[PATCH net v4 0/3] esp, ah: improve crypto algorithm selections

[PATCH net v4 0/3] esp, ah: improve crypto algorithm selections

[Eric Biggers]

This series consolidates and modernizes the lists of crypto algorithms
that are selected by the IPsec kconfig options, and adds CRYPTO_SEQIV
since it no longer gets selected automatically by other things.

See previous discussion at
https://lkml.kernel.org/netdev/20200604192322.22142-1-ebiggers@kernel.org/T/#u

Changed v3 => v4:
  - Don't say that AH is "NOT RECOMMENDED" by RFC 8221.
  - Updated commit messages (added Acked-by tags, fixed a bad Fixes tag,
    added some more explanation to patch 3).

Eric Biggers (3):
  esp, ah: consolidate the crypto algorithm selections
  esp: select CRYPTO_SEQIV
  esp, ah: modernize the crypto algorithm selections

 net/ipv4/Kconfig | 34 ++++++++++++++++++----------------
 net/ipv6/Kconfig | 34 ++++++++++++++++++----------------
 net/xfrm/Kconfig | 24 ++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 32 deletions(-)


base-commit: 89dc68533b190117e1a2fb4298d88b96b3580abf
-- 
2.26.2

[PATCH net v4 1/3] esp, ah: consolidate the crypto algorithm selections

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

Instead of duplicating the algorithm selections between INET_AH and
INET6_AH and between INET_ESP and INET6_ESP, create new tristates
XFRM_AH and XFRM_ESP that do the algorithm selections, and make these be
selected by the corresponding INET* options.

Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Corentin Labbe <clabbe@baylibre.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 net/ipv4/Kconfig | 16 ++--------------
 net/ipv6/Kconfig | 16 ++--------------
 net/xfrm/Kconfig | 20 ++++++++++++++++++++
 3 files changed, 24 insertions(+), 28 deletions(-)

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 23ba5045e3d3c1..39a7a21744dc03 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -340,11 +340,7 @@ config NET_FOU_IP_TUNNELS
 
 config INET_AH
 	tristate "IP: AH transformation"
-	select XFRM_ALGO
-	select CRYPTO
-	select CRYPTO_HMAC
-	select CRYPTO_MD5
-	select CRYPTO_SHA1
+	select XFRM_AH
 	---help---
 	  Support for IPsec AH.
 
@@ -352,15 +348,7 @@ config INET_AH
 
 config INET_ESP
 	tristate "IP: ESP transformation"
-	select XFRM_ALGO
-	select CRYPTO
-	select CRYPTO_AUTHENC
-	select CRYPTO_HMAC
-	select CRYPTO_MD5
-	select CRYPTO_CBC
-	select CRYPTO_SHA1
-	select CRYPTO_DES
-	select CRYPTO_ECHAINIV
+	select XFRM_ESP
 	---help---
 	  Support for IPsec ESP.
 
diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index 4f03aece2980fb..70313f16319dd2 100644
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -49,11 +49,7 @@ config IPV6_OPTIMISTIC_DAD
 
 config INET6_AH
 	tristate "IPv6: AH transformation"
-	select XFRM_ALGO
-	select CRYPTO
-	select CRYPTO_HMAC
-	select CRYPTO_MD5
-	select CRYPTO_SHA1
+	select XFRM_AH
 	---help---
 	  Support for IPsec AH.
 
@@ -61,15 +57,7 @@ config INET6_AH
 
 config INET6_ESP
 	tristate "IPv6: ESP transformation"
-	select XFRM_ALGO
-	select CRYPTO
-	select CRYPTO_AUTHENC
-	select CRYPTO_HMAC
-	select CRYPTO_MD5
-	select CRYPTO_CBC
-	select CRYPTO_SHA1
-	select CRYPTO_DES
-	select CRYPTO_ECHAINIV
+	select XFRM_ESP
 	---help---
 	  Support for IPsec ESP.
 
diff --git a/net/xfrm/Kconfig b/net/xfrm/Kconfig
index b7fd9c83841605..169c22140709f7 100644
--- a/net/xfrm/Kconfig
+++ b/net/xfrm/Kconfig
@@ -67,6 +67,26 @@ config XFRM_STATISTICS
 
 	  If unsure, say N.
 
+config XFRM_AH
+	tristate
+	select XFRM_ALGO
+	select CRYPTO
+	select CRYPTO_HMAC
+	select CRYPTO_MD5
+	select CRYPTO_SHA1
+
+config XFRM_ESP
+	tristate
+	select XFRM_ALGO
+	select CRYPTO
+	select CRYPTO_AUTHENC
+	select CRYPTO_HMAC
+	select CRYPTO_MD5
+	select CRYPTO_CBC
+	select CRYPTO_SHA1
+	select CRYPTO_DES
+	select CRYPTO_ECHAINIV
+
 config XFRM_IPCOMP
 	tristate
 	select XFRM_ALGO
-- 
2.26.2

[PATCH net v4 2/3] esp: select CRYPTO_SEQIV

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

Commit f23efcbcc523 ("crypto: ctr - no longer needs CRYPTO_SEQIV") made
CRYPTO_CTR stop selecting CRYPTO_SEQIV.  This breaks IPsec for most
users since GCM and several other encryption algorithms require "seqiv"
-- and RFC 8221 lists AES-GCM as "MUST" be implemented.

Just make XFRM_ESP select CRYPTO_SEQIV.

Fixes: f23efcbcc523 ("crypto: ctr - no longer needs CRYPTO_SEQIV")
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Corentin Labbe <clabbe@baylibre.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 net/xfrm/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/xfrm/Kconfig b/net/xfrm/Kconfig
index 169c22140709f7..b2ff8df2c836ef 100644
--- a/net/xfrm/Kconfig
+++ b/net/xfrm/Kconfig
@@ -86,6 +86,7 @@ config XFRM_ESP
 	select CRYPTO_SHA1
 	select CRYPTO_DES
 	select CRYPTO_ECHAINIV
+	select CRYPTO_SEQIV
 
 config XFRM_IPCOMP
 	tristate
-- 
2.26.2

[PATCH net v4 3/3] esp, ah: modernize the crypto algorithm selections

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

The crypto algorithms selected by the ESP and AH kconfig options are
out-of-date with the guidance of RFC 8221, which lists the legacy
algorithms MD5 and DES as "MUST NOT" be implemented, and some more
modern algorithms like AES-GCM and HMAC-SHA256 as "MUST" be implemented.
But the options select the legacy algorithms, not the modern ones.

Therefore, modify these options to select the MUST algorithms --
and *only* the MUST algorithms.

Also improve the help text.

Note that other algorithms may still be explicitly enabled in the
kconfig, and the choice of which to actually use is still controlled by
userspace.  This change only modifies the list of algorithms for which
kernel support is guaranteed to be present.

Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Suggested-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Corentin Labbe <clabbe@baylibre.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 net/ipv4/Kconfig | 18 ++++++++++++++++--
 net/ipv6/Kconfig | 18 ++++++++++++++++--
 net/xfrm/Kconfig | 15 +++++++++------
 3 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 39a7a21744dc03..dc9dfaef77e5a4 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -342,7 +342,14 @@ config INET_AH
 	tristate "IP: AH transformation"
 	select XFRM_AH
 	---help---
-	  Support for IPsec AH.
+	  Support for IPsec AH (Authentication Header).
+
+	  AH can be used with various authentication algorithms.  Besides
+	  enabling AH support itself, this option enables the generic
+	  implementations of the algorithms that RFC 8221 lists as MUST be
+	  implemented.  If you need any other algorithms, you'll need to enable
+	  them in the crypto API.  You should also enable accelerated
+	  implementations of any needed algorithms when available.
 
 	  If unsure, say Y.
 
@@ -350,7 +357,14 @@ config INET_ESP
 	tristate "IP: ESP transformation"
 	select XFRM_ESP
 	---help---
-	  Support for IPsec ESP.
+	  Support for IPsec ESP (Encapsulating Security Payload).
+
+	  ESP can be used with various encryption and authentication algorithms.
+	  Besides enabling ESP support itself, this option enables the generic
+	  implementations of the algorithms that RFC 8221 lists as MUST be
+	  implemented.  If you need any other algorithms, you'll need to enable
+	  them in the crypto API.  You should also enable accelerated
+	  implementations of any needed algorithms when available.
 
 	  If unsure, say Y.
 
diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index 70313f16319dd2..414a68b16869ec 100644
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -51,7 +51,14 @@ config INET6_AH
 	tristate "IPv6: AH transformation"
 	select XFRM_AH
 	---help---
-	  Support for IPsec AH.
+	  Support for IPsec AH (Authentication Header).
+
+	  AH can be used with various authentication algorithms.  Besides
+	  enabling AH support itself, this option enables the generic
+	  implementations of the algorithms that RFC 8221 lists as MUST be
+	  implemented.  If you need any other algorithms, you'll need to enable
+	  them in the crypto API.  You should also enable accelerated
+	  implementations of any needed algorithms when available.
 
 	  If unsure, say Y.
 
@@ -59,7 +66,14 @@ config INET6_ESP
 	tristate "IPv6: ESP transformation"
 	select XFRM_ESP
 	---help---
-	  Support for IPsec ESP.
+	  Support for IPsec ESP (Encapsulating Security Payload).
+
+	  ESP can be used with various encryption and authentication algorithms.
+	  Besides enabling ESP support itself, this option enables the generic
+	  implementations of the algorithms that RFC 8221 lists as MUST be
+	  implemented.  If you need any other algorithms, you'll need to enable
+	  them in the crypto API.  You should also enable accelerated
+	  implementations of any needed algorithms when available.
 
 	  If unsure, say Y.
 
diff --git a/net/xfrm/Kconfig b/net/xfrm/Kconfig
index b2ff8df2c836ef..e77ba529229cf5 100644
--- a/net/xfrm/Kconfig
+++ b/net/xfrm/Kconfig
@@ -67,26 +67,29 @@ config XFRM_STATISTICS
 
 	  If unsure, say N.
 
+# This option selects XFRM_ALGO along with the AH authentication algorithms that
+# RFC 8221 lists as MUST be implemented.
 config XFRM_AH
 	tristate
 	select XFRM_ALGO
 	select CRYPTO
 	select CRYPTO_HMAC
-	select CRYPTO_MD5
-	select CRYPTO_SHA1
+	select CRYPTO_SHA256
 
+# This option selects XFRM_ALGO along with the ESP encryption and authentication
+# algorithms that RFC 8221 lists as MUST be implemented.
 config XFRM_ESP
 	tristate
 	select XFRM_ALGO
 	select CRYPTO
+	select CRYPTO_AES
 	select CRYPTO_AUTHENC
-	select CRYPTO_HMAC
-	select CRYPTO_MD5
 	select CRYPTO_CBC
-	select CRYPTO_SHA1
-	select CRYPTO_DES
 	select CRYPTO_ECHAINIV
+	select CRYPTO_GCM
+	select CRYPTO_HMAC
 	select CRYPTO_SEQIV
+	select CRYPTO_SHA256
 
 config XFRM_IPCOMP
 	tristate
-- 
2.26.2

Re: [PATCH net v4 0/3] esp, ah: improve crypto algorithm selections

[Steffen Klassert]

On Wed, Jun 10, 2020 at 09:14:34AM -0700, Eric Biggers wrote:
> This series consolidates and modernizes the lists of crypto algorithms
> that are selected by the IPsec kconfig options, and adds CRYPTO_SEQIV
> since it no longer gets selected automatically by other things.
> 
> See previous discussion at
> https://lkml.kernel.org/netdev/20200604192322.22142-1-ebiggers@kernel.org/T/#u
> 
> Changed v3 => v4:
>   - Don't say that AH is "NOT RECOMMENDED" by RFC 8221.
>   - Updated commit messages (added Acked-by tags, fixed a bad Fixes tag,
>     added some more explanation to patch 3).

Series applied to the ipsec tree, thanks a lot Eric!