Can I extract a private key out of Tomcat's memory?

Question

I'm running Tomcat 6. I was messing around with my keystore in order to try to fix some certificate chain problems, and I accidentally rm'd the production version instead of the .new file I was working with.

Now, Tomcat is still running and still able to serve HTTPS connections (I tested it in a web browser). Obviously there must be a copy of the private key that it still has access to. My first thought was to check /proc/PID/fd, so I ran sudo lsof | grep tomcat. This properly returns a list of open files:

$ sudo lsof | head -1; sudo lsof | grep tomcat
COMMAND     PID     USER   FD      TYPE             DEVICE  SIZE/OFF       NODE NAME
java       2599     root  cwd       DIR              202,1      4096     413699 /usr/share/apache-tomcat-6.0.44/bin
java       2599     root  mem       REG              202,1     51715     413777 /usr/share/apache-tomcat-6.0.44/lib/tomcat-i18n-fr.jar
java       2599     root  mem       REG              202,1    528303     413771 /usr/share/apache-tomcat-6.0.44/lib/jasper.jar
java       2599     root  mem       REG              202,1   1250454     413767 /usr/share/apache-tomcat-6.0.44/lib/catalina.jar
java       2599     root  mem       REG              202,1    132216     413765 /usr/share/apache-tomcat-6.0.44/lib/catalina-ha.jar
java       2599     root  mem       REG              202,1     54334     413778 /usr/share/apache-tomcat-6.0.44/lib/tomcat-i18n-ja.jar
java       2599     root  mem       REG              202,1   1830791     413768 /usr/share/apache-tomcat-6.0.44/lib/ecj-4.3.1.jar
java       2599     root  mem       REG              202,1     54624     413764 /usr/share/apache-tomcat-6.0.44/lib/catalina-ant.jar
java       2599     root  mem       REG              202,1     70563     413776 /usr/share/apache-tomcat-6.0.44/lib/tomcat-i18n-es.jar
java       2599     root  mem       REG              202,1    112521     413770 /usr/share/apache-tomcat-6.0.44/lib/jasper-el.jar
java       2599     root  mem       REG              202,1     76649     413772 /usr/share/apache-tomcat-6.0.44/lib/jsp-api.jar
java       2599     root  mem       REG              202,1     34622     413769 /usr/share/apache-tomcat-6.0.44/lib/el-api.jar
java       2599     root  mem       REG              202,1    253635     413775 /usr/share/apache-tomcat-6.0.44/lib/tomcat-dbcp.jar
java       2599     root  mem       REG              202,1     15250     413763 /usr/share/apache-tomcat-6.0.44/lib/annotations-api.jar
java       2599     root  mem       REG              202,1    801374     413774 /usr/share/apache-tomcat-6.0.44/lib/tomcat-coyote.jar
java       2599     root  mem       REG              202,1    239165     413766 /usr/share/apache-tomcat-6.0.44/lib/catalina-tribes.jar
java       2599     root  mem       REG              202,1    132240     413773 /usr/share/apache-tomcat-6.0.44/lib/servlet-api.jar
java       2599     root  mem       REG              202,1     32384     413759 /usr/share/apache-tomcat-6.0.44/bin/tomcat-juli.jar
java       2599     root  mem       REG              202,1     24283     413753 /usr/share/apache-tomcat-6.0.44/bin/commons-daemon.jar
java       2599     root  mem       REG              202,1     22807     413749 /usr/share/apache-tomcat-6.0.44/bin/bootstrap.jar
java       2599     root    1w      REG              202,1  17024956     413713 /usr/share/apache-tomcat-6.0.44/logs/catalina.out
java       2599     root    2w      REG              202,1  17024956     413713 /usr/share/apache-tomcat-6.0.44/logs/catalina.out
java       2599     root    4r      REG              202,1     22807     413749 /usr/share/apache-tomcat-6.0.44/bin/bootstrap.jar
java       2599     root    5r      REG              202,1     24283     413753 /usr/share/apache-tomcat-6.0.44/bin/commons-daemon.jar
java       2599     root    6r      REG              202,1     32384     413759 /usr/share/apache-tomcat-6.0.44/bin/tomcat-juli.jar
java       2599     root    7w      REG              202,1      4072     396419 /usr/share/apache-tomcat-6.0.44/logs/catalina.2016-04-21.log
java       2599     root    8w      REG              202,1      1182     396447 /usr/share/apache-tomcat-6.0.44/logs/localhost.2016-04-21.log
java       2599     root    9w      REG              202,1         0     396448 /usr/share/apache-tomcat-6.0.44/logs/manager.2016-04-21.log
java       2599     root   10w      REG              202,1         0     396455 /usr/share/apache-tomcat-6.0.44/logs/host-manager.2016-04-21.log
java       2599     root   11r      REG              202,1    239165     413766 /usr/share/apache-tomcat-6.0.44/lib/catalina-tribes.jar
java       2599     root   12r      REG              202,1    801374     413774 /usr/share/apache-tomcat-6.0.44/lib/tomcat-coyote.jar
java       2599     root   13r      REG              202,1    253635     413775 /usr/share/apache-tomcat-6.0.44/lib/tomcat-dbcp.jar
java       2599     root   14r      REG              202,1    132240     413773 /usr/share/apache-tomcat-6.0.44/lib/servlet-api.jar
java       2599     root   15r      REG              202,1     34622     413769 /usr/share/apache-tomcat-6.0.44/lib/el-api.jar
java       2599     root   16r      REG              202,1     76649     413772 /usr/share/apache-tomcat-6.0.44/lib/jsp-api.jar
java       2599     root   17r      REG              202,1    112521     413770 /usr/share/apache-tomcat-6.0.44/lib/jasper-el.jar
java       2599     root   18r      REG              202,1     70563     413776 /usr/share/apache-tomcat-6.0.44/lib/tomcat-i18n-es.jar
java       2599     root   19r      REG              202,1     54624     413764 /usr/share/apache-tomcat-6.0.44/lib/catalina-ant.jar
java       2599     root   20r      REG              202,1   1830791     413768 /usr/share/apache-tomcat-6.0.44/lib/ecj-4.3.1.jar
java       2599     root   21r      REG              202,1     54334     413778 /usr/share/apache-tomcat-6.0.44/lib/tomcat-i18n-ja.jar
java       2599     root   22r      REG              202,1     15250     413763 /usr/share/apache-tomcat-6.0.44/lib/annotations-api.jar
java       2599     root   23r      REG              202,1    132216     413765 /usr/share/apache-tomcat-6.0.44/lib/catalina-ha.jar
java       2599     root   24r      REG              202,1   1250454     413767 /usr/share/apache-tomcat-6.0.44/lib/catalina.jar
java       2599     root   25r      REG              202,1    528303     413771 /usr/share/apache-tomcat-6.0.44/lib/jasper.jar
java       2599     root   26r      REG              202,1     51715     413777 /usr/share/apache-tomcat-6.0.44/lib/tomcat-i18n-fr.jar
bash      29579 ec2-user  cwd       DIR              202,1      4096     413708 /usr/share/apache-tomcat-6.0.44/conf
sudo      30595     root  cwd       DIR              202,1      4096     413708 /usr/share/apache-tomcat-6.0.44/conf
grep      30596 ec2-user  cwd       DIR              202,1      4096     413708 /usr/share/apache-tomcat-6.0.44/conf
lsof      30597     root  cwd       DIR              202,1      4096     413708 /usr/share/apache-tomcat-6.0.44/conf
lsof      30598     root  cwd       DIR              202,1      4096     413708 /usr/share/apache-tomcat-6.0.44/conf

but unfortunately, my keystore isn't one of them. I guess Tomcat must have loaded it into memory and then closed the file descriptor. (The keystore was in /conf above, but those file descriptors are from my open shell, not from Tomcat itself.)

So: is there any way to recover my private key? I'm on Amazon Linux; uname -a returns Linux ip-10-0-0-105 4.4.5-15.26.amzn1.x86_64 #1 SMP Wed Mar 16 17:15:34 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux.

Attaching `gdb` to a process and running `gcore` should get you a dump of all data in the process. But better test it on an unimportant server first. Finding the key inside the dump is going to be a bit tricky. But it may become a lot easier if you have a public key to compare with. — kasperd, Apr 26 '16 at 21:26

score 1 · Accepted Answer · answered Apr 26 '16 at 21:23

1

You can try using passe-partout.

I have successfully used it with Apache, not with Tomcat, but it's advertised to work with Tomcat 7.0.34 + apr 1.4.6 + jdk7-openjdk 7.u9.

answered Apr 26 '16 at 21:23

dawud

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I actually ended up finding a copy somewhere else (thank god!) but if no one else answers for a little bit, I'll go ahead and mark this as accepted. thanks. – strugee Apr 26 '16 at 21:30

Can I extract a private key out of Tomcat's memory?

1 Answers1