Rework test failure printing

Make sure it's always printed to stderr. Use a wrapper for printing a
BIGNUM rather than repeating the same ugly pattern over and over again.

diff --git a/regress/lib/libcrypto/bn/bn_mod_exp.c b/regress/lib/libcrypto/bn/bn_mod_exp.c
index 3ba8dcf..6b32340 100644 (file)
--- a/regress/lib/libcrypto/bn/bn_mod_exp.c
+++ b/regress/lib/libcrypto/bn/bn_mod_exp.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: bn_mod_exp.c,v 1.33 2023/03/29 07:46:40 tb Exp $ */
+/*     $OpenBSD: bn_mod_exp.c,v 1.34 2023/03/29 10:36:14 tb Exp $ */
 
 /*
  * Copyright (c) 2022,2023 Theo Buehler <tb@openbsd.org>
@@ -16,8 +16,9 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-#include <stdio.h>
 #include <err.h>
+#include <stdio.h>
+#include <string.h>
 
 #include <openssl/bn.h>
 #include <openssl/err.h>
@@ -71,15 +72,29 @@ static const struct mod_exp_test {
 #define N_MOD_EXP_FN (sizeof(mod_exp_fn) / sizeof(mod_exp_fn[0]))
 
 static void
-print_failure(const BIGNUM *got, const BIGNUM *a, const char *name)
+bn_print(const char *name, const BIGNUM *bn)
 {
-       fprintf(stderr, "%s test failed for a = ", name);
-       BN_print_fp(stderr, a);
-       fprintf(stderr, "\nwant 0, got ");
-       BN_print_fp(stderr, got);
+       size_t len;
+       int pad = 0;
+
+       len = strlen(name);
+       if (len < 7)
+               pad = 6 - len;
+
+       fprintf(stderr, "%s: %*s", name, pad, "");
+       BN_print_fp(stderr, bn);
        fprintf(stderr, "\n");
 }
 
+static void
+print_zero_test_failure(const BIGNUM *got, const BIGNUM *a, const char *name)
+{
+       fprintf(stderr, "%s() zero test failed:\n", name);
+
+       bn_print("a", a);
+       bn_print("got", got);
+}
+
 static int
 bn_mod_exp_zero_test(const struct mod_exp_test *test, BN_CTX *ctx, int use_random)
 {
@@ -119,7 +134,7 @@ bn_mod_exp_zero_test(const struct mod_exp_test *test, BN_CTX *ctx, int use_rando
        }
 
        if (!BN_is_zero(got)) {
-               print_failure(got, a, test->name);
+               print_zero_test_failure(got, a, test->name);
                goto err;
        }
 
@@ -156,7 +171,7 @@ bn_mod_exp_zero_word_test(BN_CTX *ctx)
        }
 
        if (!BN_is_zero(got)) {
-               print_failure(got, one, name);
+               print_zero_test_failure(got, one, name);
                goto err;
        }
 
@@ -289,29 +304,22 @@ static void
 dump_results(const BIGNUM *a, const BIGNUM *p, const BIGNUM *b, const BIGNUM *q,
     const BIGNUM *m, const BIGNUM *want, const BIGNUM *got, const char *name)
 {
-       printf("BN_mod_exp_simple() and %s() disagree", name);
+       fprintf(stderr, "BN_mod_exp_simple() and %s() disagree:\n", name);
 
-       printf("\nwant: ");
-       BN_print_fp(stdout, want);
-       printf("\ngot:  ");
-       BN_print_fp(stdout, got);
+       bn_print("want", want);
+       bn_print("got", got);
 
-       printf("\na: ");
-       BN_print_fp(stdout, a);
-       printf("\np: ");
-       BN_print_fp(stdout, p);
+       bn_print("a", a);
+       bn_print("p", p);
 
        if (b != NULL) {
-               printf("\nb: ");
-               BN_print_fp(stdout, b);
-               printf("\nq: ");
-               BN_print_fp(stdout, q);
+               bn_print("b", b);
+               bn_print("q", q);
        }
 
-       printf("\nm: ");
-       BN_print_fp(stdout, m);
+       bn_print("m", m);
 
-       printf("\n\n");
+       fprintf(stderr, "\n");
 }
 
 static int