upstream: Fix BN_is_prime_* calls in SSH, the API returns -1 on

error.

Found thanks to BoringSSL's commit 53409ee3d7595ed37da472bc73b010cd2c8a5ffd
by David Benjamin.

ok djm, dtucker

OpenBSD-Commit-ID: 1ee832be3c44b1337f76b8562ec6d203f3b072f8

1 files changed, 14 insertions, 5 deletions

diff --git a/moduli.c b/moduli.c
index 233cba8e8..48150dab2 100644
--- a/moduli.c
+++ b/moduli.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: moduli.c,v 1.32 2017/12/08 03:45:52 deraadt Exp $ */
+/* $OpenBSD: moduli.c,v 1.33 2019/01/20 02:01:59 tb Exp $ */
 /*
  * Copyright 1994 Phil Karn <karn@qualcomm.com>
  * Copyright 1996-1998, 2003 William Allen Simpson <wsimpson@greendragon.com>
@@ -582,7 +582,7 @@ prime_test(FILE *in, FILE *out, u_int32_t trials, u_int32_t generator_wanted,
         u_int32_t generator_known, in_tests, in_tries, in_type, in_size;
         unsigned long last_processed = 0, end_lineno;
         time_t time_start, time_stop;
-        int res;
+        int res, is_prime;
 
         if (trials < TRIAL_MINIMUM) {
                 error("Minimum primality trials is %d", TRIAL_MINIMUM);
@@ -753,7 +753,10 @@ prime_test(FILE *in, FILE *out, u_int32_t trials, u_int32_t generator_wanted,
                  * that p is also prime. A single pass will weed out the
                  * vast majority of composite q's.
                  */
-                if (BN_is_prime_ex(q, 1, ctx, NULL) <= 0) {
+                is_prime = BN_is_prime_ex(q, 1, ctx, NULL);
+                if (is_prime < 0)
+                        fatal("BN_is_prime_ex failed");
+                if (is_prime == 0) {
                         debug("%10u: q failed first possible prime test",
                             count_in);
                         continue;
@@ -766,14 +769,20 @@ prime_test(FILE *in, FILE *out, u_int32_t trials, u_int32_t generator_wanted,
                  * will show up on the first Rabin-Miller iteration so it
                  * doesn't hurt to specify a high iteration count.
                  */
-                if (!BN_is_prime_ex(p, trials, ctx, NULL)) {
+                is_prime = BN_is_prime_ex(p, trials, ctx, NULL);
+                if (is_prime < 0)
+                        fatal("BN_is_prime_ex failed");
+                if (is_prime == 0) {
                         debug("%10u: p is not prime", count_in);
                         continue;
                 }
                 debug("%10u: p is almost certainly prime", count_in);
 
                 /* recheck q more rigorously */
-                if (!BN_is_prime_ex(q, trials - 1, ctx, NULL)) {
+                is_prime = BN_is_prime_ex(q, trials - 1, ctx, NULL);
+                if (is_prime < 0)
+                        fatal("BN_is_prime_ex failed");
+                if (is_prime == 0) {
                         debug("%10u: q is not prime", count_in);
                         continue;
                 }