ecc: added byte conversion functions

EAP-PWD was hard coded to only work on LE architectures. This
adds 2 conversion functions to go from network byte order (BE)
to any native architecture, and vise versa.

src/ecc.c

@@ -33,6 +33,8 @@
 #include <sys/types.h>
 #include <string.h>
 
+#include <ell/ell.h>
+
 #include "ecc.h"
 
 #define MAX_TRIES 16
@@ -755,6 +757,35 @@ bool ecc_valid_point(struct ecc_point *point)
 	return vli_equal(tmp1, tmp2);
 }
 
+/*
+ * These two byte conversion functions were modified to allow for conversion
+ * to and from both BE and LE architectures.
+ */
+
+/* Big endian byte-array to native conversion */
+void ecc_be2native(uint64_t bytes[NUM_ECC_DIGITS])
+{
+	int i;
+	uint64_t tmp[NUM_ECC_DIGITS];
+
+	for (i = 0; i < NUM_ECC_DIGITS; i++)
+		tmp[NUM_ECC_DIGITS - 1 - i] = l_get_be64(&bytes[i]);
+
+	memcpy(bytes, tmp, 32);
+}
+
+/* Native to big endian byte-array conversion */
+void ecc_native2be(uint64_t native[NUM_ECC_DIGITS])
+{
+	int i;
+	uint64_t tmp[NUM_ECC_DIGITS];
+
+	for (i = 0; i < NUM_ECC_DIGITS; i++)
+		l_put_be64(native[NUM_ECC_DIGITS - 1 - i], &tmp[i]);
+
+	memcpy(native, tmp, 32);
+}
+
 /*
  * The code below was not in the original file and was added to support EAP-PWD.
  * The above ECC implementation did not include functionality for point

src/ecc.h

@@ -62,6 +62,10 @@ void ecc_point_add(struct ecc_point *ret, struct ecc_point *p,
 
 bool ecc_valid_point(struct ecc_point *point);
 
+void ecc_be2native(uint64_t bytes[NUM_ECC_DIGITS]);
+
+void ecc_native2be(uint64_t native[NUM_ECC_DIGITS]);
+
 bool ecc_compute_y(uint64_t *y, uint64_t *x);
 
 void vli_mod_inv(uint64_t *result, const uint64_t *input, const uint64_t *mod);