When user space issues a KEYCTL_PKEY_QUERY system call for a NIST P521
key, the key_size is incorrectly reported as 528 bits instead of 521.
That's because the key size obtained through crypto_sig_keysize() is in
bytes and software_key_query() multiplies by 8 to yield the size in bits.
The underlying assumption is that the key size is always a multiple of 8.
With the recent addition of NIST P521, that's no longer the case.
Fix by returning the key_size in bits from crypto_sig_keysize() and
adjusting the calculations in software_key_query().
The ->key_size() callbacks of sig_alg algorithms now return the size in
bits, whereas the ->digest_size() and ->max_size() callbacks return the
size in bytes. This matches with the units in struct keyctl_pkey_query.
Fixes: a7d45ba77d3d ("crypto: ecdsa - Register NIST P521 and extend test suite")
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
---
crypto/asymmetric_keys/public_key.c | 8 ++++----
crypto/ecdsa-p1363.c | 4 ++--
crypto/ecdsa-x962.c | 4 ++--
crypto/ecdsa.c | 2 +-
crypto/ecrdsa.c | 2 +-
crypto/rsassa-pkcs1.c | 2 +-
crypto/sig.c | 9 +++++++--
include/crypto/sig.h | 2 +-
8 files changed, 19 insertions(+), 14 deletions(-)
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index dd44a966947f..6cafb2b8aa22 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -205,6 +205,7 @@ static int software_key_query(const struct kernel_pkey_params *params,
goto error_free_tfm;
len = crypto_sig_keysize(sig);
+ info->key_size = len;
info->max_sig_size = crypto_sig_maxsize(sig);
info->max_data_size = crypto_sig_digestsize(sig);
@@ -213,8 +214,8 @@ static int software_key_query(const struct kernel_pkey_params *params,
info->supported_ops |= KEYCTL_SUPPORTS_SIGN;
if (strcmp(params->encoding, "pkcs1") == 0) {
- info->max_enc_size = len;
- info->max_dec_size = len;
+ info->max_enc_size = len / 8;
+ info->max_dec_size = len / 8;
info->supported_ops |= KEYCTL_SUPPORTS_ENCRYPT;
if (pkey->key_is_private)
@@ -235,6 +236,7 @@ static int software_key_query(const struct kernel_pkey_params *params,
goto error_free_tfm;
len = crypto_akcipher_maxsize(tfm);
+ info->key_size = len * 8;
info->max_sig_size = len;
info->max_data_size = len;
info->max_enc_size = len;
@@ -245,8 +247,6 @@ static int software_key_query(const struct kernel_pkey_params *params,
info->supported_ops |= KEYCTL_SUPPORTS_DECRYPT;
}
- info->key_size = len * 8;
-
ret = 0;
error_free_tfm:
diff --git a/crypto/ecdsa-p1363.c b/crypto/ecdsa-p1363.c
index eaae7214d69b..c4f458df18ed 100644
--- a/crypto/ecdsa-p1363.c
+++ b/crypto/ecdsa-p1363.c
@@ -21,7 +21,7 @@ static int ecdsa_p1363_verify(struct crypto_sig *tfm,
const void *digest, unsigned int dlen)
{
struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm);
- unsigned int keylen = crypto_sig_keysize(ctx->child);
+ unsigned int keylen = DIV_ROUND_UP(crypto_sig_keysize(ctx->child), 8);
unsigned int ndigits = DIV_ROUND_UP(keylen, sizeof(u64));
struct ecdsa_raw_sig sig;
@@ -45,7 +45,7 @@ static unsigned int ecdsa_p1363_max_size(struct crypto_sig *tfm)
{
struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm);
- return 2 * crypto_sig_keysize(ctx->child);
+ return 2 * DIV_ROUND_UP(crypto_sig_keysize(ctx->child), 8);
}
static unsigned int ecdsa_p1363_digest_size(struct crypto_sig *tfm)
diff --git a/crypto/ecdsa-x962.c b/crypto/ecdsa-x962.c
index 6a77c13e192b..0327e1441374 100644
--- a/crypto/ecdsa-x962.c
+++ b/crypto/ecdsa-x962.c
@@ -82,7 +82,7 @@ static int ecdsa_x962_verify(struct crypto_sig *tfm,
int err;
sig_ctx.ndigits = DIV_ROUND_UP(crypto_sig_keysize(ctx->child),
- sizeof(u64));
+ sizeof(u64) * 8);
err = asn1_ber_decoder(&ecdsasignature_decoder, &sig_ctx, src, slen);
if (err < 0)
@@ -103,7 +103,7 @@ static unsigned int ecdsa_x962_max_size(struct crypto_sig *tfm)
{
struct ecdsa_x962_ctx *ctx = crypto_sig_ctx(tfm);
struct sig_alg *alg = crypto_sig_alg(ctx->child);
- int slen = crypto_sig_keysize(ctx->child);
+ int slen = DIV_ROUND_UP(crypto_sig_keysize(ctx->child), 8);
/*
* Verify takes ECDSA-Sig-Value (described in RFC 5480) as input,
diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c
index 117526d15dde..a70b60a90a3c 100644
--- a/crypto/ecdsa.c
+++ b/crypto/ecdsa.c
@@ -167,7 +167,7 @@ static unsigned int ecdsa_key_size(struct crypto_sig *tfm)
{
struct ecc_ctx *ctx = crypto_sig_ctx(tfm);
- return DIV_ROUND_UP(ctx->curve->nbits, 8);
+ return ctx->curve->nbits;
}
static unsigned int ecdsa_digest_size(struct crypto_sig *tfm)
diff --git a/crypto/ecrdsa.c b/crypto/ecrdsa.c
index b3dd8a3ddeb7..53c9fd9f807f 100644
--- a/crypto/ecrdsa.c
+++ b/crypto/ecrdsa.c
@@ -249,7 +249,7 @@ static unsigned int ecrdsa_key_size(struct crypto_sig *tfm)
* Verify doesn't need any output, so it's just informational
* for keyctl to determine the key bit size.
*/
- return ctx->pub_key.ndigits * sizeof(u64);
+ return ctx->pub_key.ndigits * sizeof(u64) * 8;
}
static unsigned int ecrdsa_max_size(struct crypto_sig *tfm)
diff --git a/crypto/rsassa-pkcs1.c b/crypto/rsassa-pkcs1.c
index d01ac75635e0..299b2512cc95 100644
--- a/crypto/rsassa-pkcs1.c
+++ b/crypto/rsassa-pkcs1.c
@@ -301,7 +301,7 @@ static unsigned int rsassa_pkcs1_key_size(struct crypto_sig *tfm)
{
struct rsassa_pkcs1_ctx *ctx = crypto_sig_ctx(tfm);
- return ctx->key_size;
+ return ctx->key_size * 8;
}
static int rsassa_pkcs1_set_pub_key(struct crypto_sig *tfm,
diff --git a/crypto/sig.c b/crypto/sig.c
index dfc7cae90802..7399e67c6f12 100644
--- a/crypto/sig.c
+++ b/crypto/sig.c
@@ -102,6 +102,11 @@ static int sig_default_set_key(struct crypto_sig *tfm,
return -ENOSYS;
}
+static unsigned int sig_default_size(struct crypto_sig *tfm)
+{
+ return DIV_ROUND_UP(crypto_sig_keysize(tfm), 8);
+}
+
static int sig_prepare_alg(struct sig_alg *alg)
{
struct crypto_alg *base = &alg->base;
@@ -117,9 +122,9 @@ static int sig_prepare_alg(struct sig_alg *alg)
if (!alg->key_size)
return -EINVAL;
if (!alg->max_size)
- alg->max_size = alg->key_size;
+ alg->max_size = sig_default_size;
if (!alg->digest_size)
- alg->digest_size = alg->key_size;
+ alg->digest_size = sig_default_size;
base->cra_type = &crypto_sig_type;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
diff --git a/include/crypto/sig.h b/include/crypto/sig.h
index 11024708c069..fa6dafafab3f 100644
--- a/include/crypto/sig.h
+++ b/include/crypto/sig.h
@@ -128,7 +128,7 @@ static inline void crypto_free_sig(struct crypto_sig *tfm)
/**
* crypto_sig_keysize() - Get key size
*
- * Function returns the key size in bytes.
+ * Function returns the key size in bits.
* Function assumes that the key is already set in the transformation. If this
* function is called without a setkey or with a failed setkey, you may end up
* in a NULL dereference.
--
2.43.0
