Pull up the code that converts the digest to a BIGNUM - this only needs

to occur once and not be repeated if the signature generation has to be
repeated.

ok tb@

1 files changed, 10 insertions, 10 deletions

diff --git a/src/lib/libcrypto/dsa/dsa_ossl.c b/src/lib/libcrypto/dsa/dsa_ossl.c
index d864875266..9545cff5f8 100644
--- a/src/lib/libcrypto/dsa/dsa_ossl.c
+++ b/src/lib/libcrypto/dsa/dsa_ossl.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsa_ossl.c,v 1.34 2018/06/14 17:14:12 jsing Exp $ */
+/* $OpenBSD: dsa_ossl.c,v 1.35 2018/06/14 17:15:41 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -117,6 +117,15 @@ dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
         if (ctx == NULL)
                 goto err;
 
+        /*
+         * If the digest length is greater than the size of q use the
+         * BN_num_bits(dsa->q) leftmost bits of the digest, see FIPS 186-3, 4.2.
+         */
+        if (dlen > BN_num_bytes(dsa->q))
+                dlen = BN_num_bytes(dsa->q);
+        if (BN_bin2bn(dgst, dlen, &m) == NULL)
+                goto err;
+
  redo:
         if (dsa->kinv == NULL || dsa->r == NULL) {
                 if (!DSA_sign_setup(dsa, ctx, &kinv, &r))
@@ -129,15 +138,6 @@ dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
                 noredo = 1;
         }
 
-        /*
-         * If the digest length is greater than the size of q use the
-         * BN_num_bits(dsa->q) leftmost bits of the digest, see FIPS 186-3, 4.2.
-         */
-        if (dlen > BN_num_bytes(dsa->q))
-                dlen = BN_num_bytes(dsa->q);
-        if (BN_bin2bn(dgst,dlen,&m) == NULL)
-                goto err;
-
         /* Compute  s = inv(k) (m + xr) mod q */
         if (!BN_mod_mul(&xr, dsa->priv_key, r, dsa->q, ctx))    /* s = xr */
                 goto err;