Support constant BN for DH parameters

[thirdparty/openssl.git] / crypto / dh / dh_ameth.c

diff --git a/crypto/dh/dh_ameth.c b/crypto/dh/dh_ameth.c
index cd77867dee9f7cdfab49054415f1f96f56e623dc..abf68aa25d8a86cdda96969aa5d0203d0a4575a2 100644 (file)
--- a/crypto/dh/dh_ameth.c
+++ b/crypto/dh/dh_ameth.c
@@ -374,13 +374,19 @@ static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
 {
     BIGNUM *a;
-    if (src) {
-        a = BN_dup(src);
-        if (!a)
-            return 0;
-    } else
+
+    /*
+     * If source is read only just copy the pointer, so
+     * we don't have to reallocate it.
+     */
+    if (src == NULL)
         a = NULL;
-    BN_free(*dst);
+    else if (BN_get_flags(src, BN_FLG_STATIC_DATA)
+                && !BN_get_flags(src, BN_FLG_MALLOCED))
+        a = (BIGNUM *)src;
+    else if ((a = BN_dup(src)) == NULL)
+        return 0;
+    BN_clear_free(*dst);
     *dst = a;
     return 1;
 }