Make DH_METHOD opaque

Move the dh_method structure into an internal header file and provide
relevant accessors for the internal fields.

Reviewed-by: Richard Levitte <levitte@openssl.org>

crypto/dh/Makefile.in

@@ -16,9 +16,9 @@ GENERAL=Makefile
 
 LIB=$(TOP)/libcrypto.a
 LIBSRC= dh_asn1.c dh_gen.c dh_key.c dh_lib.c dh_check.c dh_err.c dh_depr.c \
-	dh_ameth.c dh_pmeth.c dh_prn.c dh_rfc5114.c dh_kdf.c
+	dh_ameth.c dh_pmeth.c dh_prn.c dh_rfc5114.c dh_kdf.c dh_meth.c
 LIBOBJ= dh_asn1.o dh_gen.o dh_key.o dh_lib.o dh_check.o dh_err.o dh_depr.o \
-	dh_ameth.o dh_pmeth.o dh_prn.o dh_rfc5114.o dh_kdf.o
+	dh_ameth.o dh_pmeth.o dh_prn.o dh_rfc5114.o dh_kdf.o dh_meth.o
 
 SRC= $(LIBSRC)
 

crypto/dh/build.info

@@ -1,4 +1,4 @@
 LIBS=../../libcrypto
 SOURCE[../../libcrypto]=\
         dh_asn1.c dh_gen.c dh_key.c dh_lib.c dh_check.c dh_err.c dh_depr.c \
-        dh_ameth.c dh_pmeth.c dh_prn.c dh_rfc5114.c dh_kdf.c
+        dh_ameth.c dh_pmeth.c dh_prn.c dh_rfc5114.c dh_kdf.c dh_meth.c

crypto/dh/dh_locl.h

@@ -36,3 +36,21 @@ struct dh_st {
     ENGINE *engine;
     CRYPTO_RWLOCK *lock;
 };
+
+struct dh_method {
+    char *name;
+    /* Methods here */
+    int (*generate_key) (DH *dh);
+    int (*compute_key) (unsigned char *key, const BIGNUM *pub_key, DH *dh);
+    /* Can be null */
+    int (*bn_mod_exp) (const DH *dh, BIGNUM *r, const BIGNUM *a,
+                       const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
+                       BN_MONT_CTX *m_ctx);
+    int (*init) (DH *dh);
+    int (*finish) (DH *dh);
+    int flags;
+    char *app_data;
+    /* If this is non-NULL, it will be used to generate parameters */
+    int (*generate_params) (DH *dh, int prime_len, int generator,
+                            BN_GENCB *cb);
+};

crypto/dh/dh_meth.c

@@ -0,0 +1,158 @@
+/*
+ * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL licenses, (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * https://www.openssl.org/source/license.html
+ * or in the file LICENSE in the source distribution.
+ */
+
+
+#include "dh_locl.h"
+#include <string.h>
+
+DH_METHOD *DH_meth_new(const char *name, int flags)
+{
+    DH_METHOD *dhm = OPENSSL_zalloc(sizeof(DH_METHOD));
+
+    if (dhm != NULL) {
+        dhm->name = OPENSSL_strdup(name);
+        dhm->flags = flags;
+    }
+
+    return dhm;
+}
+
+void DH_meth_free(DH_METHOD *dhm)
+{
+    if (dhm != NULL) {
+        if (dhm->name != NULL)
+            OPENSSL_free(dhm->name);
+        OPENSSL_free(dhm);
+    }
+}
+
+DH_METHOD *DH_meth_dup(const DH_METHOD *dhm)
+{
+    DH_METHOD *ret;
+
+    ret = OPENSSL_malloc(sizeof(DH_METHOD));
+
+    if (ret != NULL) {
+        memcpy(ret, dhm, sizeof(*dhm));
+        ret->name = OPENSSL_strdup(dhm->name);
+    }
+
+    return ret;
+}
+
+const char *DH_meth_get0_name(const DH_METHOD *dhm)
+{
+    return dhm->name;
+}
+
+int DH_meth_set1_name(DH_METHOD *dhm, const char *name)
+{
+    OPENSSL_free(dhm->name);
+    dhm->name = OPENSSL_strdup(name);
+
+    return dhm->name != NULL;
+}
+
+int DH_meth_get_flags(DH_METHOD *dhm)
+{
+    return dhm->flags;
+}
+
+int DH_meth_set_flags(DH_METHOD *dhm, int flags)
+{
+    dhm->flags = flags;
+    return 1;
+}
+
+void *DH_meth_get0_app_data(const DH_METHOD *dhm)
+{
+    return dhm->app_data;
+}
+
+int DH_meth_set0_app_data(DH_METHOD *dhm, void *app_data)
+{
+    dhm->app_data = app_data;
+    return 1;
+}
+
+int (*DH_meth_get_generate_key(const DH_METHOD *dhm)) (DH *)
+{
+    return dhm->generate_key;
+}
+
+int DH_meth_set_generate_key(DH_METHOD *dhm, int (*generate_key) (DH *))
+{
+    dhm->generate_key = generate_key;
+    return 1;
+}
+
+int (*DH_meth_get_compute_key(const DH_METHOD *dhm))
+        (unsigned char *key, const BIGNUM *pub_key, DH *dh)
+{
+    return dhm->compute_key;
+}
+
+int DH_meth_set_compute_key(DH_METHOD *dhm,
+        int (*compute_key) (unsigned char *key, const BIGNUM *pub_key, DH *dh))
+{
+    dhm->compute_key = compute_key;
+    return 1;
+}
+
+
+int (*DH_meth_get_bn_mod_exp(const DH_METHOD *dhm))
+    (const DH *, BIGNUM *, const BIGNUM *, const BIGNUM *, const BIGNUM *,
+     BN_CTX *, BN_MONT_CTX *)
+{
+    return dhm->bn_mod_exp;
+}
+
+int DH_meth_set_bn_mod_exp(DH_METHOD *dhm,
+    int (*bn_mod_exp) (const DH *, BIGNUM *, const BIGNUM *, const BIGNUM *,
+                       const BIGNUM *, BN_CTX *, BN_MONT_CTX *))
+{
+    dhm->bn_mod_exp = bn_mod_exp;
+    return 1;
+}
+
+int (*DH_meth_get_init(const DH_METHOD *dhm))(DH *)
+{
+    return dhm->init;
+}
+
+int DH_meth_set_init(DH_METHOD *dhm, int (*init)(DH *))
+{
+    dhm->init = init;
+    return 1;
+}
+
+int (*DH_meth_get_finish(const DH_METHOD *dhm)) (DH *)
+{
+    return dhm->finish;
+}
+
+int DH_meth_set_finish(DH_METHOD *dhm, int (*finish) (DH *))
+{
+    dhm->finish = finish;
+    return 1;
+}
+
+int (*DH_meth_get_generate_params(const DH_METHOD *dhm))
+        (DH *, int, int, BN_GENCB *)
+{
+    return dhm->generate_params;
+}
+
+int DH_meth_set_generate_params(DH_METHOD *dhm,
+        int (*generate_params) (DH *, int, int, BN_GENCB *))
+{
+    dhm->generate_params = generate_params;
+    return 1;
+}

include/openssl/dh.h

@@ -103,24 +103,6 @@ extern "C" {
 /* typedef struct dh_st DH; */
 /* typedef struct dh_method DH_METHOD; */
 
-struct dh_method {
-    const char *name;
-    /* Methods here */
-    int (*generate_key) (DH *dh);
-    int (*compute_key) (unsigned char *key, const BIGNUM *pub_key, DH *dh);
-    /* Can be null */
-    int (*bn_mod_exp) (const DH *dh, BIGNUM *r, const BIGNUM *a,
-                       const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
-                       BN_MONT_CTX *m_ctx);
-    int (*init) (DH *dh);
-    int (*finish) (DH *dh);
-    int flags;
-    char *app_data;
-    /* If this is non-NULL, it will be used to generate parameters */
-    int (*generate_params) (DH *dh, int prime_len, int generator,
-                            BN_GENCB *cb);
-};
-
 DECLARE_ASN1_ITEM(DHparams)
 
 # define DH_GENERATOR_2          2
@@ -222,6 +204,36 @@ ENGINE *DH_get0_engine(DH *d);
 long DH_get_length(const DH *dh);
 int DH_set_length(DH *dh, long length);
 
+DH_METHOD *DH_meth_new(const char *name, int flags);
+void DH_meth_free(DH_METHOD *dhm);
+DH_METHOD *DH_meth_dup(const DH_METHOD *dhm);
+const char *DH_meth_get0_name(const DH_METHOD *dhm);
+int DH_meth_set1_name(DH_METHOD *dhm, const char *name);
+int DH_meth_get_flags(DH_METHOD *dhm);
+int DH_meth_set_flags(DH_METHOD *dhm, int flags);
+void *DH_meth_get0_app_data(const DH_METHOD *dhm);
+int DH_meth_set0_app_data(DH_METHOD *dhm, void *app_data);
+int (*DH_meth_get_generate_key(const DH_METHOD *dhm)) (DH *);
+int DH_meth_set_generate_key(DH_METHOD *dhm, int (*generate_key) (DH *));
+int (*DH_meth_get_compute_key(const DH_METHOD *dhm))
+        (unsigned char *key, const BIGNUM *pub_key, DH *dh);
+int DH_meth_set_compute_key(DH_METHOD *dhm,
+        int (*compute_key) (unsigned char *key, const BIGNUM *pub_key, DH *dh));
+int (*DH_meth_get_bn_mod_exp(const DH_METHOD *dhm))
+    (const DH *, BIGNUM *, const BIGNUM *, const BIGNUM *, const BIGNUM *,
+     BN_CTX *, BN_MONT_CTX *);
+int DH_meth_set_bn_mod_exp(DH_METHOD *dhm,
+    int (*bn_mod_exp) (const DH *, BIGNUM *, const BIGNUM *, const BIGNUM *,
+                       const BIGNUM *, BN_CTX *, BN_MONT_CTX *));
+int (*DH_meth_get_init(const DH_METHOD *dhm))(DH *);
+int DH_meth_set_init(DH_METHOD *dhm, int (*init)(DH *));
+int (*DH_meth_get_finish(const DH_METHOD *dhm)) (DH *);
+int DH_meth_set_finish(DH_METHOD *dhm, int (*finish) (DH *));
+int (*DH_meth_get_generate_params(const DH_METHOD *dhm))
+        (DH *, int, int, BN_GENCB *);
+int DH_meth_set_generate_params(DH_METHOD *dhm,
+        int (*generate_params) (DH *, int, int, BN_GENCB *));
+
 
 # define EVP_PKEY_CTX_set_dh_paramgen_prime_len(ctx, len) \
         EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DH, EVP_PKEY_OP_PARAMGEN, \