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Decrypt SSL traffic with certificates and private keys

You can decrypt forwarded SSL traffic by uploading the private key and server certificate associated with that traffic. The certificate and key are uploaded over an HTTPS connection from a web browser to the ExtraHop system.

After upload, private keys are encrypted and stored on the ExtraHop system. To ensure that private keys are not transferable to other systems, they are encrypted with an internal key that has information specific to the appliance to which it was uploaded.

Separation of privileges is enforced so that only the SSL decryption process on the appliance can access the private keys. While you can add new private keys through the ExtraHop Admin UI, you cannot access stored private keys.

Note:Your traffic must be encrypted with a supported cipher suite. See Supported SSL cipher suites.

Upload a PEM certificate and RSA private key

Tip:You can export a password-protected key to add to your ExtraHop system by running the following command on a program such as OpenSSL:
openssl rsa -in yourcert.pem -out new.key
  1. Log in to the Administration page on the ExtraHop system through https://<extrahop-hostname-or-IP-address>/admin.
  2. In the System Configuration section, click Capture.
  3. Click SSL Decryption.
  4. In the Private Key Decryption section, select the checkbox for Require Private Keys.
  5. Click Save.
  6. In the Private Keys section, click Add Keys.
  7. In the Add PEM Certificate and RSA Private Key section, enter the following information:
    Name
    A descriptive name to identify this certificate and key.
    Enabled
    Clear this checkbox if you want to disable this SSL certificate.
    Certificate
    The public key certificate.
    Private Key
    The RSA private key.
  8. Click Add.

Next steps

Add the encrypted protocols you want to decrypt with this certificate.

Upload a PKCS#12/PFX file

PKCS#12/PFX files are archived in a secure container on the ExtraHop system and contains both public and private key pairs, which can only be accessed with a password.

Tip:To export private keys from a Java KeyStore to a PKCS#12 file, run the following command on your server, where javakeystore.jks is the path of your Java KeyStore:
keytool -importkeystore -srckeystore javakeystore.jks -destkeystore 
pkcs.p12 -srcstoretype jks -deststoretype pkcs12
  1. Log in to the Administration page on the ExtraHop system through https://<extrahop-hostname-or-IP-address>/admin.
  2. In the System Configuration section, click Capture.
  3. Click SSL Decryption.
  4. In the Private Key Decryption section, select the checkbox for Require Private Keys.
  5. Click Save.
  6. In the Private Keys section, click Add Keys.
  7. In the Add PKCS#12/PFX File With Password section, enter the following information:
    Description
    A descriptive name to identify this certificate and key.
    Enabled
    Clear this checkbox to disable this SSL certificate.
  8. Next to PKCS#12/PFX file, click Choose File.
  9. Browse to the file and select it, then click Open.
  10. In the Password field, type the password for the PKCS#13/PFX file.
  11. Click Add.
  12. Click OK.

Next steps

Add the encrypted protocols you want to decrypt with this certificate.

Add encrypted protocols

You must add each protocol that you want to decrypt for each uploaded certificate.

  1. Log in to the Administration page on the ExtraHop system through https://<extrahop-hostname-or-IP-address>/admin.
  2. In the System Configuration section, click Capture.
  3. Click SSL Decryption.
  4. In the Protocol to Port Mapping by Key section, click Add Protocol.
  5. On the Add Encrypted Protocol page, enter the following information:
    Protocol
    From the drop-down list, select the protocol you want to decrypt.
    Key
    From the drop-down list, select an uploaded private key.
    Port
    Type the source port for the protocol. By default this value is set to 443, which specifies HTTP traffic. Specify 0 to decrypt all protocol traffic.
  6. Click Add.

Supported SSL cipher suites

To decrypt SSL traffic in real time, you must configure your server applications to encrypt traffic with supported ciphers. The following information provides a list of supported cipher suites and the best practices you should consider when implementing SSL encryption.

  • Turn off SSLv2 to reduce security issues at the protocol level.
  • Turn off SSLv3, unless required for compatibility with older clients.
  • Turn off SSL compression to avoid the CRIME security vulnerability.
  • Turn off session tickets unless you are familiar with the risks that might weaken Perfect Forward Secrecy.
  • Configure the server to select the cipher suite in order of the server preference.

Cipher suites that support Perfect Forward Secrecy (PFS) can be decrypted by the ExtraHop system when session key forwarding is configured. To configure session key forwarding, see Install the ExtraHop session key forwarder on a Windows server or Install the ExtraHop session key forwarder on a Linux server.

Hex Value Name (IANA) Name (OpenSSL) PFS Support
0x04 TLS_RSA_WITH_RC4_128_MD5 RC4-MD5 No
0x05 TLS_RSA_WITH_RC4_128_SHA RC4-SHA No
0x0A TLS_RSA_WITH_3DES_EDE_CBC_SHA DES-CBC3-SHA No
0x16 TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA EDH-RSA-DES-CBC3-SHA Yes
0x2F TLS_RSA_WITH_AES_128_CBC_SHA AES128-SHA No
0x33 TLS_DHE_RSA_WITH_AES_128_CBC_SHA DHE-RSA-AES128-SHA Yes
0x35 TLS_RSA_WITH_AES_256_CBC_SHA AES256-SHA No
0x39 TLS_DHE_RSA_WITH_AES_256_CBC_SHA DHE-RSA-AES256-SHA Yes
0x3C TLS_RSA_WITH_AES_128_CBC_SHA256 AES128-SHA256 No
0x3D TLS_RSA_WITH_AES_256_CBC_SHA256 AES256-SHA256 No
0x67 TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 DHE-RSA-AES128-SHA256 Yes
0x6B TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 DHE-RSA-AES256-SHA256 Yes
0x9C TLS_RSA_WITH_AES_128_GCM_SHA256 AES128-GCM-SHA256 No
0x9D TLS_RSA_WITH_AES_256_GCM_SHA384 AES256-GCM-SHA384 No
0x9E TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 DHE-RSA-AES128-GCM-SHA256 Yes
0x9F TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 DHE-RSA-AES256-GCM-SHA384 Yes
0x1301 TLS_AES_128_GCM_SHA256 TLS_AES_128_GCM_SHA256 Yes
0x1302 TLS_AES_256_GCM_SHA384 TLS_AES_256_GCM_SHA384 Yes
0x1303 TLS_CHACHA20_POLY1305_SHA256 TLS_CHACHA20_POLY1305_SHA256 Yes
0xC007 TLS_ECDHE_ECDSA_WITH_RC4_128_SHA ECDHE-ECDSA-RC4-SHA Yes*
0xC008 TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA ECDHE-ECDSA-DES-CBC3-SHA Yes*
0xC009 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA ECDHE-ECDSA-AES128-SHA Yes*
0xC00A TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA ECDHE-ECDSA-AES256-SHA Yes*
0xC011 TLS_ECDHE_RSA_WITH_RC4_128_SHA ECDHE-RSA-RC4-SHA Yes
0xC012 TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA ECDHE-RSA-DES-CBC3-SHA Yes
0xC013 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA ECDHE-RSA-AES128-SHA Yes
0xC014 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA ECDHE-RSA-AES256-SHA Yes
0xC023 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 ECDHE-ECDSA-AES128-SHA256 Yes*
0xC024 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 ECDHE-ECDSA-AES256-SHA384 Yes*
0xC027 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 ECDHE-RSA-AES128-SHA256 Yes
0xC028 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 ECDHE-RSA-AES256-SHA384 Yes
0xC02B TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 ECDHE-ECDSA-AES128-GCM-SHA256 Yes*
0xC02C TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 ECDHE-ECDSA-AES256-GCM-SHA384 Yes*
0xC02F TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 ECDHE-RSA-AES128-GCM-SHA256 Yes
0xC030 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 ECDHE-RSA-AES256-GCM-SHA384 Yes
0xCCA8 TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 ECDHE-RSA-CHACHA20-POLY1305 Yes
0xCCA9 TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 ECDHE-ECDSA-CHACHA20-POLY1305 Yes*
0xCCAA TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 DHE-RSA-CHACHA20-POLY1305 Yes

*Requires that you configure certificate-less decryption with global protocol to port mapping.

Published 2022-06-21