Static analysis was not happy since this return can be negative and it was being fed into an unsigned argument. In reality this cannot happen since the key buffer is always set to the maximum size supported by any curves. --- src/dpp-util.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/src/dpp-util.c b/src/dpp-util.c index 31d8e2c4..ac365ccc 100644 --- a/src/dpp-util.c +++ b/src/dpp-util.c @@ -420,16 +420,20 @@ struct l_ecc_scalar *dpp_derive_k1(const struct l_ecc_point *i_proto_public, return NULL; key_len = l_ecc_scalar_get_data(m, mx_bytes, sizeof(mx_bytes)); + if (key_len < 0) + goto free_m; sha = dpp_sha_from_key_len(key_len); if (!dpp_hkdf(sha, NULL, key_len, "first intermediate key", mx_bytes, - key_len, k1, key_len)) { - l_ecc_scalar_free(m); - return NULL; - } + key_len, k1, key_len)) + goto free_m; return m; + +free_m: + l_ecc_scalar_free(m); + return NULL; } /* @@ -449,16 +453,20 @@ struct l_ecc_scalar *dpp_derive_k2(const struct l_ecc_point *i_proto_public, return NULL; key_len = l_ecc_scalar_get_data(n, nx_bytes, sizeof(nx_bytes)); + if (key_len < 0) + goto free_n; sha = dpp_sha_from_key_len(key_len); if (!dpp_hkdf(sha, NULL, key_len, "second intermediate key", nx_bytes, - key_len, k2, key_len)) { - l_ecc_scalar_free(n); - return NULL; - } + key_len, k2, key_len)) + goto free_n; return n; + +free_n: + l_ecc_scalar_free(n); + return NULL; } bool dpp_derive_ke(const uint8_t *i_nonce, const uint8_t *r_nonce, -- 2.31.1