[PATCH 0/6] Trivial set of FIPS 140-3 related changes

[PATCH 0/6] Trivial set of FIPS 140-3 related changes

[Vladis Dronov]

Hi,

This patchset and cover letter was initially composed by Nicolai Stange
and sent earlier as:

https://lore.kernel.org/all/20221108142025.13461-1-nstange@suse.de/
with a subject: [PATCH 0/4] Trivial set of FIPS 140-3 related changes

I'm adding patches 2 and 3 which (I hope) resolve issues spotted by
reviewers of previous version of the patchset. This new patchset should
ease our future kernel work on the FIPS mode.

I'm quoting Nicolai's cover letter here:

> Hi all,
> 
> these four rather unrelated patches are basically a dump of some of the
> more trivial changes required for working towards FIPS 140-3 conformance.
> 
> Please pick as you deem appropriate.
> 
> Thanks!
> 
> Nicolai

Nicolai Stange (4):
  crypto: xts - restrict key lengths to approved values in FIPS mode
  crypto: testmgr - disallow plain cbcmac(aes) in FIPS mode
  crypto: testmgr - disallow plain ghash in FIPS mode
  crypto: testmgr - allow ecdsa-nist-p256 and -p384 in FIPS mode

Vladis Dronov (2):
  crypto: xts - drop xts_check_key()
  crypto: xts - drop redundant xts key check

 arch/s390/crypto/aes_s390.c                        |  4 ----
 arch/s390/crypto/paes_s390.c                       |  2 +-
 crypto/testmgr.c                                   |  4 ++--
 drivers/crypto/atmel-aes.c                         |  2 +-
 drivers/crypto/axis/artpec6_crypto.c               |  2 +-
 drivers/crypto/cavium/cpt/cptvf_algs.c             |  8 +++-----
 drivers/crypto/cavium/nitrox/nitrox_skcipher.c     |  8 +++-----
 drivers/crypto/ccree/cc_cipher.c                   |  2 +-
 drivers/crypto/marvell/octeontx/otx_cptvf_algs.c   |  2 +-
 drivers/crypto/marvell/octeontx2/otx2_cptvf_algs.c |  2 +-
 include/crypto/xts.h                               | 24 ++++++++----------------
 11 files changed, 22 insertions(+), 38 deletions(-)

[PATCH 1/6] crypto: xts - restrict key lengths to approved values in FIPS mode

[Vladis Dronov]

From: Nicolai Stange <nstange@suse.de>

According to FIPS 140-3 IG C.I., only (total) key lengths of either
256 bits or 512 bits are allowed with xts(aes). Make xts_verify_key() to
reject anything else in FIPS mode.

As xts(aes) is the only approved xts() template instantiation in FIPS mode,
the new restriction implemented in xts_verify_key() effectively only
applies to this particular construction.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
---
 include/crypto/xts.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/crypto/xts.h b/include/crypto/xts.h
index 0f8dba69feb4..a233c1054df2 100644
--- a/include/crypto/xts.h
+++ b/include/crypto/xts.h
@@ -35,6 +35,13 @@ static inline int xts_verify_key(struct crypto_skcipher *tfm,
 	if (keylen % 2)
 		return -EINVAL;
 
+	/*
+	 * In FIPS mode only a combined key length of either 256 or
+	 * 512 bits is allowed, c.f. FIPS 140-3 IG C.I.
+	 */
+	if (fips_enabled && keylen != 32 && keylen != 64)
+		return -EINVAL;
+
 	/* ensure that the AES and tweak key are not identical */
 	if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
 			      CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
-- 
2.38.1

[PATCH 2/6] crypto: xts - drop xts_check_key()

[Vladis Dronov]

xts_check_key() is obsoleted by xts_verify_key(). Over time XTS crypto
drivers adopted the newer xts_verify_key() variant, but xts_check_key()
is still used by a number of drivers. Switch drivers to use the newer
xts_verify_key() and make a couple of cleanups. This allows us to drop
xts_check_key() completely and avoid redundancy.

Signed-off-by: Vladis Dronov <vdronov@redhat.com>
---
 arch/s390/crypto/paes_s390.c                  |  2 +-
 drivers/crypto/atmel-aes.c                    |  2 +-
 drivers/crypto/axis/artpec6_crypto.c          |  2 +-
 drivers/crypto/cavium/cpt/cptvf_algs.c        |  8 +++----
 .../crypto/cavium/nitrox/nitrox_skcipher.c    |  8 +++----
 drivers/crypto/ccree/cc_cipher.c              |  2 +-
 .../crypto/marvell/octeontx/otx_cptvf_algs.c  |  2 +-
 .../marvell/octeontx2/otx2_cptvf_algs.c       |  2 +-
 include/crypto/xts.h                          | 21 +++----------------
 9 files changed, 15 insertions(+), 34 deletions(-)

diff --git a/arch/s390/crypto/paes_s390.c b/arch/s390/crypto/paes_s390.c
index a279b7d23a5e..29dc827e0fe8 100644
--- a/arch/s390/crypto/paes_s390.c
+++ b/arch/s390/crypto/paes_s390.c
@@ -474,7 +474,7 @@ static int xts_paes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 		return rc;
 
 	/*
-	 * xts_check_key verifies the key length is not odd and makes
+	 * xts_verify_key verifies the key length is not odd and makes
 	 * sure that the two keys are not the same. This can be done
 	 * on the two protected keys as well
 	 */
diff --git a/drivers/crypto/atmel-aes.c b/drivers/crypto/atmel-aes.c
index 886bf258544c..130f8bf09a9a 100644
--- a/drivers/crypto/atmel-aes.c
+++ b/drivers/crypto/atmel-aes.c
@@ -1879,7 +1879,7 @@ static int atmel_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
 	struct atmel_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 	int err;
 
-	err = xts_check_key(crypto_skcipher_tfm(tfm), key, keylen);
+	err = xts_verify_key(tfm, key, keylen);
 	if (err)
 		return err;
 
diff --git a/drivers/crypto/axis/artpec6_crypto.c b/drivers/crypto/axis/artpec6_crypto.c
index 51c66afbe677..f6f41e316dfe 100644
--- a/drivers/crypto/axis/artpec6_crypto.c
+++ b/drivers/crypto/axis/artpec6_crypto.c
@@ -1621,7 +1621,7 @@ artpec6_crypto_xts_set_key(struct crypto_skcipher *cipher, const u8 *key,
 		crypto_skcipher_ctx(cipher);
 	int ret;
 
-	ret = xts_check_key(&cipher->base, key, keylen);
+	ret = xts_verify_key(cipher, key, keylen);
 	if (ret)
 		return ret;
 
diff --git a/drivers/crypto/cavium/cpt/cptvf_algs.c b/drivers/crypto/cavium/cpt/cptvf_algs.c
index 9eca0c302186..0b38c2600b86 100644
--- a/drivers/crypto/cavium/cpt/cptvf_algs.c
+++ b/drivers/crypto/cavium/cpt/cptvf_algs.c
@@ -232,13 +232,12 @@ static int cvm_decrypt(struct skcipher_request *req)
 static int cvm_xts_setkey(struct crypto_skcipher *cipher, const u8 *key,
 		   u32 keylen)
 {
-	struct crypto_tfm *tfm = crypto_skcipher_tfm(cipher);
-	struct cvm_enc_ctx *ctx = crypto_tfm_ctx(tfm);
+	struct cvm_enc_ctx *ctx = crypto_skcipher_ctx(cipher);
 	int err;
 	const u8 *key1 = key;
 	const u8 *key2 = key + (keylen / 2);
 
-	err = xts_check_key(tfm, key, keylen);
+	err = xts_verify_key(cipher, key, keylen);
 	if (err)
 		return err;
 	ctx->key_len = keylen;
@@ -289,8 +288,7 @@ static int cvm_validate_keylen(struct cvm_enc_ctx *ctx, u32 keylen)
 static int cvm_setkey(struct crypto_skcipher *cipher, const u8 *key,
 		      u32 keylen, u8 cipher_type)
 {
-	struct crypto_tfm *tfm = crypto_skcipher_tfm(cipher);
-	struct cvm_enc_ctx *ctx = crypto_tfm_ctx(tfm);
+	struct cvm_enc_ctx *ctx = crypto_skcipher_ctx(cipher);
 
 	ctx->cipher_type = cipher_type;
 	if (!cvm_validate_keylen(ctx, keylen)) {
diff --git a/drivers/crypto/cavium/nitrox/nitrox_skcipher.c b/drivers/crypto/cavium/nitrox/nitrox_skcipher.c
index 248b4fff1c72..138261dcd032 100644
--- a/drivers/crypto/cavium/nitrox/nitrox_skcipher.c
+++ b/drivers/crypto/cavium/nitrox/nitrox_skcipher.c
@@ -337,12 +337,11 @@ static int nitrox_3des_decrypt(struct skcipher_request *skreq)
 static int nitrox_aes_xts_setkey(struct crypto_skcipher *cipher,
 				 const u8 *key, unsigned int keylen)
 {
-	struct crypto_tfm *tfm = crypto_skcipher_tfm(cipher);
-	struct nitrox_crypto_ctx *nctx = crypto_tfm_ctx(tfm);
+	struct nitrox_crypto_ctx *nctx = crypto_skcipher_ctx(cipher);
 	struct flexi_crypto_context *fctx;
 	int aes_keylen, ret;
 
-	ret = xts_check_key(tfm, key, keylen);
+	ret = xts_verify_key(cipher, key, keylen);
 	if (ret)
 		return ret;
 
@@ -362,8 +361,7 @@ static int nitrox_aes_xts_setkey(struct crypto_skcipher *cipher,
 static int nitrox_aes_ctr_rfc3686_setkey(struct crypto_skcipher *cipher,
 					 const u8 *key, unsigned int keylen)
 {
-	struct crypto_tfm *tfm = crypto_skcipher_tfm(cipher);
-	struct nitrox_crypto_ctx *nctx = crypto_tfm_ctx(tfm);
+	struct nitrox_crypto_ctx *nctx = crypto_skcipher_ctx(cipher);
 	struct flexi_crypto_context *fctx;
 	int aes_keylen;
 
diff --git a/drivers/crypto/ccree/cc_cipher.c b/drivers/crypto/ccree/cc_cipher.c
index 309da6334a0a..2cd44d7457a4 100644
--- a/drivers/crypto/ccree/cc_cipher.c
+++ b/drivers/crypto/ccree/cc_cipher.c
@@ -460,7 +460,7 @@ static int cc_cipher_setkey(struct crypto_skcipher *sktfm, const u8 *key,
 	}
 
 	if (ctx_p->cipher_mode == DRV_CIPHER_XTS &&
-	    xts_check_key(tfm, key, keylen)) {
+	    xts_verify_key(sktfm, key, keylen)) {
 		dev_dbg(dev, "weak XTS key");
 		return -EINVAL;
 	}
diff --git a/drivers/crypto/marvell/octeontx/otx_cptvf_algs.c b/drivers/crypto/marvell/octeontx/otx_cptvf_algs.c
index 80ba77c793a7..83493dd0416f 100644
--- a/drivers/crypto/marvell/octeontx/otx_cptvf_algs.c
+++ b/drivers/crypto/marvell/octeontx/otx_cptvf_algs.c
@@ -398,7 +398,7 @@ static int otx_cpt_skcipher_xts_setkey(struct crypto_skcipher *tfm,
 	const u8 *key1 = key;
 	int ret;
 
-	ret = xts_check_key(crypto_skcipher_tfm(tfm), key, keylen);
+	ret = xts_verify_key(tfm, key, keylen);
 	if (ret)
 		return ret;
 	ctx->key_len = keylen;
diff --git a/drivers/crypto/marvell/octeontx2/otx2_cptvf_algs.c b/drivers/crypto/marvell/octeontx2/otx2_cptvf_algs.c
index 30b423605c9c..443202caa140 100644
--- a/drivers/crypto/marvell/octeontx2/otx2_cptvf_algs.c
+++ b/drivers/crypto/marvell/octeontx2/otx2_cptvf_algs.c
@@ -412,7 +412,7 @@ static int otx2_cpt_skcipher_xts_setkey(struct crypto_skcipher *tfm,
 	const u8 *key1 = key;
 	int ret;
 
-	ret = xts_check_key(crypto_skcipher_tfm(tfm), key, keylen);
+	ret = xts_verify_key(tfm, key, keylen);
 	if (ret)
 		return ret;
 	ctx->key_len = keylen;
diff --git a/include/crypto/xts.h b/include/crypto/xts.h
index a233c1054df2..5a6a2cc89d49 100644
--- a/include/crypto/xts.h
+++ b/include/crypto/xts.h
@@ -8,23 +8,6 @@
 
 #define XTS_BLOCK_SIZE 16
 
-static inline int xts_check_key(struct crypto_tfm *tfm,
-				const u8 *key, unsigned int keylen)
-{
-	/*
-	 * key consists of keys of equal size concatenated, therefore
-	 * the length must be even.
-	 */
-	if (keylen % 2)
-		return -EINVAL;
-
-	/* ensure that the AES and tweak key are not identical */
-	if (fips_enabled && !crypto_memneq(key, key + (keylen / 2), keylen / 2))
-		return -EINVAL;
-
-	return 0;
-}
-
 static inline int xts_verify_key(struct crypto_skcipher *tfm,
 				 const u8 *key, unsigned int keylen)
 {
@@ -42,7 +25,9 @@ static inline int xts_verify_key(struct crypto_skcipher *tfm,
 	if (fips_enabled && keylen != 32 && keylen != 64)
 		return -EINVAL;
 
-	/* ensure that the AES and tweak key are not identical */
+	/* ensure that the AES and tweak key are not identical
+	 * when in FIPS mode or the FORBID_WEAK_KEYS flag is set.
+	 */
 	if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
 			      CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
 	    !crypto_memneq(key, key + (keylen / 2), keylen / 2))
-- 
2.38.1

[PATCH 3/6] crypto: xts - drop redundant xts key check

[Vladis Dronov]

xts_fallback_setkey() in xts_aes_set_key() will now enforce key size
rule in FIPS mode when setting up the fallback algorithm keys, which
makes the check in xts_aes_set_key() redundant or unreachable. So just
drop this check.

xts_fallback_setkey() now makes a key size check in xts_verify_key():

xts_fallback_setkey()
  crypto_skcipher_setkey() [ skcipher_setkey_unaligned() ]
    cipher->setkey() { .setkey = xts_setkey }
      xts_setkey()
        xts_verify_key()

Signed-off-by: Vladis Dronov <vdronov@redhat.com>
---
 arch/s390/crypto/aes_s390.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
index 526c3f40f6a2..c773820e4af9 100644
--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -398,10 +398,6 @@ static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 	if (err)
 		return err;
 
-	/* In fips mode only 128 bit or 256 bit keys are valid */
-	if (fips_enabled && key_len != 32 && key_len != 64)
-		return -EINVAL;
-
 	/* Pick the correct function code based on the key length */
 	fc = (key_len == 32) ? CPACF_KM_XTS_128 :
 	     (key_len == 64) ? CPACF_KM_XTS_256 : 0;
-- 
2.38.1

[PATCH 4/6] crypto: testmgr - disallow plain cbcmac(aes) in FIPS mode

[Vladis Dronov]

From: Nicolai Stange <nstange@suse.de>

cbcmac(aes) may be used only as part of the ccm(aes) construction in FIPS
mode. Since commit d6097b8d5d55 ("crypto: api - allow algs only in specific
constructions in FIPS mode") there's support for using spawns which by
itself are marked as non-approved from approved template instantiations.
So simply mark plain cbcmac(aes) as non-approved in testmgr to block any
attempts of direct instantiations in FIPS mode.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
---
 crypto/testmgr.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 4476ac97baa5..562463a77a76 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -4501,7 +4501,6 @@ static const struct alg_test_desc alg_test_descs[] = {
 	}, {
 #endif
 		.alg = "cbcmac(aes)",
-		.fips_allowed = 1,
 		.test = alg_test_hash,
 		.suite = {
 			.hash = __VECS(aes_cbcmac_tv_template)
-- 
2.38.1

[PATCH 5/6] crypto: testmgr - disallow plain ghash in FIPS mode

[Vladis Dronov]

From: Nicolai Stange <nstange@suse.de>

ghash may be used only as part of the gcm(aes) construction in FIPS
mode. Since commit d6097b8d5d55 ("crypto: api - allow algs only in specific
constructions in FIPS mode") there's support for using spawns which by
itself are marked as non-approved from approved template instantiations.
So simply mark plain ghash as non-approved in testmgr to block any attempts
of direct instantiations in FIPS mode.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
---
 crypto/testmgr.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 562463a77a76..a223cf5f3626 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -5125,7 +5125,6 @@ static const struct alg_test_desc alg_test_descs[] = {
 	}, {
 		.alg = "ghash",
 		.test = alg_test_hash,
-		.fips_allowed = 1,
 		.suite = {
 			.hash = __VECS(ghash_tv_template)
 		}
-- 
2.38.1

[PATCH 6/6] crypto: testmgr - allow ecdsa-nist-p256 and -p384 in FIPS mode

[Vladis Dronov]

From: Nicolai Stange <nstange@suse.de>

The kernel provides implementations of the NIST ECDSA signature
verification primitives. For key sizes of 256 and 384 bits respectively
they are approved and can be enabled in FIPS mode. Do so.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
---
 crypto/testmgr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index a223cf5f3626..795c4858c741 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -5034,12 +5034,14 @@ static const struct alg_test_desc alg_test_descs[] = {
 	}, {
 		.alg = "ecdsa-nist-p256",
 		.test = alg_test_akcipher,
+		.fips_allowed = 1,
 		.suite = {
 			.akcipher = __VECS(ecdsa_nist_p256_tv_template)
 		}
 	}, {
 		.alg = "ecdsa-nist-p384",
 		.test = alg_test_akcipher,
+		.fips_allowed = 1,
 		.suite = {
 			.akcipher = __VECS(ecdsa_nist_p384_tv_template)
 		}
-- 
2.38.1

Re: [PATCH 2/6] crypto: xts - drop xts_check_key()

[Eric Biggers]

On Wed, Dec 21, 2022 at 11:41:07PM +0100, Vladis Dronov wrote:
> xts_check_key() is obsoleted by xts_verify_key(). Over time XTS crypto
> drivers adopted the newer xts_verify_key() variant, but xts_check_key()
> is still used by a number of drivers. Switch drivers to use the newer
> xts_verify_key() and make a couple of cleanups. This allows us to drop
> xts_check_key() completely and avoid redundancy.
> 
> Signed-off-by: Vladis Dronov <vdronov@redhat.com>
> ---
>  arch/s390/crypto/paes_s390.c                  |  2 +-
>  drivers/crypto/atmel-aes.c                    |  2 +-
>  drivers/crypto/axis/artpec6_crypto.c          |  2 +-
>  drivers/crypto/cavium/cpt/cptvf_algs.c        |  8 +++----
>  .../crypto/cavium/nitrox/nitrox_skcipher.c    |  8 +++----
>  drivers/crypto/ccree/cc_cipher.c              |  2 +-
>  .../crypto/marvell/octeontx/otx_cptvf_algs.c  |  2 +-
>  .../marvell/octeontx2/otx2_cptvf_algs.c       |  2 +-
>  include/crypto/xts.h                          | 21 +++----------------
>  9 files changed, 15 insertions(+), 34 deletions(-)

Reviewed-by: Eric Biggers <ebiggers@google.com>

but one comment below:

>  static inline int xts_verify_key(struct crypto_skcipher *tfm,
>  				 const u8 *key, unsigned int keylen)
>  {
> @@ -42,7 +25,9 @@ static inline int xts_verify_key(struct crypto_skcipher *tfm,
>  	if (fips_enabled && keylen != 32 && keylen != 64)
>  		return -EINVAL;
>  
> -	/* ensure that the AES and tweak key are not identical */
> +	/* ensure that the AES and tweak key are not identical
> +	 * when in FIPS mode or the FORBID_WEAK_KEYS flag is set.
> +	 */
>  	if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
>  			      CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
>  	    !crypto_memneq(key, key + (keylen / 2), keylen / 2))

Please use the kernel style for block comments:

	/*
	 * Ensure that the AES and tweak key are not identical when in FIPS mode
	 * or the FORBID_WEAK_KEYS flag is set.
	 */

- Eric

Re: [PATCH 2/6] crypto: xts - drop xts_check_key()

[Vladis Dronov]

Hi,

On Thu, Dec 22, 2022 at 12:33 AM Eric Biggers <ebiggers@kernel.org> wrote:
>
> On Wed, Dec 21, 2022 at 11:41:07PM +0100, Vladis Dronov wrote:
> ...skip...
> > -     /* ensure that the AES and tweak key are not identical */
> > +     /* ensure that the AES and tweak key are not identical
> > +      * when in FIPS mode or the FORBID_WEAK_KEYS flag is set.
> > +      */
> >       if ((fips_enabled || (crypto_skcipher_get_flags(tfm) &
> >                             CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) &&
> >           !crypto_memneq(key, key + (keylen / 2), keylen / 2))
>
> Please use the kernel style for block comments:
>
>         /*
>          * Ensure that the AES and tweak key are not identical when in FIPS mode
>          * or the FORBID_WEAK_KEYS flag is set.
>          */

Thanks Eric, I will wait a bit for more review notes and I will resend
the patchset.

Best regards,
Vladis