Openssl

Links

• Why you don't want EV certificate
• SSL confg generator
• openssl homepage
• http://gagravarr.org/writing/openssl-certs/index.shtml

Tools

• sslscan

Documentation and HOWTOs

• OpenSSL Certificate Authority Setup
• Validating a Certificate Path with OpenSSL
• How SSL and TLS work
• OpenSSL Certificate Authority
• http://dataslinger.com/index.php?/archives/5-Configuring-SSL-certificates-for-Apache,-Dovecot,-Sendmail,-and-IIS.html
• ssl cert HOWTO
• OpenSSL Command-Line HOWTO
• 1. Way: SubjectAltName Only
• OpenSSL Command-Line HOWTO
• How to Create a .PEM file for SSL Certificate Installation
• http://www.tc.umn.edu/~brams006/selfsign.html
• Verifying that a Private Key Matches a Certificate
• Getting your certificate chain right
• Verify certificate chain

Dovecot and ssl

Networksolutions certs: After creating myserver.key and myserver.csr and obtaining certs: (don't forget to insert newlines between the blocks!)

cat OV_NetworkSolutionsOVServerCA2.crt OV_USERTrustRSACertificationAuthority.crt AddTrustExternalCARoot.crt > intermediate.pem

In dovecot.conf:

ssl_cert_file = /usr/local/etc/IMAP.EXAMPLE.COM.crt
ssl_key_file = /usr/local/etc/myserver.key
#optional, only if you want to require client to provide cert
#ssl_ca_file = /usr/local/etc/intermediate.pem

Courier-imap and ssl

• http://linsec.ca/Using_Courier-IMAP_and_SSL
• http://linux.seindal.dk/2005/12/04/making-a-courier-imap-ssl-sertificate/

Networksolutions certs: After creating myserver.key and myserver.csr and obtaining certs: (don't forget to insert newlines between the blocks!)

cat AddTrustExternalCARoot.crt NetworkSolutions_CA.crt > intermediate.pem
cat myserver.key >> IMAP.EXAMPLE.COM.crt

In imapd-ssl:

TLS_CERTFILE=/usr/local/etc/courier-certs/IMAP.EXAMPLE.COM.crt
TLS_TRUSTCERTS=/usr/local/etc/courier-certs/intermediate.pem

Network Solutions certificates bundle

See http://blog.irontechsolutions.com/2008/12/10/ssl-chained-certificates-explained/

cat OV_NetworkSolutionsOVServerCA2.crt OV_USERTrustRSACertificationAuthority.crt AddTrustExternalCARoot.crt > intermediate.txt

Comodo bundle order

COMODORSAOrganizationValidationSecureServerCA. + COMODO rsa add trust ca ( + addtrustexternalcaroot )

Generate a signing request

openssl req -nodes -newkey rsa:2048 -keyout my.domain.key -out my.domain.csr

The resulting csr is the signing request, my.domain.key is the private key you save not readable for anyone but root!

Tips&Tricks

Create private key (using config file)

openssl req (-config /etc/pki/tls/www.example.com.cnf) -newkey rsa:2048 -nodes -keyout domain.key

Create CSR using config file

openssl req -config /etc/pki/tls/www.example.com.cnf -new -newkey rsa:2048 -nodes -keyout example.com.key -out www.example.com.csr

Convert der to pem

openssl x509 -inform der -in certificate.cer -out certificate.pem

Creating CSR for multiple hosts

For example http://blog.endpoint.com/2014/10/openssl-csr-with-alternative-names-one.html

Remove password from private key

https://wiki.apache.org/httpd/RemoveSSLCertPassPhrase

Examining certificates

• http://www.madboa.com/geek/openssl/#verify-standard

openssl verify cert.pem

openssl x509 -in cacert.pem -noout -text
openssl x509 -in foo.pem  -inform pem -noout -text 

openssl rsa -noout -text -in server.key
openssl req -noout -text -in server.csr
openssl rsa -noout -text -in ca.key
openssl x509 -noout -text -in ca.crt

with expiration date:

openssl x509 -noout -text -enddate -in ca.crt

1. to check CN

openssl x509 -in server.crt -noout -subject

openssl pkcs12 -info -in keyStore.p12
openssl pkcs12 -info -in keyStore.pfx

Checking a service

1. Note -CApath should point to your local collection of public CA certs

openssl s_client -connect -CApath /etc/ssl/certs host:pop3 -starttls pop3
openssl s_client -port 443 -CApath /etc/ssl/certs -host webmail.example.com -prexit
openssl s_client -connect imap.example.com:143 -starttls imap
openssl s_client -connect web.server:443 -showcerts

Check your site

• https://www.ssllabs.com/ssltest
• https://www.sslcheck.nl/

check if certs match

TODO: -clr_check too

openssl pkey -in privateKey.key -pubout -outform pem | sha256sum 
openssl x509 -in certificate.crt -pubkey -noout -outform pem | sha256sum 
openssl req -in CSR.csr -pubkey -noout -outform pem | sha256sum

These values show match Also:

openssl verify -CAfile ca-bundle foo_bar.crt

Creating your own CA and signing with it

(based on http://www.eclectica.ca/howto/ssl-cert-howto.php#rootc)

cd /etc/ssl
mkdir newcerts
(perform secret rituals)

FAQ

error 20 at 0 depth lookup: unable to get local issuer certificate

you probably need to provide the right -CAfile maybe self signed?

Verify return code: 21 (unable to verify the first certificate)

Probably requires bundle

check certificate chain

openssl s_client -connect www.example.com:443 -showcerts

check expiration date

echo | openssl s_client -servername NAME -connect HOST:PORT 2>/dev/null | openssl x509 -noout -dates

139814102202256:error:0906D06C:PEM routines:PEM_read_bio:no start line:pem_lib.c:707:Expecting: TRUSTED CERTIFICATE

i've seen this happen when someone deleted the BEGIN/END CERTIFICATE lines

SSL CTX certificate file error: error:0906D06C:PEM routines:PEM_read_bio:no start line

??

check if server supports old tls

openssl s_client -connect www.example.com:443 -tls1
openssl s_client -connect www.example.com:443 -tls1_1

or when vhost:

 openssl s_client -servername vhost.example.com -connect www.example.com:443 -tls1_1

ERROR: Certificate verification: Not trusted

seems to be an lftp issue

ssllabs checks

Chain issues Contains anchor

TODO

check smtp submission

openssl s_client -connect mail.host.com:587 -starttls smtp -tls1_