/* $OpenBSD: ct_sct.c,v 1.8 2022/01/22 00:29:59 inoguchi Exp $ */ /* * Written by Rob Stradling (rob@comodo.com), Stephen Henson (steve@openssl.org) * and Adam Eijdenberg (adam.eijdenberg@gmail.com) for the OpenSSL project 2016. */ /* ==================================================================== * Copyright (c) 2014 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * licensing@OpenSSL.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ #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 <string.h> #include "ct_local.h" SCT * SCT_new(void) { SCT *sct = calloc(1, sizeof(*sct)); if (sct == NULL) { CTerror(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; free(sct->log_id); free(sct->ext); free(sct->sig); free(sct->sct); free(sct); } void SCT_LIST_free(STACK_OF(SCT) *scts) { sk_SCT_pop_free(scts, SCT_free); } int SCT_set_version(SCT *sct, sct_version_t version) { if (version != SCT_VERSION_V1) { CTerror(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; } CTerror(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) { CTerror(CT_R_INVALID_LOG_ID_LENGTH); return 0; } 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) { CTerror(CT_R_INVALID_LOG_ID_LENGTH); return 0; } 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 = malloc(log_id_len); if (sct->log_id == NULL) { CTerror(ERR_R_MALLOC_FAILURE); return 0; } memcpy(sct->log_id, log_id, log_id_len); 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 = 4; /* XXX */ sct->sig_alg = 1; /* XXX */ sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; return 1; case NID_ecdsa_with_SHA256: sct->hash_alg = 4; /* XXX */ sct->sig_alg = 3; /* XXX */ sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET; return 1; default: CTerror(CT_R_UNRECOGNIZED_SIGNATURE_NID); return 0; } } void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len) { 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) { 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 = malloc(ext_len); if (sct->ext == NULL) { CTerror(ERR_R_MALLOC_FAILURE); return 0; } memcpy(sct->ext, ext, ext_len); sct->ext_len = ext_len; } return 1; } void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len) { 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) { 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 = malloc(sig_len); if (sct->sig == NULL) { CTerror(ERR_R_MALLOC_FAILURE); return 0; } memcpy(sct->sig, sig, sig_len); 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) { /* XXX sigalg numbers */ if (sct->hash_alg == 4) { switch (sct->sig_alg) { case 3: return NID_ecdsa_with_SHA256; case 1: 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; } if ((issuer_pkey = X509_get0_pubkey(ctx->issuer)) == NULL) goto err; 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; }