hkdf: implement ctx dup operation

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/17572)

diff --git a/providers/implementations/kdfs/hkdf.c b/providers/implementations/kdfs/hkdf.c
index 667d5e9619ff1521e1dd3d4f3fb65d57a7502a2f..e014e32d5b73cee235b7d416fba1318afbbc4633 100644 (file)
--- a/providers/implementations/kdfs/hkdf.c
+++ b/providers/implementations/kdfs/hkdf.c
@@ -34,6 +34,7 @@
 #define HKDF_MAXBUF 2048
 
 static OSSL_FUNC_kdf_newctx_fn kdf_hkdf_new;
+static OSSL_FUNC_kdf_dupctx_fn kdf_hkdf_dup;
 static OSSL_FUNC_kdf_freectx_fn kdf_hkdf_free;
 static OSSL_FUNC_kdf_reset_fn kdf_hkdf_reset;
 static OSSL_FUNC_kdf_derive_fn kdf_hkdf_derive;
@@ -126,6 +127,36 @@ static void kdf_hkdf_reset(void *vctx)
     ctx->provctx = provctx;
 }
 
+static void *kdf_hkdf_dup(void *vctx)
+{
+    const KDF_HKDF *src = (const KDF_HKDF *)vctx;
+    KDF_HKDF *dest;
+
+    dest = kdf_hkdf_new(src->provctx);
+    if (dest != NULL) {
+        if (!ossl_prov_memdup(src->salt, src->salt_len, &dest->salt,
+                              &dest->salt_len)
+                || !ossl_prov_memdup(src->key, src->key_len,
+                                     &dest->key , &dest->key_len)
+                || !ossl_prov_memdup(src->prefix, src->prefix_len,
+                                     &dest->prefix, &dest->prefix_len)
+                || !ossl_prov_memdup(src->label, src->label_len,
+                                     &dest->label, &dest->label_len)
+                || !ossl_prov_memdup(src->data, src->data_len,
+                                     &dest->data, &dest->data_len)
+                || !ossl_prov_digest_copy(&dest->digest, &src->digest))
+            goto err;
+        memcpy(dest->info, src->info, sizeof(dest->info));
+        dest->info_len = src->info_len;
+        dest->mode = src->mode;
+    }
+    return dest;
+
+ err:
+    kdf_hkdf_free(dest);
+    return NULL;
+}
+
 static size_t kdf_hkdf_size(KDF_HKDF *ctx)
 {
     int sz;
@@ -313,6 +344,7 @@ static const OSSL_PARAM *kdf_hkdf_gettable_ctx_params(ossl_unused void *ctx,
 
 const OSSL_DISPATCH ossl_kdf_hkdf_functions[] = {
     { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_hkdf_new },
+    { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_hkdf_dup },
     { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_hkdf_free },
     { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_hkdf_reset },
     { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_hkdf_derive },
@@ -728,6 +760,7 @@ static const OSSL_PARAM *kdf_tls1_3_settable_ctx_params(ossl_unused void *ctx,
 
 const OSSL_DISPATCH ossl_kdf_tls1_3_kdf_functions[] = {
     { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_hkdf_new },
+    { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_hkdf_dup },
     { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_hkdf_free },
     { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_hkdf_reset },
     { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_tls1_3_derive },