crypto: mark unused ciphers as obsolete
Subsystems (2)
PATCH 1/1 crypto: mark unused ciphers as obsolete
We have a few interesting pieces in our cipher museum, which are never used internally, and were only ever provided as generic C implementations.
Unfortunately, we cannot simply remove this code, as we cannot be sure that it is not being used via the AF_ALG socket API, however unlikely.
So let's mark the Anubis, Khazad, SEED and TEA algorithms as obsolete, which means they can only be enabled in the build if the socket API is enabled in the first place.
---
Hopefully, I will be able to convince the distro kernel maintainers to disable CRYPTO_USER_API_ENABLE_OBSOLETE in their v5.10+ builds once the iwd changes for arc4 make it downstream (Debian already has an updated version in its unstable distro). With the joint coverage of their QA, we should be able to confirm that these algos are never used, and actually remove them altogether.
crypto/Kconfig | 4 ++++ 1 file changed, 4 insertions(+)
crypto/Kconfig +4 -0
@@ -1185,6 +1185,7 @@ config CRYPTO_AES_PPC_SPE config CRYPTO_ANUBIS tristate "Anubis cipher algorithm" + depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help Anubis cipher algorithm.
@@ -1424,6 +1425,7 @@ config CRYPTO_FCRYPT config CRYPTO_KHAZAD tristate "Khazad cipher algorithm" + depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help Khazad cipher algorithm.
@@ -1487,6 +1489,7 @@ config CRYPTO_CHACHA_MIPS config CRYPTO_SEED tristate "SEED cipher algorithm" + depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help SEED cipher algorithm (RFC4269).
@@ -1613,6 +1616,7 @@ config CRYPTO_SM4 config CRYPTO_TEA tristate "TEA, XTEA and XETA cipher algorithms" + depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help TEA cipher algorithm.
Signature · 1 line
2.17.1
Quoted 7 lines
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Ard Biesheuvel
Sent: Friday, September 11, 2020 4:11 PM
To: [email protected]
Cc: [email protected]; [email protected]; Ard Biesheuvel <[email protected]>
Subject: [PATCH] crypto: mark unused ciphers as obsolete
Quoted 8 lines
<<< External Email >>>
We have a few interesting pieces in our cipher museum, which are never used internally, and were only ever provided as generic C implementations.Unfortunately, we cannot simply remove this code, as we cannot be sure that it is not being used via the
AF_ALGsocket API, however unlikely. So let's mark the Anubis, Khazad, SEED and TEA algorithms as obsolete,
Wouldn't the IKE deamon be able to utilize these algorithms through the XFRM API? I'm by no means an expert on the subject, but it looks like the cipher template is provided there directly via XFRM, so it does not need to live in the kernel source. And I know for a fact that SEED is being used for IPsec (and TLS) in Korea.
The point being, there are more users to consider beyond "internal" (meaning hard coded in the kernel source in this context?) and AF_ALG.
I'm not aware of any real use cases for Anubis, Khazad and TEA though.
Quoted 52 lines
which means they can only be enabled in the build if the socket API is enabled in the first place.
Signed-off-by Ard Biesheuvel <[email protected]>---
Hopefully, I will be able to convince the distro kernel maintainers to disableCRYPTO_USER_API_ENABLE_OBSOLETEin their v5.10+ builds once the iwd changes for arc4 make it downstream (Debian already has an updated version in its unstable distro). With the joint coverage of their QA, we should be able to confirm that these algos are never used, and actually remove them altogether.crypto/Kconfig | 4 ++++ 1 file changed, 4 insertions(+)crypto/Kconfig +4
-1@@ -1185,6 +1185,7 @@ config CRYPTO_AES_PPC_SPE config CRYPTO_ANUBIS tristate "Anubis cipher algorithm" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help Anubis cipher algorithm.@@ -1424,6 +1425,7 @@ config CRYPTO_FCRYPT config CRYPTO_KHAZAD tristate "Khazad cipher algorithm" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help Khazad cipher algorithm.@@ -1487,6 +1489,7 @@ config CRYPTO_CHACHA_MIPS config CRYPTO_SEED tristate "SEED cipher algorithm" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help SEED cipher algorithm (RFC4269).@@ -1613,6 +1616,7 @@ config CRYPTO_SM4 config CRYPTO_TEA tristate "TEA, XTEA and XETA cipher algorithms" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help TEA cipher algorithm. --
Quoted 1 line
2.17.1
Regards,
Pascal van Leeuwen
Silicon IP Architect Multi-Protocol Engines, Rambus Security Rambus ROTW Holding BV
+31-73 6581953
Note: The Inside Secure/Verimatrix Silicon IP team was recently acquired by Rambus. Please be so kind to update your e-mail address book with my new e-mail address.
** This message and any attachments are for the sole use of the intended recipient(s). It may contain information that is confidential and privileged. If you are not the intended recipient of this message, you are prohibited from printing, copying, forwarding or saving it. Please delete the message and attachments and notify the sender immediately. **
Rambus Inc.<http://www.rambus.com>
(cc Milan and dm-devel)
Quoted 12 lines · Pascal
Quoted 12 lines
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Ard Biesheuvel
Sent: Friday, September 11, 2020 4:11 PM
To: [email protected]
Cc: [email protected]; [email protected]; Ard Biesheuvel <[email protected]>
Subject: [PATCH] crypto: mark unused ciphers as obsolete<<< External Email >>>
We have a few interesting pieces in our cipher museum, which are never used internally, and were only ever provided as generic C implementations.
Quoted 9 lines
Quoted 4 lines
Unfortunately, we cannot simply remove this code, as we cannot be sure that it is not being used via the
AF_ALGsocket API, however unlikely. So let's mark the Anubis, Khazad, SEED and TEA algorithms as obsolete,Wouldn't the IKE deamon be able to utilize these algorithms through the XFRM API? I'm by no means an expert on the subject, but it looks like the cipher template is provided there directly via XFRM, so it does not need to live in the kernel source. And I know for a fact that SEED is being used for IPsec (and TLS) in Korea.
I have been staring at net/xfrm/xfrm_algo.c, and as far as I can tell, algorithms have to be mentioned there in order to be usable. None of the ciphers that this patch touches are listed there or anywhere else in the kernel.
Quoted 3 lines
The point being, there are more users to consider beyond "internal" (meaning hard coded in the kernel source in this context?) and
AF_ALG.
That is a good point, actually, since dm-crypt could be affected here as well, hence the CCs.
Milan (or others): are you aware of any of these ciphers being used for dm-crypt?
Quoted 2 lines
I'm not aware of any real use cases for Anubis, Khazad and TEA though.
OK, thanks for confirming. Removing those would be a good start.
Quoted 67 lines
Quoted 52 lines
which means they can only be enabled in the build if the socket API is enabled in the first place.
Signed-off-by Ard Biesheuvel <[email protected]>---
Hopefully, I will be able to convince the distro kernel maintainers to disableCRYPTO_USER_API_ENABLE_OBSOLETEin their v5.10+ builds once the iwd changes for arc4 make it downstream (Debian already has an updated version in its unstable distro). With the joint coverage of their QA, we should be able to confirm that these algos are never used, and actually remove them altogether.crypto/Kconfig | 4 ++++ 1 file changed, 4 insertions(+)crypto/Kconfig +4
-1@@ -1185,6 +1185,7 @@ config CRYPTO_AES_PPC_SPE config CRYPTO_ANUBIS tristate "Anubis cipher algorithm" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help Anubis cipher algorithm.@@ -1424,6 +1425,7 @@ config CRYPTO_FCRYPT config CRYPTO_KHAZAD tristate "Khazad cipher algorithm" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help Khazad cipher algorithm.@@ -1487,6 +1489,7 @@ config CRYPTO_CHACHA_MIPS config CRYPTO_SEED tristate "SEED cipher algorithm" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help SEED cipher algorithm (RFC4269).@@ -1613,6 +1616,7 @@ config CRYPTO_SM4 config CRYPTO_TEA tristate "TEA, XTEA and XETA cipher algorithms" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help TEA cipher algorithm. --Quoted 1 line
2.17.1
Regards,
Pascal van Leeuwen
Silicon IP Architect Multi-Protocol Engines, Rambus Security Rambus ROTW Holding BV
+31-73 6581953Note: The Inside Secure/Verimatrix Silicon IP team was recently acquired by Rambus. Please be so kind to update your e-mail address book with my new e-mail address.
** This message and any attachments are for the sole use of the intended recipient(s). It may contain information that is confidential and privileged. If you are not the intended recipient of this message, you are prohibited from printing, copying, forwarding or saving it. Please delete the message and attachments and notify the sender immediately. **
Rambus Inc.<http://www.rambus.com>
Quoted 34 lines
-----Original Message-----
From: Ard Biesheuvel <[email protected]>
Sent: Friday, September 11, 2020 6:30 PM
To: Van Leeuwen, Pascal <[email protected]>; [email protected]; Milan Broz <[email protected]>
Cc: [email protected]; [email protected]; [email protected]
Subject: Re: [PATCH] crypto: mark unused ciphers as obsolete<<< External Email >>>
(cc Milan and dm-devel)Quoted 12 lines · Pascal
Quoted 12 lines
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Ard Biesheuvel
Sent: Friday, September 11, 2020 4:11 PM
To: [email protected]
Cc: [email protected]; [email protected]; Ard Biesheuvel <[email protected]>
Subject: [PATCH] crypto: mark unused ciphers as obsolete<<< External Email >>>
We have a few interesting pieces in our cipher museum, which are never used internally, and were only ever provided as generic C implementations.Quoted 9 lines
Quoted 4 lines
Unfortunately, we cannot simply remove this code, as we cannot be sure that it is not being used via the
AF_ALGsocket API, however unlikely. So let's mark the Anubis, Khazad, SEED and TEA algorithms as obsolete,Wouldn't the IKE deamon be able to utilize these algorithms through the XFRM API? I'm by no means an expert on the subject, but it looks like the cipher template is provided there directly via XFRM, so it does not need to live in the kernel source. And I know for a fact that SEED is being used for IPsec (and TLS) in Korea.
Quoted 5 lines
I have been staring at
net/xfrm/xfrm_algo.c, and as far as I can tell, algorithms have to be mentioned there in order to be usable. None of the ciphers that this patch touches are listed there or anywhere else in the kernel.
Hmmm ... good point. Wasn't aware XFRM was actively allowing only a subset. Actually found this commented out code in my Pluto source (kernel_netlink.c):
/*
* Not yet implemented in Linux kernel xfrm_algo.c
{ SADB_X_EALG_SEEDCBC, "cbc(seed)" },
*/
Go figure.
Quoted 76 lines
Quoted 3 lines
The point being, there are more users to consider beyond "internal" (meaning hard coded in the kernel source in this context?) and
AF_ALG.That is a good point, actually, since dm-crypt could be affected here as well, hence the CCs.
Milan (or others): are you aware of any of these ciphers being used for dm-crypt?
Quoted 2 lines
I'm not aware of any real use cases for Anubis, Khazad and TEA though.
OK, thanks for confirming. Removing those would be a good start.
Quoted 60 lines
Quoted 52 lines
which means they can only be enabled in the build if the socket API is enabled in the first place.
Signed-off-by Ard Biesheuvel <[email protected]>---
Hopefully, I will be able to convince the distro kernel maintainers to disableCRYPTO_USER_API_ENABLE_OBSOLETEin their v5.10+ builds once the iwd changes for arc4 make it downstream (Debian already has an updated version in its unstable distro). With the joint coverage of their QA, we should be able to confirm that these algos are never used, and actually remove them altogether.crypto/Kconfig | 4 ++++ 1 file changed, 4 insertions(+)crypto/Kconfig +4
-1@@ -1185,6 +1185,7 @@ config CRYPTO_AES_PPC_SPE config CRYPTO_ANUBIS tristate "Anubis cipher algorithm" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help Anubis cipher algorithm.@@ -1424,6 +1425,7 @@ config CRYPTO_FCRYPT config CRYPTO_KHAZAD tristate "Khazad cipher algorithm" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help Khazad cipher algorithm.@@ -1487,6 +1489,7 @@ config CRYPTO_CHACHA_MIPS config CRYPTO_SEED tristate "SEED cipher algorithm" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help SEED cipher algorithm (RFC4269).@@ -1613,6 +1616,7 @@ config CRYPTO_SM4 config CRYPTO_TEA tristate "TEA, XTEA and XETA cipher algorithms" +depends on CRYPTO_USER_API_ENABLE_OBSOLETE select CRYPTO_ALGAPI help TEA cipher algorithm. --Quoted 1 line
2.17.1
Regards,
Pascal van Leeuwen
Silicon IP Architect Multi-Protocol Engines, Rambus Security Rambus ROTW Holding BV
+31-73 6581953
Quoted 9 lines
Quoted 5 lines
Note: The Inside Secure/Verimatrix Silicon IP team was recently acquired by Rambus. Please be so kind to update your e-mail address book with my new e-mail address.
** This message and any attachments are for the sole use of the intended recipient(s). It may contain information that is
confidential and privileged. If you are not the intended recipient of this message, you are prohibited from printing, copying, forwarding or saving it. Please delete the message and attachments and notify the sender immediately. **
Quoted 2 lines
Rambus Inc.<http://www.rambus.com>
Regards,
Pascal van Leeuwen
Silicon IP Architect Multi-Protocol Engines, Rambus Security Rambus ROTW Holding BV
+31-73 6581953
Note: The Inside Secure/Verimatrix Silicon IP team was recently acquired by Rambus. Please be so kind to update your e-mail address book with my new e-mail address.
** This message and any attachments are for the sole use of the intended recipient(s). It may contain information that is confidential and privileged. If you are not the intended recipient of this message, you are prohibited from printing, copying, forwarding or saving it. Please delete the message and attachments and notify the sender immediately. **
Rambus Inc.<http://www.rambus.com>
Quoted 35 lines · Ard Biesheuvel
(cc Milan and dm-devel)
Quoted 12 lines · Pascal
Quoted 12 lines
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Ard Biesheuvel
Sent: Friday, September 11, 2020 4:11 PM
To: [email protected]
Cc: [email protected]; [email protected]; Ard Biesheuvel <[email protected]>
Subject: [PATCH] crypto: mark unused ciphers as obsolete<<< External Email >>>
We have a few interesting pieces in our cipher museum, which are never used internally, and were only ever provided as generic C implementations.Quoted 9 lines
Quoted 4 lines
Unfortunately, we cannot simply remove this code, as we cannot be sure that it is not being used via the
AF_ALGsocket API, however unlikely. So let's mark the Anubis, Khazad, SEED and TEA algorithms as obsolete,Wouldn't the IKE deamon be able to utilize these algorithms through the XFRM API? I'm by no means an expert on the subject, but it looks like the cipher template is provided there directly via XFRM, so it does not need to live in the kernel source. And I know for a fact that SEED is being used for IPsec (and TLS) in Korea.
I have been staring at
net/xfrm/xfrm_algo.c, and as far as I can tell, algorithms have to be mentioned there in order to be usable. None of the ciphers that this patch touches are listed there or anywhere else in the kernel.Quoted 3 lines
The point being, there are more users to consider beyond "internal" (meaning hard coded in the kernel source in this context?) and
AF_ALG.
Quoted 5 lines
That is a good point, actually, since dm-crypt could be affected here as well, hence the CCs.
Milan (or others): are you aware of any of these ciphers being used for dm-crypt?
Cryptsetup/dm-crypt can use them (talking about Seed, Khazad, Anubis, TEA), but I think there is no real use of these.
(IOW these are used only if someone deliberately uses them - manually specifying on format.)
For dm-crypt. there should be no big harm if these are marked obsolete.
Milan
Herbert Xu
maintainerQuoted 19 lines · Ard Biesheuvel
We have a few interesting pieces in our cipher museum, which are never used internally, and were only ever provided as generic C implementations.
Unfortunately, we cannot simply remove this code, as we cannot be sure that it is not being used via the
AF_ALGsocket API, however unlikely.So let's mark the Anubis, Khazad, SEED and TEA algorithms as obsolete, which means they can only be enabled in the build if the socket API is enabled in the first place.
Signed-off-by Ard Biesheuvel <[email protected]>---
Hopefully, I will be able to convince the distro kernel maintainers to disableCRYPTO_USER_API_ENABLE_OBSOLETEin their v5.10+ builds once the iwd changes for arc4 make it downstream (Debian already has an updated version in its unstable distro). With the joint coverage of their QA, we should be able to confirm that these algos are never used, and actually remove them altogether.
Quoted 2 lines
crypto/Kconfig | 4 ++++ 1 file changed, 4 insertions(+)
Patch applied. Thanks.
Signature · 3 lines
Email: Herbert Xu <[email protected]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt