Commit 12eb6c58ff for openssl.org

commit 12eb6c58ff2a8d857924b3020d30c8d485ace0a7
Author: Pauli <ppzgs1@gmail.com>
Date:   Wed Apr 9 12:42:10 2025 +1000

    hkdf: allow salt to be set to null

    Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
    Reviewed-by: Matt Caswell <matt@openssl.org>
    (Merged from https://github.com/openssl/openssl/pull/27305)

diff --git a/providers/implementations/kdfs/hkdf.c b/providers/implementations/kdfs/hkdf.c
index 264bc5d4c1..d6dfcb78b3 100644
--- a/providers/implementations/kdfs/hkdf.c
+++ b/providers/implementations/kdfs/hkdf.c
@@ -307,13 +307,11 @@ static int hkdf_common_set_ctx_params(KDF_HKDF *ctx, const OSSL_PARAM params[])
     }

     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL) {
-        if (p->data_size != 0 && p->data != NULL) {
-            OPENSSL_free(ctx->salt);
-            ctx->salt = NULL;
-            if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->salt, 0,
-                                             &ctx->salt_len))
-                return 0;
-        }
+        OPENSSL_free(ctx->salt);
+        ctx->salt = NULL;
+        if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->salt, 0,
+                                         &ctx->salt_len))
+            return 0;
     }

     return 1;