Add testcase which hits additional branch in secp256k1_scalar_sqr

src/tests.c

@@ -855,7 +855,7 @@ void run_scalar_tests(void) {
         secp256k1_scalar zzv;
 #endif
         int overflow;
-        unsigned char chal[32][2][32] = {
+        unsigned char chal[33][2][32] = {
             {{0xff, 0xff, 0x03, 0x07, 0x00, 0x00, 0x00, 0x00,
               0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x03,
               0x00, 0x00, 0x00, 0x00, 0x00, 0xf8, 0xff, 0xff,
@@ -1111,9 +1111,17 @@ void run_scalar_tests(void) {
              {0xff, 0x01, 0x00, 0x00, 0x00, 0x00, 0xf8, 0xff,
               0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0x00, 0x00,
               0xf8, 0x07, 0x00, 0x80, 0xff, 0xff, 0xff, 0xff,
-              0xff, 0xc7, 0xff, 0xff, 0xe0, 0xff, 0xff, 0xff}}
+              0xff, 0xc7, 0xff, 0xff, 0xe0, 0xff, 0xff, 0xff}},
+            {{0x82, 0xc9, 0xfa, 0xb0, 0x68, 0x04, 0xa0, 0x00,
+              0x82, 0xc9, 0xfa, 0xb0, 0x68, 0x04, 0xa0, 0x00,
+              0xff, 0xff, 0xff, 0xff, 0xff, 0x6f, 0x03, 0xfb,
+              0xfa, 0x8a, 0x7d, 0xdf, 0x13, 0x86, 0xe2, 0x03},
+             {0x82, 0xc9, 0xfa, 0xb0, 0x68, 0x04, 0xa0, 0x00,
+              0x82, 0xc9, 0xfa, 0xb0, 0x68, 0x04, 0xa0, 0x00,
+              0xff, 0xff, 0xff, 0xff, 0xff, 0x6f, 0x03, 0xfb,
+              0xfa, 0x8a, 0x7d, 0xdf, 0x13, 0x86, 0xe2, 0x03}}
         };
-        unsigned char res[32][2][32] = {
+        unsigned char res[33][2][32] = {
             {{0x0c, 0x3b, 0x0a, 0xca, 0x8d, 0x1a, 0x2f, 0xb9,
               0x8a, 0x7b, 0x53, 0x5a, 0x1f, 0xc5, 0x22, 0xa1,
               0x07, 0x2a, 0x48, 0xea, 0x02, 0xeb, 0xb3, 0xd6,
@@ -1369,10 +1377,18 @@ void run_scalar_tests(void) {
              {0xe4, 0xf1, 0x23, 0x84, 0xe1, 0xb5, 0x9d, 0xf2,
               0xb8, 0x73, 0x8b, 0x45, 0x2b, 0x35, 0x46, 0x38,
               0x10, 0x2b, 0x50, 0xf8, 0x8b, 0x35, 0xcd, 0x34,
-              0xc8, 0x0e, 0xf6, 0xdb, 0x09, 0x35, 0xf0, 0xda}}
+              0xc8, 0x0e, 0xf6, 0xdb, 0x09, 0x35, 0xf0, 0xda}},
+            {{0xdb, 0x21, 0x5c, 0x8d, 0x83, 0x1d, 0xb3, 0x34,
+              0xc7, 0x0e, 0x43, 0xa1, 0x58, 0x79, 0x67, 0x13,
+              0x1e, 0x86, 0x5d, 0x89, 0x63, 0xe6, 0x0a, 0x46,
+              0x5c, 0x02, 0x97, 0x1b, 0x62, 0x43, 0x86, 0xf5},
+             {0xdb, 0x21, 0x5c, 0x8d, 0x83, 0x1d, 0xb3, 0x34,
+              0xc7, 0x0e, 0x43, 0xa1, 0x58, 0x79, 0x67, 0x13,
+              0x1e, 0x86, 0x5d, 0x89, 0x63, 0xe6, 0x0a, 0x46,
+              0x5c, 0x02, 0x97, 0x1b, 0x62, 0x43, 0x86, 0xf5}}
         };
         secp256k1_scalar_set_int(&one, 1);
-        for (i = 0; i < 32; i++) {
+        for (i = 0; i < 33; i++) {
             secp256k1_scalar_set_b32(&x, chal[i][0], &overflow);
             CHECK(!overflow);
             secp256k1_scalar_set_b32(&y, chal[i][1], &overflow);