2 files changed, 10 insertions, 1 deletions

diff --git a/src/cm/cm.c b/src/cm/cm.c
index c604876..a3a70a2 100644
--- a/src/cm/cm.c
+++ b/src/cm/cm.c
@@ -181,6 +181,14 @@ static int cm_init(exhaustive_t *setup) {
 			fprintf(err, "Order requested not a number: %s\n", cfg->cm_order);
 			return 1;
 		}
+		long ord_log = logint0(order, gen_2, NULL);
+		if (ord_log > cfg->bits) {
+			pari_fprintf(err,
+			             "Order requested does not fit(2^%li) into requested "
+			             "bitsize(2^%li): %Pi\n",
+			             ord_log, cfg->bits, order);
+			return 1;
+		}
 		if (delims == 0) {
 			ord_prime = (bool)isprime(order);
 		} else {
diff --git a/test/ecgen.sh b/test/ecgen.sh
index ef734d8..e9a1d85 100755
--- a/test/ecgen.sh
+++ b/test/ecgen.sh
@@ -162,9 +162,10 @@ function hex() {
 function cm() {
     start_test
     assert_raises "${ecgen} --fp --order=2147483723 32"
-    assert_raises "${ecgen} --fp --order=123456789012345678901234567890123456789012345678901234568197 137"
+    assert_raises "${ecgen} --fp --order=123456789012345678901234567890123456789012345678901234568197 196"
     assert_raises "${ecgen} --fp --order=46874566546,3546,3125 64"
     assert_raises "${ecgen} --fp --order=0 16" 1
+    assert_raises "${ecgen} --fp --order=0x1000 8" 1
 }
 
 function secg() {