#include <string.h>
#include "internal/numbers.h"
-#define API_NAME "decaf_448"
-
-#define NO_CONTEXT DECAF_EDDSA_448_SUPPORTS_CONTEXTLESS_SIGS
-#define EDDSA_USE_SIGMA_ISOGENY 0
#define COFACTOR 4
-#define EDDSA_PREHASH_BYTES 64
-
-#if NO_CONTEXT
-const uint8_t NO_CONTEXT_POINTS_HERE = 0;
-const uint8_t * const DECAF_ED448_NO_CONTEXT = &NO_CONTEXT_POINTS_HERE;
-#endif
-
-/* EDDSA_BASE_POINT_RATIO = 1 or 2
- * Because EdDSA25519 is not on E_d but on the isogenous E_sigma_d,
- * its base point is twice ours.
- */
-#define EDDSA_BASE_POINT_RATIO (1+EDDSA_USE_SIGMA_ISOGENY) /* TODO: remove */
static decaf_error_t oneshot_hash(uint8_t *out, size_t outlen,
const uint8_t *in, size_t inlen)
return DECAF_FAILURE;
if (!EVP_DigestInit_ex(hashctx, EVP_shake256(), NULL)
- || !EVP_DigestUpdate(hashctx, in, inlen)
- || !EVP_DigestFinalXOF(hashctx, out, outlen)) {
+ || !EVP_DigestUpdate(hashctx, in, inlen)
+ || !EVP_DigestFinalXOF(hashctx, out, outlen)) {
EVP_MD_CTX_free(hashctx);
return DECAF_FAILURE;
}
return DECAF_SUCCESS;
}
-
-static void clamp (
- uint8_t secret_scalar_ser[DECAF_EDDSA_448_PRIVATE_BYTES]
-) {
- uint8_t hibit = (1<<0)>>1;
+static void clamp(uint8_t secret_scalar_ser[DECAF_EDDSA_448_PRIVATE_BYTES])
+{
+ uint8_t hibit = (1 << 0) >> 1;
/* Blarg */
secret_scalar_ser[0] &= -COFACTOR;
secret_scalar_ser[DECAF_EDDSA_448_PRIVATE_BYTES - 1] = 0;
secret_scalar_ser[DECAF_EDDSA_448_PRIVATE_BYTES - 2] |= 0x80;
} else {
- secret_scalar_ser[DECAF_EDDSA_448_PRIVATE_BYTES - 1] &= hibit-1;
+ secret_scalar_ser[DECAF_EDDSA_448_PRIVATE_BYTES - 1] &= hibit - 1;
secret_scalar_ser[DECAF_EDDSA_448_PRIVATE_BYTES - 1] |= hibit;
}
}
-static decaf_error_t hash_init_with_dom(
- EVP_MD_CTX *hashctx,
- uint8_t prehashed,
- uint8_t for_prehash,
- const uint8_t *context,
- size_t context_len
-) {
+static decaf_error_t hash_init_with_dom(EVP_MD_CTX *hashctx,
+ uint8_t prehashed,
+ uint8_t for_prehash,
+ const uint8_t *context,
+ size_t context_len)
+{
const char *dom_s = "SigEd448";
uint8_t dom[2];
if (context_len > UINT8_MAX)
return DECAF_FAILURE;
-#if NO_CONTEXT
- if (context_len == 0 && context == DECAF_ED448_NO_CONTEXT) {
- (void)prehashed;
- (void)for_prehash;
- (void)context;
- (void)context_len;
- return DECAF_SUCCESS;
- }
-#endif
-
if (!EVP_DigestInit_ex(hashctx, EVP_shake256(), NULL)
- || !EVP_DigestUpdate(hashctx, dom_s, strlen(dom_s))
- || !EVP_DigestUpdate(hashctx, dom, sizeof(dom))
- || !EVP_DigestUpdate(hashctx, context, context_len))
+ || !EVP_DigestUpdate(hashctx, dom_s, strlen(dom_s))
+ || !EVP_DigestUpdate(hashctx, dom, sizeof(dom))
+ || !EVP_DigestUpdate(hashctx, context, context_len))
return DECAF_FAILURE;
return DECAF_SUCCESS;
}
/* In this file because it uses the hash */
-decaf_error_t decaf_ed448_convert_private_key_to_x448 (
- uint8_t x[DECAF_X448_PRIVATE_BYTES],
- const uint8_t ed[DECAF_EDDSA_448_PRIVATE_BYTES]
-) {
+decaf_error_t decaf_ed448_convert_private_key_to_x448(
+ uint8_t x[DECAF_X448_PRIVATE_BYTES],
+ const uint8_t ed [DECAF_EDDSA_448_PRIVATE_BYTES])
+{
/* pass the private key through oneshot_hash function */
/* and keep the first DECAF_X448_PRIVATE_BYTES bytes */
- return oneshot_hash(
- x,
- DECAF_X448_PRIVATE_BYTES,
- ed,
- DECAF_EDDSA_448_PRIVATE_BYTES
- );
+ return oneshot_hash(x,
+ DECAF_X448_PRIVATE_BYTES,
+ ed, DECAF_EDDSA_448_PRIVATE_BYTES);
}
-
-decaf_error_t decaf_ed448_derive_public_key (
- uint8_t pubkey[DECAF_EDDSA_448_PUBLIC_BYTES],
- const uint8_t privkey[DECAF_EDDSA_448_PRIVATE_BYTES]
-) {
+
+decaf_error_t decaf_ed448_derive_public_key(
+ uint8_t pubkey[DECAF_EDDSA_448_PUBLIC_BYTES],
+ const uint8_t privkey[DECAF_EDDSA_448_PRIVATE_BYTES])
+{
/* only this much used for keygen */
uint8_t secret_scalar_ser[DECAF_EDDSA_448_PRIVATE_BYTES];
curve448_scalar_t secret_scalar;
curve448_point_t p;
if (!oneshot_hash(secret_scalar_ser, sizeof(secret_scalar_ser), privkey,
- DECAF_EDDSA_448_PRIVATE_BYTES)) {
+ DECAF_EDDSA_448_PRIVATE_BYTES))
return DECAF_FAILURE;
- }
+
clamp(secret_scalar_ser);
- curve448_scalar_decode_long(secret_scalar, secret_scalar_ser, sizeof(secret_scalar_ser));
-
- /* Since we are going to mul_by_cofactor during encoding, divide by it here.
- * However, the EdDSA base point is not the same as the decaf base point if
- * the sigma isogeny is in use: the EdDSA base point is on Etwist_d/(1-d) and
- * the decaf base point is on Etwist_d, and when converted it effectively
- * picks up a factor of 2 from the isogenies. So we might start at 2 instead of 1.
+ curve448_scalar_decode_long(secret_scalar, secret_scalar_ser,
+ sizeof(secret_scalar_ser));
+
+ /*
+ * Since we are going to mul_by_cofactor during encoding, divide by it
+ * here. However, the EdDSA base point is not the same as the decaf base
+ * point if the sigma isogeny is in use: the EdDSA base point is on
+ * Etwist_d/(1-d) and the decaf base point is on Etwist_d, and when
+ * converted it effectively picks up a factor of 2 from the isogenies. So
+ * we might start at 2 instead of 1.
*/
- for (c=1; c<DECAF_448_EDDSA_ENCODE_RATIO; c <<= 1) {
- curve448_scalar_halve(secret_scalar,secret_scalar);
- }
-
- curve448_precomputed_scalarmul(p,curve448_precomputed_base,secret_scalar);
-
+ for (c = 1; c < DECAF_448_EDDSA_ENCODE_RATIO; c <<= 1)
+ curve448_scalar_halve(secret_scalar, secret_scalar);
+
+ curve448_precomputed_scalarmul(p, curve448_precomputed_base, secret_scalar);
+
curve448_point_mul_by_ratio_and_encode_like_eddsa(pubkey, p);
-
+
/* Cleanup */
curve448_scalar_destroy(secret_scalar);
curve448_point_destroy(p);
return DECAF_SUCCESS;
}
-decaf_error_t decaf_ed448_sign (
- uint8_t signature[DECAF_EDDSA_448_SIGNATURE_BYTES],
- const uint8_t privkey[DECAF_EDDSA_448_PRIVATE_BYTES],
- const uint8_t pubkey[DECAF_EDDSA_448_PUBLIC_BYTES],
- const uint8_t *message,
- size_t message_len,
- uint8_t prehashed,
- const uint8_t *context,
- size_t context_len
-) {
+decaf_error_t decaf_ed448_sign(
+ uint8_t signature[DECAF_EDDSA_448_SIGNATURE_BYTES],
+ const uint8_t privkey[DECAF_EDDSA_448_PRIVATE_BYTES],
+ const uint8_t pubkey[DECAF_EDDSA_448_PUBLIC_BYTES],
+ const uint8_t *message, size_t message_len,
+ uint8_t prehashed, const uint8_t *context,
+ size_t context_len)
+{
curve448_scalar_t secret_scalar;
EVP_MD_CTX *hashctx = EVP_MD_CTX_new();
decaf_error_t ret = DECAF_FAILURE;
curve448_scalar_t nonce_scalar;
- uint8_t nonce_point[DECAF_EDDSA_448_PUBLIC_BYTES] = {0};
+ uint8_t nonce_point[DECAF_EDDSA_448_PUBLIC_BYTES] = { 0 };
unsigned int c;
curve448_scalar_t challenge_scalar;
struct {
uint8_t secret_scalar_ser[DECAF_EDDSA_448_PRIVATE_BYTES];
uint8_t seed[DECAF_EDDSA_448_PRIVATE_BYTES];
- } __attribute__((packed)) expanded;
+ } __attribute__ ((packed)) expanded;
if (!oneshot_hash((uint8_t *)&expanded, sizeof(expanded), privkey,
DECAF_EDDSA_448_PRIVATE_BYTES))
goto err;
- clamp(expanded.secret_scalar_ser);
- curve448_scalar_decode_long(secret_scalar, expanded.secret_scalar_ser, sizeof(expanded.secret_scalar_ser));
-
+ clamp(expanded.secret_scalar_ser);
+ curve448_scalar_decode_long(secret_scalar, expanded.secret_scalar_ser,
+ sizeof(expanded.secret_scalar_ser));
+
/* Hash to create the nonce */
if (!hash_init_with_dom(hashctx, prehashed, 0, context, context_len)
- || !EVP_DigestUpdate(hashctx, expanded.seed,
- sizeof(expanded.seed))
- || !EVP_DigestUpdate(hashctx, message, message_len)) {
+ || !EVP_DigestUpdate(hashctx, expanded.seed, sizeof(expanded.seed))
+ || !EVP_DigestUpdate(hashctx, message, message_len)) {
OPENSSL_cleanse(&expanded, sizeof(expanded));
goto err;
}
OPENSSL_cleanse(&expanded, sizeof(expanded));
}
-
+
/* Decode the nonce */
{
- uint8_t nonce[2*DECAF_EDDSA_448_PRIVATE_BYTES];
+ uint8_t nonce[2 * DECAF_EDDSA_448_PRIVATE_BYTES];
if (!EVP_DigestFinalXOF(hashctx, nonce, sizeof(nonce)))
goto err;
curve448_scalar_t nonce_scalar_2;
curve448_point_t p;
- curve448_scalar_halve(nonce_scalar_2,nonce_scalar);
+ curve448_scalar_halve(nonce_scalar_2, nonce_scalar);
for (c = 2; c < DECAF_448_EDDSA_ENCODE_RATIO; c <<= 1) {
- curve448_scalar_halve(nonce_scalar_2,nonce_scalar_2);
+ curve448_scalar_halve(nonce_scalar_2, nonce_scalar_2);
}
- curve448_precomputed_scalarmul(p,curve448_precomputed_base,nonce_scalar_2);
+ curve448_precomputed_scalarmul(p, curve448_precomputed_base,
+ nonce_scalar_2);
curve448_point_mul_by_ratio_and_encode_like_eddsa(nonce_point, p);
curve448_point_destroy(p);
curve448_scalar_destroy(nonce_scalar_2);
}
{
- uint8_t challenge[2*DECAF_EDDSA_448_PRIVATE_BYTES];
+ uint8_t challenge[2 * DECAF_EDDSA_448_PRIVATE_BYTES];
/* Compute the challenge */
if (!hash_init_with_dom(hashctx, prehashed, 0, context, context_len)
- || !EVP_DigestUpdate(hashctx, nonce_point, sizeof(nonce_point))
- || !EVP_DigestUpdate(hashctx, pubkey,
- DECAF_EDDSA_448_PUBLIC_BYTES)
- || !EVP_DigestUpdate(hashctx, message, message_len)
- || !EVP_DigestFinalXOF(hashctx, challenge, sizeof(challenge)))
+ || !EVP_DigestUpdate(hashctx, nonce_point, sizeof(nonce_point))
+ || !EVP_DigestUpdate(hashctx, pubkey, DECAF_EDDSA_448_PUBLIC_BYTES)
+ || !EVP_DigestUpdate(hashctx, message, message_len)
+ || !EVP_DigestFinalXOF(hashctx, challenge, sizeof(challenge)))
goto err;
- curve448_scalar_decode_long(challenge_scalar,challenge,sizeof(challenge));
- OPENSSL_cleanse(challenge,sizeof(challenge));
+ curve448_scalar_decode_long(challenge_scalar, challenge,
+ sizeof(challenge));
+ OPENSSL_cleanse(challenge, sizeof(challenge));
}
-
- curve448_scalar_mul(challenge_scalar,challenge_scalar,secret_scalar);
- curve448_scalar_add(challenge_scalar,challenge_scalar,nonce_scalar);
-
- OPENSSL_cleanse(signature,DECAF_EDDSA_448_SIGNATURE_BYTES);
- memcpy(signature,nonce_point,sizeof(nonce_point));
- curve448_scalar_encode(&signature[DECAF_EDDSA_448_PUBLIC_BYTES],challenge_scalar);
-
+
+ curve448_scalar_mul(challenge_scalar, challenge_scalar, secret_scalar);
+ curve448_scalar_add(challenge_scalar, challenge_scalar, nonce_scalar);
+
+ OPENSSL_cleanse(signature, DECAF_EDDSA_448_SIGNATURE_BYTES);
+ memcpy(signature, nonce_point, sizeof(nonce_point));
+ curve448_scalar_encode(&signature[DECAF_EDDSA_448_PUBLIC_BYTES],
+ challenge_scalar);
+
curve448_scalar_destroy(secret_scalar);
curve448_scalar_destroy(nonce_scalar);
curve448_scalar_destroy(challenge_scalar);
return ret;
}
-
-decaf_error_t decaf_ed448_sign_prehash (
- uint8_t signature[DECAF_EDDSA_448_SIGNATURE_BYTES],
- const uint8_t privkey[DECAF_EDDSA_448_PRIVATE_BYTES],
- const uint8_t pubkey[DECAF_EDDSA_448_PUBLIC_BYTES],
- const uint8_t hash[64],
- const uint8_t *context,
- size_t context_len
-) {
- return decaf_ed448_sign(signature,privkey,pubkey,hash,64,1,context,
+decaf_error_t decaf_ed448_sign_prehash(uint8_t
+ signature
+ [DECAF_EDDSA_448_SIGNATURE_BYTES],
+ const uint8_t
+ privkey[DECAF_EDDSA_448_PRIVATE_BYTES],
+ const uint8_t
+ pubkey[DECAF_EDDSA_448_PUBLIC_BYTES],
+ const uint8_t hash[64],
+ const uint8_t *context,
+ size_t context_len)
+{
+ return decaf_ed448_sign(signature, privkey, pubkey, hash, 64, 1, context,
context_len);
- /*OPENSSL_cleanse(hash,sizeof(hash));*/
}
-decaf_error_t decaf_ed448_verify (
- const uint8_t signature[DECAF_EDDSA_448_SIGNATURE_BYTES],
- const uint8_t pubkey[DECAF_EDDSA_448_PUBLIC_BYTES],
- const uint8_t *message,
- size_t message_len,
- uint8_t prehashed,
- const uint8_t *context,
- uint8_t context_len
-) {
+decaf_error_t decaf_ed448_verify(const uint8_t
+ signature[DECAF_EDDSA_448_SIGNATURE_BYTES],
+ const uint8_t
+ pubkey[DECAF_EDDSA_448_PUBLIC_BYTES],
+ const uint8_t *message, size_t message_len,
+ uint8_t prehashed, const uint8_t *context,
+ uint8_t context_len)
+{
curve448_point_t pk_point, r_point;
- decaf_error_t error = curve448_point_decode_like_eddsa_and_mul_by_ratio(pk_point,pubkey);
+ decaf_error_t error =
+ curve448_point_decode_like_eddsa_and_mul_by_ratio(pk_point, pubkey);
curve448_scalar_t challenge_scalar;
curve448_scalar_t response_scalar;
unsigned int c;
- if (DECAF_SUCCESS != error) { return error; }
-
- error = curve448_point_decode_like_eddsa_and_mul_by_ratio(r_point,signature);
- if (DECAF_SUCCESS != error) { return error; }
-
+ if (DECAF_SUCCESS != error)
+ return error;
+
+ error =
+ curve448_point_decode_like_eddsa_and_mul_by_ratio(r_point, signature);
+ if (DECAF_SUCCESS != error)
+ return error;
+
{
/* Compute the challenge */
EVP_MD_CTX *hashctx = EVP_MD_CTX_new();
- uint8_t challenge[2*DECAF_EDDSA_448_PRIVATE_BYTES];
+ uint8_t challenge[2 * DECAF_EDDSA_448_PRIVATE_BYTES];
if (hashctx == NULL
- || !hash_init_with_dom(hashctx, prehashed, 0, context,
- context_len)
- || !EVP_DigestUpdate(hashctx, signature,
- DECAF_EDDSA_448_PUBLIC_BYTES)
- || !EVP_DigestUpdate(hashctx, pubkey,
- DECAF_EDDSA_448_PUBLIC_BYTES)
- || !EVP_DigestUpdate(hashctx, message, message_len)
- || !EVP_DigestFinalXOF(hashctx, challenge, sizeof(challenge))) {
+ || !hash_init_with_dom(hashctx, prehashed, 0, context, context_len)
+ || !EVP_DigestUpdate(hashctx, signature,
+ DECAF_EDDSA_448_PUBLIC_BYTES)
+ || !EVP_DigestUpdate(hashctx, pubkey, DECAF_EDDSA_448_PUBLIC_BYTES)
+ || !EVP_DigestUpdate(hashctx, message, message_len)
+ || !EVP_DigestFinalXOF(hashctx, challenge, sizeof(challenge))) {
EVP_MD_CTX_free(hashctx);
return DECAF_FAILURE;
}
EVP_MD_CTX_free(hashctx);
- curve448_scalar_decode_long(challenge_scalar,challenge,sizeof(challenge));
- OPENSSL_cleanse(challenge,sizeof(challenge));
+ curve448_scalar_decode_long(challenge_scalar, challenge,
+ sizeof(challenge));
+ OPENSSL_cleanse(challenge, sizeof(challenge));
}
- curve448_scalar_sub(challenge_scalar, curve448_scalar_zero, challenge_scalar);
-
- curve448_scalar_decode_long(
- response_scalar,
- &signature[DECAF_EDDSA_448_PUBLIC_BYTES],
- DECAF_EDDSA_448_PRIVATE_BYTES
- );
-
- for (c=1; c<DECAF_448_EDDSA_DECODE_RATIO; c<<=1) {
- curve448_scalar_add(response_scalar,response_scalar,response_scalar);
- }
-
-
+ curve448_scalar_sub(challenge_scalar, curve448_scalar_zero,
+ challenge_scalar);
+
+ curve448_scalar_decode_long(response_scalar,
+ &signature[DECAF_EDDSA_448_PUBLIC_BYTES],
+ DECAF_EDDSA_448_PRIVATE_BYTES);
+
+ for (c = 1; c < DECAF_448_EDDSA_DECODE_RATIO; c <<= 1)
+ curve448_scalar_add(response_scalar, response_scalar, response_scalar);
+
/* pk_point = -c(x(P)) + (cx + k)G = kG */
- curve448_base_double_scalarmul_non_secret(
- pk_point,
- response_scalar,
- pk_point,
- challenge_scalar
- );
- return decaf_succeed_if(curve448_point_eq(pk_point,r_point));
+ curve448_base_double_scalarmul_non_secret(pk_point,
+ response_scalar,
+ pk_point, challenge_scalar);
+ return decaf_succeed_if(curve448_point_eq(pk_point, r_point));
}
-
-decaf_error_t decaf_ed448_verify_prehash (
- const uint8_t signature[DECAF_EDDSA_448_SIGNATURE_BYTES],
- const uint8_t pubkey[DECAF_EDDSA_448_PUBLIC_BYTES],
- const uint8_t hash[64],
- const uint8_t *context,
- uint8_t context_len
-) {
+decaf_error_t decaf_ed448_verify_prehash(
+ const uint8_t signature[DECAF_EDDSA_448_SIGNATURE_BYTES],
+ const uint8_t pubkey[DECAF_EDDSA_448_PUBLIC_BYTES],
+ const uint8_t hash[64], const uint8_t *context,
+ uint8_t context_len)
+{
decaf_error_t ret;
-
- ret = decaf_ed448_verify(signature,pubkey,hash,64,1,context,context_len);
-
+
+ ret = decaf_ed448_verify(signature, pubkey, hash, 64, 1, context,
+ context_len);
+
return ret;
}
return decaf_ed448_sign(out_sig, private_key, public_key, message,
message_len, 0, context, context_len)
- == DECAF_SUCCESS;
+ == DECAF_SUCCESS;
}
-
int ED448_verify(const uint8_t *message, size_t message_len,
const uint8_t signature[114], const uint8_t public_key[57],
const uint8_t *context, size_t context_len)
}
int ED448_public_from_private(uint8_t out_public_key[57],
- const uint8_t private_key[57])
+ const uint8_t private_key[57])
{
return decaf_ed448_derive_public_key(out_public_key, private_key)
- == DECAF_SUCCESS;
+ == DECAF_SUCCESS;
}
projects / openssl.git / blobdiff