libssh2/tests/test_hostkey.c

/* Copyright (C) The libssh2 project and its contributors.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include "runner.h"

static const char EXPECTED_RSA_HOSTKEY[] =
    "AAAAB3NzaC1yc2EAAAABIwAAAQEArrr/JuJmaZligyfS8vcNur+mWR2ddDQtVdhHzdKU"
    "UoR6/Om6cvxpe61H1YZO1xCpLUBXmkki4HoNtYOpPB2W4V+8U4BDeVBD5crypEOE1+7B"
    "Am99fnEDxYIOZq2/jTP0yQmzCpWYS3COyFmkOL7sfX1wQMeW5zQT2WKcxC6FSWbhDqrB"
    "eNEGi687hJJoJ7YXgY/IdiYW5NcOuqRSWljjGS3dAJsHHWk4nJbhjEDXbPaeduMAwQU9"
    "i6ELfP3r+q6wdu0P4jWaoo3De1aYxnToV/ldXykpipON4NPamsb6Ph2qlJQKypq7J4iQ"
    "gkIIbCU1A31+4ExvcIVoxLQw/aTSbw==";

static const char EXPECTED_ECDSA_HOSTKEY[] =
    "AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBC+/syyeKJD9dC2ZH"
    "9Q7iJGReR4YM3rUCMsSynkyXojdfSClGCMY7JvWlt30ESjYvxoTfSRGx6WvaqYK/vPoYQ4=";

static const char EXPECTED_ED25519_HOSTKEY[] =
    "AAAAC3NzaC1lZDI1NTE5AAAAIO7Dhx/ox7Xoi/sg2GrR7j2x5NxvTGKnMH3wifd6UPCx";

int test(LIBSSH2_SESSION *session)
{
    int rc;
    size_t len, len_str;
    int type;
    size_t expected_len = 0;
    char *expected_hostkey = NULL;
    const char *hostkey;
    const char *hostkey_str;

    hostkey = libssh2_session_hostkey(session, &len, &type);
    if(!hostkey) {
        print_last_session_error("libssh2_session_hostkey()");
        return 1;
    }

    if(len < 4) {
        print_last_session_error("libssh2_session_hostkey() "
                                 "host key missing length");
        return 1;
    }

    len_str =
        ((uint32_t)((unsigned char)hostkey[0]) << 24) |
        ((uint32_t)((unsigned char)hostkey[1]) << 16) |
        ((uint32_t)((unsigned char)hostkey[2]) << 8)  |
        ((uint32_t)((unsigned char)hostkey[3]));
    hostkey_str = hostkey + 4;

    if(len_str > len - 4) {
        print_last_session_error("libssh2_session_hostkey() "
                                 "host key too short");
        return 1;
    }

    if(SSH2_IS_LITERAL(hostkey_str, len_str, "ssh-ed25519"))
        rc = ssh2_base64_decode(session, &expected_hostkey, &expected_len,
                                EXPECTED_ED25519_HOSTKEY,
                                sizeof(EXPECTED_ED25519_HOSTKEY) - 1);
    else if(SSH2_IS_LITERAL(hostkey_str, len_str, "ecdsa-sha2-nistp256"))
        rc = ssh2_base64_decode(session, &expected_hostkey, &expected_len,
                                EXPECTED_ECDSA_HOSTKEY,
                                sizeof(EXPECTED_ECDSA_HOSTKEY) - 1);
    else if(SSH2_IS_LITERAL(hostkey_str, len_str, "ssh-rsa"))
        rc = ssh2_base64_decode(session, &expected_hostkey, &expected_len,
                                EXPECTED_RSA_HOSTKEY,
                                sizeof(EXPECTED_RSA_HOSTKEY) - 1);
    else if(SSH2_IS_LITERAL(hostkey_str, len_str,
                            "ssh-ed25519-cert-v01@openssh.com")) {
        fprintf(stderr, "Signed host key: %.*s\n", (int)len_str, hostkey_str);
        return 0;
    }
    else {
        fprintf(stderr, "Unexpected type of host key: %d: %.*s\n",
                type, (int)len_str, hostkey_str);
        return 1;
    }

    if(rc) {
        print_last_session_error("ssh2_base64_decode()");
        return 1;
    }

    if(len != expected_len) {
        fprintf(stderr, "Host key does not have the expected length "
                "%lu!=%lu\n", (unsigned long)len, (unsigned long)expected_len);
        SSH2_FREE(session, expected_hostkey);
        return 1;
    }

    if(memcmp(hostkey, expected_hostkey, len)) {
        fprintf(stderr, "Host keys do not match\n");
        SSH2_FREE(session, expected_hostkey);
        return 1;
    }

    SSH2_FREE(session, expected_hostkey);
    return 0;
}