113 lines
2.4 KiB
C++
113 lines
2.4 KiB
C++
// Those tests work only with Clang and Memory Sanitizer
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#include <gtest/gtest.h>
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#include <common/ct_check.h>
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extern "C" {
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uint8_t ct_memcmp(const void *a, const void *b, size_t sz);
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}
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TEST(ConstantTime, CtCheck_Negative) {
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unsigned char a[16], b[16];
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unsigned i;
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memset(a, 42, 16);
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memset(b, 42, 16);
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ct_poison(a, 16);
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for (i = 0; i < 16; i++) {
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ct_expect_umr();
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if (a[i] != b[i]) {
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break;
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}
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ct_require_umr();
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}
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ct_purify(a, 16);
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// Ensure buffers are not optimized-out
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ASSERT_EQ(a[0], b[0]);
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}
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TEST(ConstantTime, CtCheck_Positive_NoAccess) {
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unsigned i;
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char result = 0;
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unsigned char a[16], b[16];
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memset(a, 42, sizeof(a));
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memset(b, 42, sizeof(b));
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ct_poison(a, 16);
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for (i = 0; i < 16; i++) {
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result |= a[i] ^ b[i];
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}
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ct_purify(a, 16);
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// Purify result, to allow check that otherwise
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// would be not constant-time.
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ct_purify(&result, 1);
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ASSERT_EQ(result, 0);
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}
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TEST(ConstantTime, CtCheck_Negative_UseSecretAsIndex) {
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static const unsigned char tab[2] = {1, 0};
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unsigned char a[16];
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unsigned char result;
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memset(a, 42, sizeof(a));
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ct_poison(a, 16);
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ct_expect_umr();
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result = tab[a[0] & 1];
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ct_require_umr();
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ct_purify(a, 16);
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// Ensure variables are not optimized-out
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ct_purify(&result, 1);
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ASSERT_EQ(result, 1);
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}
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TEST(ConstantTime, CtCheck_memcmp) {
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unsigned char a[16], b[16];
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memset(a, 42, sizeof(a));
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memset(b, 42, sizeof(b));
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uint8_t ret;
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ct_poison(a, 16);
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ret = ct_memcmp(a,b,16);
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ct_purify(&ret, 1);
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ASSERT_EQ(ret,0);
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b[1] = 0;
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ret = ct_memcmp(a,b,16);
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ct_purify(&ret, 1);
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ASSERT_EQ(ret,1);
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}
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TEST(ConstantTime, CtCheck_memcmp_chained) {
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unsigned char a[16], b[16], c[16], d[16];
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memset(a, 42, sizeof(a));
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memset(b, 42, sizeof(b));
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memset(d, 42, sizeof(b));
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memset(c, 41, sizeof(c));
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uint8_t ret;
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ct_poison(a, 16);
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ct_expect_umr();
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// obviously must generate UMR if if first check fails
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// and second is not done
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ret = (ct_memcmp(a,c,16)==0) && (ct_memcmp(a,b,16)==0);
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ct_require_umr();
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ct_purify(&ret, 1);
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ASSERT_EQ(ret,0);
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ct_expect_umr();
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// it's still UMR even if both checks are OK
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ret = (ct_memcmp(a,d,16)==0) && (ct_memcmp(a,b,16)==0);
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ct_require_umr();
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ct_purify(&ret, 1);
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ASSERT_EQ(ret,1);
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}
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