summaryrefslogtreecommitdiff
path: root/nx_secure/src/nx_secure_tls_send_finished.c
blob: 42a24d03ef01d936209940f300169e00cd352b9f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/***************************************************************************
 * Copyright (c) 2024 Microsoft Corporation
 * Copyright (c) 2025-present Eclipse ThreadX Contributors
 *
 * This program and the accompanying materials are made available under the
 * terms of the MIT License which is available at
 * https://opensource.org/licenses/MIT.
 *
 * SPDX-License-Identifier: MIT
 **************************************************************************/


/**************************************************************************/
/**************************************************************************/
/**                                                                       */
/** NetX Secure Component                                                 */
/**                                                                       */
/**    Transport Layer Security (TLS)                                     */
/**                                                                       */
/**************************************************************************/
/**************************************************************************/

#define NX_SECURE_SOURCE_CODE

#include "nx_secure_tls.h"

/**************************************************************************/
/*                                                                        */
/*  FUNCTION                                               RELEASE        */
/*                                                                        */
/*    _nx_secure_tls_send_finished                        PORTABLE C      */
/*                                                           6.4.3        */
/*  AUTHOR                                                                */
/*                                                                        */
/*    Timothy Stapko, Microsoft Corporation                               */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */
/*    This function generates the Finished message to send to the remote  */
/*    host. The Finished message contains a hash of all handshake         */
/*    messages received up to this point which is used to verify that     */
/*    none of the messages have been corrupted.                           */
/*                                                                        */
/*  INPUT                                                                 */
/*                                                                        */
/*    tls_session                           TLS control block             */
/*    send_packet                           Packet used to send message   */
/*                                                                        */
/*  OUTPUT                                                                */
/*                                                                        */
/*    status                                Completion status             */
/*                                                                        */
/*  CALLS                                                                 */
/*                                                                        */
/*    _nx_secure_tls_finished_hash_generate Generate Finished hash        */
/*                                                                        */
/*  CALLED BY                                                             */
/*                                                                        */
/*    _nx_secure_dtls_client_handshake      DTLS client state machine     */
/*    _nx_secure_dtls_server_handshake      DTLS server state machine     */
/*    _nx_secure_tls_client_handshake       TLS client state machine      */
/*    _nx_secure_tls_server_handshake       TLS server state machine      */
/*                                                                        */
/**************************************************************************/
UINT _nx_secure_tls_send_finished(NX_SECURE_TLS_SESSION *tls_session, NX_PACKET *send_packet)
{
UCHAR            *finished_label;
UINT             hash_size = 0;
UINT             status;
UINT             is_server;


    is_server = (tls_session -> nx_secure_tls_socket_type == NX_SECURE_TLS_SESSION_TYPE_SERVER);

#if (NX_SECURE_TLS_TLS_1_3_ENABLED)
    if(tls_session->nx_secure_tls_1_3)
    {

        /* Generate the TLS 1.3-specific finished data. */
        status = _nx_secure_tls_1_3_finished_hash_generate(tls_session, is_server, &hash_size,
                                                           send_packet -> nx_packet_append_ptr,
                                                           ((ULONG)(send_packet -> nx_packet_data_end) -
                                                            (ULONG)(send_packet -> nx_packet_append_ptr)));
    }
    else
#endif /* (NX_SECURE_TLS_TLS_1_3_ENABLED) */
    {
        /* Select our label for generating the finished hash expansion. */
        if (is_server)
        {
            finished_label = (UCHAR *)"server finished";
        }
        else
        {
            finished_label = (UCHAR *)"client finished";
        }

        if (NX_SECURE_TLS_FINISHED_HASH_SIZE > ((ULONG)(send_packet -> nx_packet_data_end) - (ULONG)(send_packet -> nx_packet_append_ptr)))
        {
            
            /* Packet buffer too small. */
            return(NX_SECURE_TLS_PACKET_BUFFER_TOO_SMALL);
        }

        /* Finally, generate the verification data required by TLS - 12 bytes using the PRF and the data
           we have collected. Place the result directly into the packet buffer. */
        status = _nx_secure_tls_finished_hash_generate(tls_session, finished_label, send_packet -> nx_packet_append_ptr);

#ifndef NX_SECURE_TLS_DISABLE_SECURE_RENEGOTIATION
        /* If we are doing secure renegotiation as per RFC 5746, we need to save off the generated
           verify data now. For TLS 1.0-1.2 this is 12 bytes. If SSLv3 is ever used, it will be 36 bytes. */
        NX_SECURE_MEMCPY(tls_session -> nx_secure_tls_local_verify_data, send_packet -> nx_packet_append_ptr, NX_SECURE_TLS_FINISHED_HASH_SIZE); /* Use case of memcpy is verified. lgtm[cpp/banned-api-usage-required-any] */
#endif

        /* The finished verify data is always 12 bytes for TLS 1.2 and earlier. */
        hash_size = NX_SECURE_TLS_FINISHED_HASH_SIZE;
    }

    /* Adjust the packet into which we just wrote the finished hash. */
    send_packet -> nx_packet_append_ptr = send_packet -> nx_packet_append_ptr + hash_size;
    send_packet -> nx_packet_length = send_packet -> nx_packet_length + hash_size;

    if (status != NX_SUCCESS)
    {
        return(status);
    }

#ifndef NX_SECURE_DISABLE_X509

    /* Finished with the handshake - we can free certificates now. */
    status = _nx_secure_tls_remote_certificate_free_all(tls_session);
#endif

    return(status);
}