From 4bb261b015d382a567563571ae4d399a16caebe2 Mon Sep 17 00:00:00 2001 From: "C. McEnroe" Date: Mon, 27 Jul 2020 21:55:29 -0400 Subject: Import LibreSSL 3.2.0 --- tls_ocsp.c | 453 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 453 insertions(+) create mode 100644 tls_ocsp.c (limited to 'tls_ocsp.c') diff --git a/tls_ocsp.c b/tls_ocsp.c new file mode 100644 index 0000000..32c372e --- /dev/null +++ b/tls_ocsp.c @@ -0,0 +1,453 @@ +/* $OpenBSD: tls_ocsp.c,v 1.19 2019/12/03 14:56:42 tb Exp $ */ +/* + * Copyright (c) 2015 Marko Kreen + * Copyright (c) 2016 Bob Beck + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include + +#include +#include + +#include +#include +#include + +#include +#include "tls_internal.h" + +#define MAXAGE_SEC (14*24*60*60) +#define JITTER_SEC (60) + +/* + * State for request. + */ + +static struct tls_ocsp * +tls_ocsp_new(void) +{ + return (calloc(1, sizeof(struct tls_ocsp))); +} + +void +tls_ocsp_free(struct tls_ocsp *ocsp) +{ + if (ocsp == NULL) + return; + + X509_free(ocsp->main_cert); + free(ocsp->ocsp_result); + free(ocsp->ocsp_url); + + free(ocsp); +} + +static int +tls_ocsp_asn1_parse_time(struct tls *ctx, ASN1_GENERALIZEDTIME *gt, time_t *gt_time) +{ + struct tm tm; + + if (gt == NULL) + return -1; + /* RFC 6960 specifies that all times in OCSP must be GENERALIZEDTIME */ + if (ASN1_time_parse(gt->data, gt->length, &tm, + V_ASN1_GENERALIZEDTIME) == -1) + return -1; + if ((*gt_time = timegm(&tm)) == -1) + return -1; + return 0; +} + +static int +tls_ocsp_fill_info(struct tls *ctx, int response_status, int cert_status, + int crl_reason, ASN1_GENERALIZEDTIME *revtime, + ASN1_GENERALIZEDTIME *thisupd, ASN1_GENERALIZEDTIME *nextupd) +{ + struct tls_ocsp_result *info = NULL; + + free(ctx->ocsp->ocsp_result); + ctx->ocsp->ocsp_result = NULL; + + if ((info = calloc(1, sizeof (struct tls_ocsp_result))) == NULL) { + tls_set_error(ctx, "calloc"); + return -1; + } + info->response_status = response_status; + info->cert_status = cert_status; + info->crl_reason = crl_reason; + if (info->response_status != OCSP_RESPONSE_STATUS_SUCCESSFUL) { + info->result_msg = + OCSP_response_status_str(info->response_status); + } else if (info->cert_status != V_OCSP_CERTSTATUS_REVOKED) { + info->result_msg = OCSP_cert_status_str(info->cert_status); + } else { + info->result_msg = OCSP_crl_reason_str(info->crl_reason); + } + info->revocation_time = info->this_update = info->next_update = -1; + if (revtime != NULL && + tls_ocsp_asn1_parse_time(ctx, revtime, &info->revocation_time) != 0) { + tls_set_error(ctx, + "unable to parse revocation time in OCSP reply"); + goto err; + } + if (thisupd != NULL && + tls_ocsp_asn1_parse_time(ctx, thisupd, &info->this_update) != 0) { + tls_set_error(ctx, + "unable to parse this update time in OCSP reply"); + goto err; + } + if (nextupd != NULL && + tls_ocsp_asn1_parse_time(ctx, nextupd, &info->next_update) != 0) { + tls_set_error(ctx, + "unable to parse next update time in OCSP reply"); + goto err; + } + ctx->ocsp->ocsp_result = info; + return 0; + + err: + free(info); + return -1; +} + +static OCSP_CERTID * +tls_ocsp_get_certid(X509 *main_cert, STACK_OF(X509) *extra_certs, + SSL_CTX *ssl_ctx) +{ + X509_NAME *issuer_name; + X509 *issuer; + X509_STORE_CTX storectx; + X509_OBJECT tmpobj; + OCSP_CERTID *cid = NULL; + X509_STORE *store; + + if ((issuer_name = X509_get_issuer_name(main_cert)) == NULL) + return NULL; + + if (extra_certs != NULL) { + issuer = X509_find_by_subject(extra_certs, issuer_name); + if (issuer != NULL) + return OCSP_cert_to_id(NULL, main_cert, issuer); + } + + if ((store = SSL_CTX_get_cert_store(ssl_ctx)) == NULL) + return NULL; + if (X509_STORE_CTX_init(&storectx, store, main_cert, extra_certs) != 1) + return NULL; + if (X509_STORE_get_by_subject(&storectx, X509_LU_X509, issuer_name, + &tmpobj) == 1) { + cid = OCSP_cert_to_id(NULL, main_cert, tmpobj.data.x509); + X509_OBJECT_free_contents(&tmpobj); + } + X509_STORE_CTX_cleanup(&storectx); + return cid; +} + +struct tls_ocsp * +tls_ocsp_setup_from_peer(struct tls *ctx) +{ + struct tls_ocsp *ocsp = NULL; + STACK_OF(OPENSSL_STRING) *ocsp_urls = NULL; + + if ((ocsp = tls_ocsp_new()) == NULL) + goto err; + + /* steal state from ctx struct */ + ocsp->main_cert = SSL_get_peer_certificate(ctx->ssl_conn); + ocsp->extra_certs = SSL_get_peer_cert_chain(ctx->ssl_conn); + if (ocsp->main_cert == NULL) { + tls_set_errorx(ctx, "no peer certificate for OCSP"); + goto err; + } + + ocsp_urls = X509_get1_ocsp(ocsp->main_cert); + if (ocsp_urls == NULL) { + tls_set_errorx(ctx, "no OCSP URLs in peer certificate"); + goto err; + } + + ocsp->ocsp_url = strdup(sk_OPENSSL_STRING_value(ocsp_urls, 0)); + if (ocsp->ocsp_url == NULL) { + tls_set_errorx(ctx, "out of memory"); + goto err; + } + + X509_email_free(ocsp_urls); + return ocsp; + + err: + tls_ocsp_free(ocsp); + X509_email_free(ocsp_urls); + return NULL; +} + +static int +tls_ocsp_verify_response(struct tls *ctx, OCSP_RESPONSE *resp) +{ + OCSP_BASICRESP *br = NULL; + ASN1_GENERALIZEDTIME *revtime = NULL, *thisupd = NULL, *nextupd = NULL; + OCSP_CERTID *cid = NULL; + STACK_OF(X509) *combined = NULL; + int response_status=0, cert_status=0, crl_reason=0; + int ret = -1; + unsigned long flags; + + if ((br = OCSP_response_get1_basic(resp)) == NULL) { + tls_set_errorx(ctx, "cannot load ocsp reply"); + goto err; + } + + /* + * Skip validation of 'extra_certs' as this should be done + * already as part of main handshake. + */ + flags = OCSP_TRUSTOTHER; + + /* now verify */ + if (OCSP_basic_verify(br, ctx->ocsp->extra_certs, + SSL_CTX_get_cert_store(ctx->ssl_ctx), flags) != 1) { + tls_set_error(ctx, "ocsp verify failed"); + goto err; + } + + /* signature OK, look inside */ + response_status = OCSP_response_status(resp); + if (response_status != OCSP_RESPONSE_STATUS_SUCCESSFUL) { + tls_set_errorx(ctx, "ocsp verify failed: response - %s", + OCSP_response_status_str(response_status)); + goto err; + } + + cid = tls_ocsp_get_certid(ctx->ocsp->main_cert, + ctx->ocsp->extra_certs, ctx->ssl_ctx); + if (cid == NULL) { + tls_set_errorx(ctx, "ocsp verify failed: no issuer cert"); + goto err; + } + + if (OCSP_resp_find_status(br, cid, &cert_status, &crl_reason, + &revtime, &thisupd, &nextupd) != 1) { + tls_set_errorx(ctx, "ocsp verify failed: no result for cert"); + goto err; + } + + if (OCSP_check_validity(thisupd, nextupd, JITTER_SEC, + MAXAGE_SEC) != 1) { + tls_set_errorx(ctx, + "ocsp verify failed: ocsp response not current"); + goto err; + } + + if (tls_ocsp_fill_info(ctx, response_status, cert_status, + crl_reason, revtime, thisupd, nextupd) != 0) + goto err; + + /* finally can look at status */ + if (cert_status != V_OCSP_CERTSTATUS_GOOD && cert_status != + V_OCSP_CERTSTATUS_UNKNOWN) { + tls_set_errorx(ctx, "ocsp verify failed: revoked cert - %s", + OCSP_crl_reason_str(crl_reason)); + goto err; + } + ret = 0; + + err: + sk_X509_free(combined); + OCSP_CERTID_free(cid); + OCSP_BASICRESP_free(br); + return ret; +} + +/* + * Process a raw OCSP response from an OCSP server request. + * OCSP details can then be retrieved with tls_peer_ocsp_* functions. + * returns 0 if certificate ok, -1 otherwise. + */ +static int +tls_ocsp_process_response_internal(struct tls *ctx, const unsigned char *response, + size_t size) +{ + int ret; + OCSP_RESPONSE *resp; + + resp = d2i_OCSP_RESPONSE(NULL, &response, size); + if (resp == NULL) { + tls_ocsp_free(ctx->ocsp); + ctx->ocsp = NULL; + tls_set_error(ctx, "unable to parse OCSP response"); + return -1; + } + ret = tls_ocsp_verify_response(ctx, resp); + OCSP_RESPONSE_free(resp); + return ret; +} + +/* TLS handshake verification callback for stapled requests */ +int +tls_ocsp_verify_cb(SSL *ssl, void *arg) +{ + const unsigned char *raw = NULL; + int size, res = -1; + struct tls *ctx; + + if ((ctx = SSL_get_app_data(ssl)) == NULL) + return -1; + + size = SSL_get_tlsext_status_ocsp_resp(ssl, &raw); + if (size <= 0) { + if (ctx->config->ocsp_require_stapling) { + tls_set_errorx(ctx, "no stapled OCSP response provided"); + return 0; + } + return 1; + } + + tls_ocsp_free(ctx->ocsp); + if ((ctx->ocsp = tls_ocsp_setup_from_peer(ctx)) == NULL) + return 0; + + if (ctx->config->verify_cert == 0 || ctx->config->verify_time == 0) + return 1; + + res = tls_ocsp_process_response_internal(ctx, raw, size); + + return (res == 0) ? 1 : 0; +} + + +/* Staple the OCSP information in ctx->ocsp to the server handshake. */ +int +tls_ocsp_stapling_cb(SSL *ssl, void *arg) +{ + int ret = SSL_TLSEXT_ERR_ALERT_FATAL; + unsigned char *ocsp_staple = NULL; + struct tls *ctx; + + if ((ctx = SSL_get_app_data(ssl)) == NULL) + goto err; + + if (ctx->keypair == NULL || ctx->keypair->ocsp_staple == NULL || + ctx->keypair->ocsp_staple_len == 0) + return SSL_TLSEXT_ERR_NOACK; + + if ((ocsp_staple = malloc(ctx->keypair->ocsp_staple_len)) == NULL) + goto err; + + memcpy(ocsp_staple, ctx->keypair->ocsp_staple, + ctx->keypair->ocsp_staple_len); + + if (SSL_set_tlsext_status_ocsp_resp(ctx->ssl_conn, ocsp_staple, + ctx->keypair->ocsp_staple_len) != 1) + goto err; + + ret = SSL_TLSEXT_ERR_OK; + err: + if (ret != SSL_TLSEXT_ERR_OK) + free(ocsp_staple); + + return ret; +} + +/* + * Public API + */ + +/* Retrieve OCSP URL from peer certificate, if present. */ +const char * +tls_peer_ocsp_url(struct tls *ctx) +{ + if (ctx->ocsp == NULL) + return NULL; + return ctx->ocsp->ocsp_url; +} + +const char * +tls_peer_ocsp_result(struct tls *ctx) +{ + if (ctx->ocsp == NULL) + return NULL; + if (ctx->ocsp->ocsp_result == NULL) + return NULL; + return ctx->ocsp->ocsp_result->result_msg; +} + +int +tls_peer_ocsp_response_status(struct tls *ctx) +{ + if (ctx->ocsp == NULL) + return -1; + if (ctx->ocsp->ocsp_result == NULL) + return -1; + return ctx->ocsp->ocsp_result->response_status; +} + +int +tls_peer_ocsp_cert_status(struct tls *ctx) +{ + if (ctx->ocsp == NULL) + return -1; + if (ctx->ocsp->ocsp_result == NULL) + return -1; + return ctx->ocsp->ocsp_result->cert_status; +} + +int +tls_peer_ocsp_crl_reason(struct tls *ctx) +{ + if (ctx->ocsp == NULL) + return -1; + if (ctx->ocsp->ocsp_result == NULL) + return -1; + return ctx->ocsp->ocsp_result->crl_reason; +} + +time_t +tls_peer_ocsp_this_update(struct tls *ctx) +{ + if (ctx->ocsp == NULL) + return -1; + if (ctx->ocsp->ocsp_result == NULL) + return -1; + return ctx->ocsp->ocsp_result->this_update; +} + +time_t +tls_peer_ocsp_next_update(struct tls *ctx) +{ + if (ctx->ocsp == NULL) + return -1; + if (ctx->ocsp->ocsp_result == NULL) + return -1; + return ctx->ocsp->ocsp_result->next_update; +} + +time_t +tls_peer_ocsp_revocation_time(struct tls *ctx) +{ + if (ctx->ocsp == NULL) + return -1; + if (ctx->ocsp->ocsp_result == NULL) + return -1; + return ctx->ocsp->ocsp_result->revocation_time; +} + +int +tls_ocsp_process_response(struct tls *ctx, const unsigned char *response, + size_t size) +{ + if ((ctx->state & TLS_HANDSHAKE_COMPLETE) == 0) + return -1; + return tls_ocsp_process_response_internal(ctx, response, size); +} -- cgit 1.4.1