Introduction
This document provides a script that can be run from a UNIX/Linux environment to simplify the process used to create a self-signed certificate and required Microsoft Azure steps when needed to configure Cisco Email Security. This script can be used for Mailbox Auto Remediation (MAR), Microsoft Office 365 LDAP Connector, or Cisco Threat Analyzer for Office 365. This script is independent and can be used with all versions of AsyncOS for Email Security Appliance (ESA).
Note: This article is a proof-of-concept and provided as an example basis. While these steps have been successfully tested, this article is intended primarily for demonstration and illustration purposes. Custom scripts are outside of the scope and supportability of Cisco. The Cisco Technical Assistance Center (TAC) will not write, update, or troubleshoot external scripts at any time. Before you attempt and construct any scripts, ensure that you have scripting knowledge when you construct the final script.
Note: Cisco TAC and Cisco Support are not entitled to troubleshoot customer-side issues with Microsoft Exchange, Microsoft Azure AD, or Office 365.
Prerequisites
Requirements
Cisco recommends that you read and understand How-to configure Azure AD and Office 365 mailbox settings for ESA.
Components Used
This document is not restricted to specific software and hardware versions.
For the purpose and execution of this script, it is under the assumption that you have OpenSSL installed. From your terminal prompt, run which openssl or openssl version in order to verify installation.
For the purpose of this article, the script will be called and executed as my_azure.sh. Feel free to name the script as you wish.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.
Azure AD Configuration Script for Cisco Email Security
From an external host (UNIX/Linux), create a script and copy and paste this text:
clear
echo "#####################################################################################
my_azure.sh by Robert Sherwin (robsherw@cisco.com) ©2018 Cisco .:|:.:|:.
Using openssl, this script will create a self-signed certificate for you to use in
order to complete the Mailbox Settings configuration for Cisco Email Security.
Please respond to the following prompts:
#####################################################################################
"
if which openssl >/dev/null; then
echo "openssl check passed: openssl is installed!" & openssl version
else
echo "You do not appear to have openssl installed." && exit
fi
echo "
Please enter a name for your cert: "
read my_cert
while [ -f $my_cert.key ];
do
echo "File exists, please enter a name for your cert: " && read my_cert
done
echo "
Thank you. The files that will be generated for your cert are: "
crt=$my_cert.crt
key=$my_cert.key
pem=$my_cert.pem
echo $crt
echo $key
echo $pem
echo ""
while true; do
read -p "Are you ready to proceed and generate these files for your configuration? $(tput smso)(y/n)$(tput sgr0) " yn
case $yn in
[Yy]* ) openssl req -x509 -sha256 -nodes -days 1825 -newkey rsa:2048 -keyout $key -out $crt
openssl rsa -in $key -out $key
cat $key $crt > $pem
echo ""
base64Thumbprint=`openssl x509 -outform der -in $crt | openssl dgst -binary -sha1 | openssl base64`
base64Value=`openssl x509 -outform der -in $crt | openssl base64 -A`
keyid=`python -c "import uuid; print(uuid.uuid4())"`
echo "
##########################################################################
Next, $(tput smul)copy$(tput rmul) the following to Azure for your manifest:
##########################################################################
"
echo "\"keyCredentials\": [
{
\"customKeyIdentifier\": \"$base64Thumbprint\",
\"keyId\": \"$keyid\",
\"type\": \"AsymmetricX509Cert\",
\"usage\": \"Verify\",
\"value\": \"$base64Value\"
}
],"
echo "
##########################################################################
Then $(tput smul)complete$(tput rmul) the Azure configuration to get the $(tput smso)Client ID$(tput sgr0) and $(tput smso)Tenant ID$(tput sgr0).
##########################################################################
"
echo "This is the $(tput smso)Thumbprint$(tput sgr0) for your ESA configuration: $base64Thumbprint"
echo "This is the $(tput smso)Certificate Private Key$(tput sgr0) for your ESA configuration: $pem
"; break;;
[Nn]* ) exit;;
* ) echo "Please answer yes or no.";;
esac
done
while true; do
read -p "Do you wish to review this certificate in detail? $(tput smso)(y/n)$(tput sgr0) " yn
case $yn in
[Yy]* ) openssl x509 -in $crt -text; echo "
Thank you!" && break;;
[Nn]* ) echo "Thank you!" && exit;;
* ) echo "Please answer yes or no.";;
esac
done
Tip: Once you have written the script, enter chmod u+x <script_name> in order to make the script executable.
A complete example of the script in action should result in:
my_host$ ./my_azure
#####################################################################################
my_azure.sh by Robert Sherwin (robsherw@cisco.com) ©2018 Cisco .:|:.:|:.
Using openssl, this script will create a self-signed certificate for you to use in
order to complete the Mailbox Settings configuration for Cisco Email Security.
Please respond to the following prompts:
#####################################################################################
openssl check passed: openssl is installed!
LibreSSL 2.2.7
Please enter a name for your cert:
technote_example
Thank you. The files that will be generated for your cert are:
technote_example.crt
technote_example.key
technote_example.pem
Are you ready to proceed and generate these files for your configuration? (y/n) y
Generating a 2048 bit RSA private key
..............................................................+++
.............................................+++
writing new private key to 'technote_example.key'
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) []:US
State or Province Name (full name) []:North Carolina
Locality Name (eg, city) []:RTP
Organization Name (eg, company) []:Cisco
Organizational Unit Name (eg, section) []:Example Dept.
Common Name (eg, fully qualified host name) []:example.local
Email Address []:joe.user@example.local
writing RSA key
##########################################################################
Next, copy the following to Azure for your manifest:
##########################################################################
"keyCredentials": [
{
"customKeyIdentifier": "wWHhkWEfuhDHTXPzzmHoSEnjbNM=",
"keyId": "338836b8-fc8d-4e1b-9a3f-b252f8368d34",
"type": "AsymmetricX509Cert",
"usage": "Verify",
"value": "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"
}
],
##########################################################################
Then complete the Azure configuration to get the Client ID and Tenant ID.
##########################################################################
This is the Thumbprint for your ESA configuration: wWHhkWEfuhDHTXPzzmHoSEnjbNM=
This is the Certificate Private Key for your ESA configuration: technote_example.pem
The script will prompt you to review the certificate in detail. Enter y or n in order to complete the script.
Do you wish to review this certificate in detail? (y/n) y
Certificate:
Data:
Version: 1 (0x0)
Serial Number: 15410674582220606938 (0xd5ddb6e21e668dda)
Signature Algorithm: sha256WithRSAEncryption
Issuer: C=US, ST=North Carolina, L=RTP, O=Cisco, OU=Example Dept., CN=example.local/emailAddress=joe.user@example.local
Validity
Not Before: Oct 18 02:00:49 2018 GMT
Not After : Oct 17 02:00:49 2023 GMT
Subject: C=US, ST=North Carolina, L=RTP, O=Cisco, OU=Example Dept., CN=example.local/emailAddress=joe.user@example.local
Subject Public Key Info:
Public Key Algorithm: rsaEncryption
Public-Key: (2048 bit)
Modulus:
00:a9:58:99:6e:c3:37:e0:31:71:94:1c:a5:cf:21:
66:19:af:f7:2a:8c:1e:e9:76:72:35:77:1b:4f:3c:
9a:41:ad:45:95:39:29:45:4d:29:96:52:98:c9:67:
cb:79:4e:2a:0e:9c:4e:ee:04:cf:85:2e:8a:0c:c2:
ff:62:57:11:fd:fe:c0:e8:fd:60:28:4a:f7:66:c4:
61:68:d8:b0:a7:99:b5:b2:28:a9:84:5f:1c:4f:92:
93:e6:ec:25:be:46:a6:2c:d7:80:f7:18:64:68:de:
f3:57:9c:81:a9:a1:0e:b8:3b:35:9a:ed:84:f4:d2:
29:ae:19:c6:66:30:a5:09:7a:c4:60:eb:32:2a:68:
94:6a:04:35:ff:9e:c8:d0:a8:e5:5c:80:5e:5c:6e:
60:7f:26:ea:dd:06:74:fc:3e:54:a1:c9:ee:4f:b8:
c0:8f:4a:4d:4c:38:2c:00:68:39:6b:3c:85:49:c3:
8b:4c:b3:da:4f:66:a8:db:d3:1b:eb:bb:e4:45:14:
32:07:13:59:cf:c8:4a:c5:e3:0b:c9:29:6c:eb:31:
b5:e6:48:89:4e:31:52:fa:8d:77:5b:7d:ea:27:1c:
8d:a7:75:f6:7e:b5:25:db:30:19:7f:82:0b:53:e5:
f9:96:4c:93:cf:c8:40:43:ed:6c:fa:ac:ff:8a:77:
72:61
Exponent: 65537 (0x10001)
Signature Algorithm: sha256WithRSAEncryption
42:aa:bb:8b:10:5b:b5:f8:68:ae:b5:a4:ef:7b:82:a1:85:0f:
46:a5:99:2c:a1:e5:82:cd:54:a4:49:e6:3e:3b:cb:66:22:26:
63:e3:ba:92:24:7d:89:c0:d5:8c:50:f8:ec:05:be:d2:f6:20:
de:91:ed:ea:92:96:97:b4:d4:66:98:a5:cf:88:4d:a7:4a:18:
73:fa:a3:77:a6:82:03:c0:76:28:c9:9b:7e:1d:83:56:19:a9:
61:65:bc:3f:bc:1b:34:ff:e2:9b:7d:75:e0:5f:f3:26:f0:55:
9c:78:de:69:8f:4a:b2:e4:d4:53:9e:16:6f:c5:57:d8:51:57:
e3:4f:d8:16:6f:c7:4c:7a:d7:70:71:f2:5b:2e:57:05:4f:4c:
15:59:84:bb:e6:2f:e8:92:31:09:a1:20:8f:92:7b:8d:5e:2a:
19:03:3e:f9:f9:fe:12:94:4f:91:51:e7:f3:8e:07:ce:0c:66:
e3:46:d1:5b:be:3b:ae:31:ae:c8:ab:2c:f8:4d:ad:8d:62:53:
e8:e9:83:27:8a:ee:1c:21:5d:be:19:19:be:fc:d5:27:25:67:
d0:f5:4d:f9:cc:28:27:48:0b:33:ba:76:a1:ae:c9:dc:87:4d:
67:7a:76:08:c5:ef:15:d6:6c:46:21:45:52:90:48:6c:ad:d5:
62:51:51:ae
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
Thank you!
At this time, you have three files: .crt, .key, and .pem.
Use the keyCredentials output as instructed, and copy the output to Azure when you set up the App Registration. The Thumbprint output and Certificate Private Key (.pem) are needed when you run the configuration steps on Cisco Email Security.
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