Merge pull request #62 from aeruder/master
miscellaneous documentation and whitespace cleanups
diff --git a/test/test_ecdsa_deterministic.c.example b/test/test_ecdsa_deterministic.c.example
index 5e5cde0..df9aa10 100644
--- a/test/test_ecdsa_deterministic.c.example
+++ b/test/test_ecdsa_deterministic.c.example
@@ -23,19 +23,19 @@
SHA256_CTX ctx;
} SHA256_HashContext;
-static void init_SHA256(uECC_HashContext *base) {
+static void init_SHA256(const uECC_HashContext *base) {
SHA256_HashContext *context = (SHA256_HashContext *)base;
SHA256_Init(&context->ctx);
}
-static void update_SHA256(uECC_HashContext *base,
+static void update_SHA256(const uECC_HashContext *base,
const uint8_t *message,
unsigned message_size) {
SHA256_HashContext *context = (SHA256_HashContext *)base;
SHA256_Update(&context->ctx, message, message_size);
}
-static void finish_SHA256(uECC_HashContext *base, uint8_t *hash_result) {
+static void finish_SHA256(const uECC_HashContext *base, uint8_t *hash_result) {
SHA256_HashContext *context = (SHA256_HashContext *)base;
SHA256_Final(hash_result, &context->ctx);
}
@@ -76,12 +76,12 @@
}
memcpy(hash, public, sizeof(hash));
- if (!uECC_sign_deterministic(private, hash, &ctx.uECC, sig, curves[c])) {
+ if (!uECC_sign_deterministic(private, hash, sizeof(hash), &ctx.uECC, sig, curves[c])) {
printf("uECC_sign() failed\n");
return 1;
}
- if (!uECC_verify(public, hash, sig, curves[c])) {
+ if (!uECC_verify(public, hash, sizeof(hash), sig, curves[c])) {
printf("uECC_verify() failed\n");
return 1;
}
diff --git a/uECC.c b/uECC.c
index ca887fa..26a95a6 100644
--- a/uECC.c
+++ b/uECC.c
@@ -172,7 +172,7 @@
#if default_RNG_defined
static uECC_RNG_Function g_rng_function = &default_RNG;
-#else
+#else
static uECC_RNG_Function g_rng_function = 0;
#endif
@@ -292,7 +292,7 @@
uECC_VLI_API void uECC_vli_rshift1(uECC_word_t *vli, wordcount_t num_words) {
uECC_word_t *end = vli;
uECC_word_t carry = 0;
-
+
vli += num_words;
while (vli-- > end) {
uECC_word_t temp = *vli;
@@ -475,7 +475,7 @@
uECC_word_t r2 = 0;
wordcount_t i, k;
-
+
for (k = 0; k < num_words * 2 - 1; ++k) {
uECC_word_t min = (k < num_words ? 0 : (k + 1) - num_words);
for (i = min; i <= k && i <= k - i; ++i) {
@@ -490,7 +490,7 @@
r1 = r2;
r2 = 0;
}
-
+
result[num_words * 2 - 1] = r0;
}
#endif /* !asm_square */
@@ -504,7 +504,7 @@
uECC_vli_mult(result, left, left, num_words);
}
#endif /* uECC_ENABLE_VLI_API */
-
+
#endif /* uECC_SQUARE_FUNC */
/* Computes result = (left + right) % mod.
@@ -546,7 +546,7 @@
uECC_word_t tmp[2 * uECC_MAX_WORDS];
uECC_word_t *v[2] = {tmp, product};
uECC_word_t index;
-
+
/* Shift mod so its highest set bit is at the maximum position. */
bitcount_t shift = (num_words * 2 * uECC_WORD_BITS) - uECC_vli_numBits(mod, num_words);
wordcount_t word_shift = shift / uECC_WORD_BITS;
@@ -646,7 +646,7 @@
uECC_Curve curve) {
uECC_vli_modMult_fast(result, left, left, curve);
}
-
+
#endif /* uECC_SQUARE_FUNC */
#define EVEN(vli) (!(vli[0] & 1))
@@ -671,7 +671,7 @@
wordcount_t num_words) {
uECC_word_t a[uECC_MAX_WORDS], b[uECC_MAX_WORDS], u[uECC_MAX_WORDS], v[uECC_MAX_WORDS];
cmpresult_t cmpResult;
-
+
if (uECC_vli_isZero(input, num_words)) {
uECC_vli_clear(result, num_words);
return;
@@ -770,14 +770,14 @@
/* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */
uECC_word_t t5[uECC_MAX_WORDS];
wordcount_t num_words = curve->num_words;
-
+
uECC_vli_modSub(t5, X2, X1, curve->p, num_words); /* t5 = x2 - x1 */
uECC_vli_modSquare_fast(t5, t5, curve); /* t5 = (x2 - x1)^2 = A */
uECC_vli_modMult_fast(X1, X1, t5, curve); /* t1 = x1*A = B */
uECC_vli_modMult_fast(X2, X2, t5, curve); /* t3 = x2*A = C */
uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = y2 - y1 */
uECC_vli_modSquare_fast(t5, Y2, curve); /* t5 = (y2 - y1)^2 = D */
-
+
uECC_vli_modSub(t5, t5, X1, curve->p, num_words); /* t5 = D - B */
uECC_vli_modSub(t5, t5, X2, curve->p, num_words); /* t5 = D - B - C = x3 */
uECC_vli_modSub(X2, X2, X1, curve->p, num_words); /* t3 = C - B */
@@ -785,7 +785,7 @@
uECC_vli_modSub(X2, X1, t5, curve->p, num_words); /* t3 = B - x3 */
uECC_vli_modMult_fast(Y2, Y2, X2, curve); /* t4 = (y2 - y1)*(B - x3) */
uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = y3 */
-
+
uECC_vli_set(X2, t5, num_words);
}
@@ -803,30 +803,30 @@
uECC_word_t t6[uECC_MAX_WORDS];
uECC_word_t t7[uECC_MAX_WORDS];
wordcount_t num_words = curve->num_words;
-
+
uECC_vli_modSub(t5, X2, X1, curve->p, num_words); /* t5 = x2 - x1 */
uECC_vli_modSquare_fast(t5, t5, curve); /* t5 = (x2 - x1)^2 = A */
uECC_vli_modMult_fast(X1, X1, t5, curve); /* t1 = x1*A = B */
uECC_vli_modMult_fast(X2, X2, t5, curve); /* t3 = x2*A = C */
uECC_vli_modAdd(t5, Y2, Y1, curve->p, num_words); /* t5 = y2 + y1 */
uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = y2 - y1 */
-
+
uECC_vli_modSub(t6, X2, X1, curve->p, num_words); /* t6 = C - B */
uECC_vli_modMult_fast(Y1, Y1, t6, curve); /* t2 = y1 * (C - B) = E */
uECC_vli_modAdd(t6, X1, X2, curve->p, num_words); /* t6 = B + C */
uECC_vli_modSquare_fast(X2, Y2, curve); /* t3 = (y2 - y1)^2 = D */
uECC_vli_modSub(X2, X2, t6, curve->p, num_words); /* t3 = D - (B + C) = x3 */
-
+
uECC_vli_modSub(t7, X1, X2, curve->p, num_words); /* t7 = B - x3 */
uECC_vli_modMult_fast(Y2, Y2, t7, curve); /* t4 = (y2 - y1)*(B - x3) */
uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = (y2 - y1)*(B - x3) - E = y3 */
-
+
uECC_vli_modSquare_fast(t7, t5, curve); /* t7 = (y2 + y1)^2 = F */
uECC_vli_modSub(t7, t7, t6, curve->p, num_words); /* t7 = F - (B + C) = x3' */
uECC_vli_modSub(t6, t7, X1, curve->p, num_words); /* t6 = x3' - B */
uECC_vli_modMult_fast(t6, t6, t5, curve); /* t6 = (y2+y1)*(x3' - B) */
uECC_vli_modSub(Y1, t6, Y1, curve->p, num_words); /* t2 = (y2+y1)*(x3' - B) - E = y3' */
-
+
uECC_vli_set(X1, t7, num_words);
}
@@ -844,7 +844,7 @@
bitcount_t i;
uECC_word_t nb;
wordcount_t num_words = curve->num_words;
-
+
uECC_vli_set(Rx[1], point, num_words);
uECC_vli_set(Ry[1], point + num_words, num_words);
@@ -858,20 +858,20 @@
nb = !uECC_vli_testBit(scalar, 0);
XYcZ_addC(Rx[1 - nb], Ry[1 - nb], Rx[nb], Ry[nb], curve);
-
+
/* Find final 1/Z value. */
uECC_vli_modSub(z, Rx[1], Rx[0], curve->p, num_words); /* X1 - X0 */
uECC_vli_modMult_fast(z, z, Ry[1 - nb], curve); /* Yb * (X1 - X0) */
uECC_vli_modMult_fast(z, z, point, curve); /* xP * Yb * (X1 - X0) */
uECC_vli_modInv(z, z, curve->p, num_words); /* 1 / (xP * Yb * (X1 - X0)) */
/* yP / (xP * Yb * (X1 - X0)) */
- uECC_vli_modMult_fast(z, z, point + num_words, curve);
+ uECC_vli_modMult_fast(z, z, point + num_words, curve);
uECC_vli_modMult_fast(z, z, Rx[1 - nb], curve); /* Xb * yP / (xP * Yb * (X1 - X0)) */
/* End 1/Z calculation */
XYcZ_add(Rx[nb], Ry[nb], Rx[1 - nb], Ry[1 - nb], curve);
apply_z(Rx[0], Ry[0], z, curve);
-
+
uECC_vli_set(result, Rx[0], num_words);
uECC_vli_set(result + num_words, Ry[0], num_words);
}
@@ -945,7 +945,7 @@
uECC_vli_clear(native, (num_bytes + (uECC_WORD_SIZE - 1)) / uECC_WORD_SIZE);
for (i = 0; i < num_bytes; ++i) {
unsigned b = num_bytes - 1 - i;
- native[b / uECC_WORD_SIZE] |=
+ native[b / uECC_WORD_SIZE] |=
(uECC_word_t)bytes[i] << (8 * (b % uECC_WORD_SIZE));
}
}
@@ -1013,15 +1013,15 @@
uECC_word_t carry;
wordcount_t num_words = curve->num_words;
wordcount_t num_bytes = curve->num_bytes;
-
+
uECC_vli_bytesToNative(private, private_key, BITS_TO_BYTES(curve->num_n_bits));
uECC_vli_bytesToNative(public, public_key, num_bytes);
uECC_vli_bytesToNative(public + num_words, public_key + num_bytes, num_bytes);
-
+
/* Regularize the bitcount for the private key so that attackers cannot use a side channel
attack to learn the number of leading zeros. */
carry = regularize_k(private, private, tmp, curve);
-
+
/* If an RNG function was specified, try to get a random initial Z value to improve
protection against side-channel attacks. */
if (g_rng_function) {
@@ -1030,7 +1030,7 @@
}
initial_Z = p2[carry];
}
-
+
EccPoint_mult(public, public, p2[!carry], initial_Z, curve->num_n_bits + 1, curve);
uECC_vli_nativeToBytes(secret, num_bytes, public);
return !EccPoint_isZero(public, curve);
@@ -1051,11 +1051,11 @@
uECC_vli_bytesToNative(point, compressed + 1, curve->num_bytes);
curve->x_side(y, point, curve);
curve->mod_sqrt(y, curve);
-
+
if ((y[0] & 0x01) != (compressed[0] & 0x01)) {
uECC_vli_sub(y, curve->p, y, curve->num_words);
}
-
+
uECC_vli_nativeToBytes(public_key, curve->num_bytes, point);
uECC_vli_nativeToBytes(public_key + curve->num_bytes, curve->num_bytes, y);
}
@@ -1070,16 +1070,16 @@
if (EccPoint_isZero(point, curve)) {
return 0;
}
-
+
/* x and y must be smaller than p. */
if (uECC_vli_cmp_unsafe(curve->p, point, num_words) != 1 ||
uECC_vli_cmp_unsafe(curve->p, point + num_words, num_words) != 1) {
return 0;
}
-
+
uECC_vli_modSquare_fast(tmp1, point + num_words, curve);
curve->x_side(tmp2, point, curve); /* tmp2 = x^3 + ax + b */
-
+
/* Make sure that y^2 == x^3 + ax + b */
return (int)(uECC_vli_equal(tmp1, tmp2, num_words));
}
@@ -1165,18 +1165,18 @@
wordcount_t num_words = curve->num_words;
wordcount_t num_n_words = BITS_TO_WORDS(curve->num_n_bits);
bitcount_t num_n_bits = curve->num_n_bits;
-
+
/* Make sure 0 < k < curve_n */
if (uECC_vli_isZero(k, num_words) || uECC_vli_cmp(curve->n, k, num_n_words) != 1) {
return 0;
}
-
+
carry = regularize_k(k, tmp, s, curve);
EccPoint_mult(p, curve->G, k2[!carry], 0, num_n_bits + 1, curve);
if (uECC_vli_isZero(p, num_words)) {
return 0;
}
-
+
/* If an RNG function was specified, get a random number
to prevent side channel analysis of k. */
if (!g_rng_function) {
@@ -1191,9 +1191,9 @@
uECC_vli_modMult(k, k, tmp, curve->n, num_n_words); /* k' = rand * k */
uECC_vli_modInv(k, k, curve->n, num_n_words); /* k = 1 / k' */
uECC_vli_modMult(k, k, tmp, curve->n, num_n_words); /* k = 1 / k */
-
+
uECC_vli_nativeToBytes(signature, curve->num_bytes, p); /* store r */
-
+
uECC_vli_bytesToNative(tmp, private_key, BITS_TO_BYTES(curve->num_n_bits)); /* tmp = d */
s[num_n_words - 1] = 0;
uECC_vli_set(s, p, num_words);
@@ -1231,7 +1231,7 @@
/* Compute an HMAC using K as a key (as in RFC 6979). Note that K is always
the same size as the hash result size. */
-static void HMAC_init(uECC_HashContext *hash_context, const uint8_t *K) {
+static void HMAC_init(const uECC_HashContext *hash_context, const uint8_t *K) {
uint8_t *pad = hash_context->tmp + 2 * hash_context->result_size;
unsigned i;
for (i = 0; i < hash_context->result_size; ++i)
@@ -1243,13 +1243,15 @@
hash_context->update_hash(hash_context, pad, hash_context->block_size);
}
-static void HMAC_update(uECC_HashContext *hash_context,
+static void HMAC_update(const uECC_HashContext *hash_context,
const uint8_t *message,
unsigned message_size) {
hash_context->update_hash(hash_context, message, message_size);
}
-static void HMAC_finish(uECC_HashContext *hash_context, const uint8_t *K, uint8_t *result) {
+static void HMAC_finish(const uECC_HashContext *hash_context,
+ const uint8_t *K,
+ uint8_t *result) {
uint8_t *pad = hash_context->tmp + 2 * hash_context->result_size;
unsigned i;
for (i = 0; i < hash_context->result_size; ++i)
@@ -1266,7 +1268,7 @@
}
/* V = HMAC_K(V) */
-static void update_V(uECC_HashContext *hash_context, uint8_t *K, uint8_t *V) {
+static void update_V(const uECC_HashContext *hash_context, uint8_t *K, uint8_t *V) {
HMAC_init(hash_context, K);
HMAC_update(hash_context, V, hash_context->result_size);
HMAC_finish(hash_context, K, V);
@@ -1281,7 +1283,7 @@
int uECC_sign_deterministic(const uint8_t *private_key,
const uint8_t *message_hash,
unsigned hash_size,
- uECC_HashContext *hash_context,
+ const uECC_HashContext *hash_context,
uint8_t *signature,
uECC_Curve curve) {
uint8_t *K = hash_context->tmp;
@@ -1295,7 +1297,7 @@
V[i] = 0x01;
K[i] = 0;
}
-
+
/* K = HMAC_K(V || 0x00 || int2octets(x) || h(m)) */
HMAC_init(hash_context, K);
V[hash_context->result_size] = 0x00;
@@ -1305,7 +1307,7 @@
HMAC_finish(hash_context, K, K);
update_V(hash_context, K, V);
-
+
/* K = HMAC_K(V || 0x01 || int2octets(x) || h(m)) */
HMAC_init(hash_context, K);
V[hash_context->result_size] = 0x01;
@@ -1335,7 +1337,7 @@
T[num_n_words - 1] &=
mask >> ((bitcount_t)(num_n_words * uECC_WORD_SIZE * 8 - num_n_bits));
}
-
+
if (uECC_sign_with_k(private_key, message_hash, hash_size, T, signature, curve)) {
return 1;
}
@@ -1376,7 +1378,7 @@
uECC_word_t r[uECC_MAX_WORDS], s[uECC_MAX_WORDS];
wordcount_t num_words = curve->num_words;
wordcount_t num_n_words = BITS_TO_WORDS(curve->num_n_bits);
-
+
rx[num_n_words - 1] = 0;
r[num_n_words - 1] = 0;
s[num_n_words - 1] = 0;
@@ -1386,7 +1388,7 @@
public + num_words, public_key + curve->num_bytes, curve->num_bytes);
uECC_vli_bytesToNative(r, signature, curve->num_bytes);
uECC_vli_bytesToNative(s, signature + curve->num_bytes, curve->num_bytes);
-
+
/* r, s must not be 0. */
if (uECC_vli_isZero(r, num_words) || uECC_vli_isZero(s, num_words)) {
return 0;
@@ -1404,7 +1406,7 @@
bits2int(u1, message_hash, hash_size, curve);
uECC_vli_modMult(u1, u1, z, curve->n, num_n_words); /* u1 = e/s */
uECC_vli_modMult(u2, r, z, curve->n, num_n_words); /* u2 = r/s */
-
+
/* Calculate sum = G + Q. */
uECC_vli_set(sum, public, num_words);
uECC_vli_set(sum + num_words, public + num_words, num_words);
@@ -1414,7 +1416,7 @@
XYcZ_add(tx, ty, sum, sum + num_words, curve);
uECC_vli_modInv(z, z, curve->p, num_words); /* z = 1/z */
apply_z(sum, sum + num_words, z, curve);
-
+
/* Use Shamir's trick to calculate u1*G + u2*Q */
points[0] = 0;
points[1] = curve->G;
@@ -1422,7 +1424,7 @@
points[3] = sum;
num_bits = smax(uECC_vli_numBits(u1, num_n_words),
uECC_vli_numBits(u2, num_n_words));
-
+
point = points[(!!uECC_vli_testBit(u1, num_bits - 1)) |
((!!uECC_vli_testBit(u2, num_bits - 1)) << 1)];
uECC_vli_set(rx, point, num_words);
@@ -1433,7 +1435,7 @@
for (i = num_bits - 2; i >= 0; --i) {
uECC_word_t index;
curve->double_jacobian(rx, ry, z, curve);
-
+
index = (!!uECC_vli_testBit(u1, i)) | ((!!uECC_vli_testBit(u2, i)) << 1);
point = points[index];
if (point) {
@@ -1448,7 +1450,7 @@
uECC_vli_modInv(z, z, curve->p, num_words); /* Z = 1/Z */
apply_z(rx, ry, z, curve);
-
+
/* v = x1 (mod n) */
if (uECC_vli_cmp_unsafe(curve->n, rx, num_n_words) != 1) {
uECC_vli_sub(rx, rx, curve->n, num_n_words);
diff --git a/uECC.h b/uECC.h
index 5775bdb..f753a51 100644
--- a/uECC.h
+++ b/uECC.h
@@ -122,8 +122,8 @@
private_key - Will be filled in with the private key. Must be as long as the curve order; this
is typically the same as the curve size, except for secp160r1. For example, if the
curve is secp256r1, private_key must be 32 bytes long.
-
- For secp160r1, private_key must be 21 bytes long! Note that the first byte will
+
+ For secp160r1, private_key must be 21 bytes long! Note that the first byte will
almost always be 0 (there is about a 1 in 2^80 chance of it being non-zero).
Returns 1 if the key pair was generated successfully, 0 if an error occurred.
@@ -265,11 +265,11 @@
}
*/
typedef struct uECC_HashContext {
- void (*init_hash)(struct uECC_HashContext *context);
- void (*update_hash)(struct uECC_HashContext *context,
+ void (*init_hash)(const struct uECC_HashContext *context);
+ void (*update_hash)(const struct uECC_HashContext *context,
const uint8_t *message,
unsigned message_size);
- void (*finish_hash)(struct uECC_HashContext *context, uint8_t *hash_result);
+ void (*finish_hash)(const struct uECC_HashContext *context, uint8_t *hash_result);
unsigned block_size; /* Hash function block size in bytes, eg 64 for SHA-256. */
unsigned result_size; /* Hash function result size in bytes, eg 32 for SHA-256. */
uint8_t *tmp; /* Must point to a buffer of at least (2 * result_size + block_size) bytes. */
@@ -299,7 +299,7 @@
int uECC_sign_deterministic(const uint8_t *private_key,
const uint8_t *message_hash,
unsigned hash_size,
- uECC_HashContext *hash_context,
+ const uECC_HashContext *hash_context,
uint8_t *signature,
uECC_Curve curve);
@@ -317,7 +317,7 @@
Returns 1 if the signature is valid, 0 if it is invalid.
*/
-int uECC_verify(const uint8_t *private_key,
+int uECC_verify(const uint8_t *public_key,
const uint8_t *message_hash,
unsigned hash_size,
const uint8_t *signature,
