Provide EVP_PKEY_CTX_md().

This handles controls with a message digest by name, looks up the message
digest and then proxies the control through with the EVP_MD *.

This is internal only for now and will be used in upcoming RSA related
changes.

Based on OpenSSL 1.1.1d.

ok inoguchi@ tb@

2 files changed, 18 insertions, 8 deletions

diff --git a/src/lib/libcrypto/evp/evp_locl.h b/src/lib/libcrypto/evp/evp_locl.h
index 0b1bea9583..8df6135493 100644
--- a/src/lib/libcrypto/evp/evp_locl.h
+++ b/src/lib/libcrypto/evp/evp_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: evp_locl.h,v 1.15 2018/11/24 11:16:44 tb Exp $ */
+/* $OpenBSD: evp_locl.h,v 1.16 2019/10/29 07:52:17 jsing Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2000.
  */
@@ -367,4 +367,6 @@ struct evp_aead_st {
             const unsigned char *ad, size_t ad_len);
 };
 
+int EVP_PKEY_CTX_md(EVP_PKEY_CTX *ctx, int optype, int cmd, const char *md_name);
+
 __END_HIDDEN_DECLS
diff --git a/src/lib/libcrypto/evp/pmeth_lib.c b/src/lib/libcrypto/evp/pmeth_lib.c
index 6b86a0ecfb..ea9b8fed0c 100644
--- a/src/lib/libcrypto/evp/pmeth_lib.c
+++ b/src/lib/libcrypto/evp/pmeth_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: pmeth_lib.c,v 1.14 2018/04/14 07:09:21 tb Exp $ */
+/* $OpenBSD: pmeth_lib.c,v 1.15 2019/10/29 07:52:17 jsing Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2006.
  */
@@ -438,17 +438,25 @@ EVP_PKEY_CTX_ctrl_str(EVP_PKEY_CTX *ctx, const char *name, const char *value)
                 return -2;
         }
         if (!strcmp(name, "digest")) {
-                const EVP_MD *md;
-                if (!value || !(md = EVP_get_digestbyname(value))) {
-                        EVPerror(EVP_R_INVALID_DIGEST);
-                        return 0;
-                }
-                return EVP_PKEY_CTX_set_signature_md(ctx, md);
+                return EVP_PKEY_CTX_md(ctx, EVP_PKEY_OP_TYPE_SIG,
+                    EVP_PKEY_CTRL_MD, value);
         }
         return ctx->pmeth->ctrl_str(ctx, name, value);
 }
 
 int
+EVP_PKEY_CTX_md(EVP_PKEY_CTX *ctx, int optype, int cmd, const char *md_name)
+{
+        const EVP_MD *md;
+
+        if ((md = EVP_get_digestbyname(md_name)) == NULL) {
+                EVPerror(EVP_R_INVALID_DIGEST);
+                return 0;
+        }
+        return EVP_PKEY_CTX_ctrl(ctx, -1, optype, cmd, 0, (void *)md);
+}
+
+int
 EVP_PKEY_CTX_get_operation(EVP_PKEY_CTX *ctx)
 {
         return ctx->operation;