diff options
| author | Stefan Berger <stefanb@linux.ibm.com> | 2024-04-18 11:24:44 -0400 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2024-04-26 17:26:09 +0800 |
| commit | bd955a4e928f4b3a5b5eb983df1726300c90201c (patch) | |
| tree | 6652ea583fd094d08ca464e7b31df26c5c522d23 | |
| parent | 5ae6d3f5c85cfc8d3ce60da776387062171cc174 (diff) | |
crypto: ecdh - Pass private key in proper byte order to check valid key
ecc_is_key_valid expects a key with the most significant digit in the last
entry of the digit array. Currently ecdh_set_secret passes a reversed key
to ecc_is_key_valid that then passes the rather simple test checking
whether the private key is in range [2, n-3]. For all current ecdh-
supported curves (NIST P192/256/384) the 'n' parameter is a rather large
number, therefore easily passing this test.
Throughout the ecdh and ecc codebase the variable 'priv' is used for a
private_key holding the bytes in proper byte order. Therefore, introduce
priv in ecdh_set_secret and copy the bytes from ctx->private_key into
priv in proper byte order by using ecc_swap_digits. Pass priv to
ecc_is_valid_key.
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Salvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| -rw-r--r-- | crypto/ecdh.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/crypto/ecdh.c b/crypto/ecdh.c index 3049f147e011..c02c9a2b9682 100644 --- a/crypto/ecdh.c +++ b/crypto/ecdh.c @@ -27,7 +27,9 @@ static int ecdh_set_secret(struct crypto_kpp *tfm, const void *buf, unsigned int len) { struct ecdh_ctx *ctx = ecdh_get_ctx(tfm); + u64 priv[ECC_MAX_DIGITS]; struct ecdh params; + int ret = 0; if (crypto_ecdh_decode_key(buf, len, ¶ms) < 0 || params.key_size > sizeof(u64) * ctx->ndigits) @@ -40,13 +42,16 @@ static int ecdh_set_secret(struct crypto_kpp *tfm, const void *buf, ctx->private_key); memcpy(ctx->private_key, params.key, params.key_size); + ecc_swap_digits(ctx->private_key, priv, ctx->ndigits); if (ecc_is_key_valid(ctx->curve_id, ctx->ndigits, - ctx->private_key, params.key_size) < 0) { + priv, params.key_size) < 0) { memzero_explicit(ctx->private_key, params.key_size); - return -EINVAL; + ret = -EINVAL; } - return 0; + memzero_explicit(priv, sizeof(priv)); + + return ret; } static int ecdh_compute_value(struct kpp_request *req) |