1 files changed, 42 insertions, 0 deletions
diff --git a/openssl/crypto/bn/divtest.c b/openssl/crypto/bn/divtest.c
new file mode 100644
index 0000000..2590b45
--- /dev/null
+++ b/openssl/crypto/bn/divtest.c
@@ -0,0 +1,42 @@
+#include <openssl/bn.h>
+#include <openssl/rand.h>
+
+static int Rand(n)
+{
+    unsigned char x[2];
+    RAND_pseudo_bytes(x, 2);
+    return (x[0] + 2 * x[1]);
+}
+
+static void bug(char *m, BIGNUM *a, BIGNUM *b)
+{
+    printf("%s!\na=", m);
+    BN_print_fp(stdout, a);
+    printf("\nb=");
+    BN_print_fp(stdout, b);
+    printf("\n");
+    fflush(stdout);
+}
+
+main()
+{
+    BIGNUM *a = BN_new(), *b = BN_new(), *c = BN_new(), *d = BN_new(),
+        *C = BN_new(), *D = BN_new();
+    BN_RECP_CTX *recp = BN_RECP_CTX_new();
+    BN_CTX *ctx = BN_CTX_new();
+
+    for (;;) {
+        BN_pseudo_rand(a, Rand(), 0, 0);
+        BN_pseudo_rand(b, Rand(), 0, 0);
+        if (BN_is_zero(b))
+            continue;
+
+        BN_RECP_CTX_set(recp, b, ctx);
+        if (BN_div(C, D, a, b, ctx) != 1)
+            bug("BN_div failed", a, b);
+        if (BN_div_recp(c, d, a, recp, ctx) != 1)
+            bug("BN_div_recp failed", a, b);
+        else if (BN_cmp(c, C) != 0 || BN_cmp(c, C) != 0)
+            bug("mismatch", a, b);
+    }
+}