archives/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-03-08 06:04:44 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

crypto: s390/phmac - Refuse clear key material by default

Browse source 
This patch exploits the new xflag PKEY_XFLAG_NOCLEARKEY from the pkey
layer. So now by default the phmac refuses the use of clear key
material ("clear key tokens") in the setkey function with
-EINVAL.

With a new kernel module parameter "clrkey" this behavior can be
controlled. By default clrkey is 'N' but for testing purpose on module
load a true value (1, 'Y') may be given to accept clear key tokens.

Note that during selftest clear keys are always used and thus the
xflag PKEY_XFLAG_NOCLEARKEY is NOT set as long as the algorithm is in
a larval state indicated by crypto_ahash_tested() returning false.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Harald Freudenberger 2026-01-15 13:00:25 +01:00 • committed by Herbert Xu
parent 2dfca61119
commit 452770a4fa
1 changed files with 20 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

29
arch/s390/crypto/phmac_s390.c
View file

@ -23,6 +23,10 @@
static struct crypto_engine *phmac_crypto_engine;
#define MAX_QLEN 10
static bool pkey_clrkey_allowed;
module_param_named(clrkey, pkey_clrkey_allowed, bool, 0444);
MODULE_PARM_DESC(clrkey, "Allow clear key material (default N)");
/*
* A simple hash walk helper
*/
@ -311,10 +315,14 @@ static inline int phmac_tfm_ctx_setkey(struct phmac_tfm_ctx *tfm_ctx,
* This function may sleep - don't call in non-sleeping context.
*/
static inline int convert_key(const u8 *key, unsigned int keylen,
struct phmac_protkey *pk)
struct phmac_protkey *pk, bool tested)
{
u32 xflags = PKEY_XFLAG_NOMEMALLOC;
int rc, i;
if (tested && !pkey_clrkey_allowed)
xflags |= PKEY_XFLAG_NOCLEARKEY;
pk->len = sizeof(pk->protkey);
/*
@ -328,7 +336,7 @@ static inline int convert_key(const u8 *key, unsigned int keylen,
}
rc = pkey_key2protkey(key, keylen,
pk->protkey, &pk->len, &pk->type,
PKEY_XFLAG_NOMEMALLOC);
xflags);
}
out:
@ -350,7 +358,7 @@ out:
* unnecessary additional conversion but never to invalid data on the
* hash operation.
*/
static int phmac_convert_key(struct phmac_tfm_ctx *tfm_ctx)
static int phmac_convert_key(struct phmac_tfm_ctx *tfm_ctx, bool tested)
{
struct phmac_protkey pk;
int rc;
@ -359,7 +367,7 @@ static int phmac_convert_key(struct phmac_tfm_ctx *tfm_ctx)
tfm_ctx->pk_state = PK_STATE_CONVERT_IN_PROGRESS;
spin_unlock_bh(&tfm_ctx->pk_lock);
rc = convert_key(tfm_ctx->keybuf, tfm_ctx->keylen, &pk);
rc = convert_key(tfm_ctx->keybuf, tfm_ctx->keylen, &pk, tested);
/* update context */
spin_lock_bh(&tfm_ctx->pk_lock);
@ -404,6 +412,7 @@ static int phmac_kmac_update(struct ahash_request *req, bool maysleep)
struct kmac_sha2_ctx *ctx = &req_ctx->kmac_ctx;
struct hash_walk_helper *hwh = &req_ctx->hwh;
unsigned int bs = crypto_ahash_blocksize(tfm);
bool tested = crypto_ahash_tested(tfm);
unsigned int offset, k, n;
int rc = 0;
@ -444,7 +453,7 @@ static int phmac_kmac_update(struct ahash_request *req, bool maysleep)
rc = -EKEYEXPIRED;
goto out;
}
rc = phmac_convert_key(tfm_ctx);
rc = phmac_convert_key(tfm_ctx, tested);
if (rc)
goto out;
spin_lock_bh(&tfm_ctx->pk_lock);
@ -480,7 +489,7 @@ static int phmac_kmac_update(struct ahash_request *req, bool maysleep)
rc = -EKEYEXPIRED;
goto out;
}
rc = phmac_convert_key(tfm_ctx);
rc = phmac_convert_key(tfm_ctx, tested);
if (rc)
goto out;
spin_lock_bh(&tfm_ctx->pk_lock);
@ -517,6 +526,7 @@ static int phmac_kmac_final(struct ahash_request *req, bool maysleep)
struct kmac_sha2_ctx *ctx = &req_ctx->kmac_ctx;
unsigned int ds = crypto_ahash_digestsize(tfm);
unsigned int bs = crypto_ahash_blocksize(tfm);
bool tested = crypto_ahash_tested(tfm);
unsigned int k, n;
int rc = 0;
@ -537,7 +547,7 @@ static int phmac_kmac_final(struct ahash_request *req, bool maysleep)
rc = -EKEYEXPIRED;
goto out;
}
rc = phmac_convert_key(tfm_ctx);
rc = phmac_convert_key(tfm_ctx, tested);
if (rc)
goto out;
spin_lock_bh(&tfm_ctx->pk_lock);
@ -741,11 +751,12 @@ static int phmac_setkey(struct crypto_ahash *tfm,
struct phmac_tfm_ctx *tfm_ctx = crypto_ahash_ctx(tfm);
unsigned int ds = crypto_ahash_digestsize(tfm);
unsigned int bs = crypto_ahash_blocksize(tfm);
bool tested = crypto_ahash_tested(tfm);
unsigned int tmpkeylen;
u8 *tmpkey = NULL;
int rc = 0;
if (!crypto_ahash_tested(tfm)) {
if (!tested) {
/*
* selftest running: key is a raw hmac clear key and needs
* to get embedded into a 'clear key token' in order to have
@ -770,7 +781,7 @@ static int phmac_setkey(struct crypto_ahash *tfm,
goto out;
/* convert raw key into protected key */
rc = phmac_convert_key(tfm_ctx);
rc = phmac_convert_key(tfm_ctx, tested);
if (rc)
goto out;