Extend EVP_PKEY_copy_parameters()

Make EVP_PKEY_copy_parameters() work if the destination has no type (e.g. if obtained from EVP_PKEY_new()) or the underlying key is NULL. This is useful where we want to copy the parameters from an existing key to a new key. Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
openssl · Dec 14, 2015 · 2986ecd · 2986ecd
1 parent d911097
commit 2986ecd
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Showing 4 changed files with 20 additions and 1 deletion.
diff --git a/crypto/dh/dh_ameth.c b/crypto/dh/dh_ameth.c
@@ -507,6 +507,11 @@ DH *DHparams_dup(DH *dh)
 
 static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 {
+    if (to->pkey.dh == NULL) {
+        to->pkey.dh = DH_new();
+        if (to->pkey.dh == NULL)
+            return 0;
+    }
     return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
                              from->ameth == &dhx_asn1_meth);
 }

diff --git a/crypto/dsa/dsa_ameth.c b/crypto/dsa/dsa_ameth.c
@@ -364,6 +364,12 @@ static int dsa_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 {
     BIGNUM *a;
 
+    if (to->pkey.dsa == NULL) {
+        to->pkey.dsa = DSA_new();
+        if (to->pkey.dsa == NULL)
+            return 0;
+    }
+
     if ((a = BN_dup(from->pkey.dsa->p)) == NULL)
         return 0;
     BN_free(to->pkey.dsa->p);

diff --git a/crypto/ec/ec_ameth.c b/crypto/ec/ec_ameth.c
@@ -402,6 +402,11 @@ static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
     EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec));
     if (group == NULL)
         return 0;
+    if (to->pkey.ec == NULL) {
+        to->pkey.ec = EC_KEY_new();
+        if (to->pkey.ec == NULL)
+            return 0;
+    }
     if (EC_KEY_set_group(to->pkey.ec, group) == 0)
         return 0;
     EC_GROUP_free(group);

diff --git a/crypto/evp/p_lib.c b/crypto/evp/p_lib.c
@@ -129,7 +129,10 @@ int EVP_PKEY_save_parameters(EVP_PKEY *pkey, int mode)
 
 int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 {
-    if (to->type != from->type) {
+    if (to->type == EVP_PKEY_NONE) {
+        if (EVP_PKEY_set_type(to, from->type) == 0)
+            return 0;
+    } else if (to->type != from->type) {
         EVPerr(EVP_F_EVP_PKEY_COPY_PARAMETERS, EVP_R_DIFFERENT_KEY_TYPES);
         goto err;
     }