static void test_div_random(void)
{
int i;
char str[MAX_RAND_STRING_SIZE];
TB_INFO(" Testing random divisions");
DEF_BIGINT(n, 2048);
DEF_BIGINT(d, 2048);
DEF_BIGINT(q, 2048);
DEF_BIGINT(r, 2048);
DEF_BIGINT(v, 2048);
for (i = 0; i < 10000; i++) {
tb_set_random_value(n, str, 1);
/* don't divide by zero */
do {
tb_set_random_value(d, str, 1);
} while (TEE_BigIntCmpS32(d, 0) == 0);
TEE_BigIntDiv(q, r, n, d);
TEE_BigIntMul(v, q, d);
TEE_BigIntAdd(v, v, r);
TB_ASSERT_BIGINT_EQ(n, v);
if (TEE_BigIntCmpS32(d, 0) > 0)
TB_ASSERT_BIGINT_LESS(r, d);
}
DEL_BIGINT(n);
DEL_BIGINT(d);
DEL_BIGINT(q);
DEL_BIGINT(r);
DEL_BIGINT(v);
}
void TEE_BigIntInvMod(TEE_BigInt *dest, const TEE_BigInt *op,
const TEE_BigInt *n)
{
if (TEE_BigIntCmpS32(n, 2) < 0 || TEE_BigIntCmpS32(op, 0) == 0)
API_PANIC("too small modulus or trying to invert zero");
mbedtls_mpi mpi_dest;
mbedtls_mpi mpi_op;
mbedtls_mpi mpi_n;
mbedtls_mpi *pop = &mpi_op;
get_mpi(&mpi_dest, dest);
get_mpi(&mpi_n, n);
if (op == dest)
pop = &mpi_dest;
else
get_mpi(&mpi_op, op);
MPI_CHECK(mbedtls_mpi_inv_mod(&mpi_dest, pop, &mpi_n));
MPI_CHECK(copy_mpi_to_bigint(&mpi_dest, dest));
mbedtls_mpi_free(&mpi_dest);
mbedtls_mpi_free(&mpi_n);
if (pop == &mpi_op)
mbedtls_mpi_free(&mpi_op);
}
/*
* TEE_BigIntInvMod
*/
void TEE_BigIntInvMod(TEE_BigInt *dest, const TEE_BigInt *op,
const TEE_BigInt *n)
{
mpanum mpa_dest = (mpa_num_base *)dest;
mpanum mpa_op = (mpa_num_base *)op;
mpanum mpa_n = (mpa_num_base *)n;
if (TEE_BigIntCmpS32(n, 2) < 0 || TEE_BigIntCmpS32(op, 0) == 0)
TEE_BigInt_Panic("too small modulus or trying to invert zero");
mpa_inv_mod(mpa_dest, mpa_op, mpa_n, mempool);
}
/*
* TEE_BigIntMulMod
*/
void TEE_BigIntMulMod(TEE_BigInt *dest, const TEE_BigInt *op1,
const TEE_BigInt *op2, const TEE_BigInt *n)
{
mpanum mpa_dest = (mpa_num_base *)dest;
mpanum mpa_op1 = (mpa_num_base *)op1;
mpanum mpa_op2 = (mpa_num_base *)op2;
mpanum mpa_n = (mpa_num_base *)n;
mpanum tmp_dest;
if (TEE_BigIntCmpS32(n, 2) < 0)
TEE_BigInt_Panic("Modulus is too short");
/*
* From the spec, mpa_dest must be of magnitude "mpa_n"
* But internal computations in mpa do not have such assumptions
* (as __mpa_div_q_r, where "r" must be of magnitude "op1",
* whereas GP provides a magnitude of "op2")
* This is a tempory variable is used, before storing the
* final result.
*/
mpa_alloc_static_temp_var(&tmp_dest, mempool);
mpa_mul_mod(tmp_dest, mpa_op1, mpa_op2, mpa_n, mempool);
if (mpa_cmp_short(tmp_dest, 0) < 0)
mpa_add(tmp_dest, tmp_dest, mpa_n, mempool);
mpa_copy(mpa_dest, tmp_dest);
mpa_free_static_temp_var(&tmp_dest, mempool);
}
void TEE_BigIntMod(TEE_BigInt *dest, const TEE_BigInt *op, const TEE_BigInt *n)
{
if (TEE_BigIntCmpS32(n, 2) < 0)
API_PANIC("Modulus is too short");
bigint_binary(dest, op, n, mbedtls_mpi_mod_mpi);
}
/*
* TEE_BigIntDiv
*/
void TEE_BigIntDiv(TEE_BigInt *dest_q, TEE_BigInt *dest_r,
const TEE_BigInt *op1, const TEE_BigInt *op2)
{
mpanum mpa_dest_q = (mpa_num_base *)dest_q;
mpanum mpa_dest_r = (mpa_num_base *)dest_r;
mpanum mpa_op1 = (mpa_num_base *)op1;
mpanum mpa_op2 = (mpa_num_base *)op2;
if (TEE_BigIntCmpS32(op2, 0) == 0)
TEE_BigInt_Panic("Divisor is zero");
mpa_div(mpa_dest_q, mpa_dest_r, mpa_op1, mpa_op2, mempool);
}
/*
* TEE_BigIntSubMod
*/
void TEE_BigIntSubMod(TEE_BigInt *dest, const TEE_BigInt *op1,
const TEE_BigInt *op2, const TEE_BigInt *n)
{
mpanum mpa_dest = (mpa_num_base *)dest;
mpanum mpa_op1 = (mpa_num_base *)op1;
mpanum mpa_op2 = (mpa_num_base *)op2;
mpanum mpa_n = (mpa_num_base *)n;
if (TEE_BigIntCmpS32(n, 2) < 0)
TEE_BigInt_Panic("Modulus is too short");
mpa_sub_mod(mpa_dest, mpa_op1, mpa_op2, mpa_n, mempool);
if (mpa_cmp_short(mpa_dest, 0) < 0)
mpa_add(mpa_dest, mpa_dest, mpa_n, mempool);
}
static void bigint_binary_mod(TEE_BigInt *dest, const TEE_BigInt *op1,
const TEE_BigInt *op2, const TEE_BigInt *n,
int (*func)(mbedtls_mpi *X, const mbedtls_mpi *A,
const mbedtls_mpi *B))
{
if (TEE_BigIntCmpS32(n, 2) < 0)
API_PANIC("Modulus is too short");
mbedtls_mpi mpi_dest;
mbedtls_mpi mpi_op1;
mbedtls_mpi mpi_op2;
mbedtls_mpi mpi_n;
mbedtls_mpi *pop1 = &mpi_op1;
mbedtls_mpi *pop2 = &mpi_op2;
mbedtls_mpi mpi_t;
get_mpi(&mpi_dest, dest);
get_mpi(&mpi_n, n);
if (op1 == dest)
pop1 = &mpi_dest;
else
get_mpi(&mpi_op1, op1);
if (op2 == dest)
pop2 = &mpi_dest;
else if (op2 == op1)
pop2 = pop1;
else
get_mpi(&mpi_op2, op2);
get_mpi(&mpi_t, NULL);
MPI_CHECK(func(&mpi_t, pop1, pop2));
MPI_CHECK(mbedtls_mpi_mod_mpi(&mpi_dest, &mpi_t, &mpi_n));
MPI_CHECK(copy_mpi_to_bigint(&mpi_dest, dest));
mbedtls_mpi_free(&mpi_dest);
if (pop1 == &mpi_op1)
mbedtls_mpi_free(&mpi_op1);
if (pop2 == &mpi_op2)
mbedtls_mpi_free(&mpi_op2);
mbedtls_mpi_free(&mpi_t);
}
