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author | Nicolai Stange <nstange@suse.de> | 2022-02-21 13:10:57 +0100 |
---|---|---|
committer | Herbert Xu <herbert@gondor.apana.org.au> | 2022-03-02 23:47:51 +0100 |
commit | c8e8236cf71f1e808120804339d2c23dc304f9cd (patch) | |
tree | ba6fe743095564f7754416c9f38a500d7af75964 /crypto | |
parent | crypto: testmgr - add keygen tests for ffdheXYZ(dh) templates (diff) | |
download | linux-c8e8236cf71f1e808120804339d2c23dc304f9cd.tar.xz linux-c8e8236cf71f1e808120804339d2c23dc304f9cd.zip |
crypto: dh - allow for passing NULL to the ffdheXYZ(dh)s' ->set_secret()
Ephemeral key generation can be requested from any of the ffdheXYZ(dh)
variants' common ->set_secret() by passing it an (encoded) struct dh
with the key parameter being unset, i.e. with ->key_size == 0. As the
whole purpose of the ffdheXYZ(dh) templates is to fill in the group
parameters as appropriate, they expect ->p and ->g to be unset in any
input struct dh as well. This means that a user would have to encode an
all-zeroes struct dh instance via crypto_dh_encode_key() when requesting
ephemeral key generation from a ffdheXYZ(dh) instance, which is kind of
pointless.
Make dh_safe_prime_set_secret() to decode a struct dh from the supplied
buffer only if the latter is non-NULL and initialize it with all zeroes
otherwise.
That is, it is now possible to call
crypto_kpp_set_secret(tfm, NULL, 0);
on any ffdheXYZ(dh) tfm for requesting ephemeral key generation.
Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r-- | crypto/dh.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/crypto/dh.c b/crypto/dh.c index 869a0476e5e2..d0d24f615b2d 100644 --- a/crypto/dh.c +++ b/crypto/dh.c @@ -444,17 +444,18 @@ static int dh_safe_prime_set_secret(struct crypto_kpp *tfm, const void *buffer, struct dh_safe_prime_instance_ctx *inst_ctx = dh_safe_prime_instance_ctx(tfm); struct dh_safe_prime_tfm_ctx *tfm_ctx = kpp_tfm_ctx(tfm); - struct dh params; + struct dh params = {}; void *buf = NULL, *key = NULL; unsigned int buf_size; int err; - err = __crypto_dh_decode_key(buffer, len, ¶ms); - if (err) - return err; - - if (params.p_size || params.g_size) - return -EINVAL; + if (buffer) { + err = __crypto_dh_decode_key(buffer, len, ¶ms); + if (err) + return err; + if (params.p_size || params.g_size) + return -EINVAL; + } params.p = inst_ctx->safe_prime->p; params.p_size = inst_ctx->safe_prime->p_size; |