summaryrefslogtreecommitdiffstats
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/ec25519.c54
-rw-r--r--src/ec25519_gf.c50
2 files changed, 8 insertions, 96 deletions
diff --git a/src/ec25519.c b/src/ec25519.c
index 736b798..a9d519c 100644
--- a/src/ec25519.c
+++ b/src/ec25519.c
@@ -35,16 +35,15 @@
*
* See http://hyperelliptic.org/EFD/g1p/auto-twisted-extended.html for add and
* double operations.
+ *
+ * Doxygen comments for public APIs can be found in the public header file.
*/
#include <libuecc/ecc.h>
-/** The identity element */
const ecc_25519_work_t ecc_25519_work_identity = {{0}, {1}, {1}, {0}};
-
-/** The ec25519 default base */
const ecc_25519_work_t ecc_25519_work_default_base = {
{0xd4, 0x6b, 0xfe, 0x7f, 0x39, 0xfa, 0x8c, 0x22,
0xe1, 0x96, 0x23, 0xeb, 0x26, 0xb7, 0x8e, 0x6a,
@@ -401,7 +400,6 @@ static void recip(unsigned int out[32], const unsigned int z[32]) {
/* 2^255 - 21 */ mult(out, t1, z11);
}
-/** Loads a point with given coordinates into its unpacked representation */
int ecc_25519_load_xy(ecc_25519_work_t *out, const ecc_int256_t *x, const ecc_int256_t *y) {
int i;
unsigned int X2[32], Y2[32], aX2[32], dX2[32], dX2Y2[32], aX2_Y2[32], _1_dX2Y2[32], r[32];
@@ -431,13 +429,6 @@ int ecc_25519_load_xy(ecc_25519_work_t *out, const ecc_int256_t *x, const ecc_in
return 1;
}
-/**
- * Stores a point's x and y coordinates
- *
- * \param x Returns the x coordinate of the point. May be NULL.
- * \param y Returns the y coordinate of the point. May be NULL.
- * \param in The unpacked point to store.
- */
void ecc_25519_store_xy(ecc_int256_t *x, ecc_int256_t *y, const ecc_25519_work_t *in) {
unsigned int X[32], Y[32], Z[32];
int i;
@@ -459,7 +450,6 @@ void ecc_25519_store_xy(ecc_int256_t *x, ecc_int256_t *y, const ecc_25519_work_t
}
}
-/** Loads a packed point into its unpacked representation */
int ecc_25519_load_packed(ecc_25519_work_t *out, const ecc_int256_t *in) {
int i;
unsigned int X2[32] /* X^2 */, aX2[32] /* aX^2 */, dX2[32] /* dX^2 */, _1_aX2[32] /* 1-aX^2 */, _1_dX2[32] /* 1-aX^2 */;
@@ -492,7 +482,6 @@ int ecc_25519_load_packed(ecc_25519_work_t *out, const ecc_int256_t *in) {
return 1;
}
-/** Stores a point into its packed representation */
void ecc_25519_store_packed(ecc_int256_t *out, const ecc_25519_work_t *in) {
ecc_int256_t y;
@@ -500,7 +489,6 @@ void ecc_25519_store_packed(ecc_int256_t *out, const ecc_25519_work_t *in) {
out->p[31] |= (y.p[0] << 7);
}
-/** Checks if a point is the identity element of the Elliptic Curve group */
int ecc_25519_is_identity(const ecc_25519_work_t *in) {
unsigned int Y_Z[32];
@@ -510,13 +498,6 @@ int ecc_25519_is_identity(const ecc_25519_work_t *in) {
return (check_zero(in->X)&check_zero(Y_Z));
}
-/**
- * Doubles a point of the Elliptic Curve
- *
- * ecc_25519_double(out, in) is equivalent to ecc_25519_add(out, in, in), but faster.
- *
- * The same pointers may be used for input and output.
- */
void ecc_25519_double(ecc_25519_work_t *out, const ecc_25519_work_t *in) {
unsigned int A[32], B[32], C[32], D[32], E[32], F[32], G[32], H[32], t0[32], t1[32], t2[32], t3[32];
@@ -538,11 +519,6 @@ void ecc_25519_double(ecc_25519_work_t *out, const ecc_25519_work_t *in) {
mult(out->Z, F, G);
}
-/**
- * Adds two points of the Elliptic Curve
- *
- * The same pointers may be used for input and output.
- */
void ecc_25519_add(ecc_25519_work_t *out, const ecc_25519_work_t *in1, const ecc_25519_work_t *in2) {
unsigned int A[32], B[32], C[32], D[32], E[32], F[32], G[32], H[32], t0[32], t1[32], t2[32], t3[32], t4[32], t5[32];
@@ -566,15 +542,6 @@ void ecc_25519_add(ecc_25519_work_t *out, const ecc_25519_work_t *in1, const ecc
mult(out->Z, F, G);
}
-/**
- * Does a scalar multiplication of a point of the Elliptic Curve with an integer of a given bit length
- *
- * To speed up scalar multiplication when it is known that not the whole 256 bits of the scalar
- * are used. The bit length should always be a constant and not computed at runtime to ensure
- * that no timing attacks are possible.
- *
- * The same pointers may be used for input and output.
- **/
void ecc_25519_scalarmult_bits(ecc_25519_work_t *out, const ecc_int256_t *n, const ecc_25519_work_t *base, unsigned bits) {
ecc_25519_work_t Q2, Q2p;
ecc_25519_work_t cur = ecc_25519_work_identity;
@@ -595,31 +562,14 @@ void ecc_25519_scalarmult_bits(ecc_25519_work_t *out, const ecc_int256_t *n, con
*out = cur;
}
-/**
- * Does a scalar multiplication of a point of the Elliptic Curve with an integer
- *
- * The same pointers may be used for input and output.
- **/
void ecc_25519_scalarmult(ecc_25519_work_t *out, const ecc_int256_t *n, const ecc_25519_work_t *base) {
ecc_25519_scalarmult_bits(out, n, base, 256);
}
-/**
- * Does a scalar multiplication of the default base point (generator element) of the Elliptic Curve with an integer of a given bit length
- *
- * The order of the base point is \f$ 2^{252} + 27742317777372353535851937790883648493 \f$.
- *
- * See the notes about \ref ecc_25519_scalarmult_bits before using this function.
- */
void ecc_25519_scalarmult_base_bits(ecc_25519_work_t *out, const ecc_int256_t *n, unsigned bits) {
ecc_25519_scalarmult_bits(out, n, &ecc_25519_work_default_base, bits);
}
-/**
- * Does a scalar multiplication of the default base point (generator element) of the Elliptic Curve with an integer
- *
- * The order of the base point is \f$ 2^{252} + 27742317777372353535851937790883648493 \f$.
- */
void ecc_25519_scalarmult_base(ecc_25519_work_t *out, const ecc_int256_t *n) {
ecc_25519_scalarmult(out, n, &ecc_25519_work_default_base);
}
diff --git a/src/ec25519_gf.c b/src/ec25519_gf.c
index 4914fa7..4059c31 100644
--- a/src/ec25519_gf.c
+++ b/src/ec25519_gf.c
@@ -25,10 +25,12 @@
*/
/** \file
- Simple finite field operations on the prime field \f$ F_q \f$ for
- \f$ q = 2^{252} + 27742317777372353535851937790883648493 \f$, which
- is the order of the base point used for ec25519
-*/
+ * Simple finite field operations on the prime field \f$ F_q \f$ for
+ * \f$ q = 2^{252} + 27742317777372353535851937790883648493 \f$, which
+ * is the order of the base point used for ec25519
+ *
+ * Doxygen comments for public APIs can be found in the public header file.
+ */
#include <libuecc/ecc.h>
@@ -40,11 +42,6 @@
#define ASR(n,s) (((n) >> s)|(IS_NEGATIVE(n)*((unsigned)-1) << (8*sizeof(n)-s)))
-/**
- * The order of the prime field
- *
- * The order is \f$ 2^{252} + 27742317777372353535851937790883648493 \f$.
- */
const ecc_int256_t ecc_25519_gf_order = {{
0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58,
0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14,
@@ -70,7 +67,6 @@ static void select(unsigned char out[32], const unsigned char r[32], const unsig
}
}
-/** Checks if an integer is equal to zero (after reduction) */
int ecc_25519_gf_is_zero(const ecc_int256_t *in) {
int i;
ecc_int256_t r;
@@ -84,11 +80,6 @@ int ecc_25519_gf_is_zero(const ecc_int256_t *in) {
return (((bits-1)>>8) & 1);
}
-/**
- * Adds two integers as Galois field elements
- *
- * The same pointers may be used for input and output.
- */
void ecc_25519_gf_add(ecc_int256_t *out, const ecc_int256_t *in1, const ecc_int256_t *in2) {
unsigned int j;
unsigned int u;
@@ -103,11 +94,6 @@ void ecc_25519_gf_add(ecc_int256_t *out, const ecc_int256_t *in1, const ecc_int2
}
}
-/**
- * Subtracts two integers as Galois field elements
- *
- * The same pointers may be used for input and output.
- */
void ecc_25519_gf_sub(ecc_int256_t *out, const ecc_int256_t *in1, const ecc_int256_t *in2) {
unsigned int j;
unsigned int u;
@@ -145,11 +131,6 @@ static void reduce(unsigned char a[32]) {
select(a, out1, out2, IS_NEGATIVE(u1));
}
-/**
- * Reduces an integer to a unique representation in the range \f$ [0,q-1] \f$
- *
- * The same pointers may be used for input and output.
- */
void ecc_25519_gf_reduce(ecc_int256_t *out, const ecc_int256_t *in) {
int i;
@@ -183,11 +164,6 @@ static void montgomery(unsigned char out[32], const unsigned char a[32], const u
}
}
-/**
- * Multiplies two integers as Galois field elements
- *
- * The same pointers may be used for input and output.
- */
void ecc_25519_gf_mult(ecc_int256_t *out, const ecc_int256_t *in1, const ecc_int256_t *in2) {
/* 2^512 mod q */
static const unsigned char C[32] = {
@@ -210,11 +186,6 @@ void ecc_25519_gf_mult(ecc_int256_t *out, const ecc_int256_t *in1, const ecc_int
montgomery(out->p, R, C);
}
-/**
- * Computes the reciprocal of a Galois field element
- *
- * The same pointers may be used for input and output.
- */
void ecc_25519_gf_recip(ecc_int256_t *out, const ecc_int256_t *in) {
static const unsigned char C[32] = {
0x01
@@ -268,15 +239,6 @@ void ecc_25519_gf_recip(ecc_int256_t *out, const ecc_int256_t *in) {
montgomery(out->p, R2, C);
}
-/**
- * Ensures some properties of a Galois field element to make it fit for use as a secret key
- *
- * This sets the 255th bit and clears the 256th and the bottom three bits (so the key
- * will be a multiple of 8). See Daniel J. Bernsteins paper "Curve25519: new Diffie-Hellman speed records."
- * for the rationale of this.
- *
- * The same pointers may be used for input and output.
- */
void ecc_25519_gf_sanitize_secret(ecc_int256_t *out, const ecc_int256_t *in) {
int i;