bird/lib/fletcher16_test.c

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/*
* BIRD Library -- Fletcher-16 Tests
*
* (c) 2015 CZ.NIC z.s.p.o.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "test/birdtest.h"
#include "lib/fletcher16.h"
static u16
straightforward_fletcher16_compute(const char *data)
{
int count = strlen(data);
u16 sum1 = 0;
u16 sum2 = 0;
int index;
for (index = 0; index < count; ++index)
{
sum1 = (sum1 + data[index]) % 255;
sum2 = (sum2 + sum1) % 255;
}
sum2 = (sum2 + sum1) % 255;
sum2 = (sum2 + sum1) % 255;
return (sum1 << 8) | sum2;
}
static u16
straightforward_fletcher16_checksum(const char *data)
{
u16 csum;
u16 c0,c1,x,y;
csum = straightforward_fletcher16_compute(data);
c0 = (csum >> 8) & 0xff;
c1 = csum & 0xff;
x = (255 + c0 - c1) % 255;
y = (510 - 2*c0 + c1) % 255;
if (!x) x = 255;
if (!y) y = 255;
return (x << 8) | y;
}
const u8 zero16[2] = {};
static int
test_fletcher16(void *out_, const void *in_, const void *expected_out_)
{
u16 *out = out_;
const char *in = in_;
const u16 *expected_out = expected_out_;
struct fletcher16_context ctxt;
fletcher16_init(&ctxt);
fletcher16_update(&ctxt, in, strlen(in));
fletcher16_update(&ctxt, zero16, 2);
*out = fletcher16_compute(&ctxt);
return *out == *expected_out;
}
static int
test_fletcher16_checksum(void *out_, const void *in_, const void *expected_out_)
{
u16 *out = out_;
const char *in = in_;
const u16 *expected_out = expected_out_;
struct fletcher16_context ctxt;
int len = strlen(in);
fletcher16_init(&ctxt);
fletcher16_update(&ctxt, in, len);
fletcher16_update(&ctxt, zero16, 2);
*out = fletcher16_final(&ctxt, len+2, len);
return *out == *expected_out;
}
static int
t_fletcher16_compute(void)
{
struct bt_pair test_vectors[] = {
{
.in = "\001\002",
.out = & ((const u16) { straightforward_fletcher16_compute("\001\002") }),
},
{
.in = "",
.out = & ((const u16) { straightforward_fletcher16_compute("") }),
},
{
.in = "a",
.out = & ((const u16) { straightforward_fletcher16_compute("a") }),
},
{
.in = "abcd",
.out = & ((const u16) { straightforward_fletcher16_compute("abcd") }),
},
{
.in = "message digest",
.out = & ((const u16) { straightforward_fletcher16_compute("message digest") }),
},
{
.in = "abcdefghijklmnopqrstuvwxyz",
.out = & ((const u16) { straightforward_fletcher16_compute("abcdefghijklmnopqrstuvwxyz") }),
},
{
.in = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
.out = & ((const u16) { straightforward_fletcher16_compute("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") }),
},
{
.in = "12345678901234567890123456789012345678901234567890123456789012345678901234567890",
.out = & ((const u16) { straightforward_fletcher16_compute("12345678901234567890123456789012345678901234567890123456789012345678901234567890") }),
},
};
return bt_assert_batch(test_vectors, test_fletcher16, bt_fmt_str, bt_fmt_unsigned);
}
static int
t_fletcher16_checksum(void)
{
struct bt_pair test_vectors[] = {
{
.in = "\001\002",
.out = & ((const u16) { straightforward_fletcher16_checksum("\001\002") }),
},
{
.in = "",
.out = & ((const u16) { straightforward_fletcher16_checksum("") }),
},
{
.in = "a",
.out = & ((const u16) { straightforward_fletcher16_checksum("a") }),
},
{
.in = "abcd",
.out = & ((const u16) { straightforward_fletcher16_checksum("abcd") }),
},
{
.in = "message digest",
.out = & ((const u16) { straightforward_fletcher16_checksum("message digest") }),
},
{
.in = "abcdefghijklmnopqrstuvwxyz",
.out = & ((const u16) { straightforward_fletcher16_checksum("abcdefghijklmnopqrstuvwxyz") }),
},
{
.in = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
.out = & ((const u16) { straightforward_fletcher16_checksum("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") }),
},
{
.in = "12345678901234567890123456789012345678901234567890123456789012345678901234567890",
.out = & ((const u16) { straightforward_fletcher16_checksum("12345678901234567890123456789012345678901234567890123456789012345678901234567890") }),
},
};
return bt_assert_batch(test_vectors, test_fletcher16_checksum, bt_fmt_str, bt_fmt_unsigned);
}
int
main(int argc, char *argv[])
{
bt_init(argc, argv);
bt_test_suite(t_fletcher16_compute, "Fletcher-16 Compute Tests");
bt_test_suite(t_fletcher16_checksum, "Fletcher-16 Checksum Tests");
return bt_exit_value();
}