/*
* Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#ifdef OPENSSL_NO_CT
# error "CT disabled"
#endif
#include <openssl/ct.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/tls1.h>
#include <openssl/x509.h>
#include "ct_local.h"
SCT *SCT_new(void)
{
SCT *sct = OPENSSL_zalloc(sizeof(*sct));
if (sct == NULL) {
CTerr(CT_F_SCT_NEW, ERR_R_MALLOC_FAILURE);
return NULL;
}
sct->entry_type = CT_LOG_ENTRY_TYPE_NOT_SET;
sct->version = SCT_VERSION_NOT_SET;
return sct;
}
void SCT_free(SCT *sct)
{
if (sct == NULL)
return;
OPENSSL_free(sct->log_id);
OPENSSL_free(sct->ext);
OPENSSL_free(sct->sig);
OPENSSL_free(sct->sct);
OPENSSL_free(sct);
}
void SCT_LIST_free(STACK_OF(SCT) *a)
{
sk_SCT_pop_free(a, SCT_free);
}
int SCT_set_version(SCT *sct, sct_version_t version)
{
if (version != SCT_VERSION_V1) {
CTerr(CT_F_SCT_SET_VERSION, CT_R_UNSUPPORTED_VERSION);
return 0;
}
sct->version = version;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
return 1;
}
int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type)
{
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
switch (entry_type) {
case CT_LOG_ENTRY_TYPE_X509:
case CT_LOG_ENTRY_TYPE_PRECERT:
sct->entry_type = entry_type;
return 1;
case CT_LOG_ENTRY_TYPE_NOT_SET:
break;
}
CTerr(CT_F_SCT_SET_LOG_ENTRY_TYPE, CT_R_UNSUPPORTED_ENTRY_TYPE);
return 0;
}
int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len)
{
if (sct->version == SCT_VERSION_V1 && log_id_len != CT_V1_HASHLEN) {
CTerr(CT_F_SCT_SET0_LOG_ID, CT_R_INVALID_LOG_ID_LENGTH);
return 0;
}
OPENSSL_free(sct->log_id);
sct->log_id = log_id;
sct->log_id_len = log_id_len;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
return 1;
}
int SCT_set1_log_id(SCT *sct, const unsigned char *log_id, size_t log_id_len)
{
if (sct->version == SCT_VERSION_V1 && log_id_len != CT_V1_HASHLEN) {
CTerr(CT_F_SCT_SET1_LOG_ID, CT_R_INVALID_LOG_ID_LENGTH);
return 0;
}
OPENSSL_free(sct->log_id);
sct->log_id = NULL;
sct->log_id_len = 0;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
if (log_id != NULL && log_id_len > 0) {
sct->log_id = OPENSSL_memdup(log_id, log_id_len);
if (sct->log_id == NULL) {
CTerr(CT_F_SCT_SET1_LOG_ID, ERR_R_MALLOC_FAILURE);
return 0;
}
sct->log_id_len = log_id_len;
}
return 1;
}
void SCT_set_timestamp(SCT *sct, uint64_t timestamp)
{
sct->timestamp = timestamp;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
}
int SCT_set_signature_nid(SCT *sct, int nid)
{
switch (nid) {
case NID_sha256WithRSAEncryption:
sct->hash_alg = TLSEXT_hash_sha256;
sct->sig_alg = TLSEXT_signature_rsa;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
return 1;
case NID_ecdsa_with_SHA256:
sct->hash_alg = TLSEXT_hash_sha256;
sct->sig_alg = TLSEXT_signature_ecdsa;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
return 1;
default:
CTerr(CT_F_SCT_SET_SIGNATURE_NID, CT_R_UNRECOGNIZED_SIGNATURE_NID);
return 0;
}
}
void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len)
{
OPENSSL_free(sct->ext);
sct->ext = ext;
sct->ext_len = ext_len;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
}
int SCT_set1_extensions(SCT *sct, const unsigned char *ext, size_t ext_len)
{
OPENSSL_free(sct->ext);
sct->ext = NULL;
sct->ext_len = 0;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
if (ext != NULL && ext_len > 0) {
sct->ext = OPENSSL_memdup(ext, ext_len);
if (sct->ext == NULL) {
CTerr(CT_F_SCT_SET1_EXTENSIONS, ERR_R_MALLOC_FAILURE);
return 0;
}
sct->ext_len = ext_len;
}
return 1;
}
void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len)
{
OPENSSL_free(sct->sig);
sct->sig = sig;
sct->sig_len = sig_len;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
}
int SCT_set1_signature(SCT *sct, const unsigned char *sig, size_t sig_len)
{
OPENSSL_free(sct->sig);
sct->sig = NULL;
sct->sig_len = 0;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
if (sig != NULL && sig_len > 0) {
sct->sig = OPENSSL_memdup(sig, sig_len);
if (sct->sig == NULL) {
CTerr(CT_F_SCT_SET1_SIGNATURE, ERR_R_MALLOC_FAILURE);
return 0;
}
sct->sig_len = sig_len;
}
return 1;
}
sct_version_t SCT_get_version(const SCT *sct)
{
return sct->version;
}
ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct)
{
return sct->entry_type;
}
size_t SCT_get0_log_id(const SCT *sct, unsigned char **log_id)
{
*log_id = sct->log_id;
return sct->log_id_len;
}
uint64_t SCT_get_timestamp(const SCT *sct)
{
return sct->timestamp;
}
int SCT_get_signature_nid(const SCT *sct)
{
if (sct->version == SCT_VERSION_V1) {
if (sct->hash_alg == TLSEXT_hash_sha256) {
switch (sct->sig_alg) {
case TLSEXT_signature_ecdsa:
return NID_ecdsa_with_SHA256;
case TLSEXT_signature_rsa:
return NID_sha256WithRSAEncryption;
default:
return NID_undef;
}
}
}
return NID_undef;
}
size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext)
{
*ext = sct->ext;
return sct->ext_len;
}
size_t SCT_get0_signature(const SCT *sct, unsigned char **sig)
{
*sig = sct->sig;
return sct->sig_len;
}
int SCT_is_complete(const SCT *sct)
{
switch (sct->version) {
case SCT_VERSION_NOT_SET:
return 0;
case SCT_VERSION_V1:
return sct->log_id != NULL && SCT_signature_is_complete(sct);
default:
return sct->sct != NULL; /* Just need cached encoding */
}
}
int SCT_signature_is_complete(const SCT *sct)
{
return SCT_get_signature_nid(sct) != NID_undef &&
sct->sig != NULL && sct->sig_len > 0;
}
sct_source_t SCT_get_source(const SCT *sct)
{
return sct->source;
}
int SCT_set_source(SCT *sct, sct_source_t source)
{
sct->source = source;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
switch (source) {
case SCT_SOURCE_TLS_EXTENSION:
case SCT_SOURCE_OCSP_STAPLED_RESPONSE:
return SCT_set_log_entry_type(sct, CT_LOG_ENTRY_TYPE_X509);
case SCT_SOURCE_X509V3_EXTENSION:
return SCT_set_log_entry_type(sct, CT_LOG_ENTRY_TYPE_PRECERT);
case SCT_SOURCE_UNKNOWN:
break;
}
/* if we aren't sure, leave the log entry type alone */
return 1;
}
sct_validation_status_t SCT_get_validation_status(const SCT *sct)
{
return sct->validation_status;
}
int SCT_validate(SCT *sct, const CT_POLICY_EVAL_CTX *ctx)
{
int is_sct_valid = -1;
SCT_CTX *sctx = NULL;
X509_PUBKEY *pub = NULL, *log_pkey = NULL;
const CTLOG *log;
/*
* With an unrecognized SCT version we don't know what such an SCT means,
* let alone validate one. So we return validation failure (0).
*/
if (sct->version != SCT_VERSION_V1) {
sct->validation_status = SCT_VALIDATION_STATUS_UNKNOWN_VERSION;
return 0;
}
log = CTLOG_STORE_get0_log_by_id(ctx->log_store,
sct->log_id, sct->log_id_len);
/* Similarly, an SCT from an unknown log also cannot be validated. */
if (log == NULL) {
sct->validation_status = SCT_VALIDATION_STATUS_UNKNOWN_LOG;
return 0;
}
sctx = SCT_CTX_new();
if (sctx == NULL)
goto err;
if (X509_PUBKEY_set(&log_pkey, CTLOG_get0_public_key(log)) != 1)
goto err;
if (SCT_CTX_set1_pubkey(sctx, log_pkey) != 1)
goto err;
if (SCT_get_log_entry_type(sct) == CT_LOG_ENTRY_TYPE_PRECERT) {
EVP_PKEY *issuer_pkey;
if (ctx->issuer == NULL) {
sct->validation_status = SCT_VALIDATION_STATUS_UNVERIFIED;
goto end;
}
issuer_pkey = X509_get0_pubkey(ctx->issuer);
if (X509_PUBKEY_set(&pub, issuer_pkey) != 1)
goto err;
if (SCT_CTX_set1_issuer_pubkey(sctx, pub) != 1)
goto err;
}
SCT_CTX_set_time(sctx, ctx->epoch_time_in_ms);
/*
* XXX: Potential for optimization. This repeats some idempotent heavy
* lifting on the certificate for each candidate SCT, and appears to not
* use any information in the SCT itself, only the certificate is
* processed. So it may make more sense to to do this just once, perhaps
* associated with the shared (by all SCTs) policy eval ctx.
*
* XXX: Failure here is global (SCT independent) and represents either an
* issue with the certificate (e.g. duplicate extensions) or an out of
* memory condition. When the certificate is incompatible with CT, we just
* mark the SCTs invalid, rather than report a failure to determine the
* validation status. That way, callbacks that want to do "soft" SCT
* processing will not abort handshakes with false positive internal
* errors. Since the function does not distinguish between certificate
* issues (peer's fault) and internal problems (out fault) the safe thing
* to do is to report a validation failure and let the callback or
* application decide what to do.
*/
if (SCT_CTX_set1_cert(sctx, ctx->cert, NULL) != 1)
sct->validation_status = SCT_VALIDATION_STATUS_UNVERIFIED;
else
sct->validation_status = SCT_CTX_verify(sctx, sct) == 1 ?
SCT_VALIDATION_STATUS_VALID : SCT_VALIDATION_STATUS_INVALID;
end:
is_sct_valid = sct->validation_status == SCT_VALIDATION_STATUS_VALID;
err:
X509_PUBKEY_free(pub);
X509_PUBKEY_free(log_pkey);
SCT_CTX_free(sctx);
return is_sct_valid;
}
int SCT_LIST_validate(const STACK_OF(SCT) *scts, CT_POLICY_EVAL_CTX *ctx)
{
int are_scts_valid = 1;
int sct_count = scts != NULL ? sk_SCT_num(scts) : 0;
int i;
for (i = 0; i < sct_count; ++i) {
int is_sct_valid = -1;
SCT *sct = sk_SCT_value(scts, i);
if (sct == NULL)
continue;
is_sct_valid = SCT_validate(sct, ctx);
if (is_sct_valid < 0)
return is_sct_valid;
are_scts_valid &= is_sct_valid;
}
return are_scts_valid;
}