Decoder resolution performance optimizations

This refactors decoder functionality to reduce calls to
OSSL_DECODER_is_a / EVP_KEYMGMT_is_a, which are substantial bottlenecks
in the performance of repeated decode operations (see #15199).

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from #17921)

(cherry picked from commit 2475544)

crypto/encode_decode/decoder_lib.c

@@ -18,6 +18,7 @@
 #include <openssl/trace.h>
 #include "internal/bio.h"
 #include "internal/provider.h"
+#include "internal/namemap.h"
 #include "crypto/decoder.h"
 #include "encoder_local.h"
 #include "internal/e_os.h"
@@ -241,6 +242,7 @@ OSSL_DECODER_INSTANCE *ossl_decoder_instance_new(OSSL_DECODER *decoder,
     /* The "input" property is mandatory */
     prop = ossl_property_find_property(props, libctx, "input");
     decoder_inst->input_type = ossl_property_get_string_value(libctx, prop);
+    decoder_inst->input_type_id = 0;
     if (decoder_inst->input_type == NULL) {
         ERR_raise_data(ERR_LIB_OSSL_DECODER, ERR_R_INVALID_PROPERTY_DEFINITION,
                        "the mandatory 'input' property is missing "
@@ -343,6 +345,8 @@ int OSSL_DECODER_CTX_add_decoder(OSSL_DECODER_CTX *ctx, OSSL_DECODER *decoder)
 struct collect_extra_decoder_data_st {
     OSSL_DECODER_CTX *ctx;
     const char *output_type;
+    int output_type_id;
+
     /*
      * 0 to check that the decoder's input type is the same as the decoder name
      * 1 to check that the decoder's input type differs from the decoder name
@@ -370,7 +374,7 @@ static void collect_extra_decoder(OSSL_DECODER *decoder, void *arg)
     const OSSL_PROVIDER *prov = OSSL_DECODER_get0_provider(decoder);
     void *provctx = OSSL_PROVIDER_get0_provider_ctx(prov);
 
-    if (OSSL_DECODER_is_a(decoder, data->output_type)) {
+    if (ossl_decoder_fast_is_a(decoder, data->output_type, &data->output_type_id)) {
         void *decoderctx = NULL;
         OSSL_DECODER_INSTANCE *di = NULL;
 
@@ -413,8 +417,9 @@ static void collect_extra_decoder(OSSL_DECODER *decoder, void *arg)
         switch (data->type_check) {
         case IS_SAME:
             /* If it differs, this is not a decoder to add for now. */
-            if (!OSSL_DECODER_is_a(decoder,
-                                   OSSL_DECODER_INSTANCE_get_input_type(di))) {
+            if (!ossl_decoder_fast_is_a(decoder,
+                                        OSSL_DECODER_INSTANCE_get_input_type(di),
+                                        &di->input_type_id)) {
                 ossl_decoder_instance_free(di);
                 OSSL_TRACE_BEGIN(DECODER) {
                     BIO_printf(trc_out,
@@ -425,8 +430,9 @@ static void collect_extra_decoder(OSSL_DECODER *decoder, void *arg)
             break;
         case IS_DIFFERENT:
             /* If it's the same, this is not a decoder to add for now. */
-            if (OSSL_DECODER_is_a(decoder,
-                                  OSSL_DECODER_INSTANCE_get_input_type(di))) {
+            if (ossl_decoder_fast_is_a(decoder,
+                                       OSSL_DECODER_INSTANCE_get_input_type(di),
+                                       &di->input_type_id)) {
                 ossl_decoder_instance_free(di);
                 OSSL_TRACE_BEGIN(DECODER) {
                     BIO_printf(trc_out,
@@ -534,6 +540,7 @@ int OSSL_DECODER_CTX_add_extra(OSSL_DECODER_CTX *ctx,
                 data.output_type
                     = OSSL_DECODER_INSTANCE_get_input_type(decoder_inst);
 
+                data.output_type_id = 0;
 
                 for (j = 0; j < numdecoders; j++)
                     collect_extra_decoder(sk_OSSL_DECODER_value(skdecoders, j),
@@ -867,7 +874,8 @@ static int decoder_process(const OSSL_PARAM params[], void *arg)
          * |new_input_type| holds the value of the "input-type" parameter
          * for the decoder we're currently considering.
          */
-        if (decoder != NULL && !OSSL_DECODER_is_a(decoder, new_input_type)) {
+        if (decoder != NULL && !ossl_decoder_fast_is_a(decoder, new_input_type,
+                                                       &new_decoder_inst->input_type_id)) {
             OSSL_TRACE_BEGIN(DECODER) {
                 BIO_printf(trc_out,
                            "(ctx %p) %s [%u] the input type doesn't match the name of the previous decoder (%p), skipping...\n",

crypto/encode_decode/decoder_meth.c

@@ -558,6 +558,24 @@ int OSSL_DECODER_is_a(const OSSL_DECODER *decoder, const char *name)
     return 0;
 }
 
+static int resolve_name(OSSL_DECODER *decoder, const char *name)
+{
+    OSSL_LIB_CTX *libctx = ossl_provider_libctx(decoder->base.prov);
+    OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
+
+    return ossl_namemap_name2num(namemap, name);
+}
+
+int ossl_decoder_fast_is_a(OSSL_DECODER *decoder, const char *name, int *id_cache)
+{
+    int id = *id_cache;
+
+    if (id <= 0)
+        *id_cache = id = resolve_name(decoder, name);
+
+    return id > 0 && ossl_decoder_get_number(decoder) == id;
+}
+
 struct do_one_data_st {
     void (*user_fn)(OSSL_DECODER *decoder, void *arg);
     void *user_arg;