Hello Herbert, hi linux kernel crypto list
With the next s390 machine generation there comes hmac(sha2) support in
hardware.
So here is a patch which exploits this hardware.
However, before pushing this into linux-next it would be nice to get
some
feedback and a review of someone really familiar with all the odds and
ends
of the in-kernel crypto implementations.
The implementation here is a shash implementation providing
hmac(sha224),
hmac(sha256), hmac(sha384) and hmac(sha512) support. This is file
arch/s390/crypto/hmac_s390.c. It would be nice to get some feedback if
we
did this the correct way. The rest of the patch is s390 specific -
ignore it.
Thanks for spending some time on this.
Harald Freudenberger
-------- Original Message --------
Subject: [PATCH v3 2/2] s390/crypto: Add hardware acceleration for HMAC
modes
Date: 2024-08-07 18:06
From: Holger Dengler <dengler@xxxxxxxxxxxxx>
To: freude@xxxxxxxxxxxxx
Cc: dengler@xxxxxxxxxxxxx, linux390-list@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx,
Heiko Carstens <hca@xxxxxxxxxxxxx>, Vasily Gorbik <gor@xxxxxxxxxxxxx>,
Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Add new shash exploiting the HMAC hardware accelerations for SHA224,
SHA256, SHA384 and SHA512 introduced with message-security assist
extension 11.
Reference-ID: SEC2304
Reviewed-by: Harald Freudenberger <freude@xxxxxxxxxxxxx>
Signed-off-by: Holger Dengler <dengler@xxxxxxxxxxxxx>
---
arch/s390/configs/debug_defconfig | 1 +
arch/s390/configs/defconfig | 1 +
arch/s390/crypto/Kconfig | 10 +
arch/s390/crypto/Makefile | 1 +
arch/s390/crypto/hmac_s390.c | 334 ++++++++++++++++++++++++++++++
arch/s390/include/asm/cpacf.h | 37 +++-
6 files changed, 376 insertions(+), 8 deletions(-)
create mode 100644 arch/s390/crypto/hmac_s390.c
diff --git a/arch/s390/configs/debug_defconfig
b/arch/s390/configs/debug_defconfig
index ea63a7342f5f..6c57f024acae 100644
--- a/arch/s390/configs/debug_defconfig
+++ b/arch/s390/configs/debug_defconfig
@@ -794,6 +794,7 @@ CONFIG_CRYPTO_GHASH_S390=m
CONFIG_CRYPTO_AES_S390=m
CONFIG_CRYPTO_DES_S390=m
CONFIG_CRYPTO_CHACHA_S390=m
+CONFIG_CRYPTO_HMAC_S390=m
CONFIG_ZCRYPT=m
CONFIG_PKEY=m
CONFIG_CRYPTO_PAES_S390=m
diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig
index d8b28ff8ff45..c75e375570fa 100644
--- a/arch/s390/configs/defconfig
+++ b/arch/s390/configs/defconfig
@@ -781,6 +781,7 @@ CONFIG_CRYPTO_GHASH_S390=m
CONFIG_CRYPTO_AES_S390=m
CONFIG_CRYPTO_DES_S390=m
CONFIG_CRYPTO_CHACHA_S390=m
+CONFIG_CRYPTO_HMAC_S390=m
CONFIG_ZCRYPT=m
CONFIG_PKEY=m
CONFIG_CRYPTO_PAES_S390=m
diff --git a/arch/s390/crypto/Kconfig b/arch/s390/crypto/Kconfig
index 06ee706b0d78..d3eb3a233693 100644
--- a/arch/s390/crypto/Kconfig
+++ b/arch/s390/crypto/Kconfig
@@ -132,4 +132,14 @@ config CRYPTO_CHACHA_S390
It is available as of z13.
+config CRYPTO_HMAC_S390
+ tristate "Keyed-hash message authentication code: HMAC"
+ depends on S390
+ select CRYPTO_HASH
+ help
+ s390 specific HMAC hardware support for SHA224, SHA256, SHA384 and
+ SHA512.
+
+ Architecture: s390
+
endmenu
diff --git a/arch/s390/crypto/Makefile b/arch/s390/crypto/Makefile
index 1b1cc478fa94..a0cb96937c3d 100644
--- a/arch/s390/crypto/Makefile
+++ b/arch/s390/crypto/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_CRYPTO_CHACHA_S390) += chacha_s390.o
obj-$(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-y += arch_random.o
crc32-vx_s390-y := crc32-vx.o crc32le-vx.o crc32be-vx.o
diff --git a/arch/s390/crypto/hmac_s390.c b/arch/s390/crypto/hmac_s390.c
new file mode 100644
index 000000000000..71b15021d4c5
--- /dev/null
+++ b/arch/s390/crypto/hmac_s390.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright IBM Corp. 2024
+ *
+ * s390 specific HMAC support.
+ */
+
+#define KMSG_COMPONENT "hmac_s390"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <asm/cpacf.h>
+#include <crypto/sha2.h>
+#include <crypto/internal/hash.h>
+#include <linux/cpufeature.h>
+#include <linux/module.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 | 64 | u8[64]
+ * | 384/512 | | 128 | u8[128]
+ */
+
+#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))
+
+struct s390_hmac_ctx {
+ u8 key[MAX_BLOCK_SIZE];
+};
+
+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 + MAX_BLOCK_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 int hash(const u8 *in, unsigned int inlen,
+ u8 *digest, unsigned int digestsize)
+{
+ struct crypto_shash *htfm;
+ const char *alg_name;
+ int ret;
+
+ switch (digestsize) {
+ case SHA224_DIGEST_SIZE:
+ alg_name = "sha224";
+ break;
+ case SHA256_DIGEST_SIZE:
+ alg_name = "sha256";
+ break;
+ case SHA384_DIGEST_SIZE:
+ alg_name = "sha384";
+ break;
+ case SHA512_DIGEST_SIZE:
+ alg_name = "sha512";
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ htfm = crypto_alloc_shash(alg_name, 0, CRYPTO_ALG_NEED_FALLBACK);
+ if (IS_ERR(htfm))
+ return PTR_ERR(htfm);
+
+ ret = crypto_shash_tfm_digest(htfm, in, inlen, digest);
+ if (ret)
+ pr_err("shash digest error: %d\n", ret);
+
+ crypto_free_shash(htfm);
+ return ret;
+}
+
+static int s390_hmac_sha2_setkey(struct crypto_shash *tfm,
+ const u8 *key, unsigned int keylen)
+{
+ struct s390_hmac_ctx *tfm_ctx = crypto_shash_ctx(tfm);
+ unsigned int ds = crypto_shash_digestsize(tfm);
+ unsigned int bs = crypto_shash_blocksize(tfm);
+
+ memset(tfm_ctx, 0, sizeof(*tfm_ctx));
+
+ if (keylen > bs)
+ return hash(key, keylen, tfm_ctx->key, ds);
+
+ memcpy(tfm_ctx->key, key, keylen);
+ return 0;
+}
+
+static int s390_hmac_sha2_init(struct shash_desc *desc)
+{
+ struct s390_hmac_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);
+
+ memcpy(ctx->param + SHA2_KEY_OFFSET(bs),
+ tfm_ctx->key, bs);
+
+ ctx->buflen = 0;
+ ctx->gr0.reg = 0;
+ switch (crypto_shash_digestsize(desc->tfm)) {
+ case SHA224_DIGEST_SIZE:
+ ctx->gr0.fc = CPACF_KMAC_HMAC_SHA_224;
+ break;
+ case SHA256_DIGEST_SIZE:
+ ctx->gr0.fc = CPACF_KMAC_HMAC_SHA_256;
+ break;
+ case SHA384_DIGEST_SIZE:
+ ctx->gr0.fc = CPACF_KMAC_HMAC_SHA_384;
+ break;
+ case SHA512_DIGEST_SIZE:
+ ctx->gr0.fc = CPACF_KMAC_HMAC_SHA_512;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int s390_hmac_sha2_update(struct shash_desc *desc,
+ const u8 *data, unsigned int len)
+{
+ struct s390_kmac_sha2_ctx *ctx = shash_desc_ctx(desc);
+ unsigned int bs = crypto_shash_blocksize(desc->tfm);
+ unsigned int offset, n;
+
+ /* 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;
+ _cpacf_kmac(&ctx->gr0.reg, ctx->param, ctx->buf, bs);
+ data += n;
+ len -= n;
+ offset = 0;
+ }
+ /* process as many blocks as possible */
+ if (len >= bs) {
+ n = (len / bs) * bs;
+ ctx->gr0.iimp = 1;
+ _cpacf_kmac(&ctx->gr0.reg, ctx->param, data, n);
+ data += n;
+ len -= n;
+ }
+store:
+ /* store incomplete block in buffer */
+ if (len)
+ memcpy(ctx->buf + offset, data, len);
+
+ return 0;
+}
+
+static int s390_hmac_sha2_final(struct shash_desc *desc, u8 *out)
+{
+ struct s390_kmac_sha2_ctx *ctx = shash_desc_ctx(desc);
+ unsigned int bs = crypto_shash_blocksize(desc->tfm);
+
+ ctx->gr0.iimp = 0;
+ kmac_sha2_set_imbl(ctx->param, ctx->buflen, bs);
+ _cpacf_kmac(&ctx->gr0.reg, ctx->param, ctx->buf, ctx->buflen % bs);
+ memcpy(out, ctx->param, crypto_shash_digestsize(desc->tfm));
+
+ return 0;
+}
+
+static int s390_hmac_sha2_digest(struct shash_desc *desc,
+ const u8 *data, unsigned int len, u8 *out)
+{
+ struct s390_kmac_sha2_ctx *ctx = shash_desc_ctx(desc);
+ unsigned int ds = crypto_shash_digestsize(desc->tfm);
+ int rc;
+
+ rc = s390_hmac_sha2_init(desc);
+ if (rc)
+ return rc;
+
+ ctx->gr0.iimp = 0;
+ kmac_sha2_set_imbl(ctx->param, len,
+ crypto_shash_blocksize(desc->tfm));
+ _cpacf_kmac(&ctx->gr0.reg, ctx->param, data, len);
+ memcpy(out, ctx->param, ds);
+
+ return 0;
+}
+
+#define S390_HMAC_SHA2_ALG(x) { \
+ .fc = CPACF_KMAC_HMAC_SHA_##x, \
+ .alg = { \
+ .init = s390_hmac_sha2_init, \
+ .update = s390_hmac_sha2_update, \
+ .final = s390_hmac_sha2_final, \
+ .digest = s390_hmac_sha2_digest, \
+ .setkey = s390_hmac_sha2_setkey, \
+ .descsize = sizeof(struct s390_kmac_sha2_ctx), \
+ .halg = { \
+ .digestsize = SHA##x##_DIGEST_SIZE, \
+ .base = { \
+ .cra_name = "hmac(sha" #x ")", \
+ .cra_driver_name = "hmac_s390_sha" #x, \
+ .cra_blocksize = SHA##x##_BLOCK_SIZE, \
+ .cra_priority = 400, \
+ .cra_ctxsize = sizeof(struct s390_hmac_ctx), \
+ .cra_module = THIS_MODULE, \
+ }, \
+ }, \
+ }, \
+}
+
+static struct s390_hmac_alg {
+ bool registered;
+ unsigned int fc;
+ struct shash_alg alg;
+} s390_hmac_algs[] = {
+ S390_HMAC_SHA2_ALG(224),
+ S390_HMAC_SHA2_ALG(256),
+ S390_HMAC_SHA2_ALG(384),
+ S390_HMAC_SHA2_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->registered)
+ continue;
+ crypto_unregister_shash(&hmac->alg);
+ }
+}
+
+static int __init hmac_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->alg);
+ if (rc) {
+ pr_err("unable to register %s\n",
+ hmac->alg.halg.base.cra_name);
+ goto out;
+ }
+ hmac->registered = true;
+ pr_debug("registered %s\n", hmac->alg.halg.base.cra_name);
+ }
+ return rc;
+out:
+ _s390_hmac_algs_unregister();
+ return rc;
+}
+
+static void __exit hmac_s390_exit(void)
+{
+ _s390_hmac_algs_unregister();
+}
+
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, hmac_s390_init);
+module_exit(hmac_s390_exit);
+
+MODULE_DESCRIPTION("S390 HMAC driver");
+MODULE_LICENSE("GPL");
diff --git a/arch/s390/include/asm/cpacf.h
b/arch/s390/include/asm/cpacf.h
index b2f355751bf6..2dbe2e2088bb 100644
--- a/arch/s390/include/asm/cpacf.h
+++ b/arch/s390/include/asm/cpacf.h
@@ -123,6 +123,10 @@
#define CPACF_KMAC_DEA 0x01
#define CPACF_KMAC_TDEA_128 0x02
#define CPACF_KMAC_TDEA_192 0x03
+#define CPACF_KMAC_HMAC_SHA_224 0x70
+#define CPACF_KMAC_HMAC_SHA_256 0x71
+#define CPACF_KMAC_HMAC_SHA_384 0x72
+#define CPACF_KMAC_HMAC_SHA_512 0x73
/*
* Function codes for the PCKMO (PERFORM CRYPTOGRAPHIC KEY MANAGEMENT)
@@ -427,35 +431,52 @@ static inline void cpacf_klmd(unsigned long func,
void *param,
}
/**
- * cpacf_kmac() - executes the KMAC (COMPUTE MESSAGE AUTHENTICATION
CODE)
- * instruction
- * @func: the function code passed to KM; see CPACF_KMAC_xxx defines
+ * _cpacf_kmac() - executes the KMAC (COMPUTE MESSAGE AUTHENTICATION
CODE)
+ * instruction and updates flags in gr0
+ * @gr0: pointer to gr0 (fc and flags) passed to KMAC; see
CPACF_KMAC_xxx defines
* @param: address of parameter block; see POP for details on each func
* @src: address of source memory area
* @src_len: length of src operand in bytes
*
* Returns 0 for the query func, number of processed bytes for digest
funcs
*/
-static inline int cpacf_kmac(unsigned long func, void *param,
- const u8 *src, long src_len)
+static inline int _cpacf_kmac(unsigned long *gr0, void *param,
+ const u8 *src, long src_len)
{
union register_pair s;
s.even = (unsigned long)src;
s.odd = (unsigned long)src_len;
asm volatile(
- " lgr 0,%[fc]\n"
+ " lgr 0,%[r0]\n"
" lgr 1,%[pba]\n"
"0: .insn rre,%[opc] << 16,0,%[src]\n"
" brc 1,0b\n" /* handle partial completion */
- : [src] "+&d" (s.pair)
- : [fc] "d" (func), [pba] "d" ((unsigned long)param),
+ " lgr %[r0],0\n"
+ : [r0] "+d" (*gr0), [src] "+&d" (s.pair)
+ : [pba] "d" ((unsigned long)param),
[opc] "i" (CPACF_KMAC)
: "cc", "memory", "0", "1");
return src_len - s.odd;
}
+/**
+ * cpacf_kmac() - executes the KMAC (COMPUTE MESSAGE AUTHENTICATION
CODE)
+ * instruction
+ * @func: function code passed to KMAC; see CPACF_KMAC_xxx defines
+ * @param: address of parameter block; see POP for details on each func
+ * @src: address of source memory area
+ * @src_len: length of src operand in bytes
+ *
+ * Returns 0 for the query func, number of processed bytes for digest
funcs
+ */
+static inline int cpacf_kmac(unsigned long func, void *param,
+ const u8 *src, long src_len)
+{
+ return _cpacf_kmac(&func, param, src, src_len);
+}
+
/**
* cpacf_kmctr() - executes the KMCTR (CIPHER MESSAGE WITH COUNTER)
instruction
* @func: the function code passed to KMCTR; see CPACF_KMCTR_xxx
defines
