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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#ifdef FREEBL_NO_DEPEND
#include "stubs.h"
#endif
#include "blapi.h"
#include "blapii.h"
#include "prerr.h"
#include "secerr.h"
#include "secmpi.h"
#include "secitem.h"
#include "mplogic.h"
#include "ec.h"
#include "ecl.h"
#include "verified/Hacl_P384.h"
#include "verified/Hacl_P521.h"
#include "secport.h"
#include "verified/Hacl_Ed25519.h"
#define EC_DOUBLECHECK PR_FALSE
SECStatus
ec_ED25519_pt_validate(const SECItem *px)
{
if (!px || !px->data || px->len != Ed25519_PUBLIC_KEYLEN) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
return SECSuccess;
}
SECStatus
ec_ED25519_scalar_validate(const SECItem *scalar)
{
if (!scalar || !scalar->data || scalar->len != Ed25519_PRIVATE_KEYLEN) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
return SECSuccess;
}
static const ECMethod kMethods[] = {
{ ECCurve25519,
ec_Curve25519_pt_mul,
ec_Curve25519_pt_validate,
ec_Curve25519_scalar_validate,
NULL,
NULL },
{
ECCurve_NIST_P256,
ec_secp256r1_pt_mul,
ec_secp256r1_pt_validate,
ec_secp256r1_scalar_validate,
ec_secp256r1_sign_digest,
ec_secp256r1_verify_digest,
},
{
ECCurve_NIST_P384,
ec_secp384r1_pt_mul,
ec_secp384r1_pt_validate,
ec_secp384r1_scalar_validate,
ec_secp384r1_sign_digest,
ec_secp384r1_verify_digest,
},
{
ECCurve_NIST_P521,
ec_secp521r1_pt_mul,
ec_secp521r1_pt_validate,
ec_secp521r1_scalar_validate,
ec_secp521r1_sign_digest,
ec_secp521r1_verify_digest,
},
{ ECCurve_Ed25519,
NULL,
ec_ED25519_pt_validate,
ec_ED25519_scalar_validate,
NULL,
NULL },
};
static const ECMethod *
ec_get_method_from_name(ECCurveName name)
{
unsigned long i;
for (i = 0; i < sizeof(kMethods) / sizeof(kMethods[0]); ++i) {
if (kMethods[i].name == name) {
return &kMethods[i];
}
}
return NULL;
}
/* Generates a new EC key pair. The private key is a supplied
* value and the public key is the result of performing a scalar
* point multiplication of that value with the curve's base point.
*/
SECStatus
ec_NewKey(ECParams *ecParams, ECPrivateKey **privKey,
const unsigned char *privKeyBytes, int privKeyLen)
{
SECStatus rv = SECFailure;
PLArenaPool *arena;
ECPrivateKey *key;
int len;
if (!ecParams || ecParams->name == ECCurve_noName ||
!privKey || !privKeyBytes || privKeyLen <= 0) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
if (ecParams->fieldID.type != ec_field_plain) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
/* Initialize an arena for the EC key. */
if (!(arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE)))
return SECFailure;
key = (ECPrivateKey *)PORT_ArenaZAlloc(arena, sizeof(ECPrivateKey));
if (!key) {
goto cleanup;
}
/* Set the version number (SEC 1 section C.4 says it should be 1) */
SECITEM_AllocItem(arena, &key->version, 1);
key->version.data[0] = 1;
/* Copy all of the fields from the ECParams argument to the
* ECParams structure within the private key.
*/
key->ecParams.arena = arena;
key->ecParams.type = ecParams->type;
key->ecParams.fieldID.size = ecParams->fieldID.size;
key->ecParams.fieldID.type = ecParams->fieldID.type;
CHECK_SEC_OK(SECITEM_CopyItem(arena, &key->ecParams.fieldID.u.prime,
&ecParams->fieldID.u.prime));
key->ecParams.fieldID.k1 = ecParams->fieldID.k1;
key->ecParams.fieldID.k2 = ecParams->fieldID.k2;
key->ecParams.fieldID.k3 = ecParams->fieldID.k3;
CHECK_SEC_OK(SECITEM_CopyItem(arena, &key->ecParams.curve.a,
&ecParams->curve.a));
CHECK_SEC_OK(SECITEM_CopyItem(arena, &key->ecParams.curve.b,
&ecParams->curve.b));
CHECK_SEC_OK(SECITEM_CopyItem(arena, &key->ecParams.curve.seed,
&ecParams->curve.seed));
CHECK_SEC_OK(SECITEM_CopyItem(arena, &key->ecParams.base,
&ecParams->base));
CHECK_SEC_OK(SECITEM_CopyItem(arena, &key->ecParams.order,
&ecParams->order));
key->ecParams.cofactor = ecParams->cofactor;
CHECK_SEC_OK(SECITEM_CopyItem(arena, &key->ecParams.DEREncoding,
&ecParams->DEREncoding));
key->ecParams.name = ecParams->name;
CHECK_SEC_OK(SECITEM_CopyItem(arena, &key->ecParams.curveOID,
&ecParams->curveOID));
SECITEM_AllocItem(arena, &key->publicValue, EC_GetPointSize(ecParams));
len = ecParams->order.len;
SECITEM_AllocItem(arena, &key->privateValue, len);
/* Copy private key */
if (privKeyLen >= len) {
memcpy(key->privateValue.data, privKeyBytes, len);
} else {
memset(key->privateValue.data, 0, (len - privKeyLen));
memcpy(key->privateValue.data + (len - privKeyLen), privKeyBytes, privKeyLen);
}
/* Compute corresponding public key */
/* Use curve specific code for point multiplication */
if (ecParams->name == ECCurve_Ed25519) {
CHECK_SEC_OK(ED_DerivePublicKey(&key->privateValue, &key->publicValue));
} else {
const ECMethod *method = ec_get_method_from_name(ecParams->name);
if (method == NULL || method->pt_mul == NULL) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
rv = SECFailure;
goto cleanup;
}
CHECK_SEC_OK(method->pt_mul(&key->publicValue, &key->privateValue, NULL));
}
NSS_DECLASSIFY(key->publicValue.data, key->publicValue.len); /* Declassifying public key to avoid false positive */
*privKey = key;
return SECSuccess;
cleanup:
PORT_FreeArena(arena, PR_TRUE);
return rv;
}
/* Generates a new EC key pair. The private key is a supplied
* random value (in seed) and the public key is the result of
* performing a scalar point multiplication of that value with
* the curve's base point.
*/
SECStatus
EC_NewKeyFromSeed(ECParams *ecParams, ECPrivateKey **privKey,
const unsigned char *seed, int seedlen)
{
return ec_NewKey(ecParams, privKey, seed, seedlen);
}
/* Generate a random private key using the algorithm A.4.1 or A.4.2 of ANSI X9.62,
* modified a la FIPS 186-2 Change Notice 1 to eliminate the bias in the
* random number generator.
*/
SECStatus
ec_GenerateRandomPrivateKey(ECParams *ecParams, SECItem *privKey)
{
SECStatus rv = SECFailure;
unsigned int len = EC_GetScalarSize(ecParams);
if (privKey->len != len || privKey->data == NULL) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
const ECMethod *method = ec_get_method_from_name(ecParams->name);
if (method == NULL || method->scalar_validate == NULL) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
uint8_t leading_coeff_mask;
switch (ecParams->name) {
case ECCurve_Ed25519:
case ECCurve25519:
case ECCurve_NIST_P256:
case ECCurve_NIST_P384:
leading_coeff_mask = 0xff;
break;
case ECCurve_NIST_P521:
leading_coeff_mask = 0x01;
break;
default:
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
/* The rejection sampling method from FIPS 186-5 A.4.2 */
int count = 100;
do {
rv = RNG_GenerateGlobalRandomBytes(privKey->data, len);
if (rv != SECSuccess) {
PORT_SetError(SEC_ERROR_NEED_RANDOM);
return SECFailure;
}
privKey->data[0] &= leading_coeff_mask;
NSS_CLASSIFY(privKey->data, privKey->len);
rv = method->scalar_validate(privKey);
} while (rv != SECSuccess && --count > 0);
if (rv != SECSuccess) { // implies count == 0
PORT_SetError(SEC_ERROR_BAD_KEY);
}
return rv;
}
/* Generates a new EC key pair. The private key is a random value and
* the public key is the result of performing a scalar point multiplication
* of that value with the curve's base point.
*/
SECStatus
EC_NewKey(ECParams *ecParams, ECPrivateKey **privKey)
{
SECStatus rv = SECFailure;
SECItem privKeyRand = { siBuffer, NULL, 0 };
if (!ecParams || ecParams->name == ECCurve_noName || !privKey) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
SECITEM_AllocItem(NULL, &privKeyRand, EC_GetScalarSize(ecParams));
if (privKeyRand.data == NULL) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
rv = SECFailure;
goto cleanup;
}
rv = ec_GenerateRandomPrivateKey(ecParams, &privKeyRand);
if (rv != SECSuccess || privKeyRand.data == NULL) {
goto cleanup;
}
/* generate public key */
CHECK_SEC_OK(ec_NewKey(ecParams, privKey, privKeyRand.data, privKeyRand.len));
cleanup:
if (privKeyRand.data) {
SECITEM_ZfreeItem(&privKeyRand, PR_FALSE);
}
#if EC_DEBUG
printf("EC_NewKey returning %s\n",
(rv == SECSuccess) ? "success" : "failure");
#endif
return rv;
}
/* Validates an EC public key as described in Section 5.2.2 of
* X9.62. The ECDH primitive when used without the cofactor does
* not address small subgroup attacks, which may occur when the
* public key is not valid. These attacks can be prevented by
* validating the public key before using ECDH.
*/
SECStatus
EC_ValidatePublicKey(ECParams *ecParams, SECItem *publicValue)
{
if (!ecParams || ecParams->name == ECCurve_noName ||
!publicValue || !publicValue->len) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
/* Uses curve specific code for point validation. */
if (ecParams->fieldID.type != ec_field_plain) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
const ECMethod *method = ec_get_method_from_name(ecParams->name);
if (method == NULL || method->pt_validate == NULL) {
/* unknown curve */
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
SECStatus rv = method->pt_validate(publicValue);
if (rv != SECSuccess) {
PORT_SetError(SEC_ERROR_BAD_KEY);
}
return rv;
}
/*
** Performs an ECDH key derivation by computing the scalar point
** multiplication of privateValue and publicValue (with or without the
** cofactor) and returns the x-coordinate of the resulting elliptic
** curve point in derived secret. If successful, derivedSecret->data
** is set to the address of the newly allocated buffer containing the
** derived secret, and derivedSecret->len is the size of the secret
** produced. It is the caller's responsibility to free the allocated
** buffer containing the derived secret.
*/
SECStatus
ECDH_Derive(SECItem *publicValue,
ECParams *ecParams,
SECItem *privateValue,
PRBool withCofactor,
SECItem *derivedSecret)
{
if (!publicValue || !publicValue->len ||
!ecParams || ecParams->name == ECCurve_noName ||
!privateValue || !privateValue->len || !derivedSecret) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
/*
* Make sure the point is on the requested curve to avoid
* certain small subgroup attacks.
*/
if (EC_ValidatePublicKey(ecParams, publicValue) != SECSuccess) {
PORT_SetError(SEC_ERROR_BAD_KEY);
return SECFailure;
}
/* Perform curve specific multiplication using ECMethod */
if (ecParams->fieldID.type != ec_field_plain) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
const ECMethod *method = ec_get_method_from_name(ecParams->name);
if (method == NULL || method->pt_validate == NULL ||
method->pt_mul == NULL) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
memset(derivedSecret, 0, sizeof(*derivedSecret));
derivedSecret = SECITEM_AllocItem(NULL, derivedSecret, EC_GetScalarSize(ecParams));
if (derivedSecret == NULL) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
return SECFailure;
}
SECStatus rv = method->pt_mul(derivedSecret, privateValue, publicValue);
if (rv != SECSuccess) {
PORT_SetError(SEC_ERROR_BAD_KEY);
SECITEM_ZfreeItem(derivedSecret, PR_FALSE);
}
return rv;
}
/* Computes the ECDSA signature (a concatenation of two values r and s)
* on the digest using the given key and the random value kb (used in
* computing s).
*/
static SECStatus
ec_SignDigestWithSeed(ECPrivateKey *key, SECItem *signature,
const SECItem *digest, const unsigned char *kb, const int kblen)
{
ECParams *ecParams = NULL;
unsigned olen; /* length in bytes of the base point order */
/* Check args */
if (!key || !signature || !digest || !kb || (kblen <= 0)) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
ecParams = &(key->ecParams);
olen = ecParams->order.len;
if (signature->data == NULL) {
/* a call to get the signature length only */
signature->len = 2 * olen;
return SECSuccess;
}
if (signature->len < 2 * olen) {
PORT_SetError(SEC_ERROR_OUTPUT_LEN);
return SECFailure;
}
/* Perform curve specific signature using ECMethod */
if (ecParams->fieldID.type != ec_field_plain) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
const ECMethod *method = ec_get_method_from_name(ecParams->name);
if (method == NULL || method->sign_digest == NULL) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
SECStatus rv = method->sign_digest(key, signature, digest, kb, kblen);
if (rv != SECSuccess) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
}
#if EC_DEBUG
printf("ECDSA signing with seed %s\n",
(rv == SECSuccess) ? "succeeded" : "failed");
#endif
return rv;
}
SECStatus
ECDSA_SignDigestWithSeed(ECPrivateKey *key, SECItem *signature,
const SECItem *digest, const unsigned char *kb, const int kblen)
{
#if EC_DEBUG || EC_DOUBLECHECK
SECItem *signature2 = SECITEM_AllocItem(NULL, NULL, signature->len);
SECStatus signSuccess = ec_SignDigestWithSeed(key, signature, digest, kb, kblen);
SECStatus signSuccessDouble = ec_SignDigestWithSeed(key, signature2, digest, kb, kblen);
int signaturesEqual = NSS_SecureMemcmp(signature->data, signature2->data, signature->len);
SECStatus rv;
if ((signaturesEqual == 0) && (signSuccess == SECSuccess) && (signSuccessDouble == SECSuccess)) {
rv = SECSuccess;
} else {
rv = SECFailure;
}
#if EC_DEBUG
printf("ECDSA signing with seed %s after signing twice\n", (rv == SECSuccess) ? "succeeded" : "failed");
#endif
SECITEM_FreeItem(signature2, PR_TRUE);
return rv;
#else
return ec_SignDigestWithSeed(key, signature, digest, kb, kblen);
#endif
}
/*
** Computes the ECDSA signature on the digest using the given key
** and a random seed.
*/
SECStatus
ECDSA_SignDigest(ECPrivateKey *key, SECItem *signature, const SECItem *digest)
{
SECItem nonceRand = { siBuffer, NULL, 0 };
if (!key) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
/* Generate random value k */
SECITEM_AllocItem(NULL, &nonceRand, EC_GetScalarSize(&key->ecParams));
if (nonceRand.data == NULL) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
return SECFailure;
}
SECStatus rv = ec_GenerateRandomPrivateKey(&key->ecParams, &nonceRand);
if (rv != SECSuccess) {
goto cleanup;
}
/* Generate ECDSA signature with the specified k value */
rv = ECDSA_SignDigestWithSeed(key, signature, digest, nonceRand.data, nonceRand.len);
NSS_DECLASSIFY(signature->data, signature->len);
cleanup:
SECITEM_ZfreeItem(&nonceRand, PR_FALSE);
#if EC_DEBUG
printf("ECDSA signing %s\n",
(rv == SECSuccess) ? "succeeded" : "failed");
#endif
return rv;
}
/*
** Checks the signature on the given digest using the key provided.
**
** The key argument must represent a valid EC public key (a point on
** the relevant curve). If it is not a valid point, then the behavior
** of this function is undefined. In cases where a public key might
** not be valid, use EC_ValidatePublicKey to check.
*/
SECStatus
ECDSA_VerifyDigest(ECPublicKey *key, const SECItem *signature,
const SECItem *digest)
{
SECStatus rv = SECFailure;
ECParams *ecParams = NULL;
/* Check args */
if (!key || !signature || !digest) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
ecParams = &(key->ecParams);
/* Perform curve specific signature verification using ECMethod */
if (ecParams->fieldID.type != ec_field_plain) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
const ECMethod *method = ec_get_method_from_name(ecParams->name);
if (method == NULL || method->verify_digest == NULL) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
rv = method->verify_digest(key, signature, digest);
if (rv != SECSuccess) {
PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
}
#if EC_DEBUG
printf("ECDSA verification %s\n",
(rv == SECSuccess) ? "succeeded" : "failed");
#endif
return rv;
}
/*EdDSA: Currently only Ed22519 is implemented.*/
/*
** Computes the EdDSA signature on the message using the given key.
*/
SECStatus
ec_ED25519_public_key_validate(const ECPublicKey *key)
{
if (!key || !(key->ecParams.name == ECCurve_Ed25519)) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
return ec_ED25519_pt_validate(&key->publicValue);
}
SECStatus
ec_ED25519_private_key_validate(const ECPrivateKey *key)
{
if (!key || !(key->ecParams.name == ECCurve_Ed25519)) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
return ec_ED25519_scalar_validate(&key->privateValue);
}
SECStatus
ED_SignMessage(ECPrivateKey *key, SECItem *signature, const SECItem *msg)
{
if (!msg || !signature || signature->len != Ed25519_SIGN_LEN) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
if (ec_ED25519_private_key_validate(key) != SECSuccess) {
return SECFailure; /* error code set by ec_ED25519_scalar_validate. */
}
if (signature->data) {
Hacl_Ed25519_sign(signature->data, key->privateValue.data, msg->len,
msg->data);
}
signature->len = ED25519_SIGN_LEN;
BLAPI_CLEAR_STACK(2048);
return SECSuccess;
}
/*
** Checks the signature on the given message using the key provided.
*/
SECStatus
ED_VerifyMessage(ECPublicKey *key, const SECItem *signature,
const SECItem *msg)
{
if (!msg || !signature || !signature->data || signature->len != Ed25519_SIGN_LEN) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
if (ec_ED25519_public_key_validate(key) != SECSuccess) {
return SECFailure; /* error code set by ec_ED25519_pt_validate. */
}
bool rv = Hacl_Ed25519_verify(key->publicValue.data, msg->len, msg->data,
signature->data);
BLAPI_CLEAR_STACK(2048);
#if EC_DEBUG
printf("ED_VerifyMessage returning %s\n",
(rv) ? "success" : "failure");
#endif
if (rv) {
return SECSuccess;
}
PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
return SECFailure;
}
SECStatus
ED_DerivePublicKey(const SECItem *privateKey, SECItem *publicKey)
{
/* Currently supporting only Ed25519.*/
if (!privateKey || privateKey->len == 0 || !publicKey || publicKey->len != Ed25519_PUBLIC_KEYLEN) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
if (ec_ED25519_scalar_validate(privateKey) != SECSuccess) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
Hacl_Ed25519_secret_to_public(publicKey->data, privateKey->data);
return SECSuccess;
}
SECStatus
X25519_DerivePublicKey(const SECItem *privateKey, SECItem *publicKey)
{
SECStatus rv = SECFailure;
/* Currently supporting only X25519.*/
if (!privateKey || privateKey->len == 0 || !publicKey || publicKey->len != X25519_PUBLIC_KEYLEN) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
const ECMethod *method = ec_get_method_from_name(ECCurve25519);
if (method == NULL || method->pt_mul == NULL) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
rv = method->pt_mul(publicKey, (SECItem *)privateKey, NULL);
return rv;
}
SECStatus
EC_DerivePublicKey(const SECItem *privateKey, const ECParams *ecParams, SECItem *publicKey)
{
if (!privateKey || privateKey->len == 0 || !publicKey || publicKey->len != EC_GetPointSize(ecParams)) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
const ECMethod *method = ec_get_method_from_name(ecParams->name);
if (method == NULL || method->pt_mul == NULL) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_ELLIPTIC_CURVE);
return SECFailure;
}
return method->pt_mul(publicKey, (SECItem *)privateKey, NULL);
}