/*
* Copyright 2012 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include <algorithm>
#include <string>
#include <vector>
#if HAVE_CONFIG_H
#include "config.h"
#endif // HAVE_CONFIG_H
#if HAVE_NSS_SSL_H
#include "webrtc/base/nssidentity.h"
#include "cert.h"
#include "cryptohi.h"
#include "keyhi.h"
#include "nss.h"
#include "pk11pub.h"
#include "sechash.h"
#include "webrtc/base/logging.h"
#include "webrtc/base/helpers.h"
#include "webrtc/base/nssstreamadapter.h"
#include "webrtc/base/safe_conversions.h"
namespace rtc {
// Certificate validity lifetime in seconds.
static const int CERTIFICATE_LIFETIME = 60*60*24*30; // 30 days, arbitrarily
// Certificate validity window in seconds.
// This is to compensate for slightly incorrect system clocks.
static const int CERTIFICATE_WINDOW = -60*60*24;
NSSKeyPair::~NSSKeyPair() {
if (privkey_)
SECKEY_DestroyPrivateKey(privkey_);
if (pubkey_)
SECKEY_DestroyPublicKey(pubkey_);
}
NSSKeyPair *NSSKeyPair::Generate() {
SECKEYPrivateKey *privkey = NULL;
SECKEYPublicKey *pubkey = NULL;
PK11RSAGenParams rsaparams;
rsaparams.keySizeInBits = 1024;
rsaparams.pe = 0x010001; // 65537 -- a common RSA public exponent.
privkey = PK11_GenerateKeyPair(NSSContext::GetSlot(),
CKM_RSA_PKCS_KEY_PAIR_GEN,
&rsaparams, &pubkey, PR_FALSE /*permanent*/,
PR_FALSE /*sensitive*/, NULL);
if (!privkey) {
LOG(LS_ERROR) << "Couldn't generate key pair";
return NULL;
}
return new NSSKeyPair(privkey, pubkey);
}
// Just make a copy.
NSSKeyPair *NSSKeyPair::GetReference() {
SECKEYPrivateKey *privkey = SECKEY_CopyPrivateKey(privkey_);
if (!privkey)
return NULL;
SECKEYPublicKey *pubkey = SECKEY_CopyPublicKey(pubkey_);
if (!pubkey) {
SECKEY_DestroyPrivateKey(privkey);
return NULL;
}
return new NSSKeyPair(privkey, pubkey);
}
NSSCertificate::NSSCertificate(CERTCertificate* cert)
: certificate_(CERT_DupCertificate(cert)) {
ASSERT(certificate_ != NULL);
}
static void DeleteCert(SSLCertificate* cert) {
delete cert;
}
NSSCertificate::NSSCertificate(CERTCertList* cert_list) {
// Copy the first cert into certificate_.
CERTCertListNode* node = CERT_LIST_HEAD(cert_list);
certificate_ = CERT_DupCertificate(node->cert);
// Put any remaining certificates into the chain.
node = CERT_LIST_NEXT(node);
std::vector<SSLCertificate*> certs;
for (; !CERT_LIST_END(node, cert_list); node = CERT_LIST_NEXT(node)) {
certs.push_back(new NSSCertificate(node->cert));
}
if (!certs.empty())
chain_.reset(new SSLCertChain(certs));
// The SSLCertChain constructor copies its input, so now we have to delete
// the originals.
std::for_each(certs.begin(), certs.end(), DeleteCert);
}
NSSCertificate::NSSCertificate(CERTCertificate* cert, SSLCertChain* chain)
: certificate_(CERT_DupCertificate(cert)) {
ASSERT(certificate_ != NULL);
if (chain)
chain_.reset(chain->Copy());
}
NSSCertificate *NSSCertificate::FromPEMString(const std::string &pem_string) {
std::string der;
if (!SSLIdentity::PemToDer(kPemTypeCertificate, pem_string, &der))
return NULL;
SECItem der_cert;
der_cert.data = reinterpret_cast<unsigned char *>(const_cast<char *>(
der.data()));
der_cert.len = checked_cast<unsigned int>(der.size());
CERTCertificate *cert = CERT_NewTempCertificate(CERT_GetDefaultCertDB(),
&der_cert, NULL, PR_FALSE, PR_TRUE);
if (!cert)
return NULL;
NSSCertificate* ret = new NSSCertificate(cert);
CERT_DestroyCertificate(cert);
return ret;
}
NSSCertificate *NSSCertificate::GetReference() const {
return new NSSCertificate(certificate_, chain_.get());
}
std::string NSSCertificate::ToPEMString() const {
return SSLIdentity::DerToPem(kPemTypeCertificate,
certificate_->derCert.data,
certificate_->derCert.len);
}
void NSSCertificate::ToDER(Buffer* der_buffer) const {
der_buffer->SetData(certificate_->derCert.data, certificate_->derCert.len);
}
static bool Certifies(CERTCertificate* parent, CERTCertificate* child) {
// TODO(bemasc): Identify stricter validation checks to use here. In the
// context of some future identity standard, it might make sense to check
// the certificates' roles, expiration dates, self-signatures (if
// self-signed), certificate transparency logging, or many other attributes.
// NOTE: Future changes to this validation may reject some previously allowed
// certificate chains. Users should be advised not to deploy chained
// certificates except in controlled environments until the validity
// requirements are finalized.
// Check that the parent's name is the same as the child's claimed issuer.
SECComparison name_status =
CERT_CompareName(&child->issuer, &parent->subject);
if (name_status != SECEqual)
return false;
// Extract the parent's public key, or fail if the key could not be read
// (e.g. certificate is corrupted).
SECKEYPublicKey* parent_key = CERT_ExtractPublicKey(parent);
if (!parent_key)
return false;
// Check that the parent's privkey was actually used to generate the child's
// signature.
SECStatus verified = CERT_VerifySignedDataWithPublicKey(
&child->signatureWrap, parent_key, NULL);
SECKEY_DestroyPublicKey(parent_key);
return verified == SECSuccess;
}
bool NSSCertificate::IsValidChain(const CERTCertList* cert_list) {
CERTCertListNode* child = CERT_LIST_HEAD(cert_list);
for (CERTCertListNode* parent = CERT_LIST_NEXT(child);
!CERT_LIST_END(parent, cert_list);
child = parent, parent = CERT_LIST_NEXT(parent)) {
if (!Certifies(parent->cert, child->cert))
return false;
}
return true;
}
bool NSSCertificate::GetDigestLength(const std::string& algorithm,
size_t* length) {
const SECHashObject *ho;
if (!GetDigestObject(algorithm, &ho))
return false;
*length = ho->length;
return true;
}
bool NSSCertificate::GetSignatureDigestAlgorithm(std::string* algorithm) const {
// The function sec_DecodeSigAlg in NSS provides this mapping functionality.
// Unfortunately it is private, so the functionality must be duplicated here.
// See https://bugzilla.mozilla.org/show_bug.cgi?id=925165 .
SECOidTag sig_alg = SECOID_GetAlgorithmTag(&certificate_->signature);
switch (sig_alg) {
case SEC_OID_PKCS1_MD5_WITH_RSA_ENCRYPTION:
*algorithm = DIGEST_MD5;
break;
case SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION:
case SEC_OID_ISO_SHA_WITH_RSA_SIGNATURE:
case SEC_OID_ISO_SHA1_WITH_RSA_SIGNATURE:
case SEC_OID_ANSIX9_DSA_SIGNATURE_WITH_SHA1_DIGEST:
case SEC_OID_BOGUS_DSA_SIGNATURE_WITH_SHA1_DIGEST:
case SEC_OID_ANSIX962_ECDSA_SHA1_SIGNATURE:
case SEC_OID_MISSI_DSS:
case SEC_OID_MISSI_KEA_DSS:
case SEC_OID_MISSI_KEA_DSS_OLD:
case SEC_OID_MISSI_DSS_OLD:
*algorithm = DIGEST_SHA_1;
break;
case SEC_OID_ANSIX962_ECDSA_SHA224_SIGNATURE:
case SEC_OID_PKCS1_SHA224_WITH_RSA_ENCRYPTION:
case SEC_OID_NIST_DSA_SIGNATURE_WITH_SHA224_DIGEST:
*algorithm = DIGEST_SHA_224;
break;
case SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE:
case SEC_OID_PKCS1_SHA256_WITH_RSA_ENCRYPTION:
case SEC_OID_NIST_DSA_SIGNATURE_WITH_SHA256_DIGEST:
*algorithm = DIGEST_SHA_256;
break;
case SEC_OID_ANSIX962_ECDSA_SHA384_SIGNATURE:
case SEC_OID_PKCS1_SHA384_WITH_RSA_ENCRYPTION:
*algorithm = DIGEST_SHA_384;
break;
case SEC_OID_ANSIX962_ECDSA_SHA512_SIGNATURE:
case SEC_OID_PKCS1_SHA512_WITH_RSA_ENCRYPTION:
*algorithm = DIGEST_SHA_512;
break;
default:
// Unknown algorithm. There are several unhandled options that are less
// common and more complex.
algorithm->clear();
return false;
}
return true;
}
bool NSSCertificate::ComputeDigest(const std::string& algorithm,
unsigned char* digest,
size_t size,
size_t* length) const {
const SECHashObject *ho;
if (!GetDigestObject(algorithm, &ho))
return false;
if (size < ho->length) // Sanity check for fit
return false;
SECStatus rv = HASH_HashBuf(ho->type, digest,
certificate_->derCert.data,
certificate_->derCert.len);
if (rv != SECSuccess)
return false;
*length = ho->length;
return true;
}
bool NSSCertificate::GetChain(SSLCertChain** chain) const {
if (!chain_)
return false;
*chain = chain_->Copy();
return true;
}
bool NSSCertificate::Equals(const NSSCertificate *tocompare) const {
if (!certificate_->derCert.len)
return false;
if (!tocompare->certificate_->derCert.len)
return false;
if (certificate_->derCert.len != tocompare->certificate_->derCert.len)
return false;
return memcmp(certificate_->derCert.data,
tocompare->certificate_->derCert.data,
certificate_->derCert.len) == 0;
}
bool NSSCertificate::GetDigestObject(const std::string &algorithm,
const SECHashObject **hop) {
const SECHashObject *ho;
HASH_HashType hash_type;
if (algorithm == DIGEST_SHA_1) {
hash_type = HASH_AlgSHA1;
// HASH_AlgSHA224 is not supported in the chromium linux build system.
#if 0
} else if (algorithm == DIGEST_SHA_224) {
hash_type = HASH_AlgSHA224;
#endif
} else if (algorithm == DIGEST_SHA_256) {
hash_type = HASH_AlgSHA256;
} else if (algorithm == DIGEST_SHA_384) {
hash_type = HASH_AlgSHA384;
} else if (algorithm == DIGEST_SHA_512) {
hash_type = HASH_AlgSHA512;
} else {
return false;
}
ho = HASH_GetHashObject(hash_type);
ASSERT(ho->length >= 20); // Can't happen
*hop = ho;
return true;
}
NSSIdentity* NSSIdentity::GenerateInternal(const SSLIdentityParams& params) {
std::string subject_name_string = "CN=" + params.common_name;
CERTName *subject_name = CERT_AsciiToName(
const_cast<char *>(subject_name_string.c_str()));
NSSIdentity *identity = NULL;
CERTSubjectPublicKeyInfo *spki = NULL;
CERTCertificateRequest *certreq = NULL;
CERTValidity *validity = NULL;
CERTCertificate *certificate = NULL;
NSSKeyPair *keypair = NSSKeyPair::Generate();
SECItem inner_der;
SECStatus rv;
PLArenaPool* arena;
SECItem signed_cert;
PRTime now = PR_Now();
PRTime not_before =
now + static_cast<PRTime>(params.not_before) * PR_USEC_PER_SEC;
PRTime not_after =
now + static_cast<PRTime>(params.not_after) * PR_USEC_PER_SEC;
inner_der.len = 0;
inner_der.data = NULL;
if (!keypair) {
LOG(LS_ERROR) << "Couldn't generate key pair";
goto fail;
}
if (!subject_name) {
LOG(LS_ERROR) << "Couldn't convert subject name " << subject_name;
goto fail;
}
spki = SECKEY_CreateSubjectPublicKeyInfo(keypair->pubkey());
if (!spki) {
LOG(LS_ERROR) << "Couldn't create SPKI";
goto fail;
}
certreq = CERT_CreateCertificateRequest(subject_name, spki, NULL);
if (!certreq) {
LOG(LS_ERROR) << "Couldn't create certificate signing request";
goto fail;
}
validity = CERT_CreateValidity(not_before, not_after);
if (!validity) {
LOG(LS_ERROR) << "Couldn't create validity";
goto fail;
}
unsigned long serial;
// Note: This serial in principle could collide, but it's unlikely
rv = PK11_GenerateRandom(reinterpret_cast<unsigned char *>(&serial),
sizeof(serial));
if (rv != SECSuccess) {
LOG(LS_ERROR) << "Couldn't generate random serial";
goto fail;
}
certificate = CERT_CreateCertificate(serial, subject_name, validity, certreq);
if (!certificate) {
LOG(LS_ERROR) << "Couldn't create certificate";
goto fail;
}
arena = certificate->arena;
rv = SECOID_SetAlgorithmID(arena, &certificate->signature,
SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION, NULL);
if (rv != SECSuccess)
goto fail;
// Set version to X509v3.
*(certificate->version.data) = 2;
certificate->version.len = 1;
if (!SEC_ASN1EncodeItem(arena, &inner_der, certificate,
SEC_ASN1_GET(CERT_CertificateTemplate)))
goto fail;
rv = SEC_DerSignData(arena, &signed_cert, inner_der.data, inner_der.len,
keypair->privkey(),
SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION);
if (rv != SECSuccess) {
LOG(LS_ERROR) << "Couldn't sign certificate";
goto fail;
}
certificate->derCert = signed_cert;
identity = new NSSIdentity(keypair, new NSSCertificate(certificate));
goto done;
fail:
delete keypair;
done:
if (certificate) CERT_DestroyCertificate(certificate);
if (subject_name) CERT_DestroyName(subject_name);
if (spki) SECKEY_DestroySubjectPublicKeyInfo(spki);
if (certreq) CERT_DestroyCertificateRequest(certreq);
if (validity) CERT_DestroyValidity(validity);
return identity;
}
NSSIdentity* NSSIdentity::Generate(const std::string &common_name) {
SSLIdentityParams params;
params.common_name = common_name;
params.not_before = CERTIFICATE_WINDOW;
params.not_after = CERTIFICATE_LIFETIME;
return GenerateInternal(params);
}
NSSIdentity* NSSIdentity::GenerateForTest(const SSLIdentityParams& params) {
return GenerateInternal(params);
}
SSLIdentity* NSSIdentity::FromPEMStrings(const std::string& private_key,
const std::string& certificate) {
std::string private_key_der;
if (!SSLIdentity::PemToDer(
kPemTypeRsaPrivateKey, private_key, &private_key_der))
return NULL;
SECItem private_key_item;
private_key_item.data = reinterpret_cast<unsigned char *>(
const_cast<char *>(private_key_der.c_str()));
private_key_item.len = checked_cast<unsigned int>(private_key_der.size());
const unsigned int key_usage = KU_KEY_ENCIPHERMENT | KU_DATA_ENCIPHERMENT |
KU_DIGITAL_SIGNATURE;
SECKEYPrivateKey* privkey = NULL;
SECStatus rv =
PK11_ImportDERPrivateKeyInfoAndReturnKey(NSSContext::GetSlot(),
&private_key_item,
NULL, NULL, PR_FALSE, PR_FALSE,
key_usage, &privkey, NULL);
if (rv != SECSuccess) {
LOG(LS_ERROR) << "Couldn't import private key";
return NULL;
}
SECKEYPublicKey *pubkey = SECKEY_ConvertToPublicKey(privkey);
if (rv != SECSuccess) {
SECKEY_DestroyPrivateKey(privkey);
LOG(LS_ERROR) << "Couldn't convert private key to public key";
return NULL;
}
// Assign to a scoped_ptr so we don't leak on error.
scoped_ptr<NSSKeyPair> keypair(new NSSKeyPair(privkey, pubkey));
scoped_ptr<NSSCertificate> cert(NSSCertificate::FromPEMString(certificate));
if (!cert) {
LOG(LS_ERROR) << "Couldn't parse certificate";
return NULL;
}
// TODO(ekr@rtfm.com): Check the public key against the certificate.
return new NSSIdentity(keypair.release(), cert.release());
}
NSSIdentity *NSSIdentity::GetReference() const {
NSSKeyPair *keypair = keypair_->GetReference();
if (!keypair)
return NULL;
NSSCertificate *certificate = certificate_->GetReference();
if (!certificate) {
delete keypair;
return NULL;
}
return new NSSIdentity(keypair, certificate);
}
NSSCertificate &NSSIdentity::certificate() const {
return *certificate_;
}
} // rtc namespace
#endif // HAVE_NSS_SSL_H