tls_nss.c

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/*
 * SSL/TLS interface functions for NSS
 * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"
#include <nspr/prtypes.h>
#include <nspr/plarenas.h>
#include <nspr/plhash.h>
#include <nspr/prio.h>
#include <nspr/prclist.h>
#include <nspr/prlock.h>
#include <nspr/prinit.h>
#include <nspr/prerror.h>
#include <nspr/prmem.h>
#include <nss/nss.h>
#include <nss/nssilckt.h>
#include <nss/ssl.h>
#include <nss/pk11func.h>
#include <nss/secerr.h>

#include "common.h"
#include "tls.h"

static int tls_nss_ref_count = 0;

static PRDescIdentity nss_layer_id;


struct tls_connection {
        PRFileDesc *fd;

        int established;
        int verify_peer;
        u8 *push_buf, *pull_buf, *pull_buf_offset;
        size_t push_buf_len, pull_buf_len;
};


static PRStatus nss_io_close(PRFileDesc *fd)
{
        wpa_printf(MSG_DEBUG, "NSS: I/O close");
        return PR_SUCCESS;
}


static PRInt32 nss_io_read(PRFileDesc *fd, void *buf, PRInt32 amount)
{
        wpa_printf(MSG_DEBUG, "NSS: I/O read(%d)", amount);
        return PR_FAILURE;
}


static PRInt32 nss_io_write(PRFileDesc *fd, const void *buf, PRInt32 amount)
{
        wpa_printf(MSG_DEBUG, "NSS: I/O write(%d)", amount);
        return PR_FAILURE;
}


static PRInt32 nss_io_writev(PRFileDesc *fd, const PRIOVec *iov,
                             PRInt32 iov_size, PRIntervalTime timeout)
{
        wpa_printf(MSG_DEBUG, "NSS: I/O writev(%d)", iov_size);
        return PR_FAILURE;
}


static PRInt32 nss_io_recv(PRFileDesc *fd, void *buf, PRInt32 amount,
                           PRIntn flags, PRIntervalTime timeout)
{
        struct tls_connection *conn = (struct tls_connection *) fd->secret;
        u8 *end;

        wpa_printf(MSG_DEBUG, "NSS: I/O recv(%d)", amount);

        if (conn->pull_buf == NULL) {
                wpa_printf(MSG_DEBUG, "NSS: No data available to be read yet");
                return PR_FAILURE;
        }

        end = conn->pull_buf + conn->pull_buf_len;
        if (end - conn->pull_buf_offset < amount)
                amount = end - conn->pull_buf_offset;
        os_memcpy(buf, conn->pull_buf_offset, amount);
        conn->pull_buf_offset += amount;
        if (conn->pull_buf_offset == end) {
                wpa_printf(MSG_DEBUG, "%s - pull_buf consumed", __func__);
                os_free(conn->pull_buf);
                conn->pull_buf = conn->pull_buf_offset = NULL;
                conn->pull_buf_len = 0;
        } else {
                wpa_printf(MSG_DEBUG, "%s - %lu bytes remaining in pull_buf",
                           __func__,
                           (unsigned long) (end - conn->pull_buf_offset));
        }
        return amount;
}


static PRInt32 nss_io_send(PRFileDesc *fd, const void *buf, PRInt32 amount,
                           PRIntn flags, PRIntervalTime timeout)
{
        struct tls_connection *conn = (struct tls_connection *) fd->secret;
        u8 *nbuf;

        wpa_printf(MSG_DEBUG, "NSS: I/O %s", __func__);
        wpa_hexdump(MSG_MSGDUMP, "NSS: I/O send data", buf, amount);

        nbuf = os_realloc(conn->push_buf, conn->push_buf_len + amount);
        if (nbuf == NULL) {
                wpa_printf(MSG_ERROR, "NSS: Failed to allocate memory for the "
                           "data to be sent");
                return PR_FAILURE;
        }
        os_memcpy(nbuf + conn->push_buf_len, buf, amount);
        conn->push_buf = nbuf;
        conn->push_buf_len += amount;

        return amount;
}


static PRInt32 nss_io_recvfrom(PRFileDesc *fd, void *buf, PRInt32 amount,
                               PRIntn flags, PRNetAddr *addr,
                               PRIntervalTime timeout)
{
        wpa_printf(MSG_DEBUG, "NSS: I/O %s", __func__);
        return PR_FAILURE;
}


static PRInt32 nss_io_sendto(PRFileDesc *fd, const void *buf, PRInt32 amount,
                             PRIntn flags, const PRNetAddr *addr,
                             PRIntervalTime timeout)
{
        wpa_printf(MSG_DEBUG, "NSS: I/O %s", __func__);
        return PR_FAILURE;
}


static PRStatus nss_io_getpeername(PRFileDesc *fd, PRNetAddr *addr)
{
        wpa_printf(MSG_DEBUG, "NSS: I/O getpeername");

        /*
         * It Looks like NSS only supports IPv4 and IPv6 TCP sockets. Provide a
         * fake IPv4 address to work around this even though we are not really
         * using TCP.
         */
        os_memset(addr, 0, sizeof(*addr));
        addr->inet.family = PR_AF_INET;

        return PR_SUCCESS;
}


static PRStatus nss_io_getsocketoption(PRFileDesc *fd,
                                       PRSocketOptionData *data)
{
        switch (data->option) {
        case PR_SockOpt_Nonblocking:
                wpa_printf(MSG_DEBUG, "NSS: I/O getsocketoption(Nonblocking)");
                data->value.non_blocking = PR_TRUE;
                return PR_SUCCESS;
        default:
                wpa_printf(MSG_DEBUG, "NSS: I/O getsocketoption(%d)",
                           data->option);
                return PR_FAILURE;
        }
}


static const PRIOMethods nss_io = {
        PR_DESC_LAYERED,
        nss_io_close,
        nss_io_read,
        nss_io_write,
        NULL /* available */,
        NULL /* available64 */,
        NULL /* fsync */,
        NULL /* fseek */,
        NULL /* fseek64 */,
        NULL /* fileinfo */,
        NULL /* fileinfo64 */,
        nss_io_writev,
        NULL /* connect */,
        NULL /* accept */,
        NULL /* bind */,
        NULL /* listen */,
        NULL /* shutdown */,
        nss_io_recv,
        nss_io_send,
        nss_io_recvfrom,
        nss_io_sendto,
        NULL /* poll */,
        NULL /* acceptread */,
        NULL /* transmitfile */,
        NULL /* getsockname */,
        nss_io_getpeername,
        NULL /* reserved_fn_6 */,
        NULL /* reserved_fn_5 */,
        nss_io_getsocketoption,
        NULL /* setsocketoption */,
        NULL /* sendfile */,
        NULL /* connectcontinue */,
        NULL /* reserved_fn_3 */,
        NULL /* reserved_fn_2 */,
        NULL /* reserved_fn_1 */,
        NULL /* reserved_fn_0 */
};


static char * nss_password_cb(PK11SlotInfo *slot, PRBool retry, void *arg)
{
        wpa_printf(MSG_ERROR, "NSS: TODO - %s", __func__);
        return NULL;
}


void * tls_init(const struct tls_config *conf)
{
        char *dir;

        tls_nss_ref_count++;
        if (tls_nss_ref_count > 1)
                return (void *) 1;

        PR_Init(PR_SYSTEM_THREAD, PR_PRIORITY_NORMAL, 1);

        nss_layer_id = PR_GetUniqueIdentity("wpa_supplicant");

        PK11_SetPasswordFunc(nss_password_cb);

        dir = getenv("SSL_DIR");
        if (dir) {
                if (NSS_Init(dir) != SECSuccess) {
                        wpa_printf(MSG_ERROR, "NSS: NSS_Init(cert_dir=%s) "
                                   "failed", dir);
                        return NULL;
                }
        } else {
                if (NSS_NoDB_Init(NULL) != SECSuccess) {
                        wpa_printf(MSG_ERROR, "NSS: NSS_NoDB_Init(NULL) "
                                   "failed");
                        return NULL;
                }
        }

        if (SSL_OptionSetDefault(SSL_V2_COMPATIBLE_HELLO, PR_FALSE) !=
            SECSuccess ||
            SSL_OptionSetDefault(SSL_ENABLE_SSL3, PR_FALSE) != SECSuccess ||
            SSL_OptionSetDefault(SSL_ENABLE_SSL2, PR_FALSE) != SECSuccess ||
            SSL_OptionSetDefault(SSL_ENABLE_TLS, PR_TRUE) != SECSuccess) {
                wpa_printf(MSG_ERROR, "NSS: SSL_OptionSetDefault failed");
                return NULL;
        }

        if (NSS_SetDomesticPolicy() != SECSuccess) {
                wpa_printf(MSG_ERROR, "NSS: NSS_SetDomesticPolicy() failed");
                return NULL;
        }

        return (void *) 1;
}

void tls_deinit(void *ssl_ctx)
{
        tls_nss_ref_count--;
        if (tls_nss_ref_count == 0) {
                if (NSS_Shutdown() != SECSuccess)
                        wpa_printf(MSG_ERROR, "NSS: NSS_Shutdown() failed");
        }
}


int tls_get_errors(void *tls_ctx)
{
        return 0;
}


static SECStatus nss_bad_cert_cb(void *arg, PRFileDesc *fd)
{
        struct tls_connection *conn = arg;
        SECStatus res = SECSuccess;
        PRErrorCode err;
        CERTCertificate *cert;
        char *subject, *issuer;

        err = PR_GetError();
        if (IS_SEC_ERROR(err))
                wpa_printf(MSG_DEBUG, "NSS: Bad Server Certificate (sec err "
                           "%d)", err - SEC_ERROR_BASE);
        else
                wpa_printf(MSG_DEBUG, "NSS: Bad Server Certificate (err %d)",
                           err);
        cert = SSL_PeerCertificate(fd);
        subject = CERT_NameToAscii(&cert->subject);
        issuer = CERT_NameToAscii(&cert->issuer);
        wpa_printf(MSG_DEBUG, "NSS: Peer certificate subject='%s' issuer='%s'",
                   subject, issuer);
        CERT_DestroyCertificate(cert);
        PR_Free(subject);
        PR_Free(issuer);
        if (conn->verify_peer)
                res = SECFailure;

        return res;
}


static void nss_handshake_cb(PRFileDesc *fd, void *client_data)
{
        struct tls_connection *conn = client_data;
        wpa_printf(MSG_DEBUG, "NSS: Handshake completed");
        conn->established = 1;
}


struct tls_connection * tls_connection_init(void *tls_ctx)
{
        struct tls_connection *conn;

        conn = os_zalloc(sizeof(*conn));
        if (conn == NULL)
                return NULL;

        conn->fd = PR_CreateIOLayerStub(nss_layer_id, &nss_io);
        if (conn->fd == NULL) {
                os_free(conn);
                return NULL;
        }
        conn->fd->secret = (void *) conn;

        conn->fd = SSL_ImportFD(NULL, conn->fd);
        if (conn->fd == NULL) {
                os_free(conn);
                return NULL;
        }

        if (SSL_OptionSet(conn->fd, SSL_SECURITY, PR_TRUE) != SECSuccess ||
            SSL_OptionSet(conn->fd, SSL_HANDSHAKE_AS_CLIENT, PR_TRUE) !=
            SECSuccess ||
            SSL_OptionSet(conn->fd, SSL_HANDSHAKE_AS_SERVER, PR_FALSE) !=
            SECSuccess ||
            SSL_OptionSet(conn->fd, SSL_ENABLE_TLS, PR_TRUE) != SECSuccess ||
            SSL_BadCertHook(conn->fd, nss_bad_cert_cb, conn) != SECSuccess ||
            SSL_HandshakeCallback(conn->fd, nss_handshake_cb, conn) !=
            SECSuccess) {
                wpa_printf(MSG_ERROR, "NSS: Failed to set options");
                PR_Close(conn->fd);
                os_free(conn);
                return NULL;
        }

        SSL_ResetHandshake(conn->fd, PR_FALSE);

        return conn;
}


void tls_connection_deinit(void *tls_ctx, struct tls_connection *conn)
{
        PR_Close(conn->fd);
        os_free(conn->push_buf);
        os_free(conn->pull_buf);
        os_free(conn);
}


int tls_connection_established(void *tls_ctx, struct tls_connection *conn)
{
        return conn->established;
}


int tls_connection_shutdown(void *tls_ctx, struct tls_connection *conn)
{
        return -1;
}


int tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
                              const struct tls_connection_params *params)
{
        wpa_printf(MSG_ERROR, "NSS: TODO - %s", __func__);
        return 0;
}


int tls_global_set_params(void *tls_ctx,
                          const struct tls_connection_params *params)
{
        return -1;
}


int tls_global_set_verify(void *tls_ctx, int check_crl)
{
        return -1;
}


int tls_connection_set_verify(void *tls_ctx, struct tls_connection *conn,
                              int verify_peer)
{
        conn->verify_peer = verify_peer;
        return 0;
}


int tls_connection_set_ia(void *tls_ctx, struct tls_connection *conn,
                          int tls_ia)
{
        return -1;
}


int tls_connection_get_keys(void *tls_ctx, struct tls_connection *conn,
                            struct tls_keys *keys)
{
        /* NSS does not export master secret or client/server random. */
        return -1;
}


int tls_connection_prf(void *tls_ctx, struct tls_connection *conn,
                       const char *label, int server_random_first,
                       u8 *out, size_t out_len)
{
        if (conn == NULL || server_random_first) {
                wpa_printf(MSG_INFO, "NSS: Unsupported PRF request "
                           "(server_random_first=%d)",
                           server_random_first);
                return -1;
        }

        if (SSL_ExportKeyingMaterial(conn->fd, label, NULL, 0, out, out_len) !=
            SECSuccess) {
                wpa_printf(MSG_INFO, "NSS: Failed to use TLS extractor "
                           "(label='%s' out_len=%d", label, (int) out_len);
                return -1;
        }

        return 0;
}


struct wpabuf * tls_connection_handshake(void *tls_ctx,
                                         struct tls_connection *conn,
                                         const struct wpabuf *in_data,
                                         struct wpabuf **appl_data)
{
        struct wpabuf *out_data;

        wpa_printf(MSG_DEBUG, "NSS: handshake: in_len=%u",
                   in_data ? (unsigned int) wpabuf_len(in_data) : 0);

        if (appl_data)
                *appl_data = NULL;

        if (in_data && wpabuf_len(in_data) > 0) {
                if (conn->pull_buf) {
                        wpa_printf(MSG_DEBUG, "%s - %lu bytes remaining in "
                                   "pull_buf", __func__,
                                   (unsigned long) conn->pull_buf_len);
                        os_free(conn->pull_buf);
                }
                conn->pull_buf = os_malloc(wpabuf_len(in_data));
                if (conn->pull_buf == NULL)
                        return NULL;
                os_memcpy(conn->pull_buf, wpabuf_head(in_data),
                          wpabuf_len(in_data));
                conn->pull_buf_offset = conn->pull_buf;
                conn->pull_buf_len = wpabuf_len(in_data);
        }

        SSL_ForceHandshake(conn->fd);

        if (conn->established && conn->push_buf == NULL) {
                /* Need to return something to get final TLS ACK. */
                conn->push_buf = os_malloc(1);
        }

        if (conn->push_buf == NULL)
                return NULL;
        out_data = wpabuf_alloc_ext_data(conn->push_buf, conn->push_buf_len);
        if (out_data == NULL)
                os_free(conn->push_buf);
        conn->push_buf = NULL;
        conn->push_buf_len = 0;
        return out_data;
}


struct wpabuf * tls_connection_server_handshake(void *tls_ctx,
                                                struct tls_connection *conn,
                                                const struct wpabuf *in_data,
                                                struct wpabuf **appl_data)
{
        return NULL;
}


struct wpabuf * tls_connection_encrypt(void *tls_ctx,
                                       struct tls_connection *conn,
                                       const struct wpabuf *in_data)
{
        PRInt32 res;
        struct wpabuf *buf;

        wpa_printf(MSG_DEBUG, "NSS: encrypt %d bytes",
                   (int) wpabuf_len(in_data));
        res = PR_Send(conn->fd, wpabuf_head(in_data), wpabuf_len(in_data), 0,
                      0);
        if (res < 0) {
                wpa_printf(MSG_ERROR, "NSS: Encryption failed");
                return NULL;
        }
        if (conn->push_buf == NULL)
                return NULL;
        buf = wpabuf_alloc_ext_data(conn->push_buf, conn->push_buf_len);
        if (buf == NULL)
                os_free(conn->push_buf);
        conn->push_buf = NULL;
        conn->push_buf_len = 0;
        return buf;
}


struct wpabuf * tls_connection_decrypt(void *tls_ctx,
                                       struct tls_connection *conn,
                                       const struct wpabuf *in_data)
{
        PRInt32 res;
        struct wpabuf *out;

        wpa_printf(MSG_DEBUG, "NSS: decrypt %d bytes",
                   (int) wpabuf_len(in_data));
        if (conn->pull_buf) {
                wpa_printf(MSG_DEBUG, "%s - %lu bytes remaining in "
                           "pull_buf", __func__,
                           (unsigned long) conn->pull_buf_len);
                os_free(conn->pull_buf);
        }
        conn->pull_buf = os_malloc(wpabuf_len(in_data));
        if (conn->pull_buf == NULL)
                return NULL;
        os_memcpy(conn->pull_buf, wpabuf_head(in_data), wpabuf_len(in_data));
        conn->pull_buf_offset = conn->pull_buf;
        conn->pull_buf_len = wpabuf_len(in_data);

        /*
         * Even though we try to disable TLS compression, it is possible that
         * this cannot be done with all TLS libraries. Add extra buffer space
         * to handle the possibility of the decrypted data being longer than
         * input data.
         */
        out = wpabuf_alloc((wpabuf_len(in_data) + 500) * 3);
        if (out == NULL)
                return NULL;

        res = PR_Recv(conn->fd, wpabuf_mhead(out), wpabuf_size(out), 0, 0);
        wpa_printf(MSG_DEBUG, "NSS: PR_Recv: %d", res);
        if (res < 0) {
                wpabuf_free(out);
                return NULL;
        }
        wpabuf_put(out, res);

        return out;
}


int tls_connection_resumed(void *tls_ctx, struct tls_connection *conn)
{
        return 0;
}


int tls_connection_set_cipher_list(void *tls_ctx, struct tls_connection *conn,
                                   u8 *ciphers)
{
        return -1;
}


int tls_get_cipher(void *tls_ctx, struct tls_connection *conn,
                   char *buf, size_t buflen)
{
        return -1;
}


int tls_connection_enable_workaround(void *tls_ctx,
                                     struct tls_connection *conn)
{
        return -1;
}


int tls_connection_client_hello_ext(void *tls_ctx, struct tls_connection *conn,
                                    int ext_type, const u8 *data,
                                    size_t data_len)
{
        return -1;
}


int tls_connection_get_failed(void *tls_ctx, struct tls_connection *conn)
{
        return 0;
}


int tls_connection_get_read_alerts(void *tls_ctx, struct tls_connection *conn)
{
        return 0;
}


int tls_connection_get_write_alerts(void *tls_ctx,
                                    struct tls_connection *conn)
{
        return 0;
}


int tls_connection_get_keyblock_size(void *tls_ctx,
                                     struct tls_connection *conn)
{
        return -1;
}


unsigned int tls_capabilities(void *tls_ctx)
{
        return 0;
}


struct wpabuf * tls_connection_ia_send_phase_finished(
        void *tls_ctx, struct tls_connection *conn, int final)
{
        return NULL;
}


int tls_connection_ia_final_phase_finished(void *tls_ctx,
                                           struct tls_connection *conn)
{
        return -1;
}


int tls_connection_ia_permute_inner_secret(void *tls_ctx,
                                           struct tls_connection *conn,
                                           const u8 *key, size_t key_len)
{
        return -1;
}


int tls_connection_set_session_ticket_cb(void *tls_ctx,
                                         struct tls_connection *conn,
                                         tls_session_ticket_cb cb,
                                         void *ctx)
{
        return -1;
}