Next pass of bn_prime.c cleanup

Garbage collect a few pointless variables and remove a loop that wasn't
really a loop. Simplify BN_CTX handling and drop some stupid comments.

ok jsing miod

1 files changed, 29 insertions, 39 deletions

diff --git a/src/lib/libcrypto/bn/bn_prime.c b/src/lib/libcrypto/bn/bn_prime.c
index ea0733b674..c3cf5b8986 100644
--- a/src/lib/libcrypto/bn/bn_prime.c
+++ b/src/lib/libcrypto/bn/bn_prime.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_prime.c,v 1.23 2022/11/09 02:01:13 tb Exp $ */
+/* $OpenBSD: bn_prime.c,v 1.24 2022/11/09 11:31:51 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -116,8 +116,6 @@
 
 #include "bn_lcl.h"
 
-#define LIBRESSL_HAS_BPSW
-
 /* NB: these functions have been "upgraded", the deprecated versions (which are
  * compatibility wrappers using these functions) are in bn_depr.c.
  * - Geoff
@@ -164,9 +162,9 @@ BN_generate_prime_ex(BIGNUM *ret, int bits, int safe, const BIGNUM *add,
 {
         BIGNUM *t;
         int found = 0;
-        int i, j, c1 = 0;
+        int loops = 0;
+        int j;
         BN_CTX *ctx;
-        int checks = 1;
 
         if (bits < 2 || (bits == 2 && safe)) {
                 /*
@@ -177,18 +175,13 @@ BN_generate_prime_ex(BIGNUM *ret, int bits, int safe, const BIGNUM *add,
                 return 0;
         }
 
-        ctx = BN_CTX_new();
-        if (ctx == NULL)
+        if ((ctx = BN_CTX_new()) == NULL)
                 goto err;
         BN_CTX_start(ctx);
         if ((t = BN_CTX_get(ctx)) == NULL)
                 goto err;
 
-#ifndef LIBRESSL_HAS_BPSW
-        checks = BN_prime_checks_for_size(bits);
-#endif
-
-loop:
+ loop:
         /* make a random number and set the top and bottom bits */
         if (add == NULL) {
                 if (!probable_prime(ret, bits))
@@ -202,16 +195,15 @@ loop:
                                 goto err;
                 }
         }
-        /* if (BN_mod_word(ret,(BN_ULONG)3) == 1) goto loop; */
-        if (!BN_GENCB_call(cb, 0, c1++))
-                /* aborted */
+
+        if (!BN_GENCB_call(cb, 0, loops++))
                 goto err;
 
         if (!safe) {
-                i = BN_is_prime_fasttest_ex(ret, checks, ctx, 0, cb);
-                if (i == -1)
+                j = BN_is_prime_fasttest_ex(ret, 1, ctx, 0, cb);
+                if (j == -1)
                         goto err;
-                if (i == 0)
+                if (j == 0)
                         goto loop;
         } else {
                 /* for "safe prime" generation,
@@ -221,33 +213,31 @@ loop:
                 if (!BN_rshift1(t, ret))
                         goto err;
 
-                for (i = 0; i < checks; i++) {
-                        j = BN_is_prime_fasttest_ex(ret, 1, ctx, 0, cb);
-                        if (j == -1)
-                                goto err;
-                        if (j == 0)
-                                goto loop;
+                j = BN_is_prime_fasttest_ex(ret, 1, ctx, 0, cb);
+                if (j == -1)
+                        goto err;
+                if (j == 0)
+                        goto loop;
 
-                        j = BN_is_prime_fasttest_ex(t, 1, ctx, 0, cb);
-                        if (j == -1)
-                                goto err;
-                        if (j == 0)
-                                goto loop;
+                j = BN_is_prime_fasttest_ex(t, 1, ctx, 0, cb);
+                if (j == -1)
+                        goto err;
+                if (j == 0)
+                        goto loop;
 
-                        if (!BN_GENCB_call(cb, 2, c1 - 1))
-                                goto err;
-                        /* We have a safe prime test pass */
-                }
+                if (!BN_GENCB_call(cb, 2, loops - 1))
+                        goto err;
+
+                /* We have a safe prime test pass */
         }
-        /* we have a prime :-) */
+
         found = 1;
 
-err:
-        if (ctx != NULL) {
-                BN_CTX_end(ctx);
-                BN_CTX_free(ctx);
-        }
+ err:
+        BN_CTX_end(ctx);
+        BN_CTX_free(ctx);
         bn_check_top(ret);
+
         return found;
 }