Restrict TLS protocols and cipher suites

As an ArcGIS Server administrator, you can specify the Transport Layer Security (TLS) protocols and encryption algorithms ArcGIS Server uses to secure communication. Your organization may be required to use specific TLS protocols and encryption algorithms, or the web server on which you deploy ArcGIS Server may only allow certain protocols and algorithms. Specifying that ArcGIS Server use the certified protocols and algorithms ensures that your site remains in compliance with your organization's security policies.

Following the POODLE vulnerability exposed in 2014, ArcGIS Server dropped support for Secure Sockets Layer (SSL) protocols at 10.3 and later, but you will still see SSL used in the software to refer to TLS protocols.

TLS protocols

By default, ArcGIS Server only uses the TLSv1.3 and TLSv1.2 protocols. You can also enable TLSv1 and TLSv1.1 protocols using the steps below.

Default encryption algorithms

ArcGIS Server is configured by default to use the following encryption algorithms in the order listed below:

• TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384

• TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384

• TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA

• TLS_RSA_WITH_AES_256_GCM_SHA384

• TLS_RSA_WITH_AES_256_CBC_SHA256

• TLS_RSA_WITH_AES_256_CBC_SHA

• TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256

• TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256

• TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA

• TLS_RSA_WITH_AES_128_GCM_SHA256

• TLS_RSA_WITH_AES_128_CBC_SHA256

• TLS_RSA_WITH_AES_128_CBC_SHA

• TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384

• TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384

• TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA

• TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA256

• TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA256

• TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA

• TLS_AES_256_GCM_SHA384 (TLSv1.3 only)

• TLS_AES_128_GCM_SHA256 (TLSv1.3 only)

For security reasons, several encryption algorithms that were enabled by default in previous versions have been disabled. These can be reenabled if needed for older clients. See Cipher suites reference below for the full list of supported algorithms.

Use the ArcGIS Server Administrator Directory to specify the TLS protocols and encryption algorithms your site will use.

1. Open the ArcGIS Server Administrator Directory and sign in as an administrator of your site.

   The URL is in the format https://gisserver.example.com:6443/arcgis/admin.

2. Click Security > Config > Update.

3. In the SSL Protocols text box, specify the protocols to be used. If specifying multiple protocols, separate each protocol with a comma, for example, TLSv1.2, TLSv1.1.

   Note:

   Ensure that the web server hosting your Web Adaptor can fully communicate over the protocols you are enabling.

4. In the Cipher Suites text box, specify the cipher suites to be used in IANA format. Separate each algorithm with a comma, for example, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, TLS_RSA_WITH_AES_128_CBC_SHA.

5. Click Update.

   An error is returned if an invalid protocol or cipher suite is specified.

Cipher suites reference

ArcGIS Server supports the following algorithms:

Cipher ID	Name (IANA format)	Name (OpenSSL format)	Key exchange	Authentication algorithm	Encryption algorithm	Bits	Hashing algorithm
0xC030	TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384	ECDHE-RSA-AES256-GCM-SHA384	ECDH	RSA	AES_256_GCM	256	SHA384
0xC028	TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384	ECDHE-RSA-AES256-SHA384	ECDH	RSA	AES_256_CBC	256	SHA384
0xC014	TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA	ECDHE-RSA-AES256-SHA	ECDH	RSA	AES_256_CBC	256	SHA
0x009F	TLS_DHE_RSA_WITH_AES_256_GCM_SHA384	DHE-RSA-AES256-GCM-SHA384	DH	RSA	AES_256_GCM	256	SHA384
0x006B	TLS_DHE_RSA_WITH_AES_256_CBC_SHA256	DHE-RSA-AES256-SHA256	DH	RSA	AES_256_CBC	256	SHA256
0x0039	TLS_DHE_RSA_WITH_AES_256_CBC_SHA	DHE-RSA-AES256-SHA	DH	RSA	AES_256_CBC	256	SHA
0x009D	TLS_RSA_WITH_AES_256_GCM_SHA384	AES256-GCM-SHA384	RSA	RSA	AES_256_GCM	256	SHA384
0x003D	TLS_RSA_WITH_AES_256_CBC_SHA256	AES256-SHA256	RSA	RSA	AES_256_CBC	256	SHA256
0x0035	TLS_RSA_WITH_AES_256_CBC_SHA	AES256-SHA	RSA	RSA	AES_256_CBC	256	SHA
0xC02F	TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256	ECDHE-RSA-AES128-GCM-SHA256	ECDH	RSA	AES_128_GCM	128	SHA256
0xC027	TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256	ECDHE-RSA-AES128-SHA256	ECDH	RSA	AES_128_CBC	128	SHA256
0xC013	TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA	ECDHE-RSA-AES128-SHA	ECDH	RSA	AES_128_CBC	128	SHA
0x009E	TLS_DHE_RSA_WITH_AES_128_GCM_SHA256	DHE-RSA-AES128-GCM-SHA256	DH	RSA	AES_128_GCM	128	SHA256
0x0067	TLS_DHE_RSA_WITH_AES_128_CBC_SHA256	DHE-RSA-AES128-SHA256	DH	RSA	AES_128_CBC	128	SHA256
0x0033	TLS_DHE_RSA_WITH_AES_128_CBC_SHA	DHE-RSA-AES128-SHA	DH	RSA	AES_128_CBC	128	SHA
0x009C	TLS_RSA_WITH_AES_128_GCM_SHA256	AES128-GCM-SHA256	RSA	RSA	AES_128_GCM	128	SHA256
0x003C	TLS_RSA_WITH_AES_128_CBC_SHA256	AES128-SHA256	RSA	RSA	AES_128_CBC	128	SHA256
0x002F	TLS_RSA_WITH_AES_128_CBC_SHA	AES128-SHA	RSA	RSA	AES_128_CBC	128	SHA
0xC012	TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA	ECDHE-RSA-DES-CBC3-SHA	ECDH	RSA	3DES_EDE_CBC	168	SHA
0x0016	SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA	EDH-RSA-DES-CBC3-SHA	DH	RSA	3DES_EDE_CBC	168	SHA
0x000A	SSL_RSA_WITH_3DES_EDE_CBC_SHA	DES-CBC3-SHA	RSA	RSA	3DES_EDE_CBC	168	SHA
0xC02C	TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384	ECDHE-ECDSA-AES256-GCM-SHA384	ECDH	ECDSA	AES_256_GCM	256	SHA384
0xC024	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384	ECDHE-ECDSA-AES256-SHA384	ECDH	ECDSA	AES_256_CBC	256	SHA384
0xC00A	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA	ECDHE-ECDSA-AES256-SHA	ECDH	ECDSA	AES_256_CBC	256	SHA
0xC02B	TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256	ECDHE-ECDSA-AES128-GCM-SHA256	ECDH	ECDSA	AES_128_GCM	128	SHA256
0xC023	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256	ECDHE-ECDSA-AES128-SHA256	ECDH	ECDSA	AES_128_CBC	128	SHA256
0xC009	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA	ECDHE-ECDSA-AES128-SHA	ECDH	ECDSA	AES_128_CBC	128	SHA
0xC008	TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA	ECDHE-ECDSA-DES-CBC3-SHA	ECDH	ECDSA	3DES_EDE_CBC	168	SHA
0xCCA8	TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256	ECDHE-RSA-CHACHA20-POLY1305	ECDH	RSA	CHACHA20 POLY1305	256	SHA256
0xCCA9	TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256	ECDHE-ECDSA-CHACHA20-POLY1305	ECDH	ECDSA	CHACHA20 POLY1305	256	SHA256
0x1301	TLS_AES_128_GCM_SHA256 (TLSv1.3 only)	TLS_AES_128_GCM_SHA256	-	-	AES_128_GCM	128	SHA256
0x1302	TLS_AES_256_GCM_SHA384 (TLSv1.3 only)	TLS_AES_256_GCM_SHA384	-	-	AES_256_GCM	256	SHA384
0x1303	TLS_CHACHA20_POLY1305_SHA256 (TLSv1.3 only)	TLS_CHACHA20_POLY1305_SHA256	-	-	CHACHA20 POLY1305	256	SHA256

Terminology

The following terms are used in the table above:

• ECDH—Elliptic-Curve Diffie-Hellman

• DH—Diffie-Hellman

• RSA—Rivest, Shamir, Adleman

• ECDSA— Elliptic Curve Digital Signature Algorithm

• AES—Advanced Encryption Standard

• GCM—Galois/Counter Mode, a mode of operation for cryptographic block ciphers

• CBC—Cipher Block Chaining

• 3DES—Triple Data Encryption Algorithm

• SHA—Secure Hashing Algorithm

• CHACHA20—ChaCha stream cipher

• POLY1305—Poly1305 authenticator