摘录。尽管您将默认签名 key 指定为 38616BDAE66E418C，但当您进行验证时，它会报告已使用 D4C0627A07510C6C 进行签名。
如果您使用 gpg 的 -v 详细选项，您将看到，如果指定的默认 key 被撤销，它将回退到下一个可用的签名 key 。
为了说明这一点，我重新创建了您的场景:
sec rsa2048/4E5CB15076F1318E
created: 2019-02-09 expires: 2021-02-08 usage: SC
trust: ultimate validity: ultimate
ssb rsa2048/3303CBB274AECA3B
created: 2019-02-09 expires: 2021-02-08 usage: E
The following key was revoked on 2019-02-09 by RSA key 4E5CB15076F1318E Herp Derp <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="8fe7eafdffcfebeafdffa1ece0e2" rel="noreferrer noopener nofollow">[email protected]</a>>
ssb rsa2048/8ABD3900E64E7972
created: 2019-02-09 revoked: 2019-02-09 usage: S
[ultimate] (1). Herp Derp <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="c6aea3b4b686a2a3b4b6e8a5a9ab" rel="noreferrer noopener nofollow">[email protected]</a>>
在撤销之前使用子 key 进行签名:
$ gpg -v --armor --detach-sign --default-key 8ABD3900E64E7972 test.txt
gpg: using pgp trust model
gpg: using "8ABD3900E64E7972" as default secret key for signing
gpg: using subkey 8ABD3900E64E7972 instead of primary key 4E5CB15076F1318E
gpg: writing to 'test.txt.asc'
gpg: RSA/SHA256 signature from: "8ABD3900E64E7972 Herp Derp <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="bfd7dacdcfffdbdacdcf91dcd0d2" rel="noreferrer noopener nofollow">[email protected]</a>>"
撤销后使用子 key 签名:
$ gpg -v --armor --detach-sign --default-key 8ABD3900E64E7972 test.txt
gpg: Note: signature key 8ABD3900E64E7972 has been revoked
gpg: using pgp trust model
gpg: using "8ABD3900E64E7972" as default secret key for signing
gpg: Note: signature key 8ABD3900E64E7972 has been revoked
gpg: writing to 'test.txt.asc'
gpg: RSA/SHA256 signature from: "4E5CB15076F1318E Herp Derp <<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="1c74796e6c5c78796e6c327f7371" rel="noreferrer noopener nofollow">[email protected]</a>>"
您可以看到，在第二个示例中，gpg 将子项标识为已撤销并回退到主键。
关于digital-signature - GPG 仍然看到了良好的迹象，撤销的子 key 仍然有效，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/54506524/