tlsv1_client_read.c

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/*
 * TLSv1 client - read handshake message
 * Copyright (c) 2006-2007, 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 "common.h"
#include "crypto/md5.h"
#include "crypto/sha1.h"
#include "crypto/tls.h"
#include "x509v3.h"
#include "tlsv1_common.h"
#include "tlsv1_record.h"
#include "tlsv1_client.h"
#include "tlsv1_client_i.h"

static int tls_process_server_key_exchange(struct tlsv1_client *conn, u8 ct,
                                           const u8 *in_data, size_t *in_len);
static int tls_process_certificate_request(struct tlsv1_client *conn, u8 ct,
                                           const u8 *in_data, size_t *in_len);
static int tls_process_server_hello_done(struct tlsv1_client *conn, u8 ct,
                                         const u8 *in_data, size_t *in_len);


static int tls_process_server_hello(struct tlsv1_client *conn, u8 ct,
                                    const u8 *in_data, size_t *in_len)
{
        const u8 *pos, *end;
        size_t left, len, i;
        u16 cipher_suite;

        if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
                wpa_printf(MSG_DEBUG, "TLSv1: Expected Handshake; "
                           "received content type 0x%x", ct);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        pos = in_data;
        left = *in_len;

        if (left < 4)
                goto decode_error;

        /* HandshakeType msg_type */
        if (*pos != TLS_HANDSHAKE_TYPE_SERVER_HELLO) {
                wpa_printf(MSG_DEBUG, "TLSv1: Received unexpected handshake "
                           "message %d (expected ServerHello)", *pos);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }
        wpa_printf(MSG_DEBUG, "TLSv1: Received ServerHello");
        pos++;
        /* uint24 length */
        len = WPA_GET_BE24(pos);
        pos += 3;
        left -= 4;

        if (len > left)
                goto decode_error;

        /* body - ServerHello */

        wpa_hexdump(MSG_MSGDUMP, "TLSv1: ServerHello", pos, len);
        end = pos + len;

        /* ProtocolVersion server_version */
        if (end - pos < 2)
                goto decode_error;
        if (WPA_GET_BE16(pos) != TLS_VERSION) {
                wpa_printf(MSG_DEBUG, "TLSv1: Unexpected protocol version in "
                           "ServerHello");
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_PROTOCOL_VERSION);
                return -1;
        }
        pos += 2;

        /* Random random */
        if (end - pos < TLS_RANDOM_LEN)
                goto decode_error;

        os_memcpy(conn->server_random, pos, TLS_RANDOM_LEN);
        pos += TLS_RANDOM_LEN;
        wpa_hexdump(MSG_MSGDUMP, "TLSv1: server_random",
                    conn->server_random, TLS_RANDOM_LEN);

        /* SessionID session_id */
        if (end - pos < 1)
                goto decode_error;
        if (end - pos < 1 + *pos || *pos > TLS_SESSION_ID_MAX_LEN)
                goto decode_error;
        if (conn->session_id_len && conn->session_id_len == *pos &&
            os_memcmp(conn->session_id, pos + 1, conn->session_id_len) == 0) {
                pos += 1 + conn->session_id_len;
                wpa_printf(MSG_DEBUG, "TLSv1: Resuming old session");
                conn->session_resumed = 1;
        } else {
                conn->session_id_len = *pos;
                pos++;
                os_memcpy(conn->session_id, pos, conn->session_id_len);
                pos += conn->session_id_len;
        }
        wpa_hexdump(MSG_MSGDUMP, "TLSv1: session_id",
                    conn->session_id, conn->session_id_len);

        /* CipherSuite cipher_suite */
        if (end - pos < 2)
                goto decode_error;
        cipher_suite = WPA_GET_BE16(pos);
        pos += 2;
        for (i = 0; i < conn->num_cipher_suites; i++) {
                if (cipher_suite == conn->cipher_suites[i])
                        break;
        }
        if (i == conn->num_cipher_suites) {
                wpa_printf(MSG_INFO, "TLSv1: Server selected unexpected "
                           "cipher suite 0x%04x", cipher_suite);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_ILLEGAL_PARAMETER);
                return -1;
        }

        if (conn->session_resumed && cipher_suite != conn->prev_cipher_suite) {
                wpa_printf(MSG_DEBUG, "TLSv1: Server selected a different "
                           "cipher suite for a resumed connection (0x%04x != "
                           "0x%04x)", cipher_suite, conn->prev_cipher_suite);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_ILLEGAL_PARAMETER);
                return -1;
        }

        if (tlsv1_record_set_cipher_suite(&conn->rl, cipher_suite) < 0) {
                wpa_printf(MSG_DEBUG, "TLSv1: Failed to set CipherSuite for "
                           "record layer");
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_INTERNAL_ERROR);
                return -1;
        }

        conn->prev_cipher_suite = cipher_suite;

        /* CompressionMethod compression_method */
        if (end - pos < 1)
                goto decode_error;
        if (*pos != TLS_COMPRESSION_NULL) {
                wpa_printf(MSG_INFO, "TLSv1: Server selected unexpected "
                           "compression 0x%02x", *pos);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_ILLEGAL_PARAMETER);
                return -1;
        }
        pos++;

        if (end != pos) {
                /* TODO: ServerHello extensions */
                wpa_hexdump(MSG_DEBUG, "TLSv1: Unexpected extra data in the "
                            "end of ServerHello", pos, end - pos);
                goto decode_error;
        }

        if (conn->session_ticket_included && conn->session_ticket_cb) {
                /* TODO: include SessionTicket extension if one was included in
                 * ServerHello */
                int res = conn->session_ticket_cb(
                        conn->session_ticket_cb_ctx, NULL, 0,
                        conn->client_random, conn->server_random,
                        conn->master_secret);
                if (res < 0) {
                        wpa_printf(MSG_DEBUG, "TLSv1: SessionTicket callback "
                                   "indicated failure");
                        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                                  TLS_ALERT_HANDSHAKE_FAILURE);
                        return -1;
                }
                conn->use_session_ticket = !!res;
        }

        if ((conn->session_resumed || conn->use_session_ticket) &&
            tls_derive_keys(conn, NULL, 0)) {
                wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_INTERNAL_ERROR);
                return -1;
        }

        *in_len = end - in_data;

        conn->state = (conn->session_resumed || conn->use_session_ticket) ?
                SERVER_CHANGE_CIPHER_SPEC : SERVER_CERTIFICATE;

        return 0;

decode_error:
        wpa_printf(MSG_DEBUG, "TLSv1: Failed to decode ServerHello");
        tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
        return -1;
}


static int tls_process_certificate(struct tlsv1_client *conn, u8 ct,
                                   const u8 *in_data, size_t *in_len)
{
        const u8 *pos, *end;
        size_t left, len, list_len, cert_len, idx;
        u8 type;
        struct x509_certificate *chain = NULL, *last = NULL, *cert;
        int reason;

        if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
                wpa_printf(MSG_DEBUG, "TLSv1: Expected Handshake; "
                           "received content type 0x%x", ct);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        pos = in_data;
        left = *in_len;

        if (left < 4) {
                wpa_printf(MSG_DEBUG, "TLSv1: Too short Certificate message "
                           "(len=%lu)", (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        type = *pos++;
        len = WPA_GET_BE24(pos);
        pos += 3;
        left -= 4;

        if (len > left) {
                wpa_printf(MSG_DEBUG, "TLSv1: Unexpected Certificate message "
                           "length (len=%lu != left=%lu)",
                           (unsigned long) len, (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        if (type == TLS_HANDSHAKE_TYPE_SERVER_KEY_EXCHANGE)
                return tls_process_server_key_exchange(conn, ct, in_data,
                                                       in_len);
        if (type == TLS_HANDSHAKE_TYPE_CERTIFICATE_REQUEST)
                return tls_process_certificate_request(conn, ct, in_data,
                                                       in_len);
        if (type == TLS_HANDSHAKE_TYPE_SERVER_HELLO_DONE)
                return tls_process_server_hello_done(conn, ct, in_data,
                                                     in_len);
        if (type != TLS_HANDSHAKE_TYPE_CERTIFICATE) {
                wpa_printf(MSG_DEBUG, "TLSv1: Received unexpected handshake "
                           "message %d (expected Certificate/"
                           "ServerKeyExchange/CertificateRequest/"
                           "ServerHelloDone)", type);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        wpa_printf(MSG_DEBUG,
                   "TLSv1: Received Certificate (certificate_list len %lu)",
                   (unsigned long) len);

        /*
         * opaque ASN.1Cert<2^24-1>;
         *
         * struct {
         *     ASN.1Cert certificate_list<1..2^24-1>;
         * } Certificate;
         */

        end = pos + len;

        if (end - pos < 3) {
                wpa_printf(MSG_DEBUG, "TLSv1: Too short Certificate "
                           "(left=%lu)", (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        list_len = WPA_GET_BE24(pos);
        pos += 3;

        if ((size_t) (end - pos) != list_len) {
                wpa_printf(MSG_DEBUG, "TLSv1: Unexpected certificate_list "
                           "length (len=%lu left=%lu)",
                           (unsigned long) list_len,
                           (unsigned long) (end - pos));
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        idx = 0;
        while (pos < end) {
                if (end - pos < 3) {
                        wpa_printf(MSG_DEBUG, "TLSv1: Failed to parse "
                                   "certificate_list");
                        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                                  TLS_ALERT_DECODE_ERROR);
                        x509_certificate_chain_free(chain);
                        return -1;
                }

                cert_len = WPA_GET_BE24(pos);
                pos += 3;

                if ((size_t) (end - pos) < cert_len) {
                        wpa_printf(MSG_DEBUG, "TLSv1: Unexpected certificate "
                                   "length (len=%lu left=%lu)",
                                   (unsigned long) cert_len,
                                   (unsigned long) (end - pos));
                        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                                  TLS_ALERT_DECODE_ERROR);
                        x509_certificate_chain_free(chain);
                        return -1;
                }

                wpa_printf(MSG_DEBUG, "TLSv1: Certificate %lu (len %lu)",
                           (unsigned long) idx, (unsigned long) cert_len);

                if (idx == 0) {
                        crypto_public_key_free(conn->server_rsa_key);
                        if (tls_parse_cert(pos, cert_len,
                                           &conn->server_rsa_key)) {
                                wpa_printf(MSG_DEBUG, "TLSv1: Failed to parse "
                                           "the certificate");
                                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                                          TLS_ALERT_BAD_CERTIFICATE);
                                x509_certificate_chain_free(chain);
                                return -1;
                        }
                }

                cert = x509_certificate_parse(pos, cert_len);
                if (cert == NULL) {
                        wpa_printf(MSG_DEBUG, "TLSv1: Failed to parse "
                                   "the certificate");
                        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                                  TLS_ALERT_BAD_CERTIFICATE);
                        x509_certificate_chain_free(chain);
                        return -1;
                }

                if (last == NULL)
                        chain = cert;
                else
                        last->next = cert;
                last = cert;

                idx++;
                pos += cert_len;
        }

        if (conn->cred &&
            x509_certificate_chain_validate(conn->cred->trusted_certs, chain,
                                            &reason) < 0) {
                int tls_reason;
                wpa_printf(MSG_DEBUG, "TLSv1: Server certificate chain "
                           "validation failed (reason=%d)", reason);
                switch (reason) {
                case X509_VALIDATE_BAD_CERTIFICATE:
                        tls_reason = TLS_ALERT_BAD_CERTIFICATE;
                        break;
                case X509_VALIDATE_UNSUPPORTED_CERTIFICATE:
                        tls_reason = TLS_ALERT_UNSUPPORTED_CERTIFICATE;
                        break;
                case X509_VALIDATE_CERTIFICATE_REVOKED:
                        tls_reason = TLS_ALERT_CERTIFICATE_REVOKED;
                        break;
                case X509_VALIDATE_CERTIFICATE_EXPIRED:
                        tls_reason = TLS_ALERT_CERTIFICATE_EXPIRED;
                        break;
                case X509_VALIDATE_CERTIFICATE_UNKNOWN:
                        tls_reason = TLS_ALERT_CERTIFICATE_UNKNOWN;
                        break;
                case X509_VALIDATE_UNKNOWN_CA:
                        tls_reason = TLS_ALERT_UNKNOWN_CA;
                        break;
                default:
                        tls_reason = TLS_ALERT_BAD_CERTIFICATE;
                        break;
                }
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, tls_reason);
                x509_certificate_chain_free(chain);
                return -1;
        }

        x509_certificate_chain_free(chain);

        *in_len = end - in_data;

        conn->state = SERVER_KEY_EXCHANGE;

        return 0;
}


static int tlsv1_process_diffie_hellman(struct tlsv1_client *conn,
                                        const u8 *buf, size_t len)
{
        const u8 *pos, *end;

        tlsv1_client_free_dh(conn);

        pos = buf;
        end = buf + len;

        if (end - pos < 3)
                goto fail;
        conn->dh_p_len = WPA_GET_BE16(pos);
        pos += 2;
        if (conn->dh_p_len == 0 || end - pos < (int) conn->dh_p_len) {
                wpa_printf(MSG_DEBUG, "TLSv1: Invalid dh_p length %lu",
                           (unsigned long) conn->dh_p_len);
                goto fail;
        }
        conn->dh_p = os_malloc(conn->dh_p_len);
        if (conn->dh_p == NULL)
                goto fail;
        os_memcpy(conn->dh_p, pos, conn->dh_p_len);
        pos += conn->dh_p_len;
        wpa_hexdump(MSG_DEBUG, "TLSv1: DH p (prime)",
                    conn->dh_p, conn->dh_p_len);

        if (end - pos < 3)
                goto fail;
        conn->dh_g_len = WPA_GET_BE16(pos);
        pos += 2;
        if (conn->dh_g_len == 0 || end - pos < (int) conn->dh_g_len)
                goto fail;
        conn->dh_g = os_malloc(conn->dh_g_len);
        if (conn->dh_g == NULL)
                goto fail;
        os_memcpy(conn->dh_g, pos, conn->dh_g_len);
        pos += conn->dh_g_len;
        wpa_hexdump(MSG_DEBUG, "TLSv1: DH g (generator)",
                    conn->dh_g, conn->dh_g_len);
        if (conn->dh_g_len == 1 && conn->dh_g[0] < 2)
                goto fail;

        if (end - pos < 3)
                goto fail;
        conn->dh_ys_len = WPA_GET_BE16(pos);
        pos += 2;
        if (conn->dh_ys_len == 0 || end - pos < (int) conn->dh_ys_len)
                goto fail;
        conn->dh_ys = os_malloc(conn->dh_ys_len);
        if (conn->dh_ys == NULL)
                goto fail;
        os_memcpy(conn->dh_ys, pos, conn->dh_ys_len);
        pos += conn->dh_ys_len;
        wpa_hexdump(MSG_DEBUG, "TLSv1: DH Ys (server's public value)",
                    conn->dh_ys, conn->dh_ys_len);

        return 0;

fail:
        wpa_printf(MSG_DEBUG, "TLSv1: Processing DH params failed");
        tlsv1_client_free_dh(conn);
        return -1;
}


static int tls_process_server_key_exchange(struct tlsv1_client *conn, u8 ct,
                                           const u8 *in_data, size_t *in_len)
{
        const u8 *pos, *end;
        size_t left, len;
        u8 type;
        const struct tls_cipher_suite *suite;

        if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
                wpa_printf(MSG_DEBUG, "TLSv1: Expected Handshake; "
                           "received content type 0x%x", ct);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        pos = in_data;
        left = *in_len;

        if (left < 4) {
                wpa_printf(MSG_DEBUG, "TLSv1: Too short ServerKeyExchange "
                           "(Left=%lu)", (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        type = *pos++;
        len = WPA_GET_BE24(pos);
        pos += 3;
        left -= 4;

        if (len > left) {
                wpa_printf(MSG_DEBUG, "TLSv1: Mismatch in ServerKeyExchange "
                           "length (len=%lu != left=%lu)",
                           (unsigned long) len, (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        end = pos + len;

        if (type == TLS_HANDSHAKE_TYPE_CERTIFICATE_REQUEST)
                return tls_process_certificate_request(conn, ct, in_data,
                                                       in_len);
        if (type == TLS_HANDSHAKE_TYPE_SERVER_HELLO_DONE)
                return tls_process_server_hello_done(conn, ct, in_data,
                                                     in_len);
        if (type != TLS_HANDSHAKE_TYPE_SERVER_KEY_EXCHANGE) {
                wpa_printf(MSG_DEBUG, "TLSv1: Received unexpected handshake "
                           "message %d (expected ServerKeyExchange/"
                           "CertificateRequest/ServerHelloDone)", type);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        wpa_printf(MSG_DEBUG, "TLSv1: Received ServerKeyExchange");

        if (!tls_server_key_exchange_allowed(conn->rl.cipher_suite)) {
                wpa_printf(MSG_DEBUG, "TLSv1: ServerKeyExchange not allowed "
                           "with the selected cipher suite");
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        wpa_hexdump(MSG_DEBUG, "TLSv1: ServerKeyExchange", pos, len);
        suite = tls_get_cipher_suite(conn->rl.cipher_suite);
        if (suite && suite->key_exchange == TLS_KEY_X_DH_anon) {
                if (tlsv1_process_diffie_hellman(conn, pos, len) < 0) {
                        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                                  TLS_ALERT_DECODE_ERROR);
                        return -1;
                }
        } else {
                wpa_printf(MSG_DEBUG, "TLSv1: UnexpectedServerKeyExchange");
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        *in_len = end - in_data;

        conn->state = SERVER_CERTIFICATE_REQUEST;

        return 0;
}


static int tls_process_certificate_request(struct tlsv1_client *conn, u8 ct,
                                           const u8 *in_data, size_t *in_len)
{
        const u8 *pos, *end;
        size_t left, len;
        u8 type;

        if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
                wpa_printf(MSG_DEBUG, "TLSv1: Expected Handshake; "
                           "received content type 0x%x", ct);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        pos = in_data;
        left = *in_len;

        if (left < 4) {
                wpa_printf(MSG_DEBUG, "TLSv1: Too short CertificateRequest "
                           "(left=%lu)", (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        type = *pos++;
        len = WPA_GET_BE24(pos);
        pos += 3;
        left -= 4;

        if (len > left) {
                wpa_printf(MSG_DEBUG, "TLSv1: Mismatch in CertificateRequest "
                           "length (len=%lu != left=%lu)",
                           (unsigned long) len, (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        end = pos + len;

        if (type == TLS_HANDSHAKE_TYPE_SERVER_HELLO_DONE)
                return tls_process_server_hello_done(conn, ct, in_data,
                                                     in_len);
        if (type != TLS_HANDSHAKE_TYPE_CERTIFICATE_REQUEST) {
                wpa_printf(MSG_DEBUG, "TLSv1: Received unexpected handshake "
                           "message %d (expected CertificateRequest/"
                           "ServerHelloDone)", type);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        wpa_printf(MSG_DEBUG, "TLSv1: Received CertificateRequest");

        conn->certificate_requested = 1;

        *in_len = end - in_data;

        conn->state = SERVER_HELLO_DONE;

        return 0;
}


static int tls_process_server_hello_done(struct tlsv1_client *conn, u8 ct,
                                         const u8 *in_data, size_t *in_len)
{
        const u8 *pos, *end;
        size_t left, len;
        u8 type;

        if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
                wpa_printf(MSG_DEBUG, "TLSv1: Expected Handshake; "
                           "received content type 0x%x", ct);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        pos = in_data;
        left = *in_len;

        if (left < 4) {
                wpa_printf(MSG_DEBUG, "TLSv1: Too short ServerHelloDone "
                           "(left=%lu)", (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        type = *pos++;
        len = WPA_GET_BE24(pos);
        pos += 3;
        left -= 4;

        if (len > left) {
                wpa_printf(MSG_DEBUG, "TLSv1: Mismatch in ServerHelloDone "
                           "length (len=%lu != left=%lu)",
                           (unsigned long) len, (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }
        end = pos + len;

        if (type != TLS_HANDSHAKE_TYPE_SERVER_HELLO_DONE) {
                wpa_printf(MSG_DEBUG, "TLSv1: Received unexpected handshake "
                           "message %d (expected ServerHelloDone)", type);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        wpa_printf(MSG_DEBUG, "TLSv1: Received ServerHelloDone");

        *in_len = end - in_data;

        conn->state = CLIENT_KEY_EXCHANGE;

        return 0;
}


static int tls_process_server_change_cipher_spec(struct tlsv1_client *conn,
                                                 u8 ct, const u8 *in_data,
                                                 size_t *in_len)
{
        const u8 *pos;
        size_t left;

        if (ct != TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC) {
                wpa_printf(MSG_DEBUG, "TLSv1: Expected ChangeCipherSpec; "
                           "received content type 0x%x", ct);
                if (conn->use_session_ticket) {
                        int res;
                        wpa_printf(MSG_DEBUG, "TLSv1: Server may have "
                                   "rejected SessionTicket");
                        conn->use_session_ticket = 0;

                        /* Notify upper layers that SessionTicket failed */
                        res = conn->session_ticket_cb(
                                conn->session_ticket_cb_ctx, NULL, 0, NULL,
                                NULL, NULL);
                        if (res < 0) {
                                wpa_printf(MSG_DEBUG, "TLSv1: SessionTicket "
                                           "callback indicated failure");
                                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                                          TLS_ALERT_HANDSHAKE_FAILURE);
                                return -1;
                        }

                        conn->state = SERVER_CERTIFICATE;
                        return tls_process_certificate(conn, ct, in_data,
                                                       in_len);
                }
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        pos = in_data;
        left = *in_len;

        if (left < 1) {
                wpa_printf(MSG_DEBUG, "TLSv1: Too short ChangeCipherSpec");
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        if (*pos != TLS_CHANGE_CIPHER_SPEC) {
                wpa_printf(MSG_DEBUG, "TLSv1: Expected ChangeCipherSpec; "
                           "received data 0x%x", *pos);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        wpa_printf(MSG_DEBUG, "TLSv1: Received ChangeCipherSpec");
        if (tlsv1_record_change_read_cipher(&conn->rl) < 0) {
                wpa_printf(MSG_DEBUG, "TLSv1: Failed to change read cipher "
                           "for record layer");
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_INTERNAL_ERROR);
                return -1;
        }

        *in_len = pos + 1 - in_data;

        conn->state = SERVER_FINISHED;

        return 0;
}


static int tls_process_server_finished(struct tlsv1_client *conn, u8 ct,
                                       const u8 *in_data, size_t *in_len)
{
        const u8 *pos, *end;
        size_t left, len, hlen;
        u8 verify_data[TLS_VERIFY_DATA_LEN];
        u8 hash[MD5_MAC_LEN + SHA1_MAC_LEN];

        if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
                wpa_printf(MSG_DEBUG, "TLSv1: Expected Finished; "
                           "received content type 0x%x", ct);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        pos = in_data;
        left = *in_len;

        if (left < 4) {
                wpa_printf(MSG_DEBUG, "TLSv1: Too short record (left=%lu) for "
                           "Finished",
                           (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_DECODE_ERROR);
                return -1;
        }

        if (pos[0] != TLS_HANDSHAKE_TYPE_FINISHED) {
                wpa_printf(MSG_DEBUG, "TLSv1: Expected Finished; received "
                           "type 0x%x", pos[0]);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        len = WPA_GET_BE24(pos + 1);

        pos += 4;
        left -= 4;

        if (len > left) {
                wpa_printf(MSG_DEBUG, "TLSv1: Too short buffer for Finished "
                           "(len=%lu > left=%lu)",
                           (unsigned long) len, (unsigned long) left);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_DECODE_ERROR);
                return -1;
        }
        end = pos + len;
        if (len != TLS_VERIFY_DATA_LEN) {
                wpa_printf(MSG_DEBUG, "TLSv1: Unexpected verify_data length "
                           "in Finished: %lu (expected %d)",
                           (unsigned long) len, TLS_VERIFY_DATA_LEN);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_DECODE_ERROR);
                return -1;
        }
        wpa_hexdump(MSG_MSGDUMP, "TLSv1: verify_data in Finished",
                    pos, TLS_VERIFY_DATA_LEN);

        hlen = MD5_MAC_LEN;
        if (conn->verify.md5_server == NULL ||
            crypto_hash_finish(conn->verify.md5_server, hash, &hlen) < 0) {
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_INTERNAL_ERROR);
                conn->verify.md5_server = NULL;
                crypto_hash_finish(conn->verify.sha1_server, NULL, NULL);
                conn->verify.sha1_server = NULL;
                return -1;
        }
        conn->verify.md5_server = NULL;
        hlen = SHA1_MAC_LEN;
        if (conn->verify.sha1_server == NULL ||
            crypto_hash_finish(conn->verify.sha1_server, hash + MD5_MAC_LEN,
                               &hlen) < 0) {
                conn->verify.sha1_server = NULL;
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_INTERNAL_ERROR);
                return -1;
        }
        conn->verify.sha1_server = NULL;

        if (tls_prf(conn->master_secret, TLS_MASTER_SECRET_LEN,
                    "server finished", hash, MD5_MAC_LEN + SHA1_MAC_LEN,
                    verify_data, TLS_VERIFY_DATA_LEN)) {
                wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive verify_data");
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_DECRYPT_ERROR);
                return -1;
        }
        wpa_hexdump_key(MSG_DEBUG, "TLSv1: verify_data (server)",
                        verify_data, TLS_VERIFY_DATA_LEN);

        if (os_memcmp(pos, verify_data, TLS_VERIFY_DATA_LEN) != 0) {
                wpa_printf(MSG_INFO, "TLSv1: Mismatch in verify_data");
                return -1;
        }

        wpa_printf(MSG_DEBUG, "TLSv1: Received Finished");

        *in_len = end - in_data;

        conn->state = (conn->session_resumed || conn->use_session_ticket) ?
                CHANGE_CIPHER_SPEC : ACK_FINISHED;

        return 0;
}


static int tls_process_application_data(struct tlsv1_client *conn, u8 ct,
                                        const u8 *in_data, size_t *in_len,
                                        u8 **out_data, size_t *out_len)
{
        const u8 *pos;
        size_t left;

        if (ct != TLS_CONTENT_TYPE_APPLICATION_DATA) {
                wpa_printf(MSG_DEBUG, "TLSv1: Expected Application Data; "
                           "received content type 0x%x", ct);
                tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                          TLS_ALERT_UNEXPECTED_MESSAGE);
                return -1;
        }

        pos = in_data;
        left = *in_len;

        wpa_hexdump(MSG_DEBUG, "TLSv1: Application Data included in Handshake",
                    pos, left);

        *out_data = os_malloc(left);
        if (*out_data) {
                os_memcpy(*out_data, pos, left);
                *out_len = left;
        }

        return 0;
}


int tlsv1_client_process_handshake(struct tlsv1_client *conn, u8 ct,
                                   const u8 *buf, size_t *len,
                                   u8 **out_data, size_t *out_len)
{
        if (ct == TLS_CONTENT_TYPE_ALERT) {
                if (*len < 2) {
                        wpa_printf(MSG_DEBUG, "TLSv1: Alert underflow");
                        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                                  TLS_ALERT_DECODE_ERROR);
                        return -1;
                }
                wpa_printf(MSG_DEBUG, "TLSv1: Received alert %d:%d",
                           buf[0], buf[1]);
                *len = 2;
                conn->state = FAILED;
                return -1;
        }

        if (ct == TLS_CONTENT_TYPE_HANDSHAKE && *len >= 4 &&
            buf[0] == TLS_HANDSHAKE_TYPE_HELLO_REQUEST) {
                size_t hr_len = WPA_GET_BE24(buf + 1);
                if (hr_len > *len - 4) {
                        wpa_printf(MSG_DEBUG, "TLSv1: HelloRequest underflow");
                        tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
                                  TLS_ALERT_DECODE_ERROR);
                        return -1;
                }
                wpa_printf(MSG_DEBUG, "TLSv1: Ignored HelloRequest");
                *len = 4 + hr_len;
                return 0;
        }

        switch (conn->state) {
        case SERVER_HELLO:
                if (tls_process_server_hello(conn, ct, buf, len))
                        return -1;
                break;
        case SERVER_CERTIFICATE:
                if (tls_process_certificate(conn, ct, buf, len))
                        return -1;
                break;
        case SERVER_KEY_EXCHANGE:
                if (tls_process_server_key_exchange(conn, ct, buf, len))
                        return -1;
                break;
        case SERVER_CERTIFICATE_REQUEST:
                if (tls_process_certificate_request(conn, ct, buf, len))
                        return -1;
                break;
        case SERVER_HELLO_DONE:
                if (tls_process_server_hello_done(conn, ct, buf, len))
                        return -1;
                break;
        case SERVER_CHANGE_CIPHER_SPEC:
                if (tls_process_server_change_cipher_spec(conn, ct, buf, len))
                        return -1;
                break;
        case SERVER_FINISHED:
                if (tls_process_server_finished(conn, ct, buf, len))
                        return -1;
                break;
        case ACK_FINISHED:
                if (out_data &&
                    tls_process_application_data(conn, ct, buf, len, out_data,
                                                 out_len))
                        return -1;
                break;
        default:
                wpa_printf(MSG_DEBUG, "TLSv1: Unexpected state %d "
                           "while processing received message",
                           conn->state);
                return -1;
        }

        if (ct == TLS_CONTENT_TYPE_HANDSHAKE)
                tls_verify_hash_add(&conn->verify, buf, *len);

        return 0;
}