误解 CSR 和 X.509 功能

Question

在花了两天时间搜索并找到问题的答案后，我意识到这些答案只会产生更多我无法解决的问题和问题，我决定在这里寻求帮助，希望我没有错过我在某处寻找的信息。

我刚刚开始了一个项目，在该项目中，在开始使用此客户端之前，我必须与客户端交换 X.509 证书。 我已经设法很好地理解了X.509证书的制作方式和原因：

• 从私钥创建 CSR;
• 此 CSR 包含数字身份和从私钥中提取的公钥;
• CSR 是自签名的，或发送给 CA，CA 使用自己的私钥对其进行签名，以验证发件人的身份;
CA 发回符合 X.509
• 标准的证书，并证明您没有伪造身份，因此 X.509 中包含的公钥是可靠的。

因此，X.509证书是一种与某人交换公钥以应对潜在的中间人攻击的方法。 使用OpenSSL，我已经能够单独模拟这些操作，以便了解这些步骤的功能。

我的第一个问题是，当我从私钥(privateKey.pem)创建CSR然后检查此私钥是否与CSR匹配时，它没有。
然后，我使用不同的私钥(signingPrivateKey.pem)对CSR进行自签名，再次检查X.509证书是否与私钥匹配，但它仍然不匹配(这似乎很正常，因为CSR也没有，但两者都应该匹配，不是吗？

以下是OpenSSL命令：

@echo off
echo "Generates private key and puts it in SigningPrivateKey.pem"
echo.
openssl genrsa -out SigningPrivateKey.pem 1024
echo "Generates private key and puts it in privateKey.pem, then create CSR"
echo.
openssl req -newkey rsa:1024 -keyout privateKey.pem -out CSR_TEST.csr -nodes

echo "Checks if CSR and privateKey matches
echo.
openssl x509 -noout -modulus -in CSR_TEST.csr | openssl md5
openssl rsa -noout -modulus -in privateKey.pem | openssl md5
echo "Self sign CSR with private key"
echo.
openssl x509 -in CSR_TEST.csr -out CSR_TEST.pem -req -signkey 
SigningPrivateKey.pem -days 1
echo. "Checks again if certificate and private key matches
openssl x509 -noout -modulus -in CSR_TEST.pem | openssl md5
openssl rsa -noout -modulus -in privateKey.pem | openssl md5  

以下是汇总的输入：

stdin = d41d8....8427e  
stdin = f3213....4538c  
Signature ok  
stdin = 82baf...a0863  
stdin = f3213...4538c

我的第二个问题是验证 X.509 的方法。 假设我设法从输入私钥制作 X.509 证书，并且提取的公钥与之匹配。我将其发送给我的客户，该客户向其发送证书。我们怎么知道这个 X.509 是可靠的？我在某处读到我们需要使用 CA 的公钥"取消签名"X.509 证书，并将输出与散列证书进行比较，但每个人似乎都说 X.509 证书是自给自足的，它本身证明了您的身份。我们只需要用OpenSSL命令检查它的真实性？ 请在这一点上减轻我的负担。

感谢您花时间阅读和理解我的问题，再次希望我不是唯一面临这些问题的人，并且这篇文章将帮助其他人。 抱歉，我还不允许在这篇文章中放置更多链接，否则我会更准确。

Answer 1

CSR/密钥比较

$ openssl req -in test.csr -modulus -noout | openssl md5
(stdin)= 76d44c1a05f535f5e78a648b41bdaf73
$ openssl rsa -in test.key -modulus -noout | openssl md5
(stdin)= 76d44c1a05f535f5e78a648b41bdaf73

您在 CSR 上使用了openssl x509。 它们不一样。 在通过 MD5 运行它之前，您显然没有查看输出：

$ openssl x509 -in test.csr -modulus -noout
unable to load certificate
139958187611800:error:0906D06C:PEM routines:PEM_read_bio:no start line:pem_lib.c:701:Expecting: TRUSTED CERTIFICATE

你尚未将其创建为证书，因此 x509 命令不起作用。

在您制作证书并再次检查后，您会得到不同的答案，因为您使用了-signkey.文档说 -signkey 用作自签名密钥，这意味着它替换了原始请求中的公钥。 如果使用-signkey privateKey.pem则命令应显示对齐方式。

正直

每个 X.509 证书都包含提供的数据(包括公钥)和签名。对于"真正的"CA，通常会有一个注释(颁发机构信息访问扩展)，说明如何查找CA的证书。 无论是手头有公钥还是必须从 Internet 检索它，签名证书中的公钥都可用于验证原始证书中的数据是否未更改。

签名 CA 本身有一个证书，因此您可以再走一步并证明它未被更改。

最终，您将获得根/自签名证书。 要么你已经拥有它并认为它是可信的，要么你没有，你把整个事情称为恶作剧。

对于不属于内置信任存储区的自签名证书，唯一可以真正验证的是它在创建后未被修改。 这样做的唯一安全好处是否认：如果有人编辑了您创建的证书并添加了一个扩展名，该扩展名大意是"妈是个臭驴推销员！"你可以证明自签名是无效的。

$ openssl x509 -in test.cer -text -noout
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 11195357966677484939 (0x9b5de6c15126a58b)
Signature Algorithm: sha256WithRSAEncryption
Issuer: C=US, ST=Washington, L=Redmond, O=Microsoft Corporation, OU=.NET Framework (CoreFX), CN=localhost
Validity
Not Before: Mar  2 01:48:00 2016 GMT
Not After : Mar  2 01:48:00 2017 GMT
Subject: C=US, ST=Washington, L=Redmond, O=Microsoft Corporation, OU=.NET Framework (CoreFX), CN=localhost
Subject Public Key Info:
Public Key Algorithm: rsaEncryption
Public-Key: (2048 bit)
Modulus:
00:af:81:c1:cb:d8:20:3f:62:4a:53:9e:d6:60:81:
75:37:23:93:a2:83:7d:48:90:e4:8a:19:de:d3:69:
73:11:56:20:96:8d:6b:e0:d3:da:a3:8a:a7:77:be:
02:ee:0b:6b:93:b7:24:e8:dc:c1:2b:63:2b:4f:a8:
0b:bc:92:5b:ce:62:4f:4c:a7:cc:60:63:06:b3:94:
03:e2:8c:93:2d:24:dd:54:6f:fe:4e:f6:a3:7f:10:
77:0b:22:15:ea:8c:bb:5b:f4:27:e8:c4:d8:9b:79:
eb:33:83:75:10:0c:5f:83:e5:5d:e9:b4:46:6d:df:
be:ee:42:53:9a:ef:33:ef:18:7b:77:60:c3:b1:a1:
b2:10:3c:2d:81:44:56:4a:0c:10:39:a0:9c:85:cf:
6b:59:74:eb:51:6f:c8:d6:62:3c:94:ae:3a:5a:0b:
b3:b4:c7:92:95:7d:43:23:91:56:6c:f3:e2:a5:2a:
fb:0c:14:2b:9e:06:81:b8:97:26:71:af:2b:82:dd:
39:0a:39:b9:39:cf:71:95:68:68:7e:49:90:a6:30:
50:ca:77:68:dc:d6:b3:78:84:2f:18:fd:b1:f6:d9:
ff:09:6b:af:7b:eb:98:dc:f9:30:d6:6f:cf:d5:03:
f5:8d:41:bf:f4:62:12:e2:4e:3a:fc:45:ea:42:bd:
88:47
Exponent: 8589935681 (0x200000441)
X509v3 extensions:
X509v3 Subject Key Identifier:
78:A5:C7:5D:51:66:73:31:D5:A9:69:24:11:4C:9B:5F:A0:0D:7B:CB
X509v3 Authority Key Identifier:
keyid:78:A5:C7:5D:51:66:73:31:D5:A9:69:24:11:4C:9B:5F:A0:0D:7B:CB
X509v3 Basic Constraints:
CA:TRUE
Signature Algorithm: sha256WithRSAEncryption
77:75:6d:05:ff:a6:ad:fe:d5:b6:d4:af:b5:40:84:0c:6d:01:
cf:6b:3f:a6:c9:73:df:d6:1f:ca:a0:a8:14:fa:1e:24:69:01:
9d:94:b1:d8:56:d0:7d:d2:b9:5b:85:50:df:d2:08:59:53:a4:
94:b9:9e:fc:ba:a7:98:2c:e7:71:98:4f:9d:4a:44:5f:fe:e0:
62:e8:a0:49:73:6a:39:fd:99:4e:1f:da:0a:5d:c2:b5:b0:e5:
7a:0b:10:c4:1b:c7:fe:6a:40:b2:4f:85:97:73:02:59:3e:60:
b9:8d:d4:81:1d:47:d9:48:ed:f8:d6:e6:b5:af:80:a1:82:74:
96:e2:0b:fd:24:0e:46:76:74:50:4d:4e:47:03:33:1d:64:70:
5c:36:fb:6e:14:ba:bf:d9:cb:ee:c4:4b:33:a8:d7:b3:64:79:
90:0f:3c:5b:ba:b6:9c:5e:45:3d:18:07:83:e2:50:80:51:b9:
98:c0:38:e4:62:25:71:d2:ab:89:1d:89:8e:54:58:82:8c:f1:
86:79:51:7d:28:db:ca:bf:72:e8:13:07:bf:d7:21:b7:3d:db:
17:51:12:3f:99:d8:fc:0d:53:37:98:c4:db:d1:47:19:d5:d8:
a8:5b:00:a1:44:a3:67:67:7b:48:89:1a:9b:56:f0:45:33:48:
11:ba:cb:7a

和

$ openssl x509 -in alsotest.cer -text -noout
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 11195357966677484939 (0x9b5de6c15126a58b)
Signature Algorithm: sha256WithRSAEncryption
Issuer: C=US, ST=Washington, L=Redmond, O=Microsoft Corporation, OU=.NET Framework (CoreFX), CN=localhost
Validity
Not Before: Mar  2 01:48:00 2016 GMT
Not After : Mar  2 01:48:00 2019 GMT
Subject: C=US, ST=Washington, L=Redmond, O=Microsoft Corporation, OU=.NET Framework (CoreFX), CN=localhost
Subject Public Key Info:
Public Key Algorithm: rsaEncryption
Public-Key: (2048 bit)
Modulus:
00:af:81:c1:cb:d8:20:3f:62:4a:53:9e:d6:60:81:
75:37:23:93:a2:83:7d:48:90:e4:8a:19:de:d3:69:
73:11:56:20:96:8d:6b:e0:d3:da:a3:8a:a7:77:be:
02:ee:0b:6b:93:b7:24:e8:dc:c1:2b:63:2b:4f:a8:
0b:bc:92:5b:ce:62:4f:4c:a7:cc:60:63:06:b3:94:
03:e2:8c:93:2d:24:dd:54:6f:fe:4e:f6:a3:7f:10:
77:0b:22:15:ea:8c:bb:5b:f4:27:e8:c4:d8:9b:79:
eb:33:83:75:10:0c:5f:83:e5:5d:e9:b4:46:6d:df:
be:ee:42:53:9a:ef:33:ef:18:7b:77:60:c3:b1:a1:
b2:10:3c:2d:81:44:56:4a:0c:10:39:a0:9c:85:cf:
6b:59:74:eb:51:6f:c8:d6:62:3c:94:ae:3a:5a:0b:
b3:b4:c7:92:95:7d:43:23:91:56:6c:f3:e2:a5:2a:
fb:0c:14:2b:9e:06:81:b8:97:26:71:af:2b:82:dd:
39:0a:39:b9:39:cf:71:95:68:68:7e:49:90:a6:30:
50:ca:77:68:dc:d6:b3:78:84:2f:18:fd:b1:f6:d9:
ff:09:6b:af:7b:eb:98:dc:f9:30:d6:6f:cf:d5:03:
f5:8d:41:bf:f4:62:12:e2:4e:3a:fc:45:ea:42:bd:
88:47
Exponent: 8589935681 (0x200000441)
X509v3 extensions:
X509v3 Subject Key Identifier:
78:A5:C7:5D:51:66:73:31:D5:A9:69:24:11:4C:9B:5F:A0:0D:7B:CB
X509v3 Authority Key Identifier:
keyid:78:A5:C7:5D:51:66:73:31:D5:A9:69:24:11:4C:9B:5F:A0:0D:7B:CB
X509v3 Basic Constraints:
CA:TRUE
Signature Algorithm: sha256WithRSAEncryption
77:75:6d:05:ff:a6:ad:fe:d5:b6:d4:af:b5:40:84:0c:6d:01:
cf:6b:3f:a6:c9:73:df:d6:1f:ca:a0:a8:14:fa:1e:24:69:01:
9d:94:b1:d8:56:d0:7d:d2:b9:5b:85:50:df:d2:08:59:53:a4:
94:b9:9e:fc:ba:a7:98:2c:e7:71:98:4f:9d:4a:44:5f:fe:e0:
62:e8:a0:49:73:6a:39:fd:99:4e:1f:da:0a:5d:c2:b5:b0:e5:
7a:0b:10:c4:1b:c7:fe:6a:40:b2:4f:85:97:73:02:59:3e:60:
b9:8d:d4:81:1d:47:d9:48:ed:f8:d6:e6:b5:af:80:a1:82:74:
96:e2:0b:fd:24:0e:46:76:74:50:4d:4e:47:03:33:1d:64:70:
5c:36:fb:6e:14:ba:bf:d9:cb:ee:c4:4b:33:a8:d7:b3:64:79:
90:0f:3c:5b:ba:b6:9c:5e:45:3d:18:07:83:e2:50:80:51:b9:
98:c0:38:e4:62:25:71:d2:ab:89:1d:89:8e:54:58:82:8c:f1:
86:79:51:7d:28:db:ca:bf:72:e8:13:07:bf:d7:21:b7:3d:db:
17:51:12:3f:99:d8:fc:0d:53:37:98:c4:db:d1:47:19:d5:d8:
a8:5b:00:a1:44:a3:67:67:7b:48:89:1a:9b:56:f0:45:33:48:
11:ba:cb:7a

为了避免眼睛疲劳：其中一个在当前过去有到期日，另一个在当前将来有到期日。(我懒得注入扩展)。

哪一个是正确的？

$ openssl verify test.cer
test.cer: C = US, ST = Washington, L = Redmond, O = Microsoft Corporation, OU = .NET Framework (CoreFX), CN = localhost
error 18 at 0 depth lookup:self signed certificate
C = US, ST = Washington, L = Redmond, O = Microsoft Corporation, OU = .NET Framework (CoreFX), CN = localhost
error 10 at 0 depth lookup:certificate has expired
OK
$ openssl verify alsotest.cer
alsotest.cer: C = US, ST = Washington, L = Redmond, O = Microsoft Corporation, OU = .NET Framework (CoreFX), CN = localhost
error 18 at 0 depth lookup:self signed certificate
OK

德拉特，他们都是对的。 还是他们？ 等等，openssl verify通常不会检查自签名，因为这通常无关紧要。

$ openssl verify -check_ss_sig test.cer
test.cer: C = US, ST = Washington, L = Redmond, O = Microsoft Corporation, OU = .NET Framework (CoreFX), CN = localhost
error 18 at 0 depth lookup:self signed certificate
C = US, ST = Washington, L = Redmond, O = Microsoft Corporation, OU = .NET Framework (CoreFX), CN = localhost
error 10 at 0 depth lookup:certificate has expired
OK
$ openssl verify -check_ss_sig alsotest.cer
alsotest.cer: C = US, ST = Washington, L = Redmond, O = Microsoft Corporation, OU = .NET Framework (CoreFX), CN = localhost
error 18 at 0 depth lookup:self signed certificate
C = US, ST = Washington, L = Redmond, O = Microsoft Corporation, OU = .NET Framework (CoreFX), CN = localhost
error 7 at 0 depth lookup:certificate signature failure
140450704717464:error:04091068:rsa routines:INT_RSA_VERIFY:bad signature:rsa_sign.c:278:
140450704717464:error:0D0C5006:asn1 encoding routines:ASN1_item_verify:EVP lib:a_verify.c:218:

我们开始吧。 此外，Test.cer 被修改(未辞职)以延长其到期日期。