ENCODER: Drop OSSL_ENCODER_PARAM_INPUT_TYPE

This was a poor substitute for using the name of the decoder implementation,
and since there is functionality to get the latter now, this parameter
can be dropped.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15570)

2 files changed, 11 insertions, 21 deletions

diff --git a/crypto/encode_decode/encoder_lib.c b/crypto/encode_decode/encoder_lib.c
index 4481773610..d90ce72528 100644
--- a/crypto/encode_decode/encoder_lib.c
+++ b/crypto/encode_decode/encoder_lib.c
@@ -36,6 +36,8 @@ struct encoder_process_data_st {
     OSSL_ENCODER_INSTANCE *prev_encoder_inst;
     unsigned char *running_output;
     size_t running_output_length;
+    /* Data type = the name of the first succeeding encoder implementation */
+    const char *data_type;
 };
 
 static int encoder_process(struct encoder_process_data_st *data);
@@ -207,10 +209,7 @@ static OSSL_ENCODER_INSTANCE *ossl_encoder_instance_new(OSSL_ENCODER *encoder,
         OSSL_PARAM_construct_utf8_ptr(OSSL_ENCODER_PARAM_OUTPUT_STRUCTURE,
                                       (char **)&encoder_inst->output_structure,
                                       0);
-    params[2] =
-        OSSL_PARAM_construct_utf8_ptr(OSSL_ENCODER_PARAM_INPUT_TYPE,
-                                      (char **)&encoder_inst->input_type, 0);
-    params[3] = OSSL_PARAM_construct_end();
+    params[2] = OSSL_PARAM_construct_end();
 
     if (!encoder->get_params(params)
         || !OSSL_PARAM_modified(&params[0]))
@@ -260,8 +259,8 @@ static int ossl_encoder_ctx_add_encoder_inst(OSSL_ENCODER_CTX *ctx,
                        "(ctx %p) Added encoder instance %p (encoder %p) with:\n",
                        (void *)ctx, (void *)ei, (void *)ei->encoder);
             BIO_printf(trc_out,
-                       "    output type: %s, output structure: %s, input type :%s\n",
-                       ei->output_type, ei->output_structure, ei->input_type);
+                       "    output type: %s, output structure: %s\n",
+                       ei->output_type, ei->output_structure);
         } OSSL_TRACE_END(ENCODER);
     }
     return ok;
@@ -363,14 +362,6 @@ OSSL_ENCODER_INSTANCE_get_encoder_ctx(OSSL_ENCODER_INSTANCE *encoder_inst)
 }
 
 const char *
-OSSL_ENCODER_INSTANCE_get_input_type(OSSL_ENCODER_INSTANCE *encoder_inst)
-{
-    if (encoder_inst == NULL)
-        return NULL;
-    return encoder_inst->input_type;
-}
-
-const char *
 OSSL_ENCODER_INSTANCE_get_output_type(OSSL_ENCODER_INSTANCE *encoder_inst)
 {
     if (encoder_inst == NULL)
@@ -566,6 +557,9 @@ static int encoder_process(struct encoder_process_data_st *data)
                 data->ctx->construct(current_encoder_inst,
                                      data->ctx->construct_data);
 
+            /* Also set the data type, using the encoder implementation name */
+            data->data_type = OSSL_ENCODER_get0_name(current_encoder);
+
             /* Assume that the constructor recorded an error */
             if (original_data != NULL)
                 ok = 1;
@@ -586,15 +580,12 @@ static int encoder_process(struct encoder_process_data_st *data)
                  */
 
                 OSSL_PARAM *abstract_p = abstract;
-                const char *prev_input_type =
-                    OSSL_ENCODER_INSTANCE_get_input_type(data->prev_encoder_inst);
                 const char *prev_output_structure =
                     OSSL_ENCODER_INSTANCE_get_output_structure(data->prev_encoder_inst);
 
-                if (prev_input_type != NULL)
-                    *abstract_p++ =
-                        OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_TYPE,
-                                                         (char *)prev_input_type, 0);
+                *abstract_p++ =
+                    OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_TYPE,
+                                                     (char *)data->data_type, 0);
                 if (prev_output_structure != NULL)
                     *abstract_p++ =
                         OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_STRUCTURE,
diff --git a/crypto/encode_decode/encoder_local.h b/crypto/encode_decode/encoder_local.h
index 0678fc2014..44bd39b757 100644
--- a/crypto/encode_decode/encoder_local.h
+++ b/crypto/encode_decode/encoder_local.h
@@ -59,7 +59,6 @@ struct ossl_decoder_st {
 struct ossl_encoder_instance_st {
     OSSL_ENCODER *encoder;        /* Never NULL */
     void *encoderctx;             /* Never NULL */
-    const char *input_type;       /* May be NULL */
     const char *output_type;      /* Never NULL */
     const char *output_structure; /* May be NULL */
 };