Import a SSL certificate into a JVM

Sometimes, it's inevitable that HTTPs is only provided, or you are unable to change third part code to ignore certificate verification.

How to import a certificate into a JVM? Here are some steps.

Step1. Fetch the certificate

openssl s_client -connect youtube.com:443 < /dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > youtube.crt

Step2. Import the certificate

keytool -import -alias youtube.com -keystore /Users/chliu/.sdkman/candidates/java/current/jre/lib/security/cacerts -file youtube.crt
Enter keystore password:<changeit>

Owner: CN=*.google.com, O=Google LLC, L=Mountain View, ST=California, C=US
Issuer: CN=Google Internet Authority G3, O=Google Trust Services, C=US
Serial number: 3b6e50a1d2080062
Valid from: Tue Jan 29 22:58:00 CST 2019 until: Tue Apr 23 22:58:00 CST 2019
Certificate fingerprints:
     MD5:  19:0D:FC:58:69:85:29:59:C4:42:71:05:21:EA:B4:2E
     SHA1: E4:A8:7B:F5:3E:9A:17:4A:E2:9F:26:8F:81:23:78:E3:15:08:85:99
     SHA256: F7:EE:A9:17:44:FD:5D:E8:09:73:4D:97:85:E4:7E:AE:FA:73:6D:6F:31:36:55:0B:07:1B:15:68:D8:81:A3:C8
Signature algorithm name: SHA256withRSA
Subject Public Key Algorithm: 2048-bit RSA key
Version: 3

Extensions:

#1: ObjectId: 1.3.6.1.5.5.7.1.1 Criticality=false
AuthorityInfoAccess [
  [
   accessMethod: caIssuers
   accessLocation: URIName: http://pki.goog/gsr2/GTSGIAG3.crt
,
   accessMethod: ocsp
   accessLocation: URIName: http://ocsp.pki.goog/GTSGIAG3
]
]

#2: ObjectId: 2.5.29.35 Criticality=false
AuthorityKeyIdentifier [
KeyIdentifier [
0000: 77 C2 B8 50 9A 67 76 76   B1 2D C2 86 D0 83 A0 7E  w..P.gvv.-......
0010: A6 7E BA 4B                                        ...K
]
]

#3: ObjectId: 2.5.29.19 Criticality=true
BasicConstraints:[
  CA:false
  PathLen: undefined
]

#4: ObjectId: 2.5.29.31 Criticality=false
CRLDistributionPoints [
  [DistributionPoint:
     [URIName: http://crl.pki.goog/GTSGIAG3.crl]
]]

#5: ObjectId: 2.5.29.32 Criticality=false
CertificatePolicies [
  [CertificatePolicyId: [1.3.6.1.4.1.11129.2.5.3]
[]  ]
  [CertificatePolicyId: [2.23.140.1.2.2]
[]  ]
]

#6: ObjectId: 2.5.29.37 Criticality=false
ExtendedKeyUsages [
  serverAuth
]

#7: ObjectId: 2.5.29.17 Criticality=false
SubjectAlternativeName [
  DNSName: *.google.com
  DNSName: *.android.com
  DNSName: *.appengine.google.com
  DNSName: *.cloud.google.com
  DNSName: *.g.co
  DNSName: *.gcp.gvt2.com
  DNSName: *.ggpht.cn
  DNSName: *.google-analytics.com
  DNSName: *.google.ca
  DNSName: *.google.cl
  DNSName: *.google.co.in
  DNSName: *.google.co.jp
  DNSName: *.google.co.uk
  DNSName: *.google.com.ar
  DNSName: *.google.com.au
  DNSName: *.google.com.br
  DNSName: *.google.com.co
  DNSName: *.google.com.mx
  DNSName: *.google.com.tr
  DNSName: *.google.com.vn
  DNSName: *.google.de
  DNSName: *.google.es
  DNSName: *.google.fr
  DNSName: *.google.hu
  DNSName: *.google.it
  DNSName: *.google.nl
  DNSName: *.google.pl
  DNSName: *.google.pt
  DNSName: *.googleadapis.com
  DNSName: *.googleapis.cn
  DNSName: *.googlecommerce.com
  DNSName: *.googlevideo.com
  DNSName: *.gstatic.cn
  DNSName: *.gstatic.com
  DNSName: *.gstaticcnapps.cn
  DNSName: *.gvt1.com
  DNSName: *.gvt2.com
  DNSName: *.metric.gstatic.com
  DNSName: *.urchin.com
  DNSName: *.url.google.com
  DNSName: *.youtube-nocookie.com
  DNSName: *.youtube.com
  DNSName: *.youtubeeducation.com
  DNSName: *.youtubekids.com
  DNSName: *.yt.be
  DNSName: *.ytimg.com
  DNSName: android.clients.google.com
  DNSName: android.com
  DNSName: developer.android.google.cn
  DNSName: developers.android.google.cn
  DNSName: g.co
  DNSName: ggpht.cn
  DNSName: goo.gl
  DNSName: google-analytics.com
  DNSName: google.com
  DNSName: googlecommerce.com
  DNSName: source.android.google.cn
  DNSName: urchin.com
  DNSName: www.goo.gl
  DNSName: youtu.be
  DNSName: youtube.com
  DNSName: youtubeeducation.com
  DNSName: youtubekids.com
  DNSName: yt.be
]

#8: ObjectId: 2.5.29.14 Criticality=false
SubjectKeyIdentifier [
KeyIdentifier [
0000: BB F4 15 80 EC F0 4E F6   58 5A B1 49 4C 82 12 48  ......N.XZ.IL..H
0010: F9 FB 7E 3B                                        ...;
]
]

Step3. Check certificate in keystore

keytool -list -v -keystore $JAVA_HOME/jre/lib/security/cacerts
keytool -list -v -keystore $JAVA_HOME/jre/lib/security/cacerts | grep youtube

Step4. Specify trust store AND PASSWRD

-Djavax.net.ssl.trustStore=$JAVA_HOME/jre/lib/security/cacerts 
-Djavax.net.ssl.trustStorePassword=changeit 
-Djavax.net.debug=all

If there are some issue that hostname in certificate didn't matched, the steps below can help to confirm the issue.

• Check the Server’s FQDN and make sure this match with the URL configured on the Certificate.
• Wildcard certificate cannot support subdomain. The subdomain also need to create a certificate. How to Fix SSL Common Name Mismatch Error