/* $OpenBSD: tls_client.c,v 1.51 2024/03/26 08:54:48 joshua 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 "tls_internal.h" struct tls * tls_client(void) { struct tls *ctx; if (tls_init() == -1) return (NULL); if ((ctx = tls_new()) == NULL) return (NULL); ctx->flags |= TLS_CLIENT; return (ctx); } int tls_connect(struct tls *ctx, const char *host, const char *port) { return tls_connect_servername(ctx, host, port, NULL); } int tls_connect_servername(struct tls *ctx, const char *host, const char *port, const char *servername) { struct addrinfo hints, *res, *res0; const char *h = NULL, *p = NULL; char *hs = NULL, *ps = NULL; int rv = -1, s = -1, ret; if ((ctx->flags & TLS_CLIENT) == 0) { tls_set_errorx(ctx, TLS_ERROR_INVALID_CONTEXT, "not a client context"); goto err; } if (host == NULL) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "host not specified"); goto err; } /* If port is NULL, try to extract a port from the specified host. */ if (port == NULL) { ret = tls_host_port(host, &hs, &ps); if (ret == -1) { tls_set_errorx(ctx, TLS_ERROR_OUT_OF_MEMORY, "out of memory"); goto err; } if (ret != 0) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "no port provided"); goto err; } } h = (hs != NULL) ? hs : host; p = (ps != NULL) ? ps : port; /* * First check if the host is specified as a numeric IP address, * either IPv4 or IPv6, before trying to resolve the host. * The AI_ADDRCONFIG resolver option will not return IPv4 or IPv6 * records if it is not configured on an interface; not considering * loopback addresses. Checking the numeric addresses first makes * sure that connection attempts to numeric addresses and especially * 127.0.0.1 or ::1 loopback addresses are always possible. */ memset(&hints, 0, sizeof(hints)); hints.ai_socktype = SOCK_STREAM; /* try as an IPv4 literal */ hints.ai_family = AF_INET; hints.ai_flags = AI_NUMERICHOST; if (getaddrinfo(h, p, &hints, &res0) != 0) { /* try again as an IPv6 literal */ hints.ai_family = AF_INET6; if (getaddrinfo(h, p, &hints, &res0) != 0) { /* last try, with name resolution and save the error */ hints.ai_family = AF_UNSPEC; hints.ai_flags = AI_ADDRCONFIG; if ((s = getaddrinfo(h, p, &hints, &res0)) != 0) { tls_set_error(ctx, TLS_ERROR_UNKNOWN, "%s", gai_strerror(s)); goto err; } } } /* It was resolved somehow; now try connecting to what we got */ s = -1; for (res = res0; res; res = res->ai_next) { s = socket(res->ai_family, res->ai_socktype, res->ai_protocol); if (s == -1) { tls_set_error(ctx, TLS_ERROR_UNKNOWN, "socket"); continue; } if (connect(s, res->ai_addr, res->ai_addrlen) == -1) { tls_set_error(ctx, TLS_ERROR_UNKNOWN, "connect"); close(s); s = -1; continue; } break; /* Connected. */ } freeaddrinfo(res0); if (s == -1) goto err; if (servername == NULL) servername = h; if (tls_connect_socket(ctx, s, servername) != 0) { close(s); goto err; } ctx->socket = s; rv = 0; err: free(hs); free(ps); return (rv); } static int tls_client_read_session(struct tls *ctx) { int sfd = ctx->config->session_fd; uint8_t *session = NULL; size_t session_len = 0; SSL_SESSION *ss = NULL; BIO *bio = NULL; struct stat sb; ssize_t n; int rv = -1; if (fstat(sfd, &sb) == -1) { tls_set_error(ctx, TLS_ERROR_UNKNOWN, "failed to stat session file"); goto err; } if (sb.st_size < 0 || sb.st_size > INT_MAX) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "invalid session file size"); goto err; } session_len = (size_t)sb.st_size; /* A zero size file means that we do not yet have a valid session. */ if (session_len == 0) goto done; if ((session = malloc(session_len)) == NULL) goto err; n = pread(sfd, session, session_len, 0); if (n < 0 || (size_t)n != session_len) { tls_set_error(ctx, TLS_ERROR_UNKNOWN, "failed to read session file"); goto err; } if ((bio = BIO_new_mem_buf(session, session_len)) == NULL) goto err; if ((ss = PEM_read_bio_SSL_SESSION(bio, NULL, tls_password_cb, NULL)) == NULL) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "failed to parse session"); goto err; } if (SSL_set_session(ctx->ssl_conn, ss) != 1) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "failed to set session"); goto err; } done: rv = 0; err: freezero(session, session_len); SSL_SESSION_free(ss); BIO_free(bio); return rv; } static int tls_client_write_session(struct tls *ctx) { int sfd = ctx->config->session_fd; SSL_SESSION *ss = NULL; BIO *bio = NULL; long data_len; char *data; off_t offset; size_t len; ssize_t n; int rv = -1; if ((ss = SSL_get1_session(ctx->ssl_conn)) == NULL) { if (ftruncate(sfd, 0) == -1) { tls_set_error(ctx, TLS_ERROR_UNKNOWN, "failed to truncate session file"); goto err; } goto done; } if ((bio = BIO_new(BIO_s_mem())) == NULL) goto err; if (PEM_write_bio_SSL_SESSION(bio, ss) == 0) goto err; if ((data_len = BIO_get_mem_data(bio, &data)) <= 0) goto err; len = (size_t)data_len; offset = 0; if (ftruncate(sfd, len) == -1) { tls_set_error(ctx, TLS_ERROR_UNKNOWN, "failed to truncate session file"); goto err; } while (len > 0) { if ((n = pwrite(sfd, data + offset, len, offset)) == -1) { tls_set_error(ctx, TLS_ERROR_UNKNOWN, "failed to write session file"); goto err; } offset += n; len -= n; } done: rv = 0; err: SSL_SESSION_free(ss); BIO_free_all(bio); return (rv); } static int tls_connect_common(struct tls *ctx, const char *servername) { union tls_addr addrbuf; size_t servername_len; int rv = -1; if ((ctx->flags & TLS_CLIENT) == 0) { tls_set_errorx(ctx, TLS_ERROR_INVALID_CONTEXT, "not a client context"); goto err; } if (servername != NULL) { if ((ctx->servername = strdup(servername)) == NULL) { tls_set_errorx(ctx, TLS_ERROR_OUT_OF_MEMORY, "out of memory"); goto err; } /* * If there's a trailing dot, remove it. While an FQDN includes * the terminating dot representing the zero-length label of * the root (RFC 8499, section 2), the SNI explicitly does not * include it (RFC 6066, section 3). */ servername_len = strlen(ctx->servername); if (servername_len > 0 && ctx->servername[servername_len - 1] == '.') ctx->servername[servername_len - 1] = '\0'; } if ((ctx->ssl_ctx = SSL_CTX_new(SSLv23_client_method())) == NULL) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "ssl context failure"); goto err; } if (tls_configure_ssl(ctx, ctx->ssl_ctx) != 0) goto err; if (tls_configure_ssl_keypair(ctx, ctx->ssl_ctx, ctx->config->keypair, 0) != 0) goto err; if (ctx->config->verify_name) { if (ctx->servername == NULL) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "server name not specified"); goto err; } } if (tls_configure_ssl_verify(ctx, ctx->ssl_ctx, SSL_VERIFY_PEER) == -1) goto err; if (ctx->config->ecdhecurves != NULL) { if (SSL_CTX_set1_groups(ctx->ssl_ctx, ctx->config->ecdhecurves, ctx->config->ecdhecurves_len) != 1) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "failed to set ecdhe curves"); goto err; } } if (SSL_CTX_set_tlsext_status_cb(ctx->ssl_ctx, tls_ocsp_verify_cb) != 1) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "ssl OCSP verification setup failure"); goto err; } if ((ctx->ssl_conn = SSL_new(ctx->ssl_ctx)) == NULL) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "ssl connection failure"); goto err; } if (SSL_set_app_data(ctx->ssl_conn, ctx) != 1) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "ssl application data failure"); goto err; } if (ctx->config->session_fd != -1) { SSL_clear_options(ctx->ssl_conn, SSL_OP_NO_TICKET); if (tls_client_read_session(ctx) == -1) goto err; } if (SSL_set_tlsext_status_type(ctx->ssl_conn, TLSEXT_STATUSTYPE_ocsp) != 1) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "ssl OCSP extension setup failure"); goto err; } /* * RFC 6066 (SNI): Literal IPv4 and IPv6 addresses are not * permitted in "HostName". */ if (ctx->servername != NULL && inet_pton(AF_INET, ctx->servername, &addrbuf) != 1 && inet_pton(AF_INET6, ctx->servername, &addrbuf) != 1) { if (SSL_set_tlsext_host_name(ctx->ssl_conn, ctx->servername) == 0) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "server name indication failure"); goto err; } } ctx->state |= TLS_CONNECTED; rv = 0; err: return (rv); } int tls_connect_socket(struct tls *ctx, int s, const char *servername) { return tls_connect_fds(ctx, s, s, servername); } int tls_connect_fds(struct tls *ctx, int fd_read, int fd_write, const char *servername) { int rv = -1; if (fd_read < 0 || fd_write < 0) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "invalid file descriptors"); goto err; } if (tls_connect_common(ctx, servername) != 0) goto err; if (SSL_set_rfd(ctx->ssl_conn, fd_read) != 1 || SSL_set_wfd(ctx->ssl_conn, fd_write) != 1) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "ssl file descriptor failure"); goto err; } rv = 0; err: return (rv); } int tls_connect_cbs(struct tls *ctx, tls_read_cb read_cb, tls_write_cb write_cb, void *cb_arg, const char *servername) { int rv = -1; if (tls_connect_common(ctx, servername) != 0) goto err; if (tls_set_cbs(ctx, read_cb, write_cb, cb_arg) != 0) goto err; rv = 0; err: return (rv); } int tls_handshake_client(struct tls *ctx) { X509 *cert = NULL; int match, ssl_ret; int rv = -1; if ((ctx->flags & TLS_CLIENT) == 0) { tls_set_errorx(ctx, TLS_ERROR_INVALID_CONTEXT, "not a client context"); goto err; } if ((ctx->state & TLS_CONNECTED) == 0) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "context not connected"); goto err; } ctx->state |= TLS_SSL_NEEDS_SHUTDOWN; ERR_clear_error(); if ((ssl_ret = SSL_connect(ctx->ssl_conn)) != 1) { rv = tls_ssl_error(ctx, ctx->ssl_conn, ssl_ret, "handshake"); goto err; } if (ctx->config->verify_name) { cert = SSL_get_peer_certificate(ctx->ssl_conn); if (cert == NULL) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "no server certificate"); goto err; } if (tls_check_name(ctx, cert, ctx->servername, &match) == -1) goto err; if (!match) { tls_set_errorx(ctx, TLS_ERROR_UNKNOWN, "name `%s' not present in server certificate", ctx->servername); goto err; } } ctx->state |= TLS_HANDSHAKE_COMPLETE; if (ctx->config->session_fd != -1) { if (tls_client_write_session(ctx) == -1) goto err; } rv = 0; err: X509_free(cert); return (rv); }