Remove BIGNUM consistency macros.

Compiling with BN_DEBUG (and if you want to take it further, BN_DEBUG_RAND)
supposedly adds consistency checks to the BN code. These are rarely if ever
used and introduce a bunch of clutter in the code. Furthermore, there are
hacks in place to undo things that the debugging code does.

Remove all of this mess and instead rely on always enabled checks, more
readable code and proper regress coverage to ensure correct behaviour.

"Good riddance." tb@

1 files changed, 1 insertions, 18 deletions

diff --git a/src/lib/libcrypto/bn/bn_exp.c b/src/lib/libcrypto/bn/bn_exp.c
index 64156f716f..3bb0dd1304 100644
--- a/src/lib/libcrypto/bn/bn_exp.c
+++ b/src/lib/libcrypto/bn/bn_exp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_exp.c,v 1.33 2022/11/24 01:30:01 jsing Exp $ */
+/* $OpenBSD: bn_exp.c,v 1.34 2022/11/26 13:56:33 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -168,7 +168,6 @@ err:
         if (r != rr && rr != NULL)
                 BN_copy(r, rr);
         BN_CTX_end(ctx);
-        bn_check_top(r);
         return (ret);
 }
 
@@ -178,9 +177,6 @@ BN_mod_exp_internal(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m
 {
         int ret;
 
-        bn_check_top(a);
-        bn_check_top(p);
-        bn_check_top(m);
 
         /* For even modulus  m = 2^k*m_odd,  it might make sense to compute
          * a^p mod m_odd  and  a^p mod 2^k  separately (with Montgomery
@@ -222,7 +218,6 @@ BN_mod_exp_internal(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m
                 ret = BN_mod_exp_recp(r, a,p, m, ctx);
         }
 
-        bn_check_top(r);
         return (ret);
 }
 
@@ -381,7 +376,6 @@ BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m,
 err:
         BN_CTX_end(ctx);
         BN_RECP_CTX_free(&recp);
-        bn_check_top(r);
         return (ret);
 }
 
@@ -401,9 +395,6 @@ BN_mod_exp_mont_internal(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p, const BIG
                 return BN_mod_exp_mont_consttime(rr, a, p, m, ctx, in_mont);
         }
 
-        bn_check_top(a);
-        bn_check_top(p);
-        bn_check_top(m);
 
         if (!BN_is_odd(m)) {
                 BNerror(BN_R_CALLED_WITH_EVEN_MODULUS);
@@ -533,7 +524,6 @@ err:
         if ((in_mont == NULL) && (mont != NULL))
                 BN_MONT_CTX_free(mont);
         BN_CTX_end(ctx);
-        bn_check_top(rr);
         return (ret);
 }
 
@@ -658,9 +648,6 @@ BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
         unsigned char *powerbuf = NULL;
         BIGNUM tmp, am;
 
-        bn_check_top(a);
-        bn_check_top(p);
-        bn_check_top(m);
 
         if (!BN_is_odd(m)) {
                 BNerror(BN_R_CALLED_WITH_EVEN_MODULUS);
@@ -937,8 +924,6 @@ BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p, const BIGNUM *m,
                 return -1;
         }
 
-        bn_check_top(p);
-        bn_check_top(m);
 
         if (!BN_is_odd(m)) {
                 BNerror(BN_R_CALLED_WITH_EVEN_MODULUS);
@@ -1052,7 +1037,6 @@ err:
         if ((in_mont == NULL) && (mont != NULL))
                 BN_MONT_CTX_free(mont);
         BN_CTX_end(ctx);
-        bn_check_top(rr);
         return (ret);
 }
 
@@ -1172,6 +1156,5 @@ BN_mod_exp_simple(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m,
 
 err:
         BN_CTX_end(ctx);
-        bn_check_top(r);
         return (ret);
 }