tenfourfox/media/mtransport/dtlsidentity.cpp

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2017-04-19 07:56:45 +00:00
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* 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 file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "dtlsidentity.h"
#include "cert.h"
#include "cryptohi.h"
#include "keyhi.h"
#include "nsError.h"
#include "pk11pub.h"
#include "prprf.h"
#include "sechash.h"
#include "ssl.h"
namespace mozilla {
DtlsIdentity::~DtlsIdentity() {
if (cert_) {
CERT_DestroyCertificate(cert_);
}
}
RefPtr<DtlsIdentity> DtlsIdentity::Generate() {
ScopedPK11SlotInfo slot(PK11_GetInternalSlot());
if (!slot) {
return nullptr;
}
uint8_t random_name[16];
SECStatus rv = PK11_GenerateRandomOnSlot(slot, random_name,
sizeof(random_name));
if (rv != SECSuccess)
return nullptr;
std::string name;
char chunk[3];
for (size_t i = 0; i < sizeof(random_name); ++i) {
PR_snprintf(chunk, sizeof(chunk), "%.2x", random_name[i]);
name += chunk;
}
std::string subject_name_string = "CN=" + name;
ScopedCERTName subject_name(CERT_AsciiToName(subject_name_string.c_str()));
if (!subject_name) {
return nullptr;
}
unsigned char paramBuf[12]; // OIDs are small
SECItem ecdsaParams = { siBuffer, paramBuf, sizeof(paramBuf) };
SECOidData* oidData = SECOID_FindOIDByTag(SEC_OID_SECG_EC_SECP256R1);
if (!oidData || (oidData->oid.len > (sizeof(paramBuf) - 2))) {
return nullptr;
}
ecdsaParams.data[0] = SEC_ASN1_OBJECT_ID;
ecdsaParams.data[1] = oidData->oid.len;
memcpy(ecdsaParams.data + 2, oidData->oid.data, oidData->oid.len);
ecdsaParams.len = oidData->oid.len + 2;
ScopedSECKEYPrivateKey private_key;
ScopedSECKEYPublicKey public_key;
SECKEYPublicKey *pubkey;
private_key =
PK11_GenerateKeyPair(slot,
CKM_EC_KEY_PAIR_GEN, &ecdsaParams, &pubkey,
PR_FALSE, PR_TRUE, nullptr);
if (private_key == nullptr)
return nullptr;
public_key = pubkey;
ScopedCERTSubjectPublicKeyInfo spki(
SECKEY_CreateSubjectPublicKeyInfo(pubkey));
if (!spki) {
return nullptr;
}
ScopedCERTCertificateRequest certreq(
CERT_CreateCertificateRequest(subject_name, spki, nullptr));
if (!certreq) {
return nullptr;
}
// From 1 day before todayto 30 days after.
// This is a sort of arbitrary range designed to be valid
// now with some slack in case the other side expects
// some before expiry.
//
// Note: explicit casts necessary to avoid
// warning C4307: '*' : integral constant overflow
static const PRTime oneDay = PRTime(PR_USEC_PER_SEC)
* PRTime(60) // sec
* PRTime(60) // min
* PRTime(24); // hours
PRTime now = PR_Now();
PRTime notBefore = now - oneDay;
PRTime notAfter = now + (PRTime(30) * oneDay);
ScopedCERTValidity validity(CERT_CreateValidity(notBefore, notAfter));
if (!validity) {
return nullptr;
}
unsigned long serial;
// Note: This serial in principle could collide, but it's unlikely
rv = PK11_GenerateRandomOnSlot(slot,
reinterpret_cast<unsigned char *>(&serial),
sizeof(serial));
if (rv != SECSuccess) {
return nullptr;
}
ScopedCERTCertificate certificate(
CERT_CreateCertificate(serial, subject_name, validity, certreq));
if (!certificate) {
return nullptr;
}
PLArenaPool *arena = certificate->arena;
rv = SECOID_SetAlgorithmID(arena, &certificate->signature,
SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE, 0);
if (rv != SECSuccess)
return nullptr;
// Set version to X509v3.
*(certificate->version.data) = SEC_CERTIFICATE_VERSION_3;
certificate->version.len = 1;
SECItem innerDER;
innerDER.len = 0;
innerDER.data = nullptr;
if (!SEC_ASN1EncodeItem(arena, &innerDER, certificate,
SEC_ASN1_GET(CERT_CertificateTemplate))) {
return nullptr;
}
SECItem *signedCert = PORT_ArenaZNew(arena, SECItem);
if (!signedCert) {
return nullptr;
}
rv = SEC_DerSignData(arena, signedCert, innerDER.data, innerDER.len,
private_key,
SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE);
if (rv != SECSuccess) {
return nullptr;
}
certificate->derCert = *signedCert;
RefPtr<DtlsIdentity> identity =
new DtlsIdentity(private_key.forget(), certificate.forget(), ssl_kea_ecdh);
return identity.forget();
}
const std::string DtlsIdentity::DEFAULT_HASH_ALGORITHM = "sha-256";
nsresult DtlsIdentity::ComputeFingerprint(const std::string algorithm,
uint8_t *digest,
size_t size,
size_t *digest_length) const {
const CERTCertificate* c = cert();
MOZ_ASSERT(c);
return ComputeFingerprint(c, algorithm, digest, size, digest_length);
}
nsresult DtlsIdentity::ComputeFingerprint(const CERTCertificate *cert,
const std::string algorithm,
uint8_t *digest,
size_t size,
size_t *digest_length) {
MOZ_ASSERT(cert);
HASH_HashType ht;
if (algorithm == "sha-1") {
ht = HASH_AlgSHA1;
} else if (algorithm == "sha-224") {
ht = HASH_AlgSHA224;
} else if (algorithm == "sha-256") {
ht = HASH_AlgSHA256;
} else if (algorithm == "sha-384") {
ht = HASH_AlgSHA384;
} else if (algorithm == "sha-512") {
ht = HASH_AlgSHA512;
} else {
return NS_ERROR_INVALID_ARG;
}
const SECHashObject *ho = HASH_GetHashObject(ht);
MOZ_ASSERT(ho);
if (!ho) {
return NS_ERROR_INVALID_ARG;
}
MOZ_ASSERT(ho->length >= 20); // Double check
if (size < ho->length) {
return NS_ERROR_INVALID_ARG;
}
SECStatus rv = HASH_HashBuf(ho->type, digest,
cert->derCert.data,
cert->derCert.len);
if (rv != SECSuccess) {
return NS_ERROR_FAILURE;
}
*digest_length = ho->length;
return NS_OK;
}
} // close namespace