Merge branch 'prepare_CF' into IPECC

src/fp/fp.c

@@ -322,6 +322,8 @@ int fp_iszero(fp_src_t in, int *iszero)
  * output is already initialized, check that the Fp contexts are consistent.
  * Else, output is initialized with the same field context as input. Returns 0
  * on success, -1 on error.
+ *
+ * Aliasing of input and output is supported.
  */
 int fp_copy(fp_t out, fp_src_t in)
 {
@@ -355,6 +357,9 @@ int fp_copy(fp_t out, fp_src_t in)
  * Fp elements in 'tab'
  *
  * Returns 0 on success, -1 on error.
+ *
+ * Aliasing of out and the selected element inside the tab is NOT supported.
+ *
  */
 int fp_tabselect(fp_t out, u8 idx, fp_src_t *tab, u8 tabsize)
 {
@@ -400,6 +405,8 @@ int fp_tabselect(fp_t out, u8 idx, fp_src_t *tab, u8 tabsize)
  * in2 are not equal or opposite, 'eq_or_opp' is set to 0. The function
  * returns 0 on success and -1 on error. 'eq_or_opp' is only meaningful
  * on success, i.e. if the return value is 0.
+ *
+ * Aliasing of inputs is supported.
  */
 int fp_eq_or_opp(fp_src_t in1, fp_src_t in2, int *eq_or_opp)
 {

src/fp/fp_add.c

@@ -19,6 +19,8 @@
 /*
  * Compute out = in1 + in2 mod p. 'out' parameter must have been initialized
  * by the caller. Returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_add(fp_t out, fp_src_t in1, fp_src_t in2)
 {
@@ -44,6 +46,8 @@ int fp_add(fp_t out, fp_src_t in1, fp_src_t in2)
 /*
  * Compute out = in + 1 mod p. 'out' parameter must have been initialized
  * by the caller. Returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_inc(fp_t out, fp_src_t in)
 {
@@ -65,6 +69,8 @@ int fp_inc(fp_t out, fp_src_t in)
 /*
  * Compute out = in1 - in2 mod p. 'out' parameter must have been initialized
  * by the caller. Returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_sub(fp_t out, fp_src_t in1, fp_src_t in2)
 {
@@ -90,6 +96,8 @@ int fp_sub(fp_t out, fp_src_t in1, fp_src_t in2)
 /*
  * Compute out = in - 1 mod p. 'out' parameter must have been initialized
  * by the caller. Returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_dec(fp_t out, fp_src_t in)
 {
@@ -111,6 +119,8 @@ int fp_dec(fp_t out, fp_src_t in)
 /*
  * Compute out = -in mod p = (p - in) mod p. 'out' parameter must have been
  * initialized by the caller. Returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_neg(fp_t out, fp_src_t in)
 {

src/fp/fp_montgomery.c

@@ -22,6 +22,8 @@
 /* Compute out = in1 + in2 mod p in the Montgomery form.
  * Inputs and outputs are in their Montgomery form.
  * Returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_add_monty(fp_t out, fp_src_t in1, fp_src_t in2)
 {
@@ -31,6 +33,8 @@ int fp_add_monty(fp_t out, fp_src_t in1, fp_src_t in2)
 /* Compute out = in1 - in2 mod p in the Montgomery form.
  * Inputs and outputs are in their Montgomery form.
  * Returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_sub_monty(fp_t out, fp_src_t in1, fp_src_t in2)
 {
@@ -40,6 +44,8 @@ int fp_sub_monty(fp_t out, fp_src_t in1, fp_src_t in2)
 /* Compute out = in1 * in2 mod p in the Montgomery form.
  * Inputs and outputs are in their Montgomery form.
  * Returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_mul_monty(fp_t out, fp_src_t in1, fp_src_t in2)
 {
@@ -49,6 +55,8 @@ int fp_mul_monty(fp_t out, fp_src_t in1, fp_src_t in2)
 /* Compute out = in * in mod p in the Montgomery form.
  * Inputs and outputs are in their Montgomery form.
  * Returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_sqr_monty(fp_t out, fp_src_t in)
 {
@@ -60,6 +68,7 @@ int fp_sqr_monty(fp_t out, fp_src_t in)
  * Inputs and outputs are in their Montgomery form.
  * Returns 0 on success, -1 on error. out must be initialized by the caler.
  *
+ * Aliasing is supported.
  */
 int fp_div_monty(fp_t out, fp_src_t in1, fp_src_t in2)
 {

src/fp/fp_mul.c

@@ -20,6 +20,9 @@
 #include "../nn/nn_div.h"
 #include "../nn/nn_modinv.h"
 
+/*
+ * Aliasing is supported.
+ */
 int fp_mul(fp_t out, fp_src_t in1, fp_src_t in2)
 {
 	int ret;
@@ -39,6 +42,9 @@ int fp_mul(fp_t out, fp_src_t in1, fp_src_t in2)
 	return ret;
 }
 
+/*
+ * Aliasing is supported.
+ */
 int fp_sqr(fp_t out, fp_src_t in)
 {
 	return fp_mul(out, in, in);
@@ -47,6 +53,8 @@ int fp_sqr(fp_t out, fp_src_t in)
 /* We use Fermat's little theorem for our inversion in Fp:
  *    x^(p-1) = 1 mod (p) means that x^(p-2) mod(p) is the modular
  *    inverse of x mod (p)
+ *
+ * Aliasing is supported.
  */
 int fp_inv(fp_t out, fp_src_t in)
 {
@@ -79,6 +87,10 @@ int fp_inv_word(fp_t out, word_t w)
 	return ret;
 }
 
+/*
+ * Aliasing of out and num is NOT supported.
+ * Aliasing of out and den is supported.
+ */
 int fp_div(fp_t out, fp_src_t num, fp_src_t den)
 {
 	int ret;
@@ -87,6 +99,9 @@ int fp_div(fp_t out, fp_src_t num, fp_src_t den)
  	ret = fp_check_initialized(den); EG(ret, err);
 	ret = fp_check_initialized(out); EG(ret, err);
 
+	/* Unsupported multi-aliasing */
+	MUST_HAVE((out != num), ret, err);
+
 	MUST_HAVE(out->ctx == num->ctx, ret, err);
 	MUST_HAVE(out->ctx == den->ctx, ret, err);
 

src/fp/fp_mul_redc1.c

@@ -31,6 +31,8 @@ ATTRIBUTE_WARN_UNUSED_RET static inline int _fp_mul_redc1(nn_t out, nn_src_t in1
 /*
  * Exported version based on previous one, that sanity checks input parameters.
  * The function returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_mul_redc1(fp_t out, fp_src_t in1, fp_src_t in2)
 {
@@ -50,6 +52,9 @@ int fp_mul_redc1(fp_t out, fp_src_t in1, fp_src_t in2)
 	return ret;
 }
 
+/*
+ * Aliasing is supported.
+ */
 int fp_sqr_redc1(fp_t out, fp_src_t in)
 {
 	return fp_mul_redc1(out, in, in);
@@ -58,6 +63,8 @@ int fp_sqr_redc1(fp_t out, fp_src_t in)
 /*
  * redcify could be done by shifting and division by p. The function returns 0
  * on success, -1 on error.
+ *
+ * Aliasing is supported.
  */
 int fp_redcify(fp_t out, fp_src_t in)
 {
@@ -75,7 +82,11 @@ int fp_redcify(fp_t out, fp_src_t in)
 	return ret;
 }
 
-/* The function returns 0 on success, -1 on error. */
+/* 
+ * The function returns 0 on success, -1 on error.
+ *
+ * Aliasing is supported.
+ */
 int fp_unredcify(fp_t out, fp_src_t in)
 {
 	int ret;

src/fp/fp_pow.c

@@ -52,7 +52,10 @@ ATTRIBUTE_WARN_UNUSED_RET static int _fp_pow_aliased(fp_t out, nn_src_t exp)
 	return ret;
 }
 
-/* Aliased version of previous one. */
+/* Aliased version of previous one.
+ *
+ * Aliasing is supported.
+ */
 int fp_pow(fp_t out, fp_src_t base, nn_src_t exp)
 {
 	int ret;

src/fp/fp_sqrt.c

@@ -100,9 +100,10 @@ ATTRIBUTE_WARN_UNUSED_RET static int legendre(fp_src_t a)
  *           - Otherwise find, by repeated squaring, the lowest i , 0 < i < m , such as t^(2^i) ≡ 1
  *           - Let b ≡ c^(2^(m-i-1)), and set r ≡ r*b, t ≡ t*b^2 , c ≡ b^2 and m = i.
  *
- * Input aliasing is supported.
- *
  * NOTE: the algorithm is NOT constant time.
+ *
+ * Aliasing is supported.
+ * 
  */
 int fp_sqrt(fp_t sqrt1, fp_t sqrt2, fp_src_t n)
 {

src/nn/nn.c

@@ -168,6 +168,8 @@ int nn_one(nn_t A)
  * Conditionally swap two nn's content *in constant time*. Swapping is done
  * if 'cnd' is not zero. Nothing is done otherwise. Returns 0 on success, -1
  * on error.
+ *
+ * Aliasing of inputs is supported.
  */
 int nn_cnd_swap(int cnd, nn_t in1, nn_t in2)
 {
@@ -361,6 +363,8 @@ int nn_cmp_word(nn_src_t in, word_t w, int *cmp)
  * function returns 0 on success and provides the comparison value in
  * 'cmp' parameter (0 if A == B, -1 if A < B, +1 if A > B). -1 is returned
  * on error, in which case 'cmp' is not meaningful.
+ *
+ * Aliasing of inputs is supported.
  */
 int nn_cmp(nn_src_t A, nn_src_t B, int *cmp)
 {
@@ -390,6 +394,8 @@ int nn_cmp(nn_src_t A, nn_src_t B, int *cmp)
  * 'dst_nn' must point to a declared nn, but *need not be initialized*; it will
  * be (manually) initialized by the function. 'src_nn' must have been
  * initialized prior to the call. The function returns 0 on success, -1 on error.
+ *
+ * Alising of input and output is supported.
  */
 int nn_copy(nn_t dst_nn, nn_src_t src_nn)
 {
@@ -565,6 +571,8 @@ int nn_export_to_buf(u8 *buf, u16 buflen, nn_src_t in_nn)
  * NN elements in 'tab'
  *
  * Returns 0 on success, -1 on error.
+ *
+ * Aliasing of out and the selected element inside the tab is NOT supported.
  */
 int nn_tabselect(nn_t out, u8 idx, nn_src_t *tab, u8 tabsize)
 {