Tuxtrooper Wiki

openssl pkcs12 -in <p12> -nodes -nokeys -passin pass:"<password>" | openssl x509 -info

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout server.key -out server.crt

Copy trusted cert into:

/etc/pki/ca-trust/source/anchors/

Exec command

sudo update-ca-trust

Fill csr_details.txt Server info:

    FQDN : srvweb01.bm.local
    hostname : srvweb01
    IP : 192.168.1.20

We want our cert to get be valid for those 3 addresses :

    https://srvweb01
    https://srvweb01.bm.local
    192.168.1.20

We should precise it into openssl configuration file :

[req]
default_bits = 2048
prompt = no
default_md = sha256
req_extensions = req_ext
distinguished_name = dn

[ dn ]
C=FR
ST=Grenoble
L=Grenoble
O=BLOGMOTION
OU=BLOGMOTION
emailAddress=cert@nospam-blogmotion.fr
CN = srvweb01.bm.local

[ req_ext ]
subjectAltName = @alt_names

[ alt_names ]
DNS.1 = srvweb01
DNS.2 = srvwebalias
IP.1 = 192.168.1.20
EOF

openssl req -nodes -newkey rsa:2048 -sha256 -days 3650 -keyout srvweb01.key -out srvweb01.csr -config csr_details.txt

remotely

DOM="FILLME"
PORT="443"
## note echo added ##
echo | openssl s_client -servername $DOM -connect $DOM:$PORT \
| openssl x509 -noout -dates

locally

openssl x509 -enddate -noout -in {/path/to/my/my.pem}

Prepare the configuration file

Choose a directory (/root/ca) to store all keys and certificates.

# mkdir /root/ca

Create the directory structure. The index.txt and serial files act as a flat file database to keep track of signed certificates.

# cd /root/ca
# mkdir certs crl newcerts private
# chmod 700 private
# touch index.txt
# echo 1000 > serial

Copy the root CA configuration file to /root/ca/openssl.cnf.

# OpenSSL root CA configuration file.
# Copy to `/root/ca/openssl.cnf`.

[ ca ]
# `man ca`
default_ca = CA_default

[ CA_default ]
# Directory and file locations.
dir               = /root/ca
certs             = $dir/certs
crl_dir           = $dir/crl
new_certs_dir     = $dir/newcerts
database          = $dir/index.txt
serial            = $dir/serial
RANDFILE          = $dir/private/.rand

# The root key and root certificate.
private_key       = $dir/private/ca.key.pem
certificate       = $dir/certs/ca.cert.pem

# For certificate revocation lists.
crlnumber         = $dir/crlnumber
crl               = $dir/crl/ca.crl.pem
crl_extensions    = crl_ext
default_crl_days  = 30

# SHA-1 is deprecated, so use SHA-2 instead.
default_md        = sha256

name_opt          = ca_default
cert_opt          = ca_default
default_days      = 375
preserve          = no
policy            = policy_strict

[ policy_strict ]
# The root CA should only sign intermediate certificates that match.
# See the POLICY FORMAT section of `man ca`.
countryName             = match
stateOrProvinceName     = match
organizationName        = match
organizationalUnitName  = optional
commonName              = supplied
emailAddress            = optional

[ policy_loose ]
# Allow the intermediate CA to sign a more diverse range of certificates.
# See the POLICY FORMAT section of the `ca` man page.
countryName             = optional
stateOrProvinceName     = optional
localityName            = optional
organizationName        = optional
organizationalUnitName  = optional
commonName              = supplied
emailAddress            = optional

[ req ]
# Options for the `req` tool (`man req`).
default_bits        = 2048
distinguished_name  = req_distinguished_name
string_mask         = utf8only

# SHA-1 is deprecated, so use SHA-2 instead.
default_md          = sha256

# Extension to add when the -x509 option is used.
x509_extensions     = v3_ca

[ req_distinguished_name ]
# See <https://en.wikipedia.org/wiki/Certificate_signing_request>.
countryName                     = Country Name (2 letter code)
stateOrProvinceName             = State or Province Name
localityName                    = Locality Name
0.organizationName              = Organization Name
organizationalUnitName          = Organizational Unit Name
commonName                      = Common Name
emailAddress                    = Email Address

# Optionally, specify some defaults.
countryName_default             = GB
stateOrProvinceName_default     = England
localityName_default            =
0.organizationName_default      = Alice Ltd
organizationalUnitName_default  =
emailAddress_default            =

[ v3_ca ]
# Extensions for a typical CA (`man x509v3_config`).
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always,issuer
basicConstraints = critical, CA:true
keyUsage = critical, digitalSignature, cRLSign, keyCertSign

[ v3_intermediate_ca ]
# Extensions for a typical intermediate CA (`man x509v3_config`).
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always,issuer
basicConstraints = critical, CA:true, pathlen:0
keyUsage = critical, digitalSignature, cRLSign, keyCertSign

[ usr_cert ]
# Extensions for client certificates (`man x509v3_config`).
basicConstraints = CA:FALSE
nsCertType = client, email
nsComment = "OpenSSL Generated Client Certificate"
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid,issuer
keyUsage = critical, nonRepudiation, digitalSignature, keyEncipherment
extendedKeyUsage = clientAuth, emailProtection

[ server_cert ]
# Extensions for server certificates (`man x509v3_config`).
basicConstraints = CA:FALSE
nsCertType = server
nsComment = "OpenSSL Generated Server Certificate"
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid,issuer:always
keyUsage = critical, digitalSignature, keyEncipherment
extendedKeyUsage = serverAuth

[ crl_ext ]
# Extension for CRLs (`man x509v3_config`).
authorityKeyIdentifier=keyid:always

[ ocsp ]
# Extension for OCSP signing certificates (`man ocsp`).
basicConstraints = CA:FALSE
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid,issuer
keyUsage = critical, digitalSignature
extendedKeyUsage = critical, OCSPSigning

The [ ca ] section is mandatory. Here we tell OpenSSL to use the options from the [ CA_default ] section. The [ CA_default ] section contains a range of defaults. Make sure you declare the directory you chose earlier (/root/ca). We’ll apply policy_strict for all root CA signatures, as the root CA is only being used to create intermediate CAs. We’ll apply policy_loose for all intermediate CA signatures, as the intermediate CA is signing server and client certificates that may come from a variety of third-parties. Options from the [ req ] section are applied when creating certificates or certificate signing requests. The [ req_distinguished_name ] section declares the information normally required in a certificate signing request. You can optionally specify some defaults. We’ll apply the v3_ca extension when we create the root certificate. We’ll apply the v3_ca_intermediate extension when we create the intermediate certificate. pathlen:0 ensures that there can be no further certificate authorities below the intermediate CA. We’ll apply the usr_cert extension when signing client certificates, such as those used for remote user authentication. We’ll apply the server_cert extension when signing server certificates, such as those used for web servers. The crl_ext extension is automatically applied when creating certificate revocation lists. We’ll apply the ocsp extension when signing the Online Certificate Status Protocol (OCSP) certificate.

Create the root key

Create the root key (ca.key.pem) and keep it absolutely secure. Anyone in possession of the root key can issue trusted certificates. Encrypt the root key with AES 256-bit encryption and a strong password.

# cd /root/ca
# openssl genrsa -aes256 -out private/ca.key.pem 4096
# chmod 400 private/ca.key.pem

Create the root certificate

Use the root key (ca.key.pem) to create a root certificate (ca.cert.pem). Give the root certificate a long expiry date, such as twenty years. Once the root certificate expires, all certificates signed by the CA become invalid.

Warning Whenever you use the req tool, you must specify a configuration file to use with the -config option, otherwise OpenSSL will default to /etc/pki/tls/openssl.cnf.

# cd /root/ca
# openssl req -config openssl.cnf \
      -key private/ca.key.pem \
      -new -x509 -days 7300 -sha256 -extensions v3_ca \
      -out certs/ca.cert.pem
# chmod 444 certs/ca.cert.pem

Verify the root certificate

# openssl x509 -noout -text -in certs/ca.cert.pem

Prepare the directory

The root CA files are kept in /root/ca. Choose a different directory (/root/ca/intermediate) to store the intermediate CA files.

# mkdir /root/ca/intermediate

Create the same directory structure used for the root CA files. It’s convenient to also create a csr directory to hold certificate signing requests.

# cd /root/ca/intermediate
# mkdir certs crl csr newcerts private
# chmod 700 private
# touch index.txt
# echo 1000 > serial

Add a crlnumber file to the intermediate CA directory tree. crlnumber is used to keep track of certificate revocation lists.

# echo 1000 > /root/ca/intermediate/crlnumber

Copy the intermediate CA configuration file to /root/ca/intermediate/openssl.cnf.

# OpenSSL intermediate CA configuration file.
# Copy to `/root/ca/intermediate/openssl.cnf`.

[ ca ]
# `man ca`
default_ca = CA_default

[ CA_default ]
# Directory and file locations.
dir               = /root/ca/intermediate
certs             = $dir/certs
crl_dir           = $dir/crl
new_certs_dir     = $dir/newcerts
database          = $dir/index.txt
serial            = $dir/serial
RANDFILE          = $dir/private/.rand

# The root key and root certificate.
private_key       = $dir/private/intermediate.key.pem
certificate       = $dir/certs/intermediate.cert.pem

# For certificate revocation lists.
crlnumber         = $dir/crlnumber
crl               = $dir/crl/intermediate.crl.pem
crl_extensions    = crl_ext
default_crl_days  = 30

# SHA-1 is deprecated, so use SHA-2 instead.
default_md        = sha256

name_opt          = ca_default
cert_opt          = ca_default
default_days      = 375
preserve          = no
policy            = policy_loose

[ policy_strict ]
# The root CA should only sign intermediate certificates that match.
# See the POLICY FORMAT section of `man ca`.
countryName             = match
stateOrProvinceName     = match
organizationName        = match
organizationalUnitName  = optional
commonName              = supplied
emailAddress            = optional

[ policy_loose ]
# Allow the intermediate CA to sign a more diverse range of certificates.
# See the POLICY FORMAT section of the `ca` man page.
countryName             = optional
stateOrProvinceName     = optional
localityName            = optional
organizationName        = optional
organizationalUnitName  = optional
commonName              = supplied
emailAddress            = optional

[ req ]
# Options for the `req` tool (`man req`).
default_bits        = 2048
distinguished_name  = req_distinguished_name
string_mask         = utf8only

# SHA-1 is deprecated, so use SHA-2 instead.
default_md          = sha256

# Extension to add when the -x509 option is used.
x509_extensions     = v3_ca

[ req_distinguished_name ]
# See <https://en.wikipedia.org/wiki/Certificate_signing_request>.
countryName                     = Country Name (2 letter code)
stateOrProvinceName             = State or Province Name
localityName                    = Locality Name
0.organizationName              = Organization Name
organizationalUnitName          = Organizational Unit Name
commonName                      = Common Name
emailAddress                    = Email Address

# Optionally, specify some defaults.
countryName_default             = GB
stateOrProvinceName_default     = England
localityName_default            =
0.organizationName_default      = Alice Ltd
organizationalUnitName_default  =
emailAddress_default            =

[ v3_ca ]
# Extensions for a typical CA (`man x509v3_config`).
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always,issuer
basicConstraints = critical, CA:true
keyUsage = critical, digitalSignature, cRLSign, keyCertSign

[ v3_intermediate_ca ]
# Extensions for a typical intermediate CA (`man x509v3_config`).
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always,issuer
basicConstraints = critical, CA:true, pathlen:0
keyUsage = critical, digitalSignature, cRLSign, keyCertSign

[ usr_cert ]
# Extensions for client certificates (`man x509v3_config`).
basicConstraints = CA:FALSE
nsCertType = client, email
nsComment = "OpenSSL Generated Client Certificate"
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid,issuer
keyUsage = critical, nonRepudiation, digitalSignature, keyEncipherment
extendedKeyUsage = clientAuth, emailProtection

[ server_cert ]
# Extensions for server certificates (`man x509v3_config`).
basicConstraints = CA:FALSE
nsCertType = server
nsComment = "OpenSSL Generated Server Certificate"
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid,issuer:always
keyUsage = critical, digitalSignature, keyEncipherment
extendedKeyUsage = serverAuth

[ crl_ext ]
# Extension for CRLs (`man x509v3_config`).
authorityKeyIdentifier=keyid:always

[ ocsp ]
# Extension for OCSP signing certificates (`man ocsp`).
basicConstraints = CA:FALSE
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid,issuer
keyUsage = critical, digitalSignature
extendedKeyUsage = critical, OCSPSigning

Create the intermediate key

Create the intermediate key (intermediate.key.pem). Encrypt the intermediate key with AES 256-bit encryption and a strong password.

# cd /root/ca
# openssl genrsa -aes256 \
      -out intermediate/private/intermediate.key.pem 4096
# chmod 400 intermediate/private/intermediate.key.pem

Create the intermediate certificate

Use the intermediate key to create a certificate signing request (CSR). The details should generally match the root CA. The Common Name, however, must be different.

Warning Make sure you specify the intermediate CA configuration file (intermediate/openssl.cnf).

# cd /root/ca
# openssl req -config intermediate/openssl.cnf -new -sha256 \
      -key intermediate/private/intermediate.key.pem \
      -out intermediate/csr/intermediate.csr.pem

To create an intermediate certificate, use the root CA with the v3_intermediate_ca extension to sign the intermediate CSR. The intermediate certificate should be valid for a shorter period than the root certificate. Ten years would be reasonable.

Warning This time, specify the root CA configuration file (/root/ca/openssl.cnf).

# cd /root/ca
# openssl ca -config openssl.cnf -extensions v3_intermediate_ca \
      -days 3650 -notext -md sha256 \
      -in intermediate/csr/intermediate.csr.pem \
      -out intermediate/certs/intermediate.cert.pem
# chmod 444 intermediate/certs/intermediate.cert.pem

The index.txt file is where the OpenSSL ca tool stores the certificate database. Do not delete or edit this file by hand. It should now contain a line that refers to the intermediate certificate.

Verify the intermediate certificate

As we did for the root certificate, check that the details of the intermediate certificate are correct.

# openssl x509 -noout -text \
      -in intermediate/certs/intermediate.cert.pem

Verify the intermediate certificate against the root certificate. An OK indicates that the chain of trust is intact.

# openssl verify -CAfile certs/ca.cert.pem \
      intermediate/certs/intermediate.cert.pem

Create the certificate chain file

When an application (eg, a web browser) tries to verify a certificate signed by the intermediate CA, it must also verify the intermediate certificate against the root certificate. To complete the chain of trust, create a CA certificate chain to present to the application.

To create the CA certificate chain, concatenate the intermediate and root certificates together. We will use this file later to verify certificates signed by the intermediate CA.

# cat intermediate/certs/intermediate.cert.pem \
      certs/ca.cert.pem > intermediate/certs/ca-chain.cert.pem
# chmod 444 intermediate/certs/ca-chain.cert.pem

Note

Our certificate chain file must include the root certificate because no client application knows about it yet. A better option, particularly if you’re administrating an intranet, is to install your root certificate on every client that needs to connect. In that case, the chain file need only contain your intermediate certificate.

We will be signing certificates using our intermediate CA. You can use these signed certificates in a variety of situations, such as to secure connections to a web server or to authenticate clients connecting to a service.

Note

The steps below are from your perspective as the certificate authority. A third-party, however, can instead create their own private key and certificate signing request (CSR) without revealing their private key to you. They give you their CSR, and you give back a signed certificate. In that scenario, skip the genrsa and req commands.

Create a key

Our root and intermediate pairs are 4096 bits. Server and client certificates normally expire after one year, so we can safely use 2048 bits instead.

Note

Although 4096 bits is slightly more secure than 2048 bits, it slows down TLS handshakes and significantly increases processor load during handshakes. For this reason, most websites use 2048-bit pairs.

If you’re creating a cryptographic pair for use with a web server (eg, Apache), you’ll need to enter this password every time you restart the web server. You may want to omit the -aes256 option to create a key without a password.

# cd /root/ca
# openssl genrsa -aes256 \
      -out intermediate/private/www.example.com.key.pem 2048
# chmod 400 intermediate/private/www.example.com.key.pem

Create a certificate

Use the private key to create a certificate signing request (CSR). The CSR details don’t need to match the intermediate CA. For server certificates, the Common Name must be a fully qualified domain name (eg, www.example.com), whereas for client certificates it can be any unique identifier (eg, an e-mail address). Note that the Common Name cannot be the same as either your root or intermediate certificate.

# cd /root/ca
# openssl req -config intermediate/openssl.cnf \
      -key intermediate/private/www.example.com.key.pem \
      -new -sha256 -out intermediate/csr/www.example.com.csr.pem

To create a certificate, use the intermediate CA to sign the CSR. If the certificate is going to be used on a server, use the server_cert extension. If the certificate is going to be used for user authentication, use the usr_cert extension. Certificates are usually given a validity of one year, though a CA will typically give a few days extra for convenience.

# cd /root/ca
# openssl ca -config intermediate/openssl.cnf \
      -extensions server_cert -days 375 -notext -md sha256 \
      -in intermediate/csr/www.example.com.csr.pem \
      -out intermediate/certs/www.example.com.cert.pem
# chmod 444 intermediate/certs/www.example.com.cert.pem

The intermediate/index.txt file should contain a line referring to this new certificate.

Verify the certificate

# openssl x509 -noout -text \
      -in intermediate/certs/www.example.com.cert.pem

The Issuer is the intermediate CA. The Subject refers to the certificate itself.

The output will also show the X509v3 extensions. When creating the certificate, you used either the server_cert or usr_cert extension. The options from the corresponding configuration section will be reflected in the output.

Use the CA certificate chain file we created earlier (ca-chain.cert.pem) to verify that the new certificate has a valid chain of trust.

# openssl verify -CAfile intermediate/certs/ca-chain.cert.pem \
      intermediate/certs/www.example.com.cert.pem

Deploy the certificate

You can now either deploy your new certificate to a server, or distribute the certificate to a client. When deploying to a server application (eg, Apache), you need to make the following files available:

  ca-chain.cert.pem
  www.example.com.key.pem
  www.example.com.cert.pem

If you’re signing a CSR from a third-party, you don’t have access to their private key so you only need to give them back the chain file (ca-chain.cert.pem) and the certificate (www.example.com.cert.pem).

A certificate revocation list (CRL) provides a list of certificates that have been revoked. A client application, such as a web browser, can use a CRL to check a server’s authenticity. A server application, such as Apache or OpenVPN, can use a CRL to deny access to clients that are no longer trusted.

Publish the CRL at a publicly accessible location (eg, http://example.com/intermediate.crl.pem). Third-parties can fetch the CRL from this location to check whether any certificates they rely on have been revoked.

Note: Some applications vendors have deprecated CRLs and are instead using the Online Certificate Status Protocol (OCSP). Prepare the configuration file

When a certificate authority signs a certificate, it will normally encode the CRL location into the certificate. Add crlDistributionPoints to the appropriate sections. In our case, add it to the [ server_cert ] section.

[ server_cert ]
# ... snipped ...
crlDistributionPoints = URI:http://example.com/intermediate.crl.pem

Create the CRL

# cd /root/ca
# openssl ca -config intermediate/openssl.cnf \
      -gencrl -out intermediate/crl/intermediate.crl.pem

Note

The CRL OPTIONS section of the ca man page contains more information on how to create CRLs.

You can check the contents of the CRL with the crl tool.

# openssl crl -in intermediate/crl/intermediate.crl.pem -noout -text

No certificates have been revoked yet, so the output will state No Revoked Certificates.

You should re-create the CRL at regular intervals. By default, the CRL expires after 30 days. This is controlled by the default_crl_days option in the [ CA_default ] section.

Revoke a certificate

Let’s walk through an example. Alice is running the Apache web server and has a private folder of heart-meltingly cute kitten pictures. Alice wants to grant her friend, Bob, access to this collection.

Bob creates a private key and certificate signing request (CSR).

$ cd /home/bob
$ openssl genrsa -out bob@example.com.key.pem 2048
$ openssl req -new -key bob@example.com.key.pem \
      -out bob@example.com.csr.pem

Bob sends his CSR to Alice, who then signs it.

# cd /root/ca
# openssl ca -config intermediate/openssl.cnf \
      -extensions usr_cert -notext -md sha256 \
      -in intermediate/csr/bob@example.com.csr.pem \
      -out intermediate/certs/bob@example.com.cert.pem

Alice verifies that the certificate is valid:

# openssl verify -CAfile intermediate/certs/ca-chain.cert.pem \
      intermediate/certs/bob@example.com.cert.pem

The index.txt file should contain a new entry.

Alice sends Bob the signed certificate. Bob installs the certificate in his web browser and is now able to access Alice’s kitten pictures. Hurray!

Sadly, it turns out that Bob is misbehaving. Bob has posted Alice’s kitten pictures to Hacker News, claiming that they’re his own and gaining huge popularity. Alice finds out and needs to revoke his access immediately.

# cd /root/ca
# openssl ca -config intermediate/openssl.cnf \
      -revoke intermediate/certs/bob@example.com.cert.pem

The line in index.txt that corresponds to Bob’s certificate now begins with the character R. This means the certificate has been revoked.

After revoking Bob’s certificate, Alice must re-create the CRL.

Server-side use of the CRL

For client certificates, it’s typically a server-side application (eg, Apache) that is doing the verification. This application needs to have local access to the CRL.

In Alice’s case, she can add the SSLCARevocationPath directive to her Apache configuration and copy the CRL to her web server. The next time that Bob connects to the web server, Apache will check his client certificate against the CRL and deny access.

Similarly, OpenVPN has a crl-verify directive so that it can block clients that have had their certificates revoked.

Client-side use of the CRL

For server certificates, it’s typically a client-side application (eg, a web browser) that performs the verification. This application must have remote access to the CRL.

If a certificate was signed with an extension that includes crlDistributionPoints, a client-side application can read this information and fetch the CRL from the specified location.

The CRL distribution points are visible in the certificate X509v3 details.

# openssl x509 -in cute-kitten-pictures.example.com.cert.pem -noout -text

The Online Certificate Status Protocol (OCSP) was created as an alternative to certificate revocation lists (CRLs). Similar to CRLs, OCSP enables a requesting party (eg, a web browser) to determine the revocation state of a certificate.

When a CA signs a certificate, they will typically include an OCSP server address (eg, http://ocsp.example.com) in the certificate. This is similar in function to crlDistributionPoints used for CRLs.

As an example, when a web browser is presented with a server certificate, it will send a query to the OCSP server address specified in the certificate. At this address, an OCSP responder listens to queries and responds with the revocation status of the certificate.

Note

It’s recommended to use OCSP instead where possible, though realistically you will tend to only need OCSP for website certificates. Some web browsers have deprecated or removed support for CRLs. Prepare the configuration file

To use OCSP, the CA must encode the OCSP server location into the certificates that it signs. Use the authorityInfoAccess option in the appropriate sections, which in our case means the [ server_cert ] section.

[ server_cert ]
# ... snipped ...
authorityInfoAccess = OCSP;URI:http://ocsp.example.com

Create the OCSP pair

The OCSP responder requires a cryptographic pair for signing the response that it sends to the requesting party. The OCSP cryptographic pair must be signed by the same CA that signed the certificate being checked.

Create a private key and encrypt it with AES-256 encryption.

# cd /root/ca
# openssl genrsa -aes256 \
      -out intermediate/private/ocsp.example.com.key.pem 4096

Create a certificate signing request (CSR). The details should generally match those of the signing CA. The Common Name, however, must be a fully qualified domain name.

# cd /root/ca
# openssl req -config intermediate/openssl.cnf -new -sha256 \
      -key intermediate/private/ocsp.example.com.key.pem \
      -out intermediate/csr/ocsp.example.com.csr.pem

Sign the CSR with the intermediate CA.

# openssl ca -config intermediate/openssl.cnf \
      -extensions ocsp -days 375 -notext -md sha256 \
      -in intermediate/csr/ocsp.example.com.csr.pem \
      -out intermediate/certs/ocsp.example.com.cert.pem

Verify that the certificate has the correct X509v3 extensions.

# openssl x509 -noout -text \
      -in intermediate/certs/ocsp.example.com.cert.pem

Revoke a certificate

The OpenSSL ocsp tool can act as an OCSP responder, but it’s only intended for testing. Production ready OCSP responders exist, but those are beyond the scope of this guide.

Create a server certificate to test.

# cd /root/ca
# openssl genrsa -out intermediate/private/test.example.com.key.pem 2048
# openssl req -config intermediate/openssl.cnf \
      -key intermediate/private/test.example.com.key.pem \
      -new -sha256 -out intermediate/csr/test.example.com.csr.pem
# openssl ca -config intermediate/openssl.cnf \
      -extensions server_cert -days 375 -notext -md sha256 \
      -in intermediate/csr/test.example.com.csr.pem \
      -out intermediate/certs/test.example.com.cert.pem

Run the OCSP responder on localhost. Rather than storing revocation status in a separate CRL file, the OCSP responder reads index.txt directly. The response is signed with the OCSP cryptographic pair (using the -rkey and -rsigner options).

# openssl ocsp -port 127.0.0.1:2560 -text -sha256 \
      -index intermediate/index.txt \
      -CA intermediate/certs/ca-chain.cert.pem \
      -rkey intermediate/private/ocsp.example.com.key.pem \
      -rsigner intermediate/certs/ocsp.example.com.cert.pem \
      -nrequest 1

In another terminal, send a query to the OCSP responder. The -cert option specifies the certificate to query.

# openssl ocsp -CAfile intermediate/certs/ca-chain.cert.pem \
      -url http://127.0.0.1:2560 -resp_text \
      -issuer intermediate/certs/intermediate.cert.pem \
      -cert intermediate/certs/test.example.com.cert.pem

The start of the output shows:

whether a successful response was received (OCSP Response Status)
the identity of the responder (Responder Id)
the revocation status of the certificate (Cert Status)

OCSP Response Data:
    OCSP Response Status: successful (0x0)
    Response Type: Basic OCSP Response
    Version: 1 (0x0)
    Responder Id: ... CN = ocsp.example.com
    Produced At: Apr 11 12:59:51 2015 GMT
    Responses:
    Certificate ID:
      Hash Algorithm: sha1
      Issuer Name Hash: E35979B6D0A973EBE8AEDED75D8C27D67D2A0334
      Issuer Key Hash: 69E8EC547F252360E5B6E77261F1D4B921D445E9
      Serial Number: 1003
    Cert Status: good
    This Update: Apr 11 12:59:51 2015 GMT

Revoke the certificate.

# openssl ca -config intermediate/openssl.cnf \
      -revoke intermediate/certs/test.example.com.cert.pem

As before, run the OCSP responder and on another terminal send a query. This time, the output shows Cert Status: revoked and a Revocation Time.

OCSP Response Data:
    OCSP Response Status: successful (0x0)
    Response Type: Basic OCSP Response
    Version: 1 (0x0)
    Responder Id: ... CN = ocsp.example.com
    Produced At: Apr 11 13:03:00 2015 GMT
    Responses:
    Certificate ID:
      Hash Algorithm: sha1
      Issuer Name Hash: E35979B6D0A973EBE8AEDED75D8C27D67D2A0334
      Issuer Key Hash: 69E8EC547F252360E5B6E77261F1D4B921D445E9
      Serial Number: 1003
    Cert Status: revoked
    Revocation Time: Apr 11 13:01:09 2015 GMT
    This Update: Apr 11 13:03:00 2015 GMT

Create PKCS12 from PEM

keytool -v -importkeystore -srckeystore test.p12 -srcstorepass 'AZert12@' -srcstoretype PKCS12 -srcalias '1' -destkeystore test.jks -deststoretype JKS -destalias 'cymerius-tomcat' -storepass 'Changeme123!'

for i in ssl2 ssl3 tls1 tls1_1 tls1_2; do 
    for c in $(openssl ciphers "ALL:eNULL" | tr ':' ' '); do
        openssl s_client -connect <server>:<port> -cipher $c -$i < /dev/null > /dev/null 2>&1 && echo -e "$i:\t$c"
    done
done

openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile more.crt

SSL

Display cert from pkcs12

Self signed cert

Add trusted CA

CentOS 7

CSR with multiple DNS alias

Certificate expiration

CA creation

Create the root pair

Prepare the configuration file

Create the root key

Create the root certificate

Verify the root certificate

Create the intermediate pair

Prepare the directory

Create the intermediate key

Create the intermediate certificate

Verify the intermediate certificate

Create the certificate chain file

Sign server and client certificates

Create a key

Create a certificate

Verify the certificate

Deploy the certificate

Certificate revocation lists

Create the CRL

Revoke a certificate

Server-side use of the CRL

Client-side use of the CRL

Online Certificate Status Protocol

Create the OCSP pair

Revoke a certificate

Keystore creation from PEM

Check available algo

Create p12 from cert and key

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