---
sourceDocument: Yokohama ServiceNow AI Platform Capabilities
sourceDocumentLink: https://www.servicenow.com/docs/r/yokohama/servicenow-platform

 Release :

    - yokohama

ft:locale :

    - en-US

ft:publication_title :

    - Yokohama ServiceNow AI Platform Capabilities

ft:clusterId :

    - platcap

bundleId :

    - platcap

workflow :

    - Platform


---

# MID Server SSH cryptographic algorithms

# MID Server SSH cryptographic algorithms {#ariaid-title1}

* Release version: Yokohama
* 
* Updated January 30, 2025
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 2 minutes to read

Summarize  
![AI sparkle icon](https://servicenow.com/docs/portal-asset/ai-sparkle-icon) Summarized using AI  
This content was generated using new OpenAI-powered functionality. Results are provided on an as is basis and are not guaranteed to be accurate or complete.  

## Summary of MID Server SSH cryptographic algorithms

The MID Server uses SSH clients for various discovery actions, establishing secure connections through an SSH handshake.
During this handshake, both client and server negotiate supported cryptographic algorithms, selecting the highest priority mutually supported algorithm for each category.
Understanding and managing these algorithms is critical for securing communications and ensuring compatibility with target systems.
Show full answer Show less  

## Key Features

* **Default Supported SSH Algorithms:**
  * **Key Exchange Algorithms:** Includes ecdh-sha2 variants, diffie-hellman groups with SHA-256, SHA-512, and SHA-1.
  * **Host Key Algorithms:** Used for public key signature during authentication; includes ssh-ed25519, rsa-sha2 variants, ecdsa-sha2 variants, ssh-rsa, ssh-dss, and their certificate forms.
  * **Cipher Algorithms:** Includes AES in CTR and CBC modes with 128-, 192-, and 256-bit keys.
  * **MAC Algorithms:** Includes various HMACs such as hmac-sha2-256, hmac-sha1, hmac-sha2-512, and md5 variants.
* **Customizing Algorithm Priorities:** Customers can modify the priority and selection of SSH algorithms via MID Server properties for each algorithm category:
  * `mid.ssh.algorithms.kex` for Key Exchange
  * `mid.ssh.algorithms.hostkey` for Host Key
  * `mid.ssh.algorithms.cipher` for Cipher
  * `mid.ssh.algorithms.mac` for MAC
  These properties accept comma-separated lists and support OpenSSH-style operators to append (+), remove (-), or prioritize (\^) algorithms in the list.
* **Important Notes:**
  * The MID Server properties do not affect Glide Import tasks, as Glide Import uses the instance-side SNCSSH client instead of the MID Server's SSH client.
  * Proper configuration of these algorithms helps align with security policies and compliance requirements.

## Practical Implications for ServiceNow Customers

By understanding and customizing SSH cryptographic algorithms, ServiceNow customers can:

* Ensure secure and compatible SSH connections for MID Server discovery and other operations.
* Adapt algorithm priorities to meet organizational security standards or to comply with regulatory frameworks.
* Resolve interoperability issues with SSH servers that require specific algorithms or disallow deprecated ones.
* Maintain control over cryptographic settings without impacting instance-side functions like Glide Import.

Customers should consider reviewing related security features such as MID Server certificate policies, mutual authentication, and FIPS enforcement to complement SSH algorithm configuration.  
The MID Server utilizes SSH clients to perform many discovery actions. During the SSH
handshake, both the client and server first determine which algorithms both parties support,
then client picks the highest priority algorithm. For the Host Key Algorithm, the client picks
highest priority algorithm which both parties support that matches the key type.

|-|
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[ ]

{#mid-ssh-algorithms__table_kvf_3v4_nhb}

## Default supported SSH algorithms by priority {#mid-ssh-algorithms__section_gjv_cpr_xnb}

Key Exchange Algorithm

1. ecdh-sha2-nistp256
2. ecdh-sha2-nistp384
3. ecdh-sha2-nistp521
4. diffie-hellman-group-exchange-sha256
5. diffie-hellman-group14-sha256
6. diffie-hellman-group16-sha512
7. diffie-hellman-group14-sha1
8. diffie-hellman-group1-sha1
9. diffie-hellman-group-exchange-sha1
{#mid-ssh-algorithms__ol_hgp_bpr_xnb}  
Host Key Algorithm (used for public key signature during authentication)

1. ssh-ed25519-cert-v01@openssh.com
2. rsa-sha2-512-cert-v01@openssh.com
3. rsa-sha2-256-cert-v01@openssh.com
4. ssh-ed25519
5. ecdsa-sha2-nistp256
6. ecdsa-sha2-nistp384
7. ecdsa-sha2-nistp521
8. rsa-sha2-512
9. rsa-sha2-256
10. ssh-rsa-cert-v01@openssh.com
11. ssh-rsa
12. ssh-dss
{#mid-ssh-algorithms__ol_x4h_jpr_xnb}  
Cipher Algorithm

1. aes128-ctr
2. aes192-ctr
3. aes256-ctr
4. aes128-cbc
5. aes192-cbc
6. aes256-cbc
{#mid-ssh-algorithms__ol_trm_qpr_xnb}  
MAC Algorithm

1. hmac-sha2-256
2. hmac-sha1
3. hmac-sha2-512
4. hmac-sha1-96
5. hmac-md5-96
6. hmac-md5
{#mid-ssh-algorithms__ol_fdf_5pr_xnb}

## Customize the SSH algorithms priority
list {#mid-ssh-algorithms__section_ogk_bqr_xnb}

The MID Server SSH algorithm priorities can be customized based on security
needs. Each algorithm is controlled by one of the following MID Server
properties.  
Note:  
Glide Import on the instance uses the default algorithm list. The four MID Server properties do not affect Glide Import because it is not run on the MID server. SNCSSH is used for Glide Import on instance for SFTP and SCP.  
* Key Exchange algorithms: mid.ssh.algorithms.kex​

* Host Key algorithms: mid.ssh.algorithms.host_key​

* Cipher algorithms: mid.ssh.algorithms.cipher​

* MAC algorithms: mid.ssh.algorithms.mac​

{#mid-ssh-algorithms__ul_oxr_ygs_xnb}  
The properties accept comma separated lists with operators. The first name in the list is highest priority, last name in list is lowest priority. Adding a comma separated list without any operators replaces the default algorithm list. The following operators are based on the OpenSSH standard syntax and modify the algorithm priority list.

* The + operator appends the comma separated list of algorithms to the default algorithm list.
* The - operator removes the comma separated list of algorithms from the default algorithm list.
* The \^ operator places the comma separated list of algorithms at the front of the default algorithm list.
{#mid-ssh-algorithms__ul_xs1_x3s_xnb}
**Related concepts**   

* [MID Server certificate check policies](https://www.servicenow.com/docs/tOKLEFH3vUlhK8cK6T9Qbg "MID Server uses three kinds of security checks to secure external traffic. The security checks use TLS/SSL certificate validation, hostname validation, and OCSP validation to improve security. Control these security checks with the MID Server certificate check policies table.")
* [MID Server authentication credentials and SOAP requests](https://www.servicenow.com/docs/BPXeR~A4Pja0FFKo5zJnNQ#mid-authentication-soap-requests "Set basic authentication credentials to update the web service invocation data. For added security, you can enforce basic authentication on each incoming SOAP request to the MID Server.")
* [MID Server unified key store](https://www.servicenow.com/docs/PC4ku1Ji6e1D~jCtGlLMdQ#mid-unified-keystore "The MID Server unified key store allows all products on the MID Server to use common certificates and key pairs. This feature allows applications to use the same secure communication channel to the MID Server that the MID Server uses to connect to the instance.")
* [MID Server command audit log](https://www.servicenow.com/docs/TKg5HoGYD3aeMymIaXTgtg "The command audit log records the commands run by the MID Server for the Discovery application. Review the commands to check for anomalies or errors.")
* [MID Server FIPS Enforced Mode](https://www.servicenow.com/docs/yxoIYPMPcSO~EwcvjLToVA#mid-fips-enforced "The MID Server supports the National Security Cloud (NSC) IL-5 environment, which requires all utilized cryptography to be FIPS validated. The MID server can be run in FIPS Enforced Mode, where only cryptographic algorithms which are FIPS validated are utilized.")
* [MID Server Governance](https://www.servicenow.com/docs/q3~hPnrT2lKXM8RCmlRC_A "Improve MID Server security by setting an automatic timeout to invalidate and shut down inactive MID Servers. You can enable this feature and set the inactivity timeout period globally and for each MID Server.")  
**Related tasks**   

* [Encrypt or decrypt MID Server configuration file values](https://www.servicenow.com/docs/se2YdJ_e18Y8Bn~j31Zp_w "The value of any MID Server parameter in the config.xml file can be encrypted. The attributes for all encrypted values are managed from within the configuration file, including the security attribute of the login password.")
* [Enable MID Server mutual authentication](https://www.servicenow.com/docs/82SMuK_ICPRrJdpDGUyjnw "Configure the MID Server to use a client certificate for authenticating to the instance. This avoids the need to create a basic authentication credentials in the Key Store for the MID Server's configuration.")
* [MID Server Azure Key Vault integration](https://www.servicenow.com/docs/8gVpuy6YYoY3ZnqDnFpTfw#mid_azure_key_vault_integration "The MID Server integration with the Azure Key vault enables Orchestration, Discovery, and Service Mapping to run without storing any credentials on the instance.")
* [Rekey a MID Server](https://www.servicenow.com/docs/bAXGhBncVeafIyy2~xKKEA "Rekey a MID Server to generate a new private key. Private keys are used to decrypt automation credentials, so that MID Servers can transmit information securely. Key pairs are initially generated when a MID Server is validated, and MID Servers should be rekeyed periodically to meet security requirements.")
* [Add SSL certificates for the MID Server](https://www.servicenow.com/docs/_ZjTMQSadkxUOParAwg7JA#add-ssl-certificates "Configure the MID Server to connect to a source over SSL.")
* [Specify an external TrustStore for the MID Server](https://www.servicenow.com/docs/L40L3~9gm~8pfHl7bZ1sbw "The MID Server JVM can utilize a TrustStore external to the MID installation directory so any certificates added to the TrustStore are not overwritten during an upgrade. It is important that this TrustStore file reside outside of the MID installation directory, and the Truststore location can be specified by adding additional parameters to the MID Server's wrapper-override.conf file.")
* [Attach a script file to a file synchronized MID Server](https://www.servicenow.com/docs/1mKnTHT3aJ0ikYKoz3j0xg#mid-server-script-attach "You can attach a script file to synchronize to a connected MID Server.")  
**Related reference**   

* [MID Server configuration file security](https://www.servicenow.com/docs/ZnQrxSVhYYvmmwNxcSR~Cw "Sensitive MID Server configuration data can be protected using several different schemes, including internal and external data encryption and external data storage.")