Commit 5e5bc836 authored by Richard Levitte's avatar Richard Levitte

Re-introduce legacy EVP_PKEY types for provided keys

EVP_PKEYs with provider side internal keys got the key type
EVP_PKEY_NONE.  This turned out to be too disruptive, so we try
instead to find a matching EVP_PKEY_ASN1_METHOD and use whatever
EVP_PKEY type it uses.

To make internal coding easier, we introduce a few internal macros to
distinguish what can be expected from a EVP_PKEY:

- evp_pkey_is_blank(), to detect an unassigned EVP_PKEY.
- evp_pkey_is_typed(), to detect that an EVP_PKEY has been assigned a
  type, which may be an old style type number or a EVP_KEYMGMT method.
- evp_pkey_is_assigned(), to detect that an EVP_PKEY has been assigned
  an key value.
- evp_pkey_is_legacy(), to detect that the internal EVP_PKEY key is a
  legacy one, i.e. will be handled via an EVP_PKEY_ASN1_METHOD and an
  EVP_PKEY_METHOD.
- evp_pkey_is_provided(), to detect that the internal EVP_PKEY key is
  a provider side one, i.e. will be handdled via an EVP_KEYMGMT and
  other provider methods.

This also introduces EVP_PKEY_KEYMGMT, to indicate that this EVP_PKEY
contains a provider side key for which there are no known
EVP_PKEY_ASN1_METHODs or EVP_PKEY_METHODs, i.e. these can only be
handled via EVP_KEYMGMT and other provider methods.

Fixes #11823
Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11913)
parent aa2cb51d
......@@ -119,7 +119,7 @@ int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
* If |to| is a legacy key and |from| isn't, we must downgrade |from|.
* If that fails, this function fails.
*/
if (to->type != EVP_PKEY_NONE && from->keymgmt != NULL)
if (evp_pkey_is_legacy(to) && evp_pkey_is_provided(from))
if (!evp_pkey_downgrade((EVP_PKEY *)from))
return 0;
......@@ -135,15 +135,15 @@ int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
* like evp_keymgmt_util_copy() and evp_pkey_export_to_provider() called
* further down help us find out if they are the same or not.
*/
if (to->type == EVP_PKEY_NONE && to->keymgmt == NULL) {
if (from->type != EVP_PKEY_NONE) {
if (evp_pkey_is_blank(to)) {
if (evp_pkey_is_legacy(from)) {
if (EVP_PKEY_set_type(to, from->type) == 0)
return 0;
} else {
if (EVP_PKEY_set_type_by_keymgmt(to, from->keymgmt) == 0)
return 0;
}
} else if (to->type != EVP_PKEY_NONE) {
} else if (evp_pkey_is_legacy(to)) {
if (to->type != from->type) {
EVPerr(EVP_F_EVP_PKEY_COPY_PARAMETERS, EVP_R_DIFFERENT_KEY_TYPES);
goto err;
......@@ -1357,19 +1357,17 @@ static int pkey_set_type(EVP_PKEY *pkey, ENGINE *e, int type, const char *str,
pkey->engine = e;
/*
* The EVP_PKEY_ASN1_METHOD |pkey_id| serves different purposes,
* depending on if we're setting this key to contain a legacy or
* a provider side "origin" key. For a legacy key, we assign it
* to the |type| field, but for a provider side key, we assign it
* to the |save_type| field, because |type| is supposed to be set
* to EVP_PKEY_NONE in that case.
* The EVP_PKEY_ASN1_METHOD |pkey_id| retains its legacy key purpose
* for any key type that has a legacy implementation, regardless of
* if the internal key is a legacy or a provider side one. When
* there is no legacy implementation for the key, the type becomes
* EVP_PKEY_KEYMGMT, which indicates that one should be cautious
* with functions that expect legacy internal keys.
*/
if (ameth != NULL) {
if (keymgmt != NULL)
pkey->save_type = ameth->pkey_id;
else if (pkey->ameth != NULL)
pkey->type = ameth->pkey_id;
}
if (ameth != NULL)
pkey->type = ameth->pkey_id;
else
pkey->type = EVP_PKEY_KEYMGMT;
#endif
}
return 1;
......@@ -1453,7 +1451,6 @@ void evp_pkey_free_legacy(EVP_PKEY *x)
ENGINE_finish(x->pmeth_engine);
x->pmeth_engine = NULL;
# endif
x->type = EVP_PKEY_NONE;
}
#endif /* FIPS_MODULE */
......@@ -1472,6 +1469,7 @@ static void evp_pkey_free_it(EVP_PKEY *x)
x->keymgmt = NULL;
x->keydata = NULL;
}
x->type = EVP_PKEY_NONE;
}
void EVP_PKEY_free(EVP_PKEY *x)
......@@ -1661,32 +1659,33 @@ int evp_pkey_downgrade(EVP_PKEY *pk)
{
EVP_KEYMGMT *keymgmt = pk->keymgmt;
void *keydata = pk->keydata;
int type = pk->save_type;
int type = pk->type;
const char *keytype = NULL;
/* If this isn't a provider side key, we're done */
if (keymgmt == NULL)
return 1;
/* Get the key type name for error reporting */
if (type != EVP_PKEY_NONE)
keytype = OBJ_nid2sn(type);
else
keytype =
evp_first_name(EVP_KEYMGMT_provider(keymgmt), keymgmt->name_id);
keytype = evp_first_name(EVP_KEYMGMT_provider(keymgmt), keymgmt->name_id);
/*
* |save_type| was set when any of the EVP_PKEY_set_type functions
* was called. It was set to EVP_PKEY_NONE if the key type wasn't
* recognised to be any of the legacy key types, and the downgrade
* isn't possible.
* If the type is EVP_PKEY_NONE, then we have a problem somewhere else
* in our code. If it's not one of the well known EVP_PKEY_xxx values,
* it should at least be EVP_PKEY_KEYMGMT at this point.
* TODO(3.0) remove this check when we're confident that the rest of the
* code treats this correctly.
*/
if (type == EVP_PKEY_NONE) {
ERR_raise_data(ERR_LIB_EVP, EVP_R_UNKNOWN_KEY_TYPE,
"key type = %s, can't downgrade", keytype);
if (!ossl_assert(type != EVP_PKEY_NONE)) {
ERR_raise_data(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR,
"keymgmt key type = %s but legacy type = EVP_PKEY_NONE",
keytype);
return 0;
}
/* Prefer the legacy key type name for error reporting */
if (type != EVP_PKEY_KEYMGMT)
keytype = OBJ_nid2sn(type);
/*
* To be able to downgrade, we steal the provider side "origin" keymgmt
* and keydata. We've already grabbed the pointers, so all we need to
......
......@@ -155,10 +155,10 @@ static EVP_PKEY_CTX *int_ctx_new(OPENSSL_CTX *libctx,
goto common;
/*
* If the key doesn't contain anything legacy, then it must be provided,
* so we extract the necessary information and use that.
* If the internal key is provided, we extract the keytype from its
* keymgmt and skip over the legacy code.
*/
if (pkey != NULL && pkey->type == EVP_PKEY_NONE) {
if (pkey != NULL && evp_pkey_is_provided(pkey)) {
/* If we have an engine, something went wrong somewhere... */
if (!ossl_assert(e == NULL))
return NULL;
......
......@@ -518,9 +518,25 @@ const EVP_CIPHER *EVP_##cname##_ecb(void) { return &cname##_ecb; }
* (type != EVP_PKEY_NONE && pkey.ptr != NULL) ## legacy (libcrypto only)
* || (keymgmt != NULL && keydata != NULL) ## provider side
*
* The easiest way to detect a legacy key is: type != EVP_PKEY_NONE
* The easiest way to detect a provider side key is: keymgmt != NULL
* The easiest way to detect a legacy key is:
*
* keymgmt == NULL && type != EVP_PKEY_NONE
*
* The easiest way to detect a provider side key is:
*
* keymgmt != NULL
*/
#define evp_pkey_is_blank(pk) \
((pk)->type == EVP_PKEY_NONE && (pk)->keymgmt == NULL)
#define evp_pkey_is_typed(pk) \
((pk)->type != EVP_PKEY_NONE || (pk)->keymgmt != NULL)
#define evp_pkey_is_assigned(pk) \
((pk)->pkey.ptr != NULL || (pk)->keydata != NULL)
#define evp_pkey_is_legacy(pk) \
((pk)->type != EVP_PKEY_NONE && (pk)->keymgmt == NULL)
#define evp_pkey_is_provided(pk) \
((pk)->keymgmt != NULL)
struct evp_pkey_st {
/* == Legacy attributes == */
int type;
......
......@@ -72,6 +72,8 @@
# define EVP_PKEY_ED25519 NID_ED25519
# define EVP_PKEY_X448 NID_X448
# define EVP_PKEY_ED448 NID_ED448
/* Special indicator that the object is uniquely provider side */
# define EVP_PKEY_KEYMGMT -1
#ifdef __cplusplus
extern "C" {
......
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