Product Documentation

ECDSA cipher suites support

ECDSA cipher suites use elliptical curve cryptography (ECC). Because of its smaller size, it is particularly helpful in environments where processing power, storage space, bandwidth, and power consumption are constrained.

The following Citrix ADC appliances now support the elliptical curve digital signature algorithm (ECDSA) cipher group:

  • Citrix ADC MPX and SDX appliances with N3 chips
  • Citrix ADC MPX 5900/8900
  • Citrix ADC SDX 8900
  • Citrix ADC VPX  appliances

To support ECDSA cipher suites on a Citrix ADC SDX appliance, an SSL core must be assigned to the VPX instance.

When the ECDHE_ECDSA cipher group is used, the server’s certificate must contain an ECDSA-capable public key.

Example:

sh ssl cipher ECDSA

1)      Cipher Name: TLS1-ECDHE-ECDSA-AES256-SHA        Priority : 1
Description: SSLv3 Kx=ECC-DHE  Au=ECDSA Enc=AES(256)  Mac=SHA1   HexCode=0xc00a
2)      Cipher Name: TLS1-ECDHE-ECDSA-AES128-SHA        Priority : 2
Description: SSLv3 Kx=ECC-DHE  Au=ECDSA Enc=AES(128)  Mac=SHA1   HexCode=0xc009
3)      Cipher Name: TLS1.2-ECDHE-ECDSA-AES256-SHA384   Priority : 3
Description: TLSv1.2 Kx=ECC-DHE  Au=ECDSA Enc=AES(256)  Mac=SHA-384   HexCode=0xc024
4)      Cipher Name: TLS1.2-ECDHE-ECDSA-AES128-SHA256   Priority : 4
Description: TLSv1.2 Kx=ECC-DHE  Au=ECDSA Enc=AES(128)  Mac=SHA-256   HexCode=0xc023
5)      Cipher Name: TLS1.2-ECDHE-ECDSA-AES256-GCM-SHA384       Priority : 5
Description: TLSv1.2 Kx=ECC-DHE  Au=ECDSA Enc=AES-GCM(256) Mac=AEAD   HexCode=0xc02c
6)      Cipher Name: TLS1.2-ECDHE-ECDSA-AES128-GCM-SHA256       Priority : 6
Description: TLSv1.2 Kx=ECC-DHE  Au=ECDSA Enc=AES-GCM(128) Mac=AEAD   HexCode=0xc02b
7)      Cipher Name: TLS1-ECDHE-ECDSA-DES-CBC3-SHA      Priority : 7
Description: SSLv3 Kx=ECC-DHE  Au=ECDSA Enc=3DES(168) Mac=SHA1   HexCode=0xc008
8)      Cipher Name: TLS1-ECDHE-ECDSA-RC4-SHA   Priority : 8
Description: SSLv3 Kx=ECC-DHE  Au=ECDSA Enc=RC4(128)  Mac=SHA1   HexCode=0xc007
9)      Cipher Name: TLS1.2-ECDHE-ECDSA-CHACHA20-POLY1305       Priority : 9
Description: TLSv1.2 Kx=ECC-DHE  Au=ECDSA Enc=CHACHA20/POLY1305(256) Mac=AEAD   HexCode=0xcca9
Done

The following table lists the ECDSA ciphers that are supported on the Citrix ADC MPX and SDX appliances with N3 chips, MPX 5900, and MPX/SDX 8900 appliances.

Cipher Name

Priority

Description

Key Exchange Algorithm

Authentication Algorithm

Encryption Algorithm (Key Size)

Message Authentication Code (MAC) Algorithm

HexCode

TLS1-ECDHE-ECDSA-AES128-SHA

1

SSLv3

ECC-DHE

ECDSA

AES(128) 

SHA1

0xc009

TLS1-ECDHE-ECDSA-AES256-SHA 

2

SSLv3

ECC-DHE 

ECDSA

AES(256) 

SHA1

0xc00a

TLS1.2-ECDHE-ECDSA-AES128-SHA256 

3

TLSv1.2

ECC-DHE 

ECDSA

AES(128)

SHA-256

0xc023

 

TLS1.2-ECDHE-ECDSA-AES256-SHA384

4

TLSv1.2

ECC-DHE 

ECDSA

AES(256) 

SHA-384  

0xc024

 

TLS1.2-ECDHE-ECDSA-AES128-GCM-SHA256 

5

TLSv1.2

ECC-DHE 

ECDSA

AES-GCM(128)

SHA-256  

0xc02b

 

TLS1.2-ECDHE-ECDSA-AES256-GCM-SHA384   

6

TLSv1.2

ECC-DHE

ECDSA

AES-GCM(256)

SHA-384

0xc02c

 

TLS1-ECDHE-ECDSA-RC4-SHA

7

SSLv3

ECC-DHE

ECDSA

RC4(128)

SHA1 

0xc007

 

TLS1-ECDHE-ECDSA-DES-CBC3-SHA 

8

SSLv3

ECC-DHE

ECDSA

3DES(168)

SHA1  

0xc008

 

TLS1.2-ECDHE-ECDSA-CHACHA20-POLY1305

9 TLSv1.2
ECC-DHE
ECDSA
CHACHA20/POLY1305(256)

AEAD
0xcca9

Important

Use the show ns hardware command to find out if your appliance has N3 chips.

Example:

sh ns hardware
              Platform: NSMPX-22000 16*CPU+24*IX+12*E1K+2*E1K+4*CVM N3 2200100
              Manufactured on: 8/19/2013
              CPU: 2900MHZ
              Host Id: 1006665862
              Serial no: ENUK6298FT
              Encoded serial no: ENUK6298FT
     Done

ECDSA/RSA cipher and certificate selection

You can bind both ECDSA and RSA server certificates at the same time to an SSL virtual server. When both ECDSA and RSA certificates are bound to the virtual server, it automatically selects the appropriate server certificate to present to the client. If the client cipher list includes RSA ciphers, but does not include ECDSA ciphers, the virtual server presents the RSA server certificate. If both ciphers are present in the client’s list, then the server certificate presented depends on the cipher priority set on the virtual server. That is, if RSA has a higher priority, the RSA certificate is presented. If ECDSA has a higher priority, the ECDSA certificate is presented to the client.

Client authentication by using an ECDSA or an RSA certificate

For client authentication, the CA certificate bound to the virtual server can be ECDSA or RSA signed. The appliance supports a mixed certificate chain. For example, the following certificate chain is supported.

Client certificate (ECDSA) <-> CA certificate (RSA) <-> Intermediate certificate (RSA) <-> Root certificate (RSA)

Note

ECDSA certificates with only the following curves are supported:

  • prime256v1
  • secp384r1
  • secp521r1 (VPX only)
  • secp224r1 (VPX only)

Create an ECDSA certificate-key pair

You can create an ECDSA certificate-key pair directly on a Citrix ADC appliance by using the CLI or the GUI. Earlier, you could install and bind an ECC certificate-key pair on the appliance, but you had to use OpenSSL to create a certificate-key pair.

Only P_256 and P_384 curves are supported.

Note

This support is available on all platforms except MPX 9700/1050/12500/15500.

To create an ECDSA certificate-key pair by using the CLI:

At the command prompt, type:

create ssl ecdsaKey \<keyFile\> -curve ( P\_256 | P\_384 ) \[-keyform ( DER | PEM )\] \[-des | -des3\] {-password }

Example:

create ecdsaKey ec_p256.ky -curve P_256
Done
create ecdsaKey ec_p384.ky -curve P_384
Done

To create an ECDSA certificate-key pair by using the GUI:

Navigate to Traffic Management > SSL > SSL Files > Keys and click Create ECDSA Key.