当你在linux通过 https 协议访问资源出现 The certificate has not yet been activated 或者类似的 certificate 验证失败的问题时。
请淡定，不要随意的改变软件设置绕开 ssl 的验证比如在wget 中加上 –no-check-certificate 参数。这样会对系统的安全性造成影响，后果会很严重。
分析此问题的原因，肯定出在证书验证的阶段，下面有一个解决此问题的方法。
linux 上的开源软件一般会使用 openssl 来做 ssl 验证，所以我们用这个工具来解决 https 验证不通过的问题。
首先，用 openssl 获取站点的证书.
openssl s_client -showcerts -connect github.com:443
返回结果如下:
[code lang=”bash”]
CONNECTED(00000003)
depth=1 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert SHA2 Extended Validation Server CA
verify error:num=20:unable to get local issuer certificate
verify return:0
—
Certificate chain
0 s:/businessCategory=Private Organization/1.3.6.1.4.1.311.60.2.1.3=US/1.3.6.1.4.1.311.60.2.1.2=Delaware/serialNumber=5157550/street=548 4th Street/postalCode=94107/C=US/ST=California/L=San Francisco/O=GitHub, Inc./CN=github.com
i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA
—–BEGIN CERTIFICATE—–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—–END CERTIFICATE—–
1 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA
i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA
—–BEGIN CERTIFICATE—–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—–END CERTIFICATE—–
—
Server certificate
subject=/businessCategory=Private Organization/1.3.6.1.4.1.311.60.2.1.3=US/1.3.6.1.4.1.311.60.2.1.2=Delaware/serialNumber=5157550/street=548 4th Street/postalCode=94107/C=US/ST=California/L=San Francisco/O=GitHub, Inc./CN=github.com
issuer=/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA
—
No client certificate CA names sent
—
SSL handshake has read 3233 bytes and written 446 bytes
—
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES128-GCM-SHA256
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
SSL-Session:
Protocol : TLSv1.2
Cipher : ECDHE-RSA-AES128-GCM-SHA256
Session-ID: 2D644C1675D1A3273104B2EA736037A18314FBD228D700669B8A64EBB09EF710
Session-ID-ctx:
Master-Key: 792ABBD9CB1ACC81DD1104005B4B93E2AFA716D7BB9AF73B7AAE2D80CCC64C313D7B6F927CFD2395B3B335D4DADFCFA7
Key-Arg : None
PSK identity: None
PSK identity hint: None
SRP username: None
Start Time: 1398835818
Timeout : 300 (sec)
Verify return code: 20 (unable to get local issuer certificate)
—
[/code]
将 —–BEGIN CERTIFICATE—– 和 —–END CERTIFICATE—– 之间，包含这两个标签的内容复制下来，保存成 github.pem 文件。
然后用 openssl 验证
openssl verify github.pem
github: OK
出现OK，说明验证通过。
然后将该文件复制到/etc/ssl/certs/ 路径下。
再试试你的git 或者 wget 来访问该站点的数据，就没有验证失败的提示了。
这个办法只是解决了验证失败的问题，但并不一定真正的验证失败的原因。
这个原因有很多可能性，我最近所碰到的这个问题，在和VPS 技术人员交流了3天之后，他们终于找到真正的原因：VPS 提供商在新开的节点上忘了给机器设置时间，导致证书过期引起验证不通过。
总结：
说了这么多，其实找到解决问题的方法，并不一定就是问题的原因，治标不治本，需要治本，还需要彻底完整的进行分析才行。
参考文章：
test-ssl-certificates-diagnosis-ssl-certificate
verify-ssl-certificate-openssl