/* $OpenBSD: tls.c,v 1.86 2021/01/21 19:09:10 eric Exp $ */ /* * Copyright (c) 2014 Joel Sing * * 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 #include #include #include #include #include #include #include "tls_internal.h" static struct tls_config *tls_config_default; static int tls_init_rv = -1; static void tls_do_init(void) { OPENSSL_init_ssl(OPENSSL_INIT_NO_LOAD_CONFIG, NULL); if (BIO_sock_init() != 1) return; if ((tls_config_default = tls_config_new_internal()) == NULL) return; tls_config_default->refcount++; tls_init_rv = 0; } int tls_init(void) { static pthread_once_t once = PTHREAD_ONCE_INIT; if (pthread_once(&once, tls_do_init) != 0) return -1; return tls_init_rv; } const char * tls_error(struct tls *ctx) { return ctx->error.msg; } void tls_error_clear(struct tls_error *error) { free(error->msg); error->msg = NULL; error->num = 0; error->tls = 0; } static int tls_error_vset(struct tls_error *error, int errnum, const char *fmt, va_list ap) { char *errmsg = NULL; int rv = -1; tls_error_clear(error); error->num = errnum; error->tls = 1; if (vasprintf(&errmsg, fmt, ap) == -1) { errmsg = NULL; goto err; } if (errnum == -1) { error->msg = errmsg; return (0); } if (asprintf(&error->msg, "%s: %s", errmsg, strerror(errnum)) == -1) { error->msg = NULL; goto err; } rv = 0; err: free(errmsg); return (rv); } int tls_error_set(struct tls_error *error, const char *fmt, ...) { va_list ap; int errnum, rv; errnum = errno; va_start(ap, fmt); rv = tls_error_vset(error, errnum, fmt, ap); va_end(ap); return (rv); } int tls_error_setx(struct tls_error *error, const char *fmt, ...) { va_list ap; int rv; va_start(ap, fmt); rv = tls_error_vset(error, -1, fmt, ap); va_end(ap); return (rv); } int tls_config_set_error(struct tls_config *config, const char *fmt, ...) { va_list ap; int errnum, rv; errnum = errno; va_start(ap, fmt); rv = tls_error_vset(&config->error, errnum, fmt, ap); va_end(ap); return (rv); } int tls_config_set_errorx(struct tls_config *config, const char *fmt, ...) { va_list ap; int rv; va_start(ap, fmt); rv = tls_error_vset(&config->error, -1, fmt, ap); va_end(ap); return (rv); } int tls_set_error(struct tls *ctx, const char *fmt, ...) { va_list ap; int errnum, rv; errnum = errno; va_start(ap, fmt); rv = tls_error_vset(&ctx->error, errnum, fmt, ap); va_end(ap); return (rv); } int tls_set_errorx(struct tls *ctx, const char *fmt, ...) { va_list ap; int rv; va_start(ap, fmt); rv = tls_error_vset(&ctx->error, -1, fmt, ap); va_end(ap); return (rv); } int tls_set_ssl_errorx(struct tls *ctx, const char *fmt, ...) { va_list ap; int rv; /* Only set an error if a more specific one does not already exist. */ if (ctx->error.tls != 0) return (0); va_start(ap, fmt); rv = tls_error_vset(&ctx->error, -1, fmt, ap); va_end(ap); return (rv); } struct tls_sni_ctx * tls_sni_ctx_new(void) { return (calloc(1, sizeof(struct tls_sni_ctx))); } void tls_sni_ctx_free(struct tls_sni_ctx *sni_ctx) { if (sni_ctx == NULL) return; SSL_CTX_free(sni_ctx->ssl_ctx); X509_free(sni_ctx->ssl_cert); free(sni_ctx); } struct tls * tls_new(void) { struct tls *ctx; if ((ctx = calloc(1, sizeof(*ctx))) == NULL) return (NULL); tls_reset(ctx); if (tls_configure(ctx, tls_config_default) == -1) { free(ctx); return NULL; } return (ctx); } int tls_configure(struct tls *ctx, struct tls_config *config) { if (config == NULL) config = tls_config_default; pthread_mutex_lock(&config->mutex); config->refcount++; pthread_mutex_unlock(&config->mutex); tls_config_free(ctx->config); ctx->config = config; ctx->keypair = config->keypair; if ((ctx->flags & TLS_SERVER) != 0) return (tls_configure_server(ctx)); return (0); } int tls_cert_hash(X509 *cert, char **hash) { char d[EVP_MAX_MD_SIZE], *dhex = NULL; int dlen, rv = -1; free(*hash); *hash = NULL; if (X509_digest(cert, EVP_sha256(), d, &dlen) != 1) goto err; if (tls_hex_string(d, dlen, &dhex, NULL) != 0) goto err; if (asprintf(hash, "SHA256:%s", dhex) == -1) { *hash = NULL; goto err; } rv = 0; err: free(dhex); return (rv); } int tls_cert_pubkey_hash(X509 *cert, char **hash) { char d[EVP_MAX_MD_SIZE], *dhex = NULL; int dlen, rv = -1; free(*hash); *hash = NULL; if (X509_pubkey_digest(cert, EVP_sha256(), d, &dlen) != 1) goto err; if (tls_hex_string(d, dlen, &dhex, NULL) != 0) goto err; if (asprintf(hash, "SHA256:%s", dhex) == -1) { *hash = NULL; goto err; } rv = 0; err: free(dhex); return (rv); } static int tls_keypair_to_pkey(struct tls *ctx, struct tls_keypair *keypair, EVP_PKEY **pkey) { BIO *bio = NULL; X509 *x509 = NULL; char *mem; size_t len; int ret = -1; *pkey = NULL; if (ctx->config->use_fake_private_key) { mem = keypair->cert_mem; len = keypair->cert_len; } else { mem = keypair->key_mem; len = keypair->key_len; } if (mem == NULL) return (0); if (len > INT_MAX) { tls_set_errorx(ctx, ctx->config->use_fake_private_key ? "cert too long" : "key too long"); goto err; } if ((bio = BIO_new_mem_buf(mem, len)) == NULL) { tls_set_errorx(ctx, "failed to create buffer"); goto err; } if (ctx->config->use_fake_private_key) { if ((x509 = PEM_read_bio_X509(bio, NULL, tls_password_cb, NULL)) == NULL) { tls_set_errorx(ctx, "failed to read X509 certificate"); goto err; } if ((*pkey = X509_get_pubkey(x509)) == NULL) { tls_set_errorx(ctx, "failed to retrieve pubkey"); goto err; } } else { if ((*pkey = PEM_read_bio_PrivateKey(bio, NULL, tls_password_cb, NULL)) == NULL) { tls_set_errorx(ctx, "failed to read private key"); goto err; } } ret = 0; err: BIO_free(bio); X509_free(x509); return (ret); } int tls_configure_ssl_keypair(struct tls *ctx, SSL_CTX *ssl_ctx, struct tls_keypair *keypair, int required) { EVP_PKEY *pkey = NULL; if (!required && keypair->cert_mem == NULL && keypair->key_mem == NULL) return(0); if (keypair->cert_mem != NULL) { if (keypair->cert_len > INT_MAX) { tls_set_errorx(ctx, "certificate too long"); goto err; } if (SSL_CTX_use_certificate_chain_mem(ssl_ctx, keypair->cert_mem, keypair->cert_len) != 1) { tls_set_errorx(ctx, "failed to load certificate"); goto err; } } if (tls_keypair_to_pkey(ctx, keypair, &pkey) == -1) goto err; if (pkey != NULL) { if (keypair->pubkey_hash != NULL) { RSA *rsa; /* XXX only RSA for now for relayd privsep */ if ((rsa = EVP_PKEY_get1_RSA(pkey)) != NULL) { RSA_set_ex_data(rsa, 0, keypair->pubkey_hash); RSA_free(rsa); } } if (SSL_CTX_use_PrivateKey(ssl_ctx, pkey) != 1) { tls_set_errorx(ctx, "failed to load private key"); goto err; } EVP_PKEY_free(pkey); pkey = NULL; } if (!ctx->config->skip_private_key_check && SSL_CTX_check_private_key(ssl_ctx) != 1) { tls_set_errorx(ctx, "private/public key mismatch"); goto err; } return (0); err: EVP_PKEY_free(pkey); return (1); } int tls_configure_ssl(struct tls *ctx, SSL_CTX *ssl_ctx) { SSL_CTX_clear_mode(ssl_ctx, SSL_MODE_AUTO_RETRY); SSL_CTX_set_mode(ssl_ctx, SSL_MODE_ENABLE_PARTIAL_WRITE); SSL_CTX_set_mode(ssl_ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER); SSL_CTX_set_options(ssl_ctx, SSL_OP_NO_SSLv2); SSL_CTX_set_options(ssl_ctx, SSL_OP_NO_SSLv3); SSL_CTX_clear_options(ssl_ctx, SSL_OP_NO_TLSv1); SSL_CTX_clear_options(ssl_ctx, SSL_OP_NO_TLSv1_1); SSL_CTX_clear_options(ssl_ctx, SSL_OP_NO_TLSv1_2); SSL_CTX_clear_options(ssl_ctx, SSL_OP_NO_TLSv1_3); if ((ctx->config->protocols & TLS_PROTOCOL_TLSv1_0) == 0) SSL_CTX_set_options(ssl_ctx, SSL_OP_NO_TLSv1); if ((ctx->config->protocols & TLS_PROTOCOL_TLSv1_1) == 0) SSL_CTX_set_options(ssl_ctx, SSL_OP_NO_TLSv1_1); if ((ctx->config->protocols & TLS_PROTOCOL_TLSv1_2) == 0) SSL_CTX_set_options(ssl_ctx, SSL_OP_NO_TLSv1_2); if ((ctx->config->protocols & TLS_PROTOCOL_TLSv1_3) == 0) SSL_CTX_set_options(ssl_ctx, SSL_OP_NO_TLSv1_3); if (ctx->config->alpn != NULL) { if (SSL_CTX_set_alpn_protos(ssl_ctx, ctx->config->alpn, ctx->config->alpn_len) != 0) { tls_set_errorx(ctx, "failed to set alpn"); goto err; } } if (ctx->config->ciphers != NULL) { if (SSL_CTX_set_cipher_list(ssl_ctx, ctx->config->ciphers) != 1) { tls_set_errorx(ctx, "failed to set ciphers"); goto err; } } if (ctx->config->verify_time == 0) { X509_VERIFY_PARAM_set_flags(ssl_ctx->param, X509_V_FLAG_NO_CHECK_TIME); } /* Disable any form of session caching by default */ SSL_CTX_set_session_cache_mode(ssl_ctx, SSL_SESS_CACHE_OFF); SSL_CTX_set_options(ssl_ctx, SSL_OP_NO_TICKET); return (0); err: return (-1); } static int tls_ssl_cert_verify_cb(X509_STORE_CTX *x509_ctx, void *arg) { struct tls *ctx = arg; int x509_err; if (ctx->config->verify_cert == 0) return (1); if ((X509_verify_cert(x509_ctx)) < 0) { tls_set_errorx(ctx, "X509 verify cert failed"); return (0); } x509_err = X509_STORE_CTX_get_error(x509_ctx); if (x509_err == X509_V_OK) return (1); tls_set_errorx(ctx, "certificate verification failed: %s", X509_verify_cert_error_string(x509_err)); return (0); } int tls_configure_ssl_verify(struct tls *ctx, SSL_CTX *ssl_ctx, int verify) { size_t ca_len = ctx->config->ca_len; char *ca_mem = ctx->config->ca_mem; char *crl_mem = ctx->config->crl_mem; size_t crl_len = ctx->config->crl_len; char *ca_free = NULL; STACK_OF(X509_INFO) *xis = NULL; X509_STORE *store; X509_INFO *xi; BIO *bio = NULL; int rv = -1; int i; SSL_CTX_set_verify(ssl_ctx, verify, NULL); SSL_CTX_set_cert_verify_callback(ssl_ctx, tls_ssl_cert_verify_cb, ctx); if (ctx->config->verify_depth >= 0) SSL_CTX_set_verify_depth(ssl_ctx, ctx->config->verify_depth); if (ctx->config->verify_cert == 0) goto done; /* If no CA has been specified, attempt to load the default. */ if (ctx->config->ca_mem == NULL && ctx->config->ca_path == NULL) { if (tls_config_load_file(&ctx->error, "CA", tls_default_ca_cert_file(), &ca_mem, &ca_len) != 0) goto err; ca_free = ca_mem; } if (ca_mem != NULL) { if (ca_len > INT_MAX) { tls_set_errorx(ctx, "ca too long"); goto err; } if (SSL_CTX_load_verify_mem(ssl_ctx, ca_mem, ca_len) != 1) { tls_set_errorx(ctx, "ssl verify memory setup failure"); goto err; } } else if (SSL_CTX_load_verify_locations(ssl_ctx, NULL, ctx->config->ca_path) != 1) { tls_set_errorx(ctx, "ssl verify locations failure"); goto err; } if (crl_mem != NULL) { if (crl_len > INT_MAX) { tls_set_errorx(ctx, "crl too long"); goto err; } if ((bio = BIO_new_mem_buf(crl_mem, crl_len)) == NULL) { tls_set_errorx(ctx, "failed to create buffer"); goto err; } if ((xis = PEM_X509_INFO_read_bio(bio, NULL, tls_password_cb, NULL)) == NULL) { tls_set_errorx(ctx, "failed to parse crl"); goto err; } store = SSL_CTX_get_cert_store(ssl_ctx); for (i = 0; i < sk_X509_INFO_num(xis); i++) { xi = sk_X509_INFO_value(xis, i); if (xi->crl == NULL) continue; if (!X509_STORE_add_crl(store, xi->crl)) { tls_set_error(ctx, "failed to add crl"); goto err; } xi->crl = NULL; } X509_VERIFY_PARAM_set_flags(store->param, X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL); } done: rv = 0; err: sk_X509_INFO_pop_free(xis, X509_INFO_free); BIO_free(bio); free(ca_free); return (rv); } void tls_free(struct tls *ctx) { if (ctx == NULL) return; tls_reset(ctx); free(ctx); } void tls_reset(struct tls *ctx) { struct tls_sni_ctx *sni, *nsni; tls_config_free(ctx->config); ctx->config = NULL; SSL_CTX_free(ctx->ssl_ctx); SSL_free(ctx->ssl_conn); X509_free(ctx->ssl_peer_cert); ctx->ssl_conn = NULL; ctx->ssl_ctx = NULL; ctx->ssl_peer_cert = NULL; /* X509 objects in chain are freed with the SSL */ ctx->ssl_peer_chain = NULL; ctx->socket = -1; ctx->state = 0; free(ctx->servername); ctx->servername = NULL; free(ctx->error.msg); ctx->error.msg = NULL; ctx->error.num = -1; tls_conninfo_free(ctx->conninfo); ctx->conninfo = NULL; tls_ocsp_free(ctx->ocsp); ctx->ocsp = NULL; for (sni = ctx->sni_ctx; sni != NULL; sni = nsni) { nsni = sni->next; tls_sni_ctx_free(sni); } ctx->sni_ctx = NULL; ctx->read_cb = NULL; ctx->write_cb = NULL; ctx->cb_arg = NULL; } int tls_ssl_error(struct tls *ctx, SSL *ssl_conn, int ssl_ret, const char *prefix) { const char *errstr = "unknown error"; unsigned long err; int ssl_err; ssl_err = SSL_get_error(ssl_conn, ssl_ret); switch (ssl_err) { case SSL_ERROR_NONE: case SSL_ERROR_ZERO_RETURN: return (0); case SSL_ERROR_WANT_READ: return (TLS_WANT_POLLIN); case SSL_ERROR_WANT_WRITE: return (TLS_WANT_POLLOUT); case SSL_ERROR_SYSCALL: if ((err = ERR_peek_error()) != 0) { errstr = ERR_error_string(err, NULL); } else if (ssl_ret == 0) { if ((ctx->state & TLS_HANDSHAKE_COMPLETE) != 0) { ctx->state |= TLS_EOF_NO_CLOSE_NOTIFY; return (0); } errstr = "unexpected EOF"; } else if (ssl_ret == -1) { errstr = strerror(errno); } tls_set_ssl_errorx(ctx, "%s failed: %s", prefix, errstr); return (-1); case SSL_ERROR_SSL: if ((err = ERR_peek_error()) != 0) { errstr = ERR_error_string(err, NULL); } tls_set_ssl_errorx(ctx, "%s failed: %s", prefix, errstr); return (-1); case SSL_ERROR_WANT_CONNECT: case SSL_ERROR_WANT_ACCEPT: case SSL_ERROR_WANT_X509_LOOKUP: default: tls_set_ssl_errorx(ctx, "%s failed (%i)", prefix, ssl_err); return (-1); } } int tls_handshake(struct tls *ctx) { int rv = -1; tls_error_clear(&ctx->error); if ((ctx->flags & (TLS_CLIENT | TLS_SERVER_CONN)) == 0) { tls_set_errorx(ctx, "invalid operation for context"); goto out; } if ((ctx->state & TLS_HANDSHAKE_COMPLETE) != 0) { tls_set_errorx(ctx, "handshake already completed"); goto out; } if ((ctx->flags & TLS_CLIENT) != 0) rv = tls_handshake_client(ctx); else if ((ctx->flags & TLS_SERVER_CONN) != 0) rv = tls_handshake_server(ctx); if (rv == 0) { ctx->ssl_peer_cert = SSL_get_peer_certificate(ctx->ssl_conn); ctx->ssl_peer_chain = SSL_get_peer_cert_chain(ctx->ssl_conn); if (tls_conninfo_populate(ctx) == -1) rv = -1; if (ctx->ocsp == NULL) ctx->ocsp = tls_ocsp_setup_from_peer(ctx); } out: /* Prevent callers from performing incorrect error handling */ errno = 0; return (rv); } ssize_t tls_read(struct tls *ctx, void *buf, size_t buflen) { ssize_t rv = -1; int ssl_ret; tls_error_clear(&ctx->error); if ((ctx->state & TLS_HANDSHAKE_COMPLETE) == 0) { if ((rv = tls_handshake(ctx)) != 0) goto out; } if (buflen > INT_MAX) { tls_set_errorx(ctx, "buflen too long"); goto out; } ERR_clear_error(); if ((ssl_ret = SSL_read(ctx->ssl_conn, buf, buflen)) > 0) { rv = (ssize_t)ssl_ret; goto out; } rv = (ssize_t)tls_ssl_error(ctx, ctx->ssl_conn, ssl_ret, "read"); out: /* Prevent callers from performing incorrect error handling */ errno = 0; return (rv); } ssize_t tls_write(struct tls *ctx, const void *buf, size_t buflen) { ssize_t rv = -1; int ssl_ret; tls_error_clear(&ctx->error); if ((ctx->state & TLS_HANDSHAKE_COMPLETE) == 0) { if ((rv = tls_handshake(ctx)) != 0) goto out; } if (buflen > INT_MAX) { tls_set_errorx(ctx, "buflen too long"); goto out; } ERR_clear_error(); if ((ssl_ret = SSL_write(ctx->ssl_conn, buf, buflen)) > 0) { rv = (ssize_t)ssl_ret; goto out; } rv = (ssize_t)tls_ssl_error(ctx, ctx->ssl_conn, ssl_ret, "write"); out: /* Prevent callers from performing incorrect error handling */ errno = 0; return (rv); } int tls_close(struct tls *ctx) { int ssl_ret; int rv = 0; tls_error_clear(&ctx->error); if ((ctx->flags & (TLS_CLIENT | TLS_SERVER_CONN)) == 0) { tls_set_errorx(ctx, "invalid operation for context"); rv = -1; goto out; } if (ctx->state & TLS_SSL_NEEDS_SHUTDOWN) { ERR_clear_error(); ssl_ret = SSL_shutdown(ctx->ssl_conn); if (ssl_ret < 0) { rv = tls_ssl_error(ctx, ctx->ssl_conn, ssl_ret, "shutdown"); if (rv == TLS_WANT_POLLIN || rv == TLS_WANT_POLLOUT) goto out; } ctx->state &= ~TLS_SSL_NEEDS_SHUTDOWN; } if (ctx->socket != -1) { if (shutdown(ctx->socket, SHUT_RDWR) != 0) { if (rv == 0 && errno != ENOTCONN && errno != ECONNRESET) { tls_set_error(ctx, "shutdown"); rv = -1; } } if (close(ctx->socket) != 0) { if (rv == 0) { tls_set_error(ctx, "close"); rv = -1; } } ctx->socket = -1; } if ((ctx->state & TLS_EOF_NO_CLOSE_NOTIFY) != 0) { tls_set_errorx(ctx, "EOF without close notify"); rv = -1; } out: /* Prevent callers from performing incorrect error handling */ errno = 0; return (rv); }