误解CSR和X.509功能

时间：2017-04-20 09:27:58

标签： ssl x509certificate sign pem csr

在花了两天的时间搜索并找到我的问题的答案后才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，希望我没有错过我的信息。寻找某个地方。

我刚刚开始了一个项目，在开始使用此客户端之前，我必须与客户交换X.509证书。 我已经设法理解X.509证书的制作方式和原因：

  • 使用私钥制作CSR;
  • 此CSR包含数字身份和从私钥中提取的公钥;
  • CSR会自行签名或发送给使用自己的私钥签名的CA，以验证发件人的身份;
  • CA发回与X.509标准相匹配的证书，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的方法，以对抗潜在的中间人攻击。 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，它不会。
然后我使用不同的私钥（signingPrivateKey.pem）自我签署CSR，再次检查X.509证书是否与私钥匹配，它仍然不是（这似乎正常，因为CSR不是两者都应该匹配，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生成X.509证书，并且提取的公钥与之匹配。我把它发送给我的客户，他们发送证书给。 我们怎么知道X.509可靠？我读过某个地方，我们需要用CA的公钥“取消签名”X.509证书，将输出与散列证书进行比较，但每个人似乎都说X .509证书是自我保护的，它证明了你自己的身份。我们只需要用OpenSSL命令检查它的authencity？ 请点亮我这一点。

感谢您抽出时间阅读并理解我的问题，我再次希望我不是唯一一个面临这些问题的人，这篇文章将帮助其他人。 很抱歉，我不允许在这篇文章中添加更多链接，否则我会更准确。

1 个答案:

答案 0 :(得分：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。他们不一样。在通过MD5运行之前，你显然没有看输出：

$ 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

您尚未将其转换为证书，因此x509命令无效。

您在制作证书后再次检查，因为您使用了-signkey，所以会得到不同的答案。 documentation表示-signkey用作自签名密钥，这意味着替换原始请求中的公钥。如果您使用-signkey privateKey.pem，您的命令应显示对齐方式。

完整性

每个X.509证书都包含呈现的数据（包括公钥）和签名。对于“真正的”CA，通常会有一个说明（权限信息访问扩展），说明如何查找CA的证书。无论您是手头还是必须从互联网上检索，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发生变化。

签名CA本身有证书，所以你可以再迈出一步，证明它没有被改变。

最终，您将获得root /自签名证书。要么你已经拥有它并认为它是可靠的，要么你没有，并且你称之为malarkey。

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就是拒绝：如果有人编辑了您创建的证书，并添加了一个扩展名，说明“您的母亲是一个臭驴推销员！”您可以证明自签名签名无效。

$ 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

为了免除眼睛疲劳：其中一个在当前的过去有一个到期，另一个在当前的未来有一个到期日。 （我懒得注入扩展名。）

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
不，他们都是正确的。或者是他们？等等，openssl verify不会正常检查自签名签名，因为它通常无关紧要。

$ 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:

我们走了。修改了alsotest.cer（未经过重新签名）以延长其到期日期。

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