From 11d8f681b8fca4ed65999deb1f546c8e1dafab6e Mon Sep 17 00:00:00 2001
From: manison <manison@users.noreply.github.com>
Date: Mon, 21 Aug 2023 08:30:58 +0200
Subject: [PATCH] Implement settable param OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY
 for EC keys

This is required for EVP_PKEY_set1_encoded_public_key (used by
CMS_decrypt_set1_pkey_and_peer for example).

Signed-off-by: manison <manison@users.noreply.github.com>
---
 src/keymgmt.c | 38 +++++++++++++++++++++++++++++++
 src/objects.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/objects.h |  4 ++++
 3 files changed, 104 insertions(+)

diff --git a/src/keymgmt.c b/src/keymgmt.c
index 59261c5f..e1b11ea9 100644
--- a/src/keymgmt.c
+++ b/src/keymgmt.c
@@ -1003,6 +1003,8 @@ DISPATCH_KEYMGMT_FN(ec, export_types);
 DISPATCH_KEYMGMT_FN(ec, query_operation_name);
 DISPATCH_KEYMGMT_FN(ec, get_params);
 DISPATCH_KEYMGMT_FN(ec, gettable_params);
+DISPATCH_KEYMGMT_FN(ec, set_params);
+DISPATCH_KEYMGMT_FN(ec, settable_params);
 
 static void *p11prov_ec_new(void *provctx)
 {
@@ -1373,6 +1375,40 @@ static const OSSL_PARAM *p11prov_ec_gettable_params(void *provctx)
     return params;
 }
 
+static int p11prov_ec_set_params(void *keydata, const OSSL_PARAM params[])
+{
+    P11PROV_OBJ *key = (P11PROV_OBJ *)keydata;
+    const OSSL_PARAM *p;
+
+    P11PROV_debug("ec set params %p", keydata);
+
+    if (key == NULL) {
+        return RET_OSSL_ERR;
+    }
+
+    p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY);
+    if (p) {
+        if (p->data_type != OSSL_PARAM_OCTET_STRING) {
+            return RET_OSSL_ERR;
+        }
+        if (p11prov_obj_set_ec_encoded_public_key(key, p->data, p->data_size)
+            != CKR_OK) {
+            return RET_OSSL_ERR;
+        }
+    }
+
+    return RET_OSSL_OK;
+}
+
+static const OSSL_PARAM *p11prov_ec_settable_params(void *provctx)
+{
+    static const OSSL_PARAM params[] = {
+        OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY, NULL, 0),
+        OSSL_PARAM_END,
+    };
+    return params;
+}
+
 const OSSL_DISPATCH p11prov_ec_keymgmt_functions[] = {
     DISPATCH_KEYMGMT_ELEM(ec, NEW, new),
     DISPATCH_KEYMGMT_ELEM(ec, GEN_INIT, gen_init),
@@ -1391,6 +1427,8 @@ const OSSL_DISPATCH p11prov_ec_keymgmt_functions[] = {
     DISPATCH_KEYMGMT_ELEM(ec, QUERY_OPERATION_NAME, query_operation_name),
     DISPATCH_KEYMGMT_ELEM(ec, GET_PARAMS, get_params),
     DISPATCH_KEYMGMT_ELEM(ec, GETTABLE_PARAMS, gettable_params),
+    DISPATCH_KEYMGMT_ELEM(ec, SET_PARAMS, set_params),
+    DISPATCH_KEYMGMT_ELEM(ec, SETTABLE_PARAMS, settable_params),
     { 0, NULL },
 };
 
diff --git a/src/objects.c b/src/objects.c
index 9395b306..368734c1 100644
--- a/src/objects.c
+++ b/src/objects.c
@@ -2557,3 +2557,65 @@ CK_RV p11prov_obj_import_key(P11PROV_OBJ *key, CK_KEY_TYPE type,
     }
     return rv;
 }
+
+CK_RV p11prov_obj_set_ec_encoded_public_key(P11PROV_OBJ *key,
+                                            const void *pubkey,
+                                            size_t pubkey_len)
+{
+    CK_RV rv;
+    CK_ATTRIBUTE *pub;
+    CK_ATTRIBUTE *ecpoint;
+    CK_ATTRIBUTE new_pub;
+    ASN1_OCTET_STRING oct;
+    unsigned char *der = NULL;
+    int len;
+
+    if (key->handle != CK_INVALID_HANDLE) {
+        /*
+         * not a mock object, cannot set public key to a token object backed by
+         * an actual handle
+         */
+        P11PROV_raise(key->ctx, CKR_KEY_INDIGESTIBLE,
+                      "Cannot change public key of a token object");
+        return CKR_KEY_INDIGESTIBLE;
+    }
+
+    pub = p11prov_obj_get_attr(key, CKA_P11PROV_PUB_KEY);
+    if (!pub) {
+        P11PROV_raise(key->ctx, CKR_KEY_INDIGESTIBLE, "No public key found");
+        return CKR_KEY_INDIGESTIBLE;
+    }
+
+    ecpoint = p11prov_obj_get_attr(key, CKA_EC_POINT);
+    if (!ecpoint) {
+        P11PROV_raise(key->ctx, CKR_KEY_INDIGESTIBLE, "No public key found");
+        return CKR_KEY_INDIGESTIBLE;
+    }
+
+    OPENSSL_free(pub->pValue);
+    memset(pub, 0, sizeof(CK_ATTRIBUTE));
+    new_pub.type = CKA_P11PROV_PUB_KEY;
+    new_pub.pValue = (CK_VOID_PTR)pubkey;
+    new_pub.ulValueLen = (CK_ULONG)pubkey_len;
+    rv = p11prov_copy_attr(pub, &new_pub);
+    if (rv != CKR_OK) {
+        return rv;
+    }
+
+    oct.data = (unsigned char *)pubkey;
+    oct.length = (int)pubkey_len;
+    oct.flags = 0;
+
+    len = i2d_ASN1_OCTET_STRING(&oct, &der);
+    if (len < 0) {
+        P11PROV_raise(key->ctx, CKR_KEY_INDIGESTIBLE,
+                      "Failure to encode EC point to DER");
+        return CKR_KEY_INDIGESTIBLE;
+    }
+
+    OPENSSL_free(ecpoint->pValue);
+    ecpoint->pValue = der;
+    ecpoint->ulValueLen = len;
+
+    return CKR_OK;
+}
diff --git a/src/objects.h b/src/objects.h
index 8edafccd..cfd17f10 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -63,6 +63,10 @@ int p11prov_obj_key_cmp(P11PROV_OBJ *obj1, P11PROV_OBJ *obj2, CK_KEY_TYPE type,
 CK_RV p11prov_obj_import_key(P11PROV_OBJ *key, CK_KEY_TYPE type,
                              CK_OBJECT_CLASS class, const OSSL_PARAM params[]);
 
+CK_RV p11prov_obj_set_ec_encoded_public_key(P11PROV_OBJ *key,
+                                            const void *pubkey,
+                                            size_t pubkey_len);
+
 #define ED25519 "ED25519"
 #define ED25519_BIT_SIZE 256
 #define ED25519_BYTE_SIZE ED25519_BIT_SIZE / 8