Extract Secp192r1 from the prototype
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index 727283f..787a700 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -4570,6 +4570,7 @@
/* Forward declarations */
#if defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED)
static int ecp_mod_p192(mbedtls_mpi *);
+static int ecp_mod_p192_raw(mbedtls_mpi_uint *Np, size_t Nn);
#endif
#if defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED)
static int ecp_mod_p224(mbedtls_mpi *);
@@ -4884,10 +4885,12 @@
}
#define WIDTH 8 / sizeof(mbedtls_mpi_uint)
-#define A(i) N->p + (i) * WIDTH
-#define ADD(i) add64(p, A(i), &c)
+#define A(i) Np + (i) * WIDTH
+#define ADD(i) add64(p, A(i), &c)
#define NEXT p += WIDTH; carry64(p, &c)
#define LAST p += WIDTH; *p = c; while (++p < end) *p = 0
+#define RESET last_carry[0] = c; c = 0; p = Np
+#define ADD_LAST add64(p, last_carry, &c)
/*
* Fast quasi-reduction modulo p192 (FIPS 186-3 D.2.1)
@@ -4895,28 +4898,47 @@
static int ecp_mod_p192(mbedtls_mpi *N)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
- mbedtls_mpi_uint c = 0;
- mbedtls_mpi_uint *p, *end;
-
- /* Make sure we have enough blocks so that A(5) is legal */
- MBEDTLS_MPI_CHK(mbedtls_mpi_grow(N, 6 * WIDTH));
-
- p = N->p;
- end = p + N->n;
-
- ADD(3); ADD(5); NEXT; // A0 += A3 + A5
- ADD(3); ADD(4); ADD(5); NEXT; // A1 += A3 + A4 + A5
- ADD(4); ADD(5); LAST; // A2 += A4 + A5
+ size_t expected_width = 2 * ((192 + biL - 1) / biL);
+ MBEDTLS_MPI_CHK(mbedtls_mpi_grow(N, expected_width));
+ ret = ecp_mod_p192_raw(N->p, expected_width);
cleanup:
return ret;
}
+static int ecp_mod_p192_raw(mbedtls_mpi_uint *Np, size_t Nn)
+{
+ mbedtls_mpi_uint c = 0, last_carry[WIDTH] = { 0 };
+ mbedtls_mpi_uint *p, *end;
+
+ if (Nn != 2*((192 + biL - 1)/biL)) {
+ return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+ }
+
+ p = Np;
+ end = p + Nn;
+
+ ADD(3); ADD(5); NEXT; // A0 += A3 + A5
+ ADD(3); ADD(4); ADD(5); NEXT; // A1 += A3 + A4 + A5
+ ADD(4); ADD(5); // A2 += A4 + A5
+
+ RESET;
+
+ ADD_LAST; NEXT;
+ ADD_LAST; NEXT;
+
+ LAST;
+
+ return 0;
+}
+
#undef WIDTH
#undef A
#undef ADD
#undef NEXT
#undef LAST
+#undef RESET
+#undef ADD_LAST
#endif /* MBEDTLS_ECP_DP_SECP192R1_ENABLED */
#if defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED) || \