OpenVPN simple installation
I have to make VPN between Debian 9.7 and another Linux or ASUS router with VPN support. I have seen different options for ciphers and other settings. Is there good and bad choices for OpenVPN settings and risk to have vulnerable link?
linux openvpn
asked Feb 28 at 15:24
i486i486
1488
add a comment |
I have to make VPN between Debian 9.7 and another Linux or ASUS router with VPN support. I have seen different options for ciphers and other settings. Is there good and bad choices for OpenVPN settings and risk to have vulnerable link?
linux openvpn
asked Feb 28 at 15:24
i486i486
1488
1
Check out github.com/angristan/openvpn-install if you want a zero-config, sane-defaults installation script.
– slhck
Feb 28 at 19:07
add a comment |
I have to make VPN between Debian 9.7 and another Linux or ASUS router with VPN support. I have seen different options for ciphers and other settings. Is there good and bad choices for OpenVPN settings and risk to have vulnerable link?
linux openvpn
asked Feb 28 at 15:24
i486i486
1488
I have to make VPN between Debian 9.7 and another Linux or ASUS router with VPN support. I have seen different options for ciphers and other settings. Is there good and bad choices for OpenVPN settings and risk to have vulnerable link?
linux openvpn
linux openvpn
asked Feb 28 at 15:24
i486i486
1488
asked Feb 28 at 15:24
i486i486
1488
asked Feb 28 at 15:24
i486i486
1488
asked Feb 28 at 15:24
i486i486
1488
asked Feb 28 at 15:24
i486i486
1488
1488
1
Check out github.com/angristan/openvpn-install if you want a zero-config, sane-defaults installation script.
– slhck
Feb 28 at 19:07
add a comment |
1
Check out github.com/angristan/openvpn-install if you want a zero-config, sane-defaults installation script.
– slhck
Feb 28 at 19:07
1
1
Check out github.com/angristan/openvpn-install if you want a zero-config, sane-defaults installation script.
– slhck
Feb 28 at 19:07
Check out github.com/angristan/openvpn-install if you want a zero-config, sane-defaults installation script.
– slhck
Feb 28 at 19:07
add a comment |
1 Answer
1
active
oldest
votes
This is an opinion answer. This answer may get out of date easily. OpenVPN provides a guide on tuning secuirty options here.
OpenVPN has three options for cryptography. You choose the ciphers on certificates, the hash used for authentication, and the cipher used for the tunnel's data encryption separately.
Generally you want to use the strongest available cryptography for both of the authentication components. As of writing, SHA256 (Diffie-Hellman RSA) is almost always used during authentication, combined with an RSA 4096 public/private key pair or certificate chain. OpenVPN has a guide for generating your authentication certificates here.
While performance on authentication doesn't matter (2 seconds to connect the VPN versus 2.5 seconds), performance on the data encryption cipher can be a point of compromise. When using two big-core computers, performance isn't an issue; always use the strongest available cipher. When one of the machines is an embedded system, performance is limited. The two main choices for cipher in OpenVPN are aes-128-gbc or aes-256-gbc. If using OpenVPN version older than 2.4, use AES-CBC instead of GBC. On embedded systems such as routers, aes-128 might get 15Mbps of bandwidth but aes-256 might only get 4Mbps. You have to test performance yourself, weigh the needed performance and security, and decide which one to use. Never use DES or RC4; these are 'broken' ciphers.
answered Feb 28 at 18:45
AndyAndy
1,056311
What about ECDSA? OpenVPN 2.4 included support for that.
– slhck
Feb 28 at 19:07
The stock firmware of router has limited settings: i.imgur.com/ici0iAE.png There are only MS-CHAPv1 and Auto for Authentication. I have to install Tomato or OpenWrt for better VPN.
– i486
Feb 28 at 20:09
2
@i486 PPTP is not the same thing as openVPN.
– Andy
Feb 28 at 21:13
@slhck Elliptic curve cryptography is also an option. It is not as common and requires more configuration. Last I saw it wasn't a native option in OpenVPN and you have to manually install your crypto libraries on both the server and client. Given that RSA 4096 is already ridiculously beyond the cryptography strength generally required, I wouldn't recommend ECDSA to a first timer.
– Andy
Feb 28 at 21:20
@Andy From what I've read RSA (including 4096) is not that strong any more. There are security experts that consider it fundamentally insecure now. There's a reason ECDSA, Ed25519, and other elliptical curve based cryptography are gaining traction.
– Cliff Armstrong
Feb 28 at 22:04
|
show 2 more comments
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1 Answer
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1 Answer
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oldest
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This is an opinion answer. This answer may get out of date easily. OpenVPN provides a guide on tuning secuirty options here.
OpenVPN has three options for cryptography. You choose the ciphers on certificates, the hash used for authentication, and the cipher used for the tunnel's data encryption separately.
Generally you want to use the strongest available cryptography for both of the authentication components. As of writing, SHA256 (Diffie-Hellman RSA) is almost always used during authentication, combined with an RSA 4096 public/private key pair or certificate chain. OpenVPN has a guide for generating your authentication certificates here.
While performance on authentication doesn't matter (2 seconds to connect the VPN versus 2.5 seconds), performance on the data encryption cipher can be a point of compromise. When using two big-core computers, performance isn't an issue; always use the strongest available cipher. When one of the machines is an embedded system, performance is limited. The two main choices for cipher in OpenVPN are aes-128-gbc or aes-256-gbc. If using OpenVPN version older than 2.4, use AES-CBC instead of GBC. On embedded systems such as routers, aes-128 might get 15Mbps of bandwidth but aes-256 might only get 4Mbps. You have to test performance yourself, weigh the needed performance and security, and decide which one to use. Never use DES or RC4; these are 'broken' ciphers.
answered Feb 28 at 18:45
AndyAndy
1,056311
What about ECDSA? OpenVPN 2.4 included support for that.
– slhck
Feb 28 at 19:07
The stock firmware of router has limited settings: i.imgur.com/ici0iAE.png There are only MS-CHAPv1 and Auto for Authentication. I have to install Tomato or OpenWrt for better VPN.
– i486
Feb 28 at 20:09
2
@i486 PPTP is not the same thing as openVPN.
– Andy
Feb 28 at 21:13
@slhck Elliptic curve cryptography is also an option. It is not as common and requires more configuration. Last I saw it wasn't a native option in OpenVPN and you have to manually install your crypto libraries on both the server and client. Given that RSA 4096 is already ridiculously beyond the cryptography strength generally required, I wouldn't recommend ECDSA to a first timer.
– Andy
Feb 28 at 21:20
@Andy From what I've read RSA (including 4096) is not that strong any more. There are security experts that consider it fundamentally insecure now. There's a reason ECDSA, Ed25519, and other elliptical curve based cryptography are gaining traction.
– Cliff Armstrong
Feb 28 at 22:04
|
show 2 more comments
This is an opinion answer. This answer may get out of date easily. OpenVPN provides a guide on tuning secuirty options here.
OpenVPN has three options for cryptography. You choose the ciphers on certificates, the hash used for authentication, and the cipher used for the tunnel's data encryption separately.
Generally you want to use the strongest available cryptography for both of the authentication components. As of writing, SHA256 (Diffie-Hellman RSA) is almost always used during authentication, combined with an RSA 4096 public/private key pair or certificate chain. OpenVPN has a guide for generating your authentication certificates here.
While performance on authentication doesn't matter (2 seconds to connect the VPN versus 2.5 seconds), performance on the data encryption cipher can be a point of compromise. When using two big-core computers, performance isn't an issue; always use the strongest available cipher. When one of the machines is an embedded system, performance is limited. The two main choices for cipher in OpenVPN are aes-128-gbc or aes-256-gbc. If using OpenVPN version older than 2.4, use AES-CBC instead of GBC. On embedded systems such as routers, aes-128 might get 15Mbps of bandwidth but aes-256 might only get 4Mbps. You have to test performance yourself, weigh the needed performance and security, and decide which one to use. Never use DES or RC4; these are 'broken' ciphers.
answered Feb 28 at 18:45
AndyAndy
1,056311
What about ECDSA? OpenVPN 2.4 included support for that.
– slhck
Feb 28 at 19:07
The stock firmware of router has limited settings: i.imgur.com/ici0iAE.png There are only MS-CHAPv1 and Auto for Authentication. I have to install Tomato or OpenWrt for better VPN.
– i486
Feb 28 at 20:09
2
@i486 PPTP is not the same thing as openVPN.
– Andy
Feb 28 at 21:13
@slhck Elliptic curve cryptography is also an option. It is not as common and requires more configuration. Last I saw it wasn't a native option in OpenVPN and you have to manually install your crypto libraries on both the server and client. Given that RSA 4096 is already ridiculously beyond the cryptography strength generally required, I wouldn't recommend ECDSA to a first timer.
– Andy
Feb 28 at 21:20
@Andy From what I've read RSA (including 4096) is not that strong any more. There are security experts that consider it fundamentally insecure now. There's a reason ECDSA, Ed25519, and other elliptical curve based cryptography are gaining traction.
– Cliff Armstrong
Feb 28 at 22:04
|
show 2 more comments
This is an opinion answer. This answer may get out of date easily. OpenVPN provides a guide on tuning secuirty options here.
OpenVPN has three options for cryptography. You choose the ciphers on certificates, the hash used for authentication, and the cipher used for the tunnel's data encryption separately.
Generally you want to use the strongest available cryptography for both of the authentication components. As of writing, SHA256 (Diffie-Hellman RSA) is almost always used during authentication, combined with an RSA 4096 public/private key pair or certificate chain. OpenVPN has a guide for generating your authentication certificates here.
While performance on authentication doesn't matter (2 seconds to connect the VPN versus 2.5 seconds), performance on the data encryption cipher can be a point of compromise. When using two big-core computers, performance isn't an issue; always use the strongest available cipher. When one of the machines is an embedded system, performance is limited. The two main choices for cipher in OpenVPN are aes-128-gbc or aes-256-gbc. If using OpenVPN version older than 2.4, use AES-CBC instead of GBC. On embedded systems such as routers, aes-128 might get 15Mbps of bandwidth but aes-256 might only get 4Mbps. You have to test performance yourself, weigh the needed performance and security, and decide which one to use. Never use DES or RC4; these are 'broken' ciphers.
answered Feb 28 at 18:45
AndyAndy
1,056311
This is an opinion answer. This answer may get out of date easily. OpenVPN provides a guide on tuning secuirty options here.
OpenVPN has three options for cryptography. You choose the ciphers on certificates, the hash used for authentication, and the cipher used for the tunnel's data encryption separately.
Generally you want to use the strongest available cryptography for both of the authentication components. As of writing, SHA256 (Diffie-Hellman RSA) is almost always used during authentication, combined with an RSA 4096 public/private key pair or certificate chain. OpenVPN has a guide for generating your authentication certificates here.
While performance on authentication doesn't matter (2 seconds to connect the VPN versus 2.5 seconds), performance on the data encryption cipher can be a point of compromise. When using two big-core computers, performance isn't an issue; always use the strongest available cipher. When one of the machines is an embedded system, performance is limited. The two main choices for cipher in OpenVPN are aes-128-gbc or aes-256-gbc. If using OpenVPN version older than 2.4, use AES-CBC instead of GBC. On embedded systems such as routers, aes-128 might get 15Mbps of bandwidth but aes-256 might only get 4Mbps. You have to test performance yourself, weigh the needed performance and security, and decide which one to use. Never use DES or RC4; these are 'broken' ciphers.
answered Feb 28 at 18:45
AndyAndy
1,056311
edited Feb 28 at 21:46
answered Feb 28 at 18:45
AndyAndy
1,056311
answered Feb 28 at 18:45
AndyAndy
1,056311
answered Feb 28 at 18:45
AndyAndy
1,056311
1,056311
What about ECDSA? OpenVPN 2.4 included support for that.
– slhck
Feb 28 at 19:07
The stock firmware of router has limited settings: i.imgur.com/ici0iAE.png There are only MS-CHAPv1 and Auto for Authentication. I have to install Tomato or OpenWrt for better VPN.
– i486
Feb 28 at 20:09
2
@i486 PPTP is not the same thing as openVPN.
– Andy
Feb 28 at 21:13
@slhck Elliptic curve cryptography is also an option. It is not as common and requires more configuration. Last I saw it wasn't a native option in OpenVPN and you have to manually install your crypto libraries on both the server and client. Given that RSA 4096 is already ridiculously beyond the cryptography strength generally required, I wouldn't recommend ECDSA to a first timer.
– Andy
Feb 28 at 21:20
@Andy From what I've read RSA (including 4096) is not that strong any more. There are security experts that consider it fundamentally insecure now. There's a reason ECDSA, Ed25519, and other elliptical curve based cryptography are gaining traction.
– Cliff Armstrong
Feb 28 at 22:04
|
show 2 more comments
What about ECDSA? OpenVPN 2.4 included support for that.
– slhck
Feb 28 at 19:07
The stock firmware of router has limited settings: i.imgur.com/ici0iAE.png There are only MS-CHAPv1 and Auto for Authentication. I have to install Tomato or OpenWrt for better VPN.
– i486
Feb 28 at 20:09
2
@i486 PPTP is not the same thing as openVPN.
– Andy
Feb 28 at 21:13
@slhck Elliptic curve cryptography is also an option. It is not as common and requires more configuration. Last I saw it wasn't a native option in OpenVPN and you have to manually install your crypto libraries on both the server and client. Given that RSA 4096 is already ridiculously beyond the cryptography strength generally required, I wouldn't recommend ECDSA to a first timer.
– Andy
Feb 28 at 21:20
@Andy From what I've read RSA (including 4096) is not that strong any more. There are security experts that consider it fundamentally insecure now. There's a reason ECDSA, Ed25519, and other elliptical curve based cryptography are gaining traction.
– Cliff Armstrong
Feb 28 at 22:04
What about ECDSA? OpenVPN 2.4 included support for that.
– slhck
Feb 28 at 19:07
What about ECDSA? OpenVPN 2.4 included support for that.
– slhck
Feb 28 at 19:07
The stock firmware of router has limited settings: i.imgur.com/ici0iAE.png There are only MS-CHAPv1 and Auto for Authentication. I have to install Tomato or OpenWrt for better VPN.
– i486
Feb 28 at 20:09
The stock firmware of router has limited settings: i.imgur.com/ici0iAE.png There are only MS-CHAPv1 and Auto for Authentication. I have to install Tomato or OpenWrt for better VPN.
– i486
Feb 28 at 20:09
2
2
@i486 PPTP is not the same thing as openVPN.
– Andy
Feb 28 at 21:13
@i486 PPTP is not the same thing as openVPN.
– Andy
Feb 28 at 21:13
@slhck Elliptic curve cryptography is also an option. It is not as common and requires more configuration. Last I saw it wasn't a native option in OpenVPN and you have to manually install your crypto libraries on both the server and client. Given that RSA 4096 is already ridiculously beyond the cryptography strength generally required, I wouldn't recommend ECDSA to a first timer.
– Andy
Feb 28 at 21:20
@slhck Elliptic curve cryptography is also an option. It is not as common and requires more configuration. Last I saw it wasn't a native option in OpenVPN and you have to manually install your crypto libraries on both the server and client. Given that RSA 4096 is already ridiculously beyond the cryptography strength generally required, I wouldn't recommend ECDSA to a first timer.
– Andy
Feb 28 at 21:20
@Andy From what I've read RSA (including 4096) is not that strong any more. There are security experts that consider it fundamentally insecure now. There's a reason ECDSA, Ed25519, and other elliptical curve based cryptography are gaining traction.
– Cliff Armstrong
Feb 28 at 22:04
@Andy From what I've read RSA (including 4096) is not that strong any more. There are security experts that consider it fundamentally insecure now. There's a reason ECDSA, Ed25519, and other elliptical curve based cryptography are gaining traction.
– Cliff Armstrong
Feb 28 at 22:04
|
show 2 more comments
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1
Check out github.com/angristan/openvpn-install if you want a zero-config, sane-defaults installation script.
– slhck
Feb 28 at 19:07