| Message ID | 20190529224844.25203-1-richard@nod.at (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | [RFC,1/2] crypto: Allow working with key references | expand |
On Thu, May 30, 2019 at 12:48:43AM +0200, Richard Weinberger wrote: > Some crypto accelerators allow working with secure or hidden keys. > This keys are not exposed to Linux nor main memory. To use them > for a crypto operation they are referenced with a device specific id. > > This patch adds a new flag, CRYPTO_TFM_REQ_REF_KEY. > If this flag is set, crypto drivers should tread the key as > specified via setkey as reference and not as regular key. > Since we reuse the key data structure such a reference is limited > by the key size of the chiper and is chip specific. > > TODO: If the cipher implementation or the driver does not > support reference keys, we need a way to detect this an fail > upon setkey. > How should the driver indicate that it supports this feature? > > Signed-off-by: Richard Weinberger <richard@nod.at> We already have existing drivers doing this. Please have a look at how they're doing it and use the same paradigm. You can grep for paes under drivers/crypto. Cheers,
----- Ursprüngliche Mail ----- > Von: "Herbert Xu" <herbert@gondor.apana.org.au> > An: "richard" <richard@nod.at> > CC: "Linux Crypto Mailing List" <linux-crypto@vger.kernel.org>, linux-arm-kernel@lists.infradead.org, "linux-kernel" > <linux-kernel@vger.kernel.org>, linux-imx@nxp.com, festevam@gmail.com, "kernel" <kernel@pengutronix.de>, "Sascha Hauer" > <s.hauer@pengutronix.de>, shawnguo@kernel.org, davem@davemloft.net, "david" <david@sigma-star.at> > Gesendet: Donnerstag, 30. Mai 2019 04:33:57 > Betreff: Re: [RFC PATCH 1/2] crypto: Allow working with key references > On Thu, May 30, 2019 at 12:48:43AM +0200, Richard Weinberger wrote: >> Some crypto accelerators allow working with secure or hidden keys. >> This keys are not exposed to Linux nor main memory. To use them >> for a crypto operation they are referenced with a device specific id. >> >> This patch adds a new flag, CRYPTO_TFM_REQ_REF_KEY. >> If this flag is set, crypto drivers should tread the key as >> specified via setkey as reference and not as regular key. >> Since we reuse the key data structure such a reference is limited >> by the key size of the chiper and is chip specific. >> >> TODO: If the cipher implementation or the driver does not >> support reference keys, we need a way to detect this an fail >> upon setkey. >> How should the driver indicate that it supports this feature? >> >> Signed-off-by: Richard Weinberger <richard@nod.at> > > We already have existing drivers doing this. Please have a look > at how they're doing it and use the same paradigm. You can grep > for paes under drivers/crypto. Thanks for the pointer. So the preferred way is defining a new crypto algorithm prefixed with "p" and reusing setkey to provide the key reference. Thanks, //richard
On 30.05.19 09:23, Richard Weinberger wrote: > ----- Ursprüngliche Mail ----- >> Von: "Herbert Xu" <herbert@gondor.apana.org.au> >> An: "richard" <richard@nod.at> >> CC: "Linux Crypto Mailing List" <linux-crypto@vger.kernel.org>, linux-arm-kernel@lists.infradead.org, "linux-kernel" >> <linux-kernel@vger.kernel.org>, linux-imx@nxp.com, festevam@gmail.com, "kernel" <kernel@pengutronix.de>, "Sascha Hauer" >> <s.hauer@pengutronix.de>, shawnguo@kernel.org, davem@davemloft.net, "david" <david@sigma-star.at> >> Gesendet: Donnerstag, 30. Mai 2019 04:33:57 >> Betreff: Re: [RFC PATCH 1/2] crypto: Allow working with key references >> On Thu, May 30, 2019 at 12:48:43AM +0200, Richard Weinberger wrote: >>> Some crypto accelerators allow working with secure or hidden keys. >>> This keys are not exposed to Linux nor main memory. To use them >>> for a crypto operation they are referenced with a device specific id. >>> >>> This patch adds a new flag, CRYPTO_TFM_REQ_REF_KEY. >>> If this flag is set, crypto drivers should tread the key as >>> specified via setkey as reference and not as regular key. >>> Since we reuse the key data structure such a reference is limited >>> by the key size of the chiper and is chip specific. >>> >>> TODO: If the cipher implementation or the driver does not >>> support reference keys, we need a way to detect this an fail >>> upon setkey. >>> How should the driver indicate that it supports this feature? >>> >>> Signed-off-by: Richard Weinberger <richard@nod.at> >> We already have existing drivers doing this. Please have a look >> at how they're doing it and use the same paradigm. You can grep >> for paes under drivers/crypto. > Thanks for the pointer. > So the preferred way is defining a new crypto algorithm prefixed with > "p" and reusing setkey to provide the key reference. The "p" in paes is because we call it "protected key aes". I think you are not limited to the "p". What Herbert tries to point out is that you may define your own cipher with an unique name and there you can handle your secure key references as you like. You may use the s390 paes implementation as a starting point. regards Harald Freudenberger <freude@linux.ibm.com> > > Thanks, > //richard >
On Mon, Jun 03, 2019 at 09:59:53AM +0200, Harald Freudenberger wrote: > > The "p" in paes is because we call it "protected key aes". I think you are not limited > to the "p". What Herbert tries to point out is that you may define your own > cipher with an unique name and there you can handle your secure key references > as you like. You may use the s390 paes implementation as a starting point. Well we have one other driver that is also using the paes name ccree so I think we should all use this name for hardware keys with AES. Only the driver name needs to be unique. Cheers,
diff --git a/include/linux/crypto.h b/include/linux/crypto.h index f2565a103158..737ea00e026b 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -121,6 +121,7 @@ #define CRYPTO_TFM_REQ_FORBID_WEAK_KEYS 0x00000100 #define CRYPTO_TFM_REQ_MAY_SLEEP 0x00000200 #define CRYPTO_TFM_REQ_MAY_BACKLOG 0x00000400 +#define CRYPTO_TFM_REQ_REF_KEY 0x00000800 #define CRYPTO_TFM_RES_WEAK_KEY 0x00100000 #define CRYPTO_TFM_RES_BAD_KEY_LEN 0x00200000 #define CRYPTO_TFM_RES_BAD_KEY_SCHED 0x00400000
Some crypto accelerators allow working with secure or hidden keys. This keys are not exposed to Linux nor main memory. To use them for a crypto operation they are referenced with a device specific id. This patch adds a new flag, CRYPTO_TFM_REQ_REF_KEY. If this flag is set, crypto drivers should tread the key as specified via setkey as reference and not as regular key. Since we reuse the key data structure such a reference is limited by the key size of the chiper and is chip specific. TODO: If the cipher implementation or the driver does not support reference keys, we need a way to detect this an fail upon setkey. How should the driver indicate that it supports this feature? Signed-off-by: Richard Weinberger <richard@nod.at> --- include/linux/crypto.h | 1 + 1 file changed, 1 insertion(+)