Implement EVP_PKEY_derive_SKEY

crypto/evp/evp_local.h

@@ -155,6 +155,7 @@ struct evp_keyexch_st {
     OSSL_FUNC_keyexch_settable_ctx_params_fn *settable_ctx_params;
     OSSL_FUNC_keyexch_get_ctx_params_fn *get_ctx_params;
     OSSL_FUNC_keyexch_gettable_ctx_params_fn *gettable_ctx_params;
+    OSSL_FUNC_keyexch_derive_opaque_fn *derive_opaque;
 } /* EVP_KEYEXCH */;
 
 struct evp_signature_st {

crypto/evp/exchange.c

@@ -115,9 +115,15 @@ static void *evp_keyexch_from_algorithm(int name_id,
                 = OSSL_FUNC_keyexch_settable_ctx_params(fns);
             sparamfncnt++;
             break;
+        case OSSL_FUNC_KEYEXCH_DERIVE_OPAQUE:
+            if (exchange->derive_opaque != NULL)
+                break;
+            exchange->derive_opaque = OSSL_FUNC_keyexch_derive_opaque(fns);
+            fncnt++;
+            break;
         }
     }
-    if (fncnt != 4
+    if ((fncnt != 4 && fncnt != 5)
             || (gparamfncnt != 0 && gparamfncnt != 2)
             || (sparamfncnt != 0 && sparamfncnt != 2)) {
         /*
@@ -534,6 +540,36 @@ int EVP_PKEY_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *pkeylen)
         return ctx->pmeth->derive(ctx, key, pkeylen);
 }
 
+int EVP_PKEY_derive_SKEY(EVP_PKEY_CTX *ctx, EVP_SKEY *skey)
+{
+    if (ctx == NULL || skey == NULL) {
+        ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
+        return 0;
+    }
+
+    if (!EVP_PKEY_CTX_IS_DERIVE_OP(ctx)) {
+        ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_INITIALIZED);
+        return 0;
+    }
+
+    if (ctx->op.kex.algctx == NULL || ctx->op.kex.exchange->derive_opaque == NULL) {
+        ERR_raise(ERR_R_EVP_LIB, ERR_R_UNSUPPORTED);
+        return 0;
+    }
+
+    if (skey->keymgmt->prov != ctx->op.kex.exchange->prov) {
+        ERR_raise(ERR_R_EVP_LIB, ERR_R_UNSUPPORTED);
+        return 0;
+    }
+
+    if (skey->keydata != NULL) {
+        ERR_raise(ERR_R_EVP_LIB, ERR_R_UNSUPPORTED);
+        return 0;
+    }
+
+    return ctx->op.kex.exchange->derive_opaque(ctx->op.kex.algctx, &(skey->keydata));
+}
+
 int evp_keyexch_get_number(const EVP_KEYEXCH *keyexch)
 {
     return keyexch->name_id;

crypto/evp/kdf_lib.c

@@ -147,8 +147,10 @@ int EVP_KDF_derive(EVP_KDF_CTX *ctx, unsigned char *key, size_t keylen,
 int EVP_KDF_derive_SKEY(EVP_KDF_CTX *ctx, EVP_SKEY *skey,
                         const OSSL_PARAM params[])
 {
-    if (ctx == NULL || skey == NULL)
+    if (ctx == NULL || skey == NULL) {
+        ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
         return 0;
+    }
 
     if (ctx->meth->derive_opaque == NULL) {
         ERR_raise(ERR_R_EVP_LIB, ERR_R_UNSUPPORTED);

doc/man3/EVP_PKEY_derive.pod

@@ -3,7 +3,8 @@
 =head1 NAME
 
 EVP_PKEY_derive_init, EVP_PKEY_derive_init_ex,
-EVP_PKEY_derive_set_peer_ex, EVP_PKEY_derive_set_peer, EVP_PKEY_derive
+EVP_PKEY_derive_set_peer_ex, EVP_PKEY_derive_set_peer, EVP_PKEY_derive,
+EVP_PKEY-derive_SKEY
 - derive public key algorithm shared secret
 
 =head1 SYNOPSIS
@@ -16,6 +17,7 @@ EVP_PKEY_derive_set_peer_ex, EVP_PKEY_derive_set_peer, EVP_PKEY_derive
                                  int validate_peer);
  int EVP_PKEY_derive_set_peer(EVP_PKEY_CTX *ctx, EVP_PKEY *peer);
  int EVP_PKEY_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen);
+ int EVP_PKEY_derive_SKEY(EVP_PKEY_CTX *ctx, EVP_SKEY *skey);
 
 =head1 DESCRIPTION
 
@@ -42,6 +44,9 @@ parameter should contain the length of the I<key> buffer, if the call is
 successful the shared secret is written to I<key> and the amount of data
 written to I<keylen>.
 
+EVP_PKEY_derive_SKEY() is similar to EVP_PKEY_derive() but accepts an B<EVP_SKEY>
+object that would store an opaque data for the derived key.
+
 =head1 NOTES
 
 After the call to EVP_PKEY_derive_init(), algorithm
@@ -53,7 +58,7 @@ context if several operations are performed using the same parameters.
 
 =head1 RETURN VALUES
 
-EVP_PKEY_derive_init() and EVP_PKEY_derive() return 1
+EVP_PKEY_derive_init(), EVP_PKEY_derive(), and EVP_PKEY_derive_SKEY() return 1
 for success and 0 or a negative value for failure.
 In particular a return value of -2 indicates the operation is not supported by
 the public key algorithm.
@@ -112,9 +117,11 @@ functions were originally added in OpenSSL 1.0.0.
 The EVP_PKEY_derive_init_ex() and EVP_PKEY_derive_set_peer_ex() functions were
 added in OpenSSL 3.0.
 
+The EVP_PKEY_derive_SKEY() function was added in OpenSSL 3.5.
+
 =head1 COPYRIGHT
 
-Copyright 2006-2022 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2006-2024 The OpenSSL Project Authors. All Rights Reserved.
 
 Licensed under the Apache License 2.0 (the "License").  You may not use
 this file except in compliance with the License.  You can obtain a copy

include/openssl/core_dispatch.h

@@ -714,6 +714,7 @@ OSSL_CORE_MAKE_FUNC(const OSSL_PARAM *, keymgmt_export_types_ex,
 # define OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS         8
 # define OSSL_FUNC_KEYEXCH_GET_CTX_PARAMS              9
 # define OSSL_FUNC_KEYEXCH_GETTABLE_CTX_PARAMS        10
+# define OSSL_FUNC_KEYEXCH_DERIVE_OPAQUE              11
 
 OSSL_CORE_MAKE_FUNC(void *, keyexch_newctx, (void *provctx))
 OSSL_CORE_MAKE_FUNC(int, keyexch_init, (void *ctx, void *provkey,
@@ -731,6 +732,7 @@ OSSL_CORE_MAKE_FUNC(int, keyexch_get_ctx_params, (void *ctx,
                                                      OSSL_PARAM params[]))
 OSSL_CORE_MAKE_FUNC(const OSSL_PARAM *, keyexch_gettable_ctx_params,
                     (void *ctx, void *provctx))
+OSSL_CORE_MAKE_FUNC(int, keyexch_derive_opaque, (void *ctx, void *secret))
 
 /* Signature */
 

include/openssl/evp.h

@@ -1982,6 +1982,7 @@ int EVP_PKEY_derive_set_peer_ex(EVP_PKEY_CTX *ctx, EVP_PKEY *peer,
                                 int validate_peer);
 int EVP_PKEY_derive_set_peer(EVP_PKEY_CTX *ctx, EVP_PKEY *peer);
 int EVP_PKEY_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen);
+int EVP_PKEY_derive_SKEY(EVP_PKEY_CTX *ctx, EVP_SKEY *skey);
 
 int EVP_PKEY_encapsulate_init(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[]);
 int EVP_PKEY_auth_encapsulate_init(EVP_PKEY_CTX *ctx, EVP_PKEY *authpriv,

util/libcrypto.num

@@ -5758,3 +5758,4 @@ EVP_SKEY_up_ref                         ?	3_5_0	EXIST::FUNCTION:
 EVP_SKEY_free                           ?	3_5_0	EXIST::FUNCTION:
 EVP_SKEY_dup                            ?	3_5_0	EXIST::FUNCTION:
 EVP_KDF_derive_SKEY                     ?	3_5_0	EXIST::FUNCTION:
+EVP_PKEY_derive_SKEY                    ?	3_5_0	EXIST::FUNCTION: