Question

我想知道pem文件是否同时包含私钥和公钥？什么是pem代表什么？

Answer 1

PEM文件可能包含任何内容，包括公钥，私钥或两者，因为PEM文件不是标准文件。实际上，PEM只意味着该文件包含base64编码的数据位。它通过引用旧的Privacy-Enhanced Mail标准称为PEM文件，该标准在S / MIME之前作为邮件安全标准。这些标准规定了特定base64格式的各种密钥和消息的格式。例如，请参阅RFC 1421。

通常，PEM文件包含base64编码的密钥或证书，其中包含-----BEGIN <whatever>-----和-----END <whatever>----形式的页眉和页脚行。随着时间的推移，<whatever>已经发展出许多可能性，包括私钥，公钥，X509证书，PKCS7数据，包含多个证书的文件，包含私钥和X509证书的文件，PKCS＃10证书签名请求， ...

Answer 2

您可以使用以下命令decode PEM格式化x509 certificate：

openssl x509 -in cert.pem -text -noout

PEM证书contains仅限公钥或私钥或。

对于以下example：

你会得到：

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 0 (0x0)
    Signature Algorithm: ecdsa-with-SHA256
        Issuer: C = BE, O = GnuTLS, OU = GnuTLS certificate authority, ST = Leuven, CN = GnuTLS certificate authority
        Validity
            Not Before: May 23 20:38:21 2011 GMT
            Not After : Dec 22 07:41:51 2012 GMT
        Subject: C = BE, O = GnuTLS, OU = GnuTLS certificate authority, ST = Leuven, CN = GnuTLS certificate authority
        Subject Public Key Info:
            Public Key Algorithm: id-ecPublicKey
                Public-Key: (256 bit)
                pub:
                    04:52:d8:8d:23:8a:e3:67:d7:86:36:b1:20:0b:09:
                    7d:c8:c9:ba:a2:20:95:2f:c5:4a:63:fa:83:5f:ce:
                    78:2f:8f:f3:62:ca:fd:b7:f7:80:56:9d:6e:17:b9:
                    0e:11:4c:48:b2:c0:af:3b:59:17:16:30:68:09:07:
                    99:17:fe:dd:a7
                ASN1 OID: prime256v1
                NIST CURVE: P-256
        X509v3 extensions:
            X509v3 Basic Constraints: critical
                CA:TRUE
            X509v3 Key Usage: critical
                Certificate Sign, CRL Sign
            X509v3 Subject Key Identifier: 
                F0:B4:81:FE:98:12:BF:B5:28:B9:64:40:03:CB:CC:1F:66:4E:28:03
    Signature Algorithm: ecdsa-with-SHA256
         30:45:02:20:31:ae:c0:3d:4a:3f:21:be:85:17:fc:f0:c7:b2:
         31:07:2a:38:56:43:d1:36:d5:95:e1:7e:52:c0:06:43:87:a7:
         02:21:00:97:8c:0e:b8:3c:0a:41:af:ae:a5:cf:06:7e:d5:c4:
         d8:2f:ff:e2:62:80:34:10:ba:22:dd:35:81:46:93:22:9a

要了解Public Key Algorithm和Signature Algorithm部分之间的差异，请阅读this（两者都是公开的）。

.pem文件是否包含私钥和公钥？

2 个答案: