Fix DH_get_nid() so that it does not cache values.

[openssl.git] / crypto / dh / dh_key.c

diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c
index 5748be810f7261985238e54439fab0bd8423cfa2..918949d95365acb7980f88542a972c19b4addaee 100644 (file)
--- a/crypto/dh/dh_key.c
+++ b/crypto/dh/dh_key.c
@@ -18,6 +18,13 @@
 #include "dh_local.h"
 #include "crypto/bn.h"
 #include "crypto/dh.h"
+#include "crypto/security_bits.h"
+
+#ifdef FIPS_MODE
+# define MIN_STRENGTH 112
+#else
+# define MIN_STRENGTH 80
+#endif
 
 static int generate_key(DH *dh);
 static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
@@ -246,17 +253,15 @@ static int generate_key(DH *dh)
     if (generate_new_key) {
         /* Is it an approved safe prime ?*/
         if (DH_get_nid(dh) != NID_undef) {
-            /*
-             * The safe prime group code sets N = 2*s
-             * (where s = max security strength supported).
-             * N = dh->length (N = maximum bit length of private key)
-             */
-            if (dh->length == 0
-                || dh->params.q == NULL
+            int max_strength =
+                    ifc_ffc_compute_security_bits(BN_num_bits(dh->params.p));
+
+            if (dh->params.q == NULL
                 || dh->length > BN_num_bits(dh->params.q))
                 goto err;
+            /* dh->length = maximum bit length of generated private key */
             if (!ffc_generate_private_key(ctx, &dh->params, dh->length,
-                                          dh->length / 2, priv_key))
+                                          max_strength, priv_key))
                 goto err;
         } else {
 #ifdef FIPS_MODE
@@ -288,7 +293,8 @@ static int generate_key(DH *dh)
                  * Max Private key size N = len(q)
                  */
                 if (!ffc_generate_private_key(ctx, &dh->params,
-                                              BN_num_bits(dh->params.q), 112,
+                                              BN_num_bits(dh->params.q),
+                                              MIN_STRENGTH,
                                               priv_key))
                     goto err;
             }