Fix bn_test's bc output and shut it up a little.

bn_test's output is meant to be piped to bc, but this got broken somewhat:

- OpenSSL uses uppercase hex rather than BoringSSL's lowercase. bc only accepts
  uppercase. Document that this needs some shell pipeline until we replace
  them with better tests because this is all ridiculous.

- Some stderr outputs moved to stdout to avoid cluttering stdout. Just remove
  them. The operations are fast enough to not need progress.

- To cut down on noise, only write the bc transcript given a command-line flag.
  Also remove the -results flag since it's pointless. (It writes only the
  results and not the inputs.)

Change-Id: I08f87cac1e03fab461f0dc40b9d4285bd877807d
Reviewed-on: https://boringssl-review.googlesource.com/4896
Reviewed-by: Adam Langley <agl@google.com>

1 files changed, 207 insertions, 248 deletions

diff --git a/crypto/bn/bn_test.cc b/crypto/bn/bn_test.cc
index 6dd87ecd..6a7d48c4 100644
--- a/crypto/bn/bn_test.cc
+++ b/crypto/bn/bn_test.cc
@@ -72,6 +72,7 @@
 #define __STDC_FORMAT_MACROS
 #endif
 
+#include <errno.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -83,6 +84,12 @@
 #include "../crypto/test/scoped_types.h"
 
 
+// This program tests the BIGNUM implementation. It takes an optional -bc
+// argument to write a transcript compatible with the UNIX bc utility.
+//
+// TODO(davidben): Rather than generate random inputs and depend on bc to check
+// the results, most of these tests should use known answers.
+
 static const int num0 = 100; // number of tests
 static const int num1 = 50;  // additional tests for some functions
 static const int num2 = 5;   // number of tests for slow functions
@@ -116,10 +123,6 @@ static bool test_hex2bn(FILE *fp, BN_CTX *ctx);
 static bool test_asc2bn(FILE *fp, BN_CTX *ctx);
 static bool test_rand();
 
-// g_results can be set to true to cause the result of each computation to be
-// printed.
-static bool g_results = false;
-
 static const uint8_t kSample[] =
     "\xC6\x4F\x43\x04\x2A\xEA\xCA\x6E\x58\x36\x80\x5B\xE8\xC9"
     "\x9B\x04\x5D\x48\x36\xC2\xFD\x16\xC9\x64\xF0";
@@ -127,7 +130,15 @@ static const uint8_t kSample[] =
 // A wrapper around puts that takes its arguments in the same order as our *_fp
 // functions.
 static void puts_fp(FILE *out, const char *m) {
-  fputs(m, out);
+  if (out != nullptr) {
+    fputs(m, out);
+  }
+}
+
+static void flush_fp(FILE *out) {
+  if (out != nullptr) {
+    fflush(out);
+  }
 }
 
 static void message(FILE *out, const char *m) {
@@ -139,11 +150,24 @@ static void message(FILE *out, const char *m) {
 int main(int argc, char *argv[]) {
   CRYPTO_library_init();
 
+  ScopedFILE bc_file;
   argc--;
   argv++;
   while (argc >= 1) {
-    if (strcmp(*argv, "-results") == 0) {
-      g_results = true;
+    if (strcmp(*argv, "-bc") == 0) {
+      if (argc < 2) {
+        fprintf(stderr, "Missing parameter to -bc\n");
+        return 1;
+      }
+      bc_file.reset(fopen(argv[1], "w+"));
+      if (!bc_file) {
+        fprintf(stderr, "Failed to open %s: %s\n", argv[1], strerror(errno));
+      }
+      argc--;
+      argv++;
+    } else {
+      fprintf(stderr, "Unknown option: %s\n", argv[0]);
+      return 1;
     }
     argc--;
     argv++;
@@ -155,165 +179,167 @@ int main(int argc, char *argv[]) {
     return 1;
   }
 
-  if (!g_results) {
-    puts_fp(stdout, "obase=16\nibase=16\n");
-  }
+  puts_fp(bc_file.get(), "/* This script, when run through the UNIX bc utility, "
+                         "should produce a sequence of zeros. */\n");
+  puts_fp(bc_file.get(), "/* tr a-f A-F < bn_test.out | sed s/BAsE/base/ | bc "
+                         "| grep -v 0 */\n");
+  puts_fp(bc_file.get(), "obase=16\nibase=16\n");
 
-  message(stdout, "BN_add");
-  if (!test_add(stdout)) {
+  message(bc_file.get(), "BN_add");
+  if (!test_add(bc_file.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_sub");
-  if (!test_sub(stdout)) {
+  message(bc_file.get(), "BN_sub");
+  if (!test_sub(bc_file.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_lshift1");
-  if (!test_lshift1(stdout)) {
+  message(bc_file.get(), "BN_lshift1");
+  if (!test_lshift1(bc_file.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_lshift (fixed)");
+  message(bc_file.get(), "BN_lshift (fixed)");
   ScopedBIGNUM sample(BN_bin2bn(kSample, sizeof(kSample) - 1, NULL));
   if (!sample) {
     return 1;
   }
-  if (!test_lshift(stdout, ctx.get(), bssl::move(sample))) {
+  if (!test_lshift(bc_file.get(), ctx.get(), bssl::move(sample))) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_lshift");
-  if (!test_lshift(stdout, ctx.get(), nullptr)) {
+  message(bc_file.get(), "BN_lshift");
+  if (!test_lshift(bc_file.get(), ctx.get(), nullptr)) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_rshift1");
-  if (!test_rshift1(stdout)) {
+  message(bc_file.get(), "BN_rshift1");
+  if (!test_rshift1(bc_file.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_rshift");
-  if (!test_rshift(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_rshift");
+  if (!test_rshift(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_sqr");
-  if (!test_sqr(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_sqr");
+  if (!test_sqr(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_mul");
-  if (!test_mul(stdout)) {
+  message(bc_file.get(), "BN_mul");
+  if (!test_mul(bc_file.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_div");
-  if (!test_div(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_div");
+  if (!test_div(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_div_word");
-  if (!test_div_word(stdout)) {
+  message(bc_file.get(), "BN_div_word");
+  if (!test_div_word(bc_file.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_mod");
-  if (!test_mod(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_mod");
+  if (!test_mod(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_mod_mul");
-  if (!test_mod_mul(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_mod_mul");
+  if (!test_mod_mul(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_mont");
-  if (!test_mont(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_mont");
+  if (!test_mont(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_mod_exp");
-  if (!test_mod_exp(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_mod_exp");
+  if (!test_mod_exp(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_mod_exp_mont_consttime");
-  if (!test_mod_exp_mont_consttime(stdout, ctx.get()) ||
-      !test_mod_exp_mont5(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_mod_exp_mont_consttime");
+  if (!test_mod_exp_mont_consttime(bc_file.get(), ctx.get()) ||
+      !test_mod_exp_mont5(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_exp");
-  if (!test_exp(stdout, ctx.get()) ||
+  message(bc_file.get(), "BN_exp");
+  if (!test_exp(bc_file.get(), ctx.get()) ||
       !test_exp_mod_zero()) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_mod_sqrt");
-  if (!test_mod_sqrt(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_mod_sqrt");
+  if (!test_mod_sqrt(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "Small prime generation");
-  if (!test_small_prime(stdout, ctx.get())) {
+  message(bc_file.get(), "Small prime generation");
+  if (!test_small_prime(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_sqrt");
-  if (!test_sqrt(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_sqrt");
+  if (!test_sqrt(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_bn2bin_padded");
-  if (!test_bn2bin_padded(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_bn2bin_padded");
+  if (!test_bn2bin_padded(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_dec2bn");
-  if (!test_dec2bn(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_dec2bn");
+  if (!test_dec2bn(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_hex2bn");
-  if (!test_hex2bn(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_hex2bn");
+  if (!test_hex2bn(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_asc2bn");
-  if (!test_asc2bn(stdout, ctx.get())) {
+  message(bc_file.get(), "BN_asc2bn");
+  if (!test_asc2bn(bc_file.get(), ctx.get())) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
-  message(stdout, "BN_rand");
+  message(bc_file.get(), "BN_rand");
   if (!test_rand()) {
     return 1;
   }
-  fflush(stdout);
+  flush_fp(bc_file.get());
 
   printf("PASS\n");
   return 0;
@@ -337,12 +363,10 @@ static bool test_add(FILE *fp) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " + ");
-        BN_print_fp(fp, b.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " + ");
+      BN_print_fp(fp, b.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, c.get());
       puts_fp(fp, "\n");
     }
@@ -387,12 +411,10 @@ static bool test_sub(FILE *fp) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " - ");
-        BN_print_fp(fp, b.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " - ");
+      BN_print_fp(fp, b.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, c.get());
       puts_fp(fp, "\n");
     }
@@ -435,21 +457,17 @@ static bool test_div(FILE *fp, BN_CTX *ctx) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " / ");
-        BN_print_fp(fp, b.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " / ");
+      BN_print_fp(fp, b.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, d.get());
       puts_fp(fp, "\n");
 
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " % ");
-        BN_print_fp(fp, b.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " % ");
+      BN_print_fp(fp, b.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, c.get());
       puts_fp(fp, "\n");
     }
@@ -506,11 +524,9 @@ static bool test_lshift1(FILE *fp) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " * 2");
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " * 2");
+      puts_fp(fp, " - ");
       BN_print_fp(fp, b.get());
       puts_fp(fp, "\n");
     }
@@ -547,12 +563,10 @@ static bool test_rshift(FILE *fp, BN_CTX *ctx) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " / ");
-        BN_print_fp(fp, c.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " / ");
+      BN_print_fp(fp, c.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, b.get());
       puts_fp(fp, "\n");
     }
@@ -582,11 +596,9 @@ static bool test_rshift1(FILE *fp) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " / 2");
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " / 2");
+      puts_fp(fp, " - ");
       BN_print_fp(fp, b.get());
       puts_fp(fp, "\n");
     }
@@ -627,12 +639,10 @@ static bool test_lshift(FILE *fp, BN_CTX *ctx, ScopedBIGNUM a) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " * ");
-        BN_print_fp(fp, c.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " * ");
+      BN_print_fp(fp, c.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, b.get());
       puts_fp(fp, "\n");
     }
@@ -683,12 +693,10 @@ static bool test_mul(FILE *fp) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " * ");
-        BN_print_fp(fp, b.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " * ");
+      BN_print_fp(fp, b.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, c.get());
       puts_fp(fp, "\n");
     }
@@ -737,12 +745,10 @@ static bool test_sqr(FILE *fp, BN_CTX *ctx) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " * ");
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " * ");
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, c.get());
       puts_fp(fp, "\n");
     }
@@ -765,12 +771,10 @@ static bool test_sqr(FILE *fp, BN_CTX *ctx) {
     return false;
   }
   if (fp != NULL) {
-    if (!g_results) {
-      BN_print_fp(fp, a.get());
-      puts_fp(fp, " * ");
-      BN_print_fp(fp, a.get());
-      puts_fp(fp, " - ");
-    }
+    BN_print_fp(fp, a.get());
+    puts_fp(fp, " * ");
+    BN_print_fp(fp, a.get());
+    puts_fp(fp, " - ");
     BN_print_fp(fp, c.get());
     puts_fp(fp, "\n");
   }
@@ -793,12 +797,10 @@ static bool test_sqr(FILE *fp, BN_CTX *ctx) {
     return false;
   }
   if (fp != NULL) {
-    if (!g_results) {
-      BN_print_fp(fp, a.get());
-      puts_fp(fp, " * ");
-      BN_print_fp(fp, a.get());
-      puts_fp(fp, " - ");
-    }
+    BN_print_fp(fp, a.get());
+    puts_fp(fp, " * ");
+    BN_print_fp(fp, a.get());
+    puts_fp(fp, " - ");
     BN_print_fp(fp, c.get());
     puts_fp(fp, "\n");
   }
@@ -853,21 +855,17 @@ static bool test_div_word(FILE *fp) {
     }
 
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " / ");
-        print_word(fp, s);
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " / ");
+      print_word(fp, s);
+      puts_fp(fp, " - ");
       BN_print_fp(fp, b.get());
       puts_fp(fp, "\n");
 
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " % ");
-        print_word(fp, s);
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " % ");
+      print_word(fp, s);
+      puts_fp(fp, " - ");
       print_word(fp, r);
       puts_fp(fp, "\n");
     }
@@ -916,14 +914,12 @@ static bool test_mont(FILE *fp, BN_CTX *ctx) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " * ");
-        BN_print_fp(fp, b.get());
-        puts_fp(fp, " % ");
-        BN_print_fp(fp, &mont->N);
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " * ");
+      BN_print_fp(fp, b.get());
+      puts_fp(fp, " % ");
+      BN_print_fp(fp, &mont->N);
+      puts_fp(fp, " - ");
       BN_print_fp(fp, A.get());
       puts_fp(fp, "\n");
     }
@@ -960,12 +956,10 @@ static bool test_mod(FILE *fp, BN_CTX *ctx) {
       return false;
     }
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " % ");
-        BN_print_fp(fp, b.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " % ");
+      BN_print_fp(fp, b.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, c.get());
       puts_fp(fp, "\n");
     }
@@ -1007,22 +1001,20 @@ static bool test_mod_mul(FILE *fp, BN_CTX *ctx) {
         return false;
       }
       if (fp != NULL) {
-        if (!g_results) {
-          BN_print_fp(fp, a.get());
-          puts_fp(fp, " * ");
-          BN_print_fp(fp, b.get());
-          puts_fp(fp, " % ");
+        BN_print_fp(fp, a.get());
+        puts_fp(fp, " * ");
+        BN_print_fp(fp, b.get());
+        puts_fp(fp, " % ");
+        BN_print_fp(fp, c.get());
+        if (a->neg != b->neg && !BN_is_zero(e.get())) {
+          // If  (a*b) % c  is negative,  c  must be added
+          // in order to obtain the normalized remainder
+          // (new with OpenSSL 0.9.7, previous versions of
+          // BN_mod_mul could generate negative results)
+          puts_fp(fp, " + ");
           BN_print_fp(fp, c.get());
-          if (a->neg != b->neg && !BN_is_zero(e.get())) {
-            // If  (a*b) % c  is negative,  c  must be added
-            // in order to obtain the normalized remainder
-            // (new with OpenSSL 0.9.7, previous versions of
-            // BN_mod_mul could generate negative results)
-            puts_fp(fp, " + ");
-            BN_print_fp(fp, c.get());
-          }
-          puts_fp(fp, " - ");
         }
+        puts_fp(fp, " - ");
         BN_print_fp(fp, e.get());
         puts_fp(fp, "\n");
       }
@@ -1059,14 +1051,12 @@ static bool test_mod_exp(FILE *fp, BN_CTX *ctx) {
     }
 
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " ^ ");
-        BN_print_fp(fp, b.get());
-        puts_fp(fp, " % ");
-        BN_print_fp(fp, c.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " ^ ");
+      BN_print_fp(fp, b.get());
+      puts_fp(fp, " % ");
+      BN_print_fp(fp, c.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, d.get());
       puts_fp(fp, "\n");
     }
@@ -1102,14 +1092,12 @@ static bool test_mod_exp_mont_consttime(FILE *fp, BN_CTX *ctx) {
     }
 
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " ^ ");
-        BN_print_fp(fp, b.get());
-        puts_fp(fp, " % ");
-        BN_print_fp(fp, c.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " ^ ");
+      BN_print_fp(fp, b.get());
+      puts_fp(fp, " % ");
+      BN_print_fp(fp, c.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, d.get());
       puts_fp(fp, "\n");
     }
@@ -1210,12 +1198,10 @@ static bool test_exp(FILE *fp, BN_CTX *ctx) {
     }
 
     if (fp != NULL) {
-      if (!g_results) {
-        BN_print_fp(fp, a.get());
-        puts_fp(fp, " ^ ");
-        BN_print_fp(fp, b.get());
-        puts_fp(fp, " - ");
-      }
+      BN_print_fp(fp, a.get());
+      puts_fp(fp, " ^ ");
+      BN_print_fp(fp, b.get());
+      puts_fp(fp, " - ");
       BN_print_fp(fp, d.get());
       puts_fp(fp, "\n");
     }
@@ -1254,32 +1240,15 @@ static bool test_exp_mod_zero(void) {
   }
 
   if (!BN_is_zero(r.get())) {
-    printf("1**0 mod 1 = ");
-    BN_print_fp(stdout, r.get());
-    printf(", should be 0\n");
+    fprintf(stderr, "1**0 mod 1 = ");
+    BN_print_fp(stderr, r.get());
+    fprintf(stderr, ", should be 0\n");
     return false;
   }
 
   return true;
 }
 
-static int genprime_cb(int p, int n, BN_GENCB *arg) {
-  char c = '*';
-
-  if (p == 0) {
-    c = '.';
-  } else if (p == 1) {
-    c = '+';
-  } else if (p == 2) {
-    c = '*';
-  } else if (p == 3) {
-    c = '\n';
-  }
-  putc(c, stdout);
-  fflush(stdout);
-  return 1;
-}
-
 static bool test_mod_sqrt(FILE *fp, BN_CTX *ctx) {
   ScopedBIGNUM a(BN_new());
   ScopedBIGNUM p(BN_new());
@@ -1288,9 +1257,6 @@ static bool test_mod_sqrt(FILE *fp, BN_CTX *ctx) {
     return false;
   }
 
-  BN_GENCB cb;
-  BN_GENCB_set(&cb, genprime_cb, NULL);
-
   for (int i = 0; i < 16; i++) {
     if (i < 8) {
       const unsigned kPrimes[8] = {2, 3, 5, 7, 11, 13, 17, 19};
@@ -1300,10 +1266,9 @@ static bool test_mod_sqrt(FILE *fp, BN_CTX *ctx) {
     } else {
       if (!BN_set_word(a.get(), 32) ||
           !BN_set_word(r.get(), 2 * i + 1) ||
-          !BN_generate_prime_ex(p.get(), 256, 0, a.get(), r.get(), &cb)) {
+          !BN_generate_prime_ex(p.get(), 256, 0, a.get(), r.get(), nullptr)) {
         return false;
       }
-      putc('\n', stdout);
     }
     p->neg = rand_neg();
 
@@ -1339,13 +1304,7 @@ static bool test_mod_sqrt(FILE *fp, BN_CTX *ctx) {
         fprintf(stderr, "\n");
         return false;
       }
-
-      putc('.', stdout);
-      fflush(stdout);
     }
-
-    putc('\n', stdout);
-    fflush(stderr);
   }
   return true;
 }