EVP: Add EVP_PKEY_get0_provider() and EVP_PKEY_CTX_get0_provider()

Fixes #16058

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16063)

1 files changed, 23 insertions, 1 deletions

diff --git a/crypto/evp/pmeth_lib.c b/crypto/evp/pmeth_lib.c
index e5975081e1..7b835a5eb6 100644
--- a/crypto/evp/pmeth_lib.c
+++ b/crypto/evp/pmeth_lib.c
@@ -1531,11 +1531,33 @@ OSSL_LIB_CTX *EVP_PKEY_CTX_get0_libctx(EVP_PKEY_CTX *ctx)
     return ctx->libctx;
 }
 
-const char *EVP_PKEY_CTX_get0_propq(EVP_PKEY_CTX *ctx)
+const char *EVP_PKEY_CTX_get0_propq(const EVP_PKEY_CTX *ctx)
 {
     return ctx->propquery;
 }
 
+const OSSL_PROVIDER *EVP_PKEY_CTX_get0_provider(const EVP_PKEY_CTX *ctx)
+{
+    if (EVP_PKEY_CTX_IS_SIGNATURE_OP(ctx)) {
+        if (ctx->op.sig.signature != NULL)
+            return EVP_SIGNATURE_get0_provider(ctx->op.sig.signature);
+    } else if (EVP_PKEY_CTX_IS_DERIVE_OP(ctx)) {
+        if (ctx->op.kex.exchange != NULL)
+            return EVP_KEYEXCH_get0_provider(ctx->op.kex.exchange);
+    } else if (EVP_PKEY_CTX_IS_KEM_OP(ctx)) {
+        if (ctx->op.encap.kem != NULL)
+            return EVP_KEM_get0_provider(ctx->op.encap.kem);
+    } else if (EVP_PKEY_CTX_IS_ASYM_CIPHER_OP(ctx)) {
+        if (ctx->op.ciph.cipher != NULL)
+            return EVP_ASYM_CIPHER_get0_provider(ctx->op.ciph.cipher);
+    } else if (EVP_PKEY_CTX_IS_GEN_OP(ctx)) {
+        if (ctx->keymgmt != NULL)
+            return EVP_KEYMGMT_get0_provider(ctx->keymgmt);
+    }
+
+    return NULL;
+}
+
 /* Utility functions to send a string of hex string to a ctrl */
 
 int EVP_PKEY_CTX_str2ctrl(EVP_PKEY_CTX *ctx, int cmd, const char *str)