[PATCH v5 0/3] New s390 specific protected key hmac

[PATCH v5 0/3] New s390 specific protected key hmac

[Harald Freudenberger]

Add support for protected key hmac ("phmac") for s390 arch.

With the latest machine generation there is now support for
protected key (that is a key wrapped by a master key stored
in firmware) hmac for sha2 (sha224, sha256, sha384 and sha512)
for the s390 specific CPACF instruction kmac.

This patch adds support via 4 new shashes registered as
phmac(sha224), phmac(sha256), phmac(sha384) and phmac(sha512).

Please note that as of now, there is no selftest enabled for
these shashes, but the implementation has been tested with
testcases via AF_ALG interface. However, there may come an
improvement soon to use the available clear key hmac selftests.

Changelog:
v1: Initial version
v2: Increase HASH_MAX_DESCSIZE generic (not just for arch s390).
    Fix one finding to use kmemdup instead of kmalloc/memcpy from test
    robot. Remove unneeded cpacf subfunctions checks. Simplify
    clone_tfm() function. Rebased to s390/features.
v3: Feedback from Herbert: Use GFP_ATOMIC in setkey function.
    Feedback from Holger: rework tfm clone function, move convert key
    invocation from setkey to init function. Rebased to updated
    s390/features from 11/7/2024. Ready for integration if there are
    no complains on v3.
v4: Rewind back more or less to v2. Add code to check for non-sleeping
    context. Non-sleeping context during attempt to derive the
    protected key from raw key material is not accepted and
    -EOPNOTSUPP is returned (also currently all derivation pathes
    would in fact never sleep). In general the phmac implementation is
    not to be used within non-sleeping context and the code header
    mentions this. Tested with (patched) dm-integrity - works fine.
v5: As suggested by Herbert now the shashes have been marked as
    'internal' and wrapped by ahashes which use the cryptd if an
    atomic context is detected. So the visible phmac algorithms are
    now ahashes. Unfortunately the dm-integrity implementation
    currently requests and deals only with shashes and this phmac
    implementation is not fitting to the original goal any more...

Harald Freudenberger (1):
  s390/crypto: New s390 specific protected key hash phmac

Holger Dengler (2):
  crypto: api - Adjust HASH_MAX_DESCSIZE for s390-phmac context
  s390/crypto: Add protected key hmac subfunctions for KMAC

 arch/s390/configs/debug_defconfig |   1 +
 arch/s390/configs/defconfig       |   1 +
 arch/s390/crypto/Makefile         |   1 +
 arch/s390/crypto/phmac_s390.c     | 661 ++++++++++++++++++++++++++++++
 arch/s390/include/asm/cpacf.h     |   4 +
 drivers/crypto/Kconfig            |  12 +
 include/crypto/hash.h             |   5 +-
 7 files changed, 682 insertions(+), 3 deletions(-)
 create mode 100644 arch/s390/crypto/phmac_s390.c


base-commit: 3f020399e4f1c690ce87b4c472f75b1fc89e07d5
--
2.43.0

[PATCH v5 1/3] crypto: api - Adjust HASH_MAX_DESCSIZE for s390-phmac context

[Harald Freudenberger]

From: Holger Dengler <dengler@linux.ibm.com>

The phmac context exceeds the generic "worst case".
Change this define to cover the s390 specific 'phmac(sha512)'
which is a "protected" key hmac-sha2 implementation.

Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
---
 include/crypto/hash.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index 2d5ea9f9ff43..5b724dd7c5a7 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -159,10 +159,9 @@ struct shash_desc {
 #define HASH_MAX_DIGESTSIZE	 64
 
 /*
- * Worst case is hmac(sha3-224-generic).  Its context is a nested 'shash_desc'
- * containing a 'struct sha3_state'.
+ * The max case is currently the s390 specific shash 'phmac(sha512)'.
  */
-#define HASH_MAX_DESCSIZE	(sizeof(struct shash_desc) + 360)
+#define HASH_MAX_DESCSIZE	(sizeof(struct shash_desc) + 376)
 
 #define SHASH_DESC_ON_STACK(shash, ctx)					     \
 	char __##shash##_desc[sizeof(struct shash_desc) + HASH_MAX_DESCSIZE] \
-- 
2.43.0

[PATCH v5 2/3] s390/crypto: Add protected key hmac subfunctions for KMAC

[Harald Freudenberger]

From: Holger Dengler <dengler@linux.ibm.com>

The CPACF KMAC instruction supports new subfunctions for
protected key hmac. Add defines for these 4 new subfuctions.

Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
---
 arch/s390/include/asm/cpacf.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/s390/include/asm/cpacf.h b/arch/s390/include/asm/cpacf.h
index 59ab1192e2d5..0468dd5c4690 100644
--- a/arch/s390/include/asm/cpacf.h
+++ b/arch/s390/include/asm/cpacf.h
@@ -129,6 +129,10 @@
 #define CPACF_KMAC_HMAC_SHA_256	0x71
 #define CPACF_KMAC_HMAC_SHA_384	0x72
 #define CPACF_KMAC_HMAC_SHA_512	0x73
+#define CPACF_KMAC_PHMAC_SHA_224	0x78
+#define CPACF_KMAC_PHMAC_SHA_256	0x79
+#define CPACF_KMAC_PHMAC_SHA_384	0x7a
+#define CPACF_KMAC_PHMAC_SHA_512	0x7b
 
 /*
  * Function codes for the PCKMO (PERFORM CRYPTOGRAPHIC KEY MANAGEMENT)
-- 
2.43.0

[PATCH v5 3/3] s390/crypto: New s390 specific protected key hash phmac

[Harald Freudenberger]

Add support for protected key hmac ("phmac") for s390 arch.

With the latest machine generation there is now support for
protected key (that is a key wrapped by a master key stored
in firmware) hmac for sha2 (sha224, sha256, sha384 and sha512)
for the s390 specific CPACF instruction kmac.

This patch adds support via 4 new ahashes registered as
phmac(sha224), phmac(sha256), phmac(sha384) and phmac(sha512).
Under the hood there are also 4 shashes marked as internal
registered which are used by the ahashes either directly or
via cryptd (in case of atomic context).

Please note that as of now, there is no selftest enabled for
these hashes, but the implementation has been tested with
testcases via AF_ALG interface.

Co-developed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
---
 arch/s390/configs/debug_defconfig |   1 +
 arch/s390/configs/defconfig       |   1 +
 arch/s390/crypto/Makefile         |   1 +
 arch/s390/crypto/phmac_s390.c     | 661 ++++++++++++++++++++++++++++++
 drivers/crypto/Kconfig            |  12 +
 5 files changed, 676 insertions(+)
 create mode 100644 arch/s390/crypto/phmac_s390.c

diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig
index d8d227ab82de..c857618087fe 100644
--- a/arch/s390/configs/debug_defconfig
+++ b/arch/s390/configs/debug_defconfig
@@ -813,6 +813,7 @@ CONFIG_PKEY_EP11=m
 CONFIG_PKEY_PCKMO=m
 CONFIG_PKEY_UV=m
 CONFIG_CRYPTO_PAES_S390=m
+CONFIG_CRYPTO_PHMAC_S390=m
 CONFIG_CRYPTO_DEV_VIRTIO=m
 CONFIG_SYSTEM_BLACKLIST_KEYRING=y
 CONFIG_CORDIC=m
diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig
index 6c2f2bb4fbf8..94bde39967a5 100644
--- a/arch/s390/configs/defconfig
+++ b/arch/s390/configs/defconfig
@@ -800,6 +800,7 @@ CONFIG_PKEY_EP11=m
 CONFIG_PKEY_PCKMO=m
 CONFIG_PKEY_UV=m
 CONFIG_CRYPTO_PAES_S390=m
+CONFIG_CRYPTO_PHMAC_S390=m
 CONFIG_CRYPTO_DEV_VIRTIO=m
 CONFIG_SYSTEM_BLACKLIST_KEYRING=y
 CONFIG_CORDIC=m
diff --git a/arch/s390/crypto/Makefile b/arch/s390/crypto/Makefile
index a0cb96937c3d..47637140b95c 100644
--- a/arch/s390/crypto/Makefile
+++ b/arch/s390/crypto/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_S390_PRNG) += prng.o
 obj-$(CONFIG_CRYPTO_GHASH_S390) += ghash_s390.o
 obj-$(CONFIG_CRYPTO_CRC32_S390) += crc32-vx_s390.o
 obj-$(CONFIG_CRYPTO_HMAC_S390) += hmac_s390.o
+obj-$(CONFIG_CRYPTO_PHMAC_S390) += phmac_s390.o
 obj-y += arch_random.o
 
 crc32-vx_s390-y := crc32-vx.o crc32le-vx.o crc32be-vx.o
diff --git a/arch/s390/crypto/phmac_s390.c b/arch/s390/crypto/phmac_s390.c
new file mode 100644
index 000000000000..042031e7e32e
--- /dev/null
+++ b/arch/s390/crypto/phmac_s390.c
@@ -0,0 +1,661 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright IBM Corp. 2024
+ *
+ * s390 specific HMAC support for protected keys.
+ */
+
+#define KMSG_COMPONENT	"phmac_s390"
+#define pr_fmt(fmt)	KMSG_COMPONENT ": " fmt
+
+#include <asm/cpacf.h>
+#include <asm/pkey.h>
+#include <crypto/cryptd.h>
+#include <crypto/internal/hash.h>
+#include <crypto/sha2.h>
+#include <linux/cpufeature.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+
+/*
+ * KMAC param block layout for sha2 function codes:
+ * The layout of the param block for the KMAC instruction depends on the
+ * blocksize of the used hashing sha2-algorithm function codes. The param block
+ * contains the hash chaining value (cv), the input message bit-length (imbl)
+ * and the hmac-secret (key). To prevent code duplication, the sizes of all
+ * these are calculated based on the blocksize.
+ *
+ * param-block:
+ * +-------+
+ * | cv    |
+ * +-------+
+ * | imbl  |
+ * +-------+
+ * | key   |
+ * +-------+
+ *
+ * sizes:
+ * part | sh2-alg | calculation | size | type
+ * -----+---------+-------------+------+--------
+ * cv   | 224/256 | blocksize/2 |   32 |  u64[8]
+ *      | 384/512 |             |   64 | u128[8]
+ * imbl | 224/256 | blocksize/8 |    8 |     u64
+ *      | 384/512 |             |   16 |    u128
+ * key  | 224/256 | blocksize   |   96 |  u8[96]
+ *      | 384/512 |             |  160 | u8[160]
+ */
+
+#define MAX_DIGEST_SIZE		SHA512_DIGEST_SIZE
+#define MAX_IMBL_SIZE		sizeof(u128)
+#define MAX_BLOCK_SIZE		SHA512_BLOCK_SIZE
+
+#define SHA2_CV_SIZE(bs)	((bs) >> 1)
+#define SHA2_IMBL_SIZE(bs)	((bs) >> 3)
+
+#define SHA2_IMBL_OFFSET(bs)	(SHA2_CV_SIZE(bs))
+#define SHA2_KEY_OFFSET(bs)	(SHA2_CV_SIZE(bs) + SHA2_IMBL_SIZE(bs))
+
+#define PHMAC_SHA256_KEY_SIZE	(SHA256_BLOCK_SIZE + 32)
+#define PHMAC_SHA512_KEY_SIZE	(SHA512_BLOCK_SIZE + 32)
+#define PHMAC_MAX_KEY_SIZE	PHMAC_SHA512_KEY_SIZE
+
+struct phmac_protkey {
+	u32 type;
+	u32 len;
+	u8 protkey[PHMAC_MAX_KEY_SIZE];
+};
+
+struct s390_phmac_ctx {
+	u8 *key;
+	unsigned int keylen;
+
+	struct phmac_protkey pk;
+	/* spinlock to atomic update pk */
+	spinlock_t pk_lock;
+};
+
+struct s390_async_phmac_ctx {
+	struct cryptd_ahash *cryptd_tfm;
+};
+
+union s390_kmac_gr0 {
+	unsigned long reg;
+	struct {
+		unsigned long		: 48;
+		unsigned long ikp	:  1;
+		unsigned long iimp	:  1;
+		unsigned long ccup	:  1;
+		unsigned long		:  6;
+		unsigned long fc	:  7;
+	};
+};
+
+struct s390_kmac_sha2_ctx {
+	u8 param[MAX_DIGEST_SIZE + MAX_IMBL_SIZE + PHMAC_MAX_KEY_SIZE];
+	union s390_kmac_gr0 gr0;
+	u8 buf[MAX_BLOCK_SIZE];
+	unsigned int buflen;
+};
+
+/*
+ * kmac_sha2_set_imbl - sets the input message bit-length based on the blocksize
+ */
+static inline void kmac_sha2_set_imbl(u8 *param, unsigned int buflen,
+				      unsigned int blocksize)
+{
+	u8 *imbl = param + SHA2_IMBL_OFFSET(blocksize);
+
+	switch (blocksize) {
+	case SHA256_BLOCK_SIZE:
+		*(u64 *)imbl = (u64)buflen * BITS_PER_BYTE;
+		break;
+	case SHA512_BLOCK_SIZE:
+		*(u128 *)imbl = (u128)buflen * BITS_PER_BYTE;
+		break;
+	default:
+		break;
+	}
+}
+
+static inline int phmac_keyblob2pkey(const u8 *key, unsigned int keylen,
+				     struct phmac_protkey *pk)
+{
+	int i, rc = -EIO;
+
+	/* try three times in case of busy card */
+	for (i = 0; rc && i < 3; i++) {
+		if (rc == -EBUSY && msleep_interruptible(1000))
+			return -EINTR;
+		rc = pkey_key2protkey(key, keylen,
+				      pk->protkey, &pk->len, &pk->type);
+	}
+
+	return rc;
+}
+
+static inline int phmac_convert_key(struct s390_phmac_ctx *tfm_ctx)
+{
+	struct phmac_protkey pk;
+	int rc;
+
+	pk.len = sizeof(pk.protkey);
+	rc = phmac_keyblob2pkey(tfm_ctx->key, tfm_ctx->keylen, &pk);
+	if (rc)
+		return rc;
+
+	spin_lock_bh(&tfm_ctx->pk_lock);
+	tfm_ctx->pk = pk;
+	spin_unlock_bh(&tfm_ctx->pk_lock);
+
+	return 0;
+}
+
+static int s390_sync_phmac_setkey(struct crypto_shash *tfm,
+				  const u8 *key, unsigned int keylen)
+{
+	struct s390_phmac_ctx *tfm_ctx = crypto_shash_ctx(tfm);
+	int rc = -ENOMEM;
+
+	if (tfm_ctx->keylen) {
+		kfree_sensitive(tfm_ctx->key);
+		tfm_ctx->key = NULL;
+		tfm_ctx->keylen = 0;
+	}
+
+	tfm_ctx->key = kmemdup(key, keylen, GFP_ATOMIC);
+	if (!tfm_ctx->key)
+		goto out;
+	tfm_ctx->keylen = keylen;
+
+	rc = phmac_convert_key(tfm_ctx);
+	if (rc)
+		goto out;
+
+	rc = -EINVAL;
+	switch (crypto_shash_digestsize(tfm)) {
+	case SHA224_DIGEST_SIZE:
+	case SHA256_DIGEST_SIZE:
+		if (tfm_ctx->pk.type != PKEY_KEYTYPE_HMAC_512)
+			goto out;
+		break;
+	case SHA384_DIGEST_SIZE:
+	case SHA512_DIGEST_SIZE:
+		if (tfm_ctx->pk.type != PKEY_KEYTYPE_HMAC_1024)
+			goto out;
+		break;
+	default:
+		goto out;
+	}
+	rc = 0;
+
+out:
+	pr_debug("rc=%d\n", rc);
+	return rc;
+}
+
+static int s390_sync_phmac_init(struct shash_desc *desc)
+{
+	struct s390_phmac_ctx *tfm_ctx = crypto_shash_ctx(desc->tfm);
+	struct s390_kmac_sha2_ctx *ctx = shash_desc_ctx(desc);
+	unsigned int bs = crypto_shash_blocksize(desc->tfm);
+
+	spin_lock_bh(&tfm_ctx->pk_lock);
+	memcpy(ctx->param + SHA2_KEY_OFFSET(bs),
+	       tfm_ctx->pk.protkey, tfm_ctx->pk.len);
+	spin_unlock_bh(&tfm_ctx->pk_lock);
+
+	ctx->buflen = 0;
+	ctx->gr0.reg = 0;
+
+	switch (crypto_shash_digestsize(desc->tfm)) {
+	case SHA224_DIGEST_SIZE:
+		ctx->gr0.fc = CPACF_KMAC_PHMAC_SHA_224;
+		break;
+	case SHA256_DIGEST_SIZE:
+		ctx->gr0.fc = CPACF_KMAC_PHMAC_SHA_256;
+		break;
+	case SHA384_DIGEST_SIZE:
+		ctx->gr0.fc = CPACF_KMAC_PHMAC_SHA_384;
+		break;
+	case SHA512_DIGEST_SIZE:
+		ctx->gr0.fc = CPACF_KMAC_PHMAC_SHA_512;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int s390_sync_phmac_update(struct shash_desc *desc,
+				  const u8 *data, unsigned int len)
+{
+	struct s390_phmac_ctx *tfm_ctx = crypto_shash_ctx(desc->tfm);
+	struct s390_kmac_sha2_ctx *ctx = shash_desc_ctx(desc);
+	unsigned int bs = crypto_shash_blocksize(desc->tfm);
+	unsigned int offset, n, k;
+
+	/* check current buffer */
+	offset = ctx->buflen % bs;
+	ctx->buflen += len;
+	if (offset + len < bs)
+		goto store;
+
+	/* process one stored block */
+	if (offset) {
+		n = bs - offset;
+		memcpy(ctx->buf + offset, data, n);
+		ctx->gr0.iimp = 1;
+		for (k = bs;;) {
+			k -= _cpacf_kmac(&ctx->gr0.reg, ctx->param,
+					 ctx->buf + bs - k, k);
+			if (!k)
+				break;
+			if (phmac_convert_key(tfm_ctx))
+				return -EIO;
+			spin_lock_bh(&tfm_ctx->pk_lock);
+			memcpy(ctx->param + SHA2_KEY_OFFSET(bs),
+			       tfm_ctx->pk.protkey, tfm_ctx->pk.len);
+			spin_unlock_bh(&tfm_ctx->pk_lock);
+		}
+		data += n;
+		len -= n;
+		offset = 0;
+	}
+	/* process as many blocks as possible */
+	if (len >= bs) {
+		n = (len / bs) * bs;
+		ctx->gr0.iimp = 1;
+		for (k = n;;) {
+			k -= _cpacf_kmac(&ctx->gr0.reg, ctx->param,
+					 data + n - k, k);
+			if (!k)
+				break;
+			if (phmac_convert_key(tfm_ctx))
+				return -EIO;
+			spin_lock_bh(&tfm_ctx->pk_lock);
+			memcpy(ctx->param + SHA2_KEY_OFFSET(bs),
+			       tfm_ctx->pk.protkey, tfm_ctx->pk.len);
+			spin_unlock_bh(&tfm_ctx->pk_lock);
+		}
+		data += n;
+		len -= n;
+	}
+store:
+	/* store incomplete block in buffer */
+	if (len)
+		memcpy(ctx->buf + offset, data, len);
+
+	return 0;
+}
+
+static int s390_sync_phmac_final(struct shash_desc *desc, u8 *out)
+{
+	struct s390_phmac_ctx *tfm_ctx = crypto_shash_ctx(desc->tfm);
+	struct s390_kmac_sha2_ctx *ctx = shash_desc_ctx(desc);
+	unsigned int bs = crypto_shash_blocksize(desc->tfm);
+	unsigned int n, k;
+
+	n = ctx->buflen % bs;
+	ctx->gr0.iimp = 0;
+	kmac_sha2_set_imbl(ctx->param, ctx->buflen, bs);
+	for (k = n;;) {
+		k -= _cpacf_kmac(&ctx->gr0.reg, ctx->param,
+				 ctx->buf + n - k, k);
+		if (!k)
+			break;
+		if (phmac_convert_key(tfm_ctx))
+			return -EIO;
+		spin_lock_bh(&tfm_ctx->pk_lock);
+		memcpy(ctx->param + SHA2_KEY_OFFSET(bs),
+		       tfm_ctx->pk.protkey, tfm_ctx->pk.len);
+		spin_unlock_bh(&tfm_ctx->pk_lock);
+	}
+	memcpy(out, ctx->param, crypto_shash_digestsize(desc->tfm));
+
+	return 0;
+}
+
+static int s390_sync_phmac_digest(struct shash_desc *desc,
+				  const u8 *data, unsigned int len, u8 *out)
+{
+	struct s390_phmac_ctx *tfm_ctx = crypto_shash_ctx(desc->tfm);
+	struct s390_kmac_sha2_ctx *ctx = shash_desc_ctx(desc);
+	unsigned int ds = crypto_shash_digestsize(desc->tfm);
+	unsigned int bs = crypto_shash_blocksize(desc->tfm);
+	unsigned int k;
+	int rc;
+
+	rc = s390_sync_phmac_init(desc);
+	if (rc)
+		return rc;
+
+	ctx->gr0.iimp = 0;
+	kmac_sha2_set_imbl(ctx->param, len, bs);
+	for (k = len;;) {
+		k -= _cpacf_kmac(&ctx->gr0.reg, ctx->param,
+				 data + len - k, k);
+		if (!k)
+			break;
+		if (phmac_convert_key(tfm_ctx))
+			return -EIO;
+		spin_lock_bh(&tfm_ctx->pk_lock);
+		memcpy(ctx->param + SHA2_KEY_OFFSET(bs),
+		       tfm_ctx->pk.protkey, tfm_ctx->pk.len);
+		spin_unlock_bh(&tfm_ctx->pk_lock);
+	}
+	memcpy(out, ctx->param, ds);
+
+	return 0;
+}
+
+static int s390_sync_phmac_init_tfm(struct crypto_shash *tfm)
+{
+	struct s390_phmac_ctx *tfm_ctx = crypto_shash_ctx(tfm);
+
+	tfm_ctx->key = NULL;
+	tfm_ctx->keylen = 0;
+	spin_lock_init(&tfm_ctx->pk_lock);
+
+	return 0;
+}
+
+static void s390_sync_phmac_exit_tfm(struct crypto_shash *tfm)
+{
+	struct s390_phmac_ctx *tfm_ctx = crypto_shash_ctx(tfm);
+
+	memzero_explicit(&tfm_ctx->pk, sizeof(tfm_ctx->pk));
+	kfree_sensitive(tfm_ctx->key);
+}
+
+#define S390_SYNC_PHMAC_ALG(x)						\
+{									\
+	.init = s390_sync_phmac_init,					\
+	.update = s390_sync_phmac_update,				\
+	.final = s390_sync_phmac_final,					\
+	.digest = s390_sync_phmac_digest,				\
+	.setkey = s390_sync_phmac_setkey,				\
+	.init_tfm = s390_sync_phmac_init_tfm,				\
+	.exit_tfm = s390_sync_phmac_exit_tfm,				\
+	.descsize = sizeof(struct s390_kmac_sha2_ctx),			\
+	.halg = {							\
+		.digestsize = SHA##x##_DIGEST_SIZE,			\
+		.base = {						\
+			.cra_name = "__phmac(sha" #x ")",		\
+			.cra_driver_name = "__phmac_s390_sha" #x,	\
+			.cra_blocksize = SHA##x##_BLOCK_SIZE,		\
+			.cra_priority = 0,				\
+			.cra_flags = CRYPTO_ALG_INTERNAL,		\
+			.cra_ctxsize = sizeof(struct s390_phmac_ctx),	\
+			.cra_module = THIS_MODULE,			\
+		},							\
+	},								\
+}
+
+static int s390_async_phmac_init(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct s390_async_phmac_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct ahash_request *cryptd_req = ahash_request_ctx(req);
+	struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
+
+	if (in_atomic() && cryptd_ahash_queued(cryptd_tfm)) {
+		memcpy(cryptd_req, req, sizeof(*req));
+		ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
+		return crypto_ahash_init(cryptd_req);
+	} else {
+		struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
+		struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
+
+		desc->tfm = child;
+		return crypto_shash_init(desc);
+	}
+}
+
+static int s390_async_phmac_update(struct ahash_request *req)
+{
+	struct ahash_request *cryptd_req = ahash_request_ctx(req);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct s390_async_phmac_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
+
+	if (in_atomic() && cryptd_ahash_queued(cryptd_tfm)) {
+		memcpy(cryptd_req, req, sizeof(*req));
+		ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
+		return crypto_ahash_update(cryptd_req);
+	} else {
+		struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
+
+		return shash_ahash_update(req, desc);
+	}
+}
+
+static int s390_async_phmac_final(struct ahash_request *req)
+{
+	struct ahash_request *cryptd_req = ahash_request_ctx(req);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct s390_async_phmac_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
+
+	if (in_atomic() && cryptd_ahash_queued(cryptd_tfm)) {
+		memcpy(cryptd_req, req, sizeof(*req));
+		ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
+		return crypto_ahash_final(cryptd_req);
+	} else {
+		struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
+
+		return crypto_shash_final(desc, req->result);
+	}
+}
+
+static int s390_async_phmac_digest(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct s390_async_phmac_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct ahash_request *cryptd_req = ahash_request_ctx(req);
+	struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
+
+	if (in_atomic() && cryptd_ahash_queued(cryptd_tfm)) {
+		memcpy(cryptd_req, req, sizeof(*req));
+		ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
+		return crypto_ahash_digest(cryptd_req);
+	} else {
+		struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
+		struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
+
+		desc->tfm = child;
+		return shash_ahash_digest(req, desc);
+	}
+}
+
+static int s390_async_phmac_setkey(struct crypto_ahash *tfm,
+				   const u8 *key, unsigned int keylen)
+{
+	struct s390_async_phmac_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
+
+	if (in_atomic() && cryptd_ahash_queued(cryptd_tfm)) {
+		struct crypto_ahash *child = &cryptd_tfm->base;
+
+		crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+		crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
+				       & CRYPTO_TFM_REQ_MASK);
+		return crypto_ahash_setkey(child, key, keylen);
+	} else {
+		struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
+
+		return crypto_shash_setkey(child, key, keylen);
+	}
+}
+
+static int s390_async_phmac_import(struct ahash_request *req, const void *in)
+{
+	struct ahash_request *cryptd_req = ahash_request_ctx(req);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct s390_async_phmac_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
+
+	desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
+
+	return crypto_shash_import(desc, in);
+}
+
+static int s390_async_phmac_export(struct ahash_request *req, void *out)
+{
+	struct ahash_request *cryptd_req = ahash_request_ctx(req);
+	struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
+
+	return crypto_shash_export(desc, out);
+}
+
+static int s390_async_phmac_init_tfm(struct crypto_ahash *tfm)
+{
+	struct s390_async_phmac_ctx *ctx = crypto_ahash_ctx(tfm);
+	const char *tfm_drv_name = crypto_ahash_driver_name(tfm);
+	char ahash_alg_name[CRYPTO_MAX_ALG_NAME];
+	struct cryptd_ahash *cryptd_tfm;
+	int rc = 0;
+
+	if (snprintf(ahash_alg_name, CRYPTO_MAX_ALG_NAME, "__%s",
+		     tfm_drv_name) >= CRYPTO_MAX_ALG_NAME) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	cryptd_tfm = cryptd_alloc_ahash(ahash_alg_name, CRYPTO_ALG_INTERNAL,
+					CRYPTO_ALG_INTERNAL);
+	if (IS_ERR(cryptd_tfm)) {
+		rc = PTR_ERR(cryptd_tfm);
+		goto out;
+	}
+	ctx->cryptd_tfm = cryptd_tfm;
+	crypto_ahash_set_reqsize(tfm,
+				 sizeof(struct ahash_request) +
+				 crypto_ahash_reqsize(&cryptd_tfm->base));
+
+out:
+	pr_debug("alg='%s' rc=%d\n", crypto_ahash_alg_name(tfm), rc);
+	return rc;
+}
+
+static void s390_async_phmac_exit_tfm(struct crypto_ahash *tfm)
+{
+	struct s390_async_phmac_ctx *ctx = crypto_ahash_ctx(tfm);
+
+	cryptd_free_ahash(ctx->cryptd_tfm);
+}
+
+#define S390_ASYNC_PHMAC_ALG(x)						\
+{									\
+	.init = s390_async_phmac_init,					\
+	.update = s390_async_phmac_update,				\
+	.final = s390_async_phmac_final,				\
+	.digest = s390_async_phmac_digest,				\
+	.setkey = s390_async_phmac_setkey,				\
+	.import = s390_async_phmac_import,				\
+	.export = s390_async_phmac_export,				\
+	.init_tfm = s390_async_phmac_init_tfm,				\
+	.exit_tfm = s390_async_phmac_exit_tfm,				\
+	.halg = {							\
+		.digestsize = SHA##x##_DIGEST_SIZE,			\
+		.statesize = sizeof(struct s390_kmac_sha2_ctx),		\
+		.base = {						\
+			.cra_name = "phmac(sha" #x ")",			\
+			.cra_driver_name = "phmac_s390_sha" #x,		\
+			.cra_blocksize = SHA##x##_BLOCK_SIZE,		\
+			.cra_priority = 400,				\
+			.cra_flags = CRYPTO_ALG_ASYNC,			\
+			.cra_ctxsize = sizeof(struct s390_async_phmac_ctx),  \
+			.cra_module = THIS_MODULE,			\
+		},							\
+	},								\
+}
+
+static struct s390_hmac_alg {
+	unsigned int fc;
+	struct shash_alg sync_alg;
+	bool sync_registered;
+	struct ahash_alg async_alg;
+	bool async_registered;
+} s390_hmac_algs[] = {
+	{
+		.fc = CPACF_KMAC_PHMAC_SHA_224,
+		.sync_alg = S390_SYNC_PHMAC_ALG(224),
+		.async_alg = S390_ASYNC_PHMAC_ALG(224),
+	}, {
+		.fc = CPACF_KMAC_PHMAC_SHA_256,
+		.sync_alg = S390_SYNC_PHMAC_ALG(256),
+		.async_alg = S390_ASYNC_PHMAC_ALG(256),
+	}, {
+		.fc = CPACF_KMAC_PHMAC_SHA_384,
+		.sync_alg = S390_SYNC_PHMAC_ALG(384),
+		.async_alg = S390_ASYNC_PHMAC_ALG(384),
+	}, {
+		.fc = CPACF_KMAC_PHMAC_SHA_512,
+		.sync_alg = S390_SYNC_PHMAC_ALG(512),
+		.async_alg = S390_ASYNC_PHMAC_ALG(512),
+	}
+};
+
+static __always_inline void _s390_hmac_algs_unregister(void)
+{
+	struct s390_hmac_alg *hmac;
+	int i;
+
+	for (i = ARRAY_SIZE(s390_hmac_algs) - 1; i >= 0; i--) {
+		hmac = &s390_hmac_algs[i];
+		if (hmac->async_registered)
+			crypto_unregister_ahash(&hmac->async_alg);
+		if (hmac->sync_registered)
+			crypto_unregister_shash(&hmac->sync_alg);
+	}
+}
+
+static int __init phmac_s390_init(void)
+{
+	struct s390_hmac_alg *hmac;
+	int i, rc = -ENODEV;
+
+	for (i = 0; i < ARRAY_SIZE(s390_hmac_algs); i++) {
+		hmac = &s390_hmac_algs[i];
+		if (!cpacf_query_func(CPACF_KMAC, hmac->fc))
+			continue;
+		rc = crypto_register_shash(&hmac->sync_alg);
+		if (rc) {
+			pr_err("unable to register %s\n",
+			       hmac->sync_alg.halg.base.cra_name);
+			goto out;
+		}
+		hmac->sync_registered = true;
+		pr_debug("registered %s\n", hmac->sync_alg.halg.base.cra_name);
+		rc = crypto_register_ahash(&hmac->async_alg);
+		if (rc) {
+			pr_err("unable to register %s\n",
+			       hmac->async_alg.halg.base.cra_name);
+			goto out;
+		}
+		hmac->async_registered = true;
+		pr_debug("registered %s\n", hmac->async_alg.halg.base.cra_name);
+	}
+	return rc;
+out:
+	_s390_hmac_algs_unregister();
+	return rc;
+}
+
+static void __exit phmac_s390_exit(void)
+{
+	_s390_hmac_algs_unregister();
+}
+
+module_init(phmac_s390_init);
+module_exit(phmac_s390_exit);
+
+MODULE_ALIAS_CRYPTO("phmac(sha224)");
+MODULE_ALIAS_CRYPTO("phmac(sha256)");
+MODULE_ALIAS_CRYPTO("phmac(sha384)");
+MODULE_ALIAS_CRYPTO("phmac(sha512)");
+
+MODULE_DESCRIPTION("S390 HMAC driver for protected keys");
+MODULE_LICENSE("GPL");
diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 0a9cdd31cbd9..519305e04f18 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -187,6 +187,18 @@ config CRYPTO_PAES_S390
 	  Select this option if you want to use the paes cipher
 	  for example to use protected key encrypted devices.
 
+config CRYPTO_PHMAC_S390
+	tristate "PHMAC cipher algorithms"
+	depends on S390
+	depends on PKEY
+	select CRYPTO_HASH
+	help
+	  This is the s390 hardware accelerated implementation of the
+	  protected key HMAC support for SHA224, SHA256, SHA384 and SHA512.
+
+	  Select this option if you want to use the phmac digests
+	  for example to use dm-integrity with secure/protected keys.
+
 config S390_PRNG
 	tristate "Pseudo random number generator device driver"
 	depends on S390
-- 
2.43.0

Re: [PATCH v5 3/3] s390/crypto: New s390 specific protected key hash phmac

[Herbert Xu]

On Fri, Nov 22, 2024 at 03:34:27PM +0100, Harald Freudenberger wrote:
>
> +static inline int phmac_keyblob2pkey(const u8 *key, unsigned int keylen,
> +				     struct phmac_protkey *pk)
> +{
> +	int i, rc = -EIO;
> +
> +	/* try three times in case of busy card */
> +	for (i = 0; rc && i < 3; i++) {
> +		if (rc == -EBUSY && msleep_interruptible(1000))
> +			return -EINTR;

You can't sleep in crypto calls in general.

Now there are specific circumstances where sleeping is allowed,
e.g., when the MAY_SLEEP flag is set, but I don't think this will
be acceptable for your purpose.

I see the same problem exists in paes_s390, which was not reviewed
on linux-crypto.

So what exactly causes the EBUSY? The 3 retries followed by failure
seem rather dangerous too given that this could be used by the block
layer for critical data that cannot fail.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH v5 3/3] s390/crypto: New s390 specific protected key hash phmac

[Harald Freudenberger]

On 2024-11-25 07:09, Herbert Xu wrote:
> On Fri, Nov 22, 2024 at 03:34:27PM +0100, Harald Freudenberger wrote:
>> 
>> +static inline int phmac_keyblob2pkey(const u8 *key, unsigned int 
>> keylen,
>> +				     struct phmac_protkey *pk)
>> +{
>> +	int i, rc = -EIO;
>> +
>> +	/* try three times in case of busy card */
>> +	for (i = 0; rc && i < 3; i++) {
>> +		if (rc == -EBUSY && msleep_interruptible(1000))
>> +			return -EINTR;
> 
> You can't sleep in crypto calls in general.
> 
> Now there are specific circumstances where sleeping is allowed,
> e.g., when the MAY_SLEEP flag is set, but I don't think this will
> be acceptable for your purpose.
> 
> I see the same problem exists in paes_s390, which was not reviewed
> on linux-crypto.
> 
> So what exactly causes the EBUSY? The 3 retries followed by failure
> seem rather dangerous too given that this could be used by the block
> layer for critical data that cannot fail.
> 
> Cheers,

Well, I fear the paes implementation is similar broken. The EBUSY
is a reaction of the zcrpyt/AP bus when no eligible crypto card has
been found and a ansynchronous bus scan is running. In that case the
caller should retry in the hope that the bus scan detects a eligible 
card.
Please note that the sleep only happens in in_task() context for the
paes implementation.
For the phmac implementation - didn't you suggest to wrap this with
an asynchronous hmac to be able to sleep in the wrapped synchronous 
hmac?

Re: [PATCH v5 3/3] s390/crypto: New s390 specific protected key hash phmac

[Herbert Xu]

On Mon, Nov 25, 2024 at 02:00:52PM +0100, Harald Freudenberger wrote:
>
> Well, I fear the paes implementation is similar broken. The EBUSY
> is a reaction of the zcrpyt/AP bus when no eligible crypto card has
> been found and a ansynchronous bus scan is running. In that case the
> caller should retry in the hope that the bus scan detects a eligible card.

So this is a rare event, right? Can we expect this to eventually
succeed? Or are there situations where this can legitimately fail?

> Please note that the sleep only happens in in_task() context for the
> paes implementation.

That's still broken.  There are situations where in_task() is
true but you can't sleep, e.g., spin locks held without preemption.

In general, you cannot determine whether you can sleep safely.  That's
why we rely on the user to tell us whether we can sleep or not.

> For the phmac implementation - didn't you suggest to wrap this with
> an asynchronous hmac to be able to sleep in the wrapped synchronous hmac?

I don't think this is a viable strategy since these are not short
sleeps.

I think you're better off making both paes and phmac async.  However,
they can remain synchronous in practice until you actually need to
sleep.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt