diff options
Diffstat (limited to '')
| -rw-r--r-- | tls.c | 828 |
1 files changed, 828 insertions, 0 deletions
diff --git a/tls.c b/tls.c new file mode 100644 index 0000000..3d6723b --- /dev/null +++ b/tls.c @@ -0,0 +1,828 @@ +/* $OpenBSD: tls.c,v 1.85 2020/05/24 15:12:54 jsing Exp $ */ +/* + * Copyright (c) 2014 Joel Sing <jsing@openbsd.org> + * + * 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 <sys/socket.h> + +#include <errno.h> +#include <limits.h> +#include <pthread.h> +#include <stdlib.h> +#include <unistd.h> + +#include <openssl/bio.h> +#include <openssl/err.h> +#include <openssl/evp.h> +#include <openssl/pem.h> +#include <openssl/safestack.h> +#include <openssl/ssl.h> +#include <openssl/x509.h> + +#include <tls.h> +#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); +} + +int +tls_configure_ssl_keypair(struct tls *ctx, SSL_CTX *ssl_ctx, + struct tls_keypair *keypair, int required) +{ + EVP_PKEY *pkey = NULL; + BIO *bio = 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 (keypair->key_mem != NULL) { + if (keypair->key_len > INT_MAX) { + tls_set_errorx(ctx, "key too long"); + goto err; + } + + if ((bio = BIO_new_mem_buf(keypair->key_mem, + keypair->key_len)) == NULL) { + tls_set_errorx(ctx, "failed to create buffer"); + goto err; + } + if ((pkey = PEM_read_bio_PrivateKey(bio, NULL, tls_password_cb, + NULL)) == NULL) { + tls_set_errorx(ctx, "failed to read private key"); + goto err; + } + + 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; + } + BIO_free(bio); + bio = NULL; + 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); + BIO_free(bio); + + 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); +} |