gnupg - 如何在不导入的情况下显示 gpg key 详细信息？

Question

我有一份 postgresql apt 存储库 gpg key 的副本，并且想查看文件中 gpg key 的详细信息。是否可以在不将其导入 key 环的情况下实现？

Answer 1

查看 OpenPGP 关键数据时，您可以获得多个详细级别:基本摘要、此摘要的机器可读输出或各个 OpenPGP 数据包的详细(且非常技术性)列表。

基本关键信息

对于 OpenPGP key 文件的短暂峰值，您可以简单地将文件名作为参数或通过 STDIN 传递到 key 数据中。如果没有传递命令，GnuPG 会尝试猜测您想要做什么——对于关键数据，这会在关键上打印摘要:

$ gpg a4ff2279.asc
gpg: WARNING: no command supplied.  Trying to guess what you mean ...
pub   rsa8192 2012-12-25 [SC]
      0D69E11F12BDBA077B3726AB4E1F799AA4FF2279
uid           Jens Erat (born 1988-01-19 in Stuttgart, Germany)
uid           Jens Erat <jens.erat@fsfe.org>
uid           Jens Erat <jens.erat@uni-konstanz.de>
uid           Jens Erat <jabber@jenserat.de>
uid           Jens Erat <email@jenserat.de>
uid           [jpeg image of size 12899]
sub   rsa4096 2012-12-26 [E] [revoked: 2014-03-26]
sub   rsa4096 2012-12-26 [S] [revoked: 2014-03-26]
sub   rsa2048 2013-01-23 [S] [expires: 2023-01-21]
sub   rsa2048 2013-01-23 [E] [expires: 2023-01-21]
sub   rsa4096 2014-03-26 [S] [expires: 2020-09-03]
sub   rsa4096 2014-03-26 [E] [expires: 2020-09-03]
sub   rsa4096 2014-11-22 [A] [revoked: 2016-03-01]
sub   rsa4096 2016-02-24 [A] [expires: 2020-02-23]

通过设置 --keyid-format 0xlong, long key IDs are printed 而不是 insecure short key IDs :

$ gpg a4ff2279.asc                                                                 
gpg: WARNING: no command supplied.  Trying to guess what you mean ...
pub   rsa8192/0x4E1F799AA4FF2279 2012-12-25 [SC]
      0D69E11F12BDBA077B3726AB4E1F799AA4FF2279
uid                             Jens Erat (born 1988-01-19 in Stuttgart, Germany)
uid                             Jens Erat <jens.erat@fsfe.org>
uid                             Jens Erat <jens.erat@uni-konstanz.de>
uid                             Jens Erat <jabber@jenserat.de>
uid                             Jens Erat <email@jenserat.de>
uid                             [jpeg image of size 12899]
sub   rsa4096/0x0F3ED8E6759A536E 2012-12-26 [E] [revoked: 2014-03-26]
sub   rsa4096/0x2D6761A7CC85941A 2012-12-26 [S] [revoked: 2014-03-26]
sub   rsa2048/0x9FF7E53ACB4BD3EE 2013-01-23 [S] [expires: 2023-01-21]
sub   rsa2048/0x5C88F5D83E2554DF 2013-01-23 [E] [expires: 2023-01-21]
sub   rsa4096/0x8E78E44DFB1B55E9 2014-03-26 [S] [expires: 2020-09-03]
sub   rsa4096/0xCC73B287A4388025 2014-03-26 [E] [expires: 2020-09-03]
sub   rsa4096/0x382D23D4C9773A5C 2014-11-22 [A] [revoked: 2016-03-01]
sub   rsa4096/0xFF37A70EDCBB4926 2016-02-24 [A] [expires: 2020-02-23]
pub   rsa1024/0x7F60B22EA4FF2279 2014-06-16 [SCEA] [revoked: 2016-08-16]

提供-v或-vv甚至会添加更多信息。不过，在这种情况下，我更喜欢打印包裹详细信息(见下文)。

机器可读输出

GnuPG 还具有冒号分隔的输出格式，该格式易于解析且格式稳定。 format is documented in GnuPG doc/DETAILS file 。接收此格式的选项是--with-colons。

$ gpg --with-colons a4ff2279.asc
gpg: WARNING: no command supplied.  Trying to guess what you mean ...
pub:-:8192:1:4E1F799AA4FF2279:1356475387:::-:
uid:::::::::Jens Erat (born 1988-01-19 in Stuttgart, Germany):
uid:::::::::Jens Erat <jens.erat@fsfe.org>:
uid:::::::::Jens Erat <jens.erat@uni-konstanz.de>:
uid:::::::::Jens Erat <jabber@jenserat.de>:
uid:::::::::Jens Erat <email@jenserat.de>:
uat:::::::::1 12921:
sub:-:4096:1:0F3ED8E6759A536E:1356517233:1482747633:::
sub:-:4096:1:2D6761A7CC85941A:1356517456:1482747856:::
sub:-:2048:1:9FF7E53ACB4BD3EE:1358985314:1674345314:::
sub:-:2048:1:5C88F5D83E2554DF:1358985467:1674345467:::
sub:-:4096:1:8E78E44DFB1B55E9:1395870592:1599164118:::
sub:-:4096:1:CC73B287A4388025:1395870720:1599164118:::
sub:-:4096:1:382D23D4C9773A5C:1416680427:1479752427:::
sub:-:4096:1:FF37A70EDCBB4926:1456322829:1582466829:::

自 GnuPG 2.1.23 起，gpg: 警告:未提供命令。试图猜测你的意思...警告可以通过使用--import-options show-only选项和--import命令来省略(当然，这也可以在没有 --with-colons 的情况下工作):

$ gpg --with-colons --import-options show-only --import a4ff2279
[snip]

对于旧版本:警告消息打印在 STDERR 上，因此您只需读取 STDIN 即可从警告中分离出关键信息。

技术细节:列出 OpenPGP 数据包

无需安装任何其他软件包，您就可以使用 gpg --list-packets [file] 查看文件中包含的 OpenPGP 数据包的信息。

$ gpg --list-packets a4ff2279.asc
:public key packet:
    version 4, algo 1, created 1356475387, expires 0
    pkey[0]: [8192 bits]
    pkey[1]: [17 bits]
    keyid: 4E1F799AA4FF2279
:user ID packet: "Jens Erat (born 1988-01-19 in Stuttgart, Germany)"
:signature packet: algo 1, keyid 4E1F799AA4FF2279
    version 4, created 1356516623, md5len 0, sigclass 0x13
    digest algo 2, begin of digest 18 46
    hashed subpkt 27 len 1 (key flags: 03)
[snip]

pgpdump [file] 工具的工作方式与 gpg --list-packets 类似，并提供类似的输出，但解析所有这些算法标识符到可读表示。它可能适用于所有相关发行版(在 Debian 衍生版本上，该软件包与该工具本身一样称为 pgpdump)。

$ pgpdump a4ff2279.asc
Old: Public Key Packet(tag 6)(1037 bytes)
    Ver 4 - new
    Public key creation time - Tue Dec 25 23:43:07 CET 2012
    Pub alg - RSA Encrypt or Sign(pub 1)
    RSA n(8192 bits) - ...
    RSA e(17 bits) - ...
Old: User ID Packet(tag 13)(49 bytes)
    User ID - Jens Erat (born 1988-01-19 in Stuttgart, Germany)
Old: Signature Packet(tag 2)(1083 bytes)
    Ver 4 - new
    Sig type - Positive certification of a User ID and Public Key packet(0x13).
    Pub alg - RSA Encrypt or Sign(pub 1)
    Hash alg - SHA1(hash 2)
    Hashed Sub: key flags(sub 27)(1 bytes)
[snip]