C++ LIBSSH2_ALLOC函数代码示例

/* {{{ libssh2_session_last_error
 * Returns error code and populates an error string into errmsg
 * If want_buf is non-zero then the string placed into errmsg must be freed by the calling program
 * Otherwise it is assumed to be owned by libssh2
 */
LIBSSH2_API int
libssh2_session_last_error(LIBSSH2_SESSION * session, char **errmsg,
                           int *errmsg_len, int want_buf)
{
    /* No error to report */
    if (!session->err_code) {
        if (errmsg) {
            if (want_buf) {
                *errmsg = LIBSSH2_ALLOC(session, 1);
                if (*errmsg) {
                    **errmsg = 0;
                }
            } else {
                *errmsg = (char *) "";
            }
        }
        if (errmsg_len) {
            *errmsg_len = 0;
        }
        return 0;
    }

    if (errmsg) {
        char *serrmsg = session->err_msg ? session->err_msg : (char *) "";
        int ownbuf = session->err_msg ? session->err_should_free : 0;

        if (want_buf) {
            if (ownbuf) {
                /* Just give the calling program the buffer */
                *errmsg = serrmsg;
                session->err_should_free = 0;
            } else {
                /* Make a copy so the calling program can own it */
                *errmsg = LIBSSH2_ALLOC(session, session->err_msglen + 1);
                if (*errmsg) {
                    memcpy(*errmsg, session->err_msg, session->err_msglen);
                    (*errmsg)[session->err_msglen] = 0;
                }
            }
        } else {
            *errmsg = serrmsg;
        }
    }

    if (errmsg_len) {
        *errmsg_len = session->err_msglen;
    }

    return session->err_code;
}

static int
agent_transact_pageant(LIBSSH2_AGENT *agent, agent_transaction_ctx_t transctx)
{
    HWND hwnd;
    char mapname[23];
    HANDLE filemap;
    unsigned char *p;
    unsigned char *p2;
    int id;
    COPYDATASTRUCT cds;

    if (!transctx || 4 + transctx->request_len > PAGEANT_MAX_MSGLEN)
        return _libssh2_error(agent->session, LIBSSH2_ERROR_INVAL,
                              "illegal input");

    hwnd = FindWindow("Pageant", "Pageant");
    if (!hwnd)
        return _libssh2_error(agent->session, LIBSSH2_ERROR_AGENT_PROTOCOL,
                              "found no pageant");

    sprintf(mapname, "PageantRequest%08x", (unsigned)GetCurrentThreadId());
    filemap = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE,
				0, PAGEANT_MAX_MSGLEN, mapname);

    if (filemap == NULL || filemap == INVALID_HANDLE_VALUE)
        return _libssh2_error(agent->session, LIBSSH2_ERROR_AGENT_PROTOCOL,
                              "failed setting up pageant filemap");

    p2 = p = MapViewOfFile(filemap, FILE_MAP_WRITE, 0, 0, 0);
    _libssh2_store_str(&p2, (const char *)transctx->request,
                       transctx->request_len);

    cds.dwData = PAGEANT_COPYDATA_ID;
    cds.cbData = 1 + strlen(mapname);
    cds.lpData = mapname;

    id = SendMessage(hwnd, WM_COPYDATA, (WPARAM) NULL, (LPARAM) &cds);
    if (id > 0) {
	transctx->response_len = _libssh2_ntohu32(p);
        if (transctx->response_len > PAGEANT_MAX_MSGLEN) {
            UnmapViewOfFile(p);
            CloseHandle(filemap);
            return _libssh2_error(agent->session, LIBSSH2_ERROR_AGENT_PROTOCOL,
                                  "agent setup fail");
        }
	transctx->response = LIBSSH2_ALLOC(agent->session,
                                           transctx->response_len);
	if (!transctx->response) {
            UnmapViewOfFile(p);
            CloseHandle(filemap);
            return _libssh2_error(agent->session, LIBSSH2_ERROR_ALLOC,
                                  "agent malloc");
        }
        memcpy(transctx->response, p + 4, transctx->response_len);
    }

    UnmapViewOfFile(p);
    CloseHandle(filemap);
    return 0;
}

/* {{{ libssh2_banner_set
 * Set the local banner
 */
LIBSSH2_API int
libssh2_banner_set(LIBSSH2_SESSION * session, const char *banner)
{
    int banner_len = banner ? strlen(banner) : 0;

    if (session->local.banner) {
        LIBSSH2_FREE(session, session->local.banner);
        session->local.banner = NULL;
    }

    if (!banner_len) {
        return 0;
    }

    session->local.banner = LIBSSH2_ALLOC(session, banner_len + 3);
    if (!session->local.banner) {
        libssh2_error(session, LIBSSH2_ERROR_ALLOC,
                      "Unable to allocate memory for local banner", 0);
        return -1;
    }

    memcpy(session->local.banner, banner, banner_len);
    session->local.banner[banner_len] = '\0';
    _libssh2_debug(session, LIBSSH2_DBG_TRANS, "Setting local Banner: %s",
                   session->local.banner);
    session->local.banner[banner_len++] = '\r';
    session->local.banner[banner_len++] = '\n';
    session->local.banner[banner_len++] = '\0';

    return 0;
}

/*
 * hostkey_method_ssh_dss_signv
 *
 * Construct a signature from an array of vectors
 */
static int
hostkey_method_ssh_dss_signv(LIBSSH2_SESSION * session,
                             unsigned char **signature,
                             unsigned long *signature_len,
                             unsigned long veccount,
                             const struct iovec datavec[],
                             void **abstract)
{
    libssh2_dsa_ctx *dsactx = (libssh2_dsa_ctx *) (*abstract);
    unsigned char hash[SHA_DIGEST_LENGTH];
    libssh2_sha1_ctx ctx;
    unsigned int i;

    *signature = LIBSSH2_ALLOC(session, 2 * SHA_DIGEST_LENGTH);
    if (!*signature) {
        return -1;
    }

    *signature_len = 2 * SHA_DIGEST_LENGTH;
    memset(*signature, 0, 2 * SHA_DIGEST_LENGTH);

    libssh2_sha1_init(&ctx);
    for(i = 0; i < veccount; i++) {
        libssh2_sha1_update(ctx, datavec[i].iov_base, datavec[i].iov_len);
    }
    libssh2_sha1_final(ctx, hash);

    if (_libssh2_dsa_sha1_sign(dsactx, hash, SHA_DIGEST_LENGTH, *signature)) {
        LIBSSH2_FREE(session, *signature);
        return -1;
    }

    return 0;
}

int
_libssh2_rsa_sha1_sign(LIBSSH2_SESSION * session,
                       libssh2_rsa_ctx * rsactx,
                       const unsigned char *hash,
                       unsigned long hash_len,
                       unsigned char **signature, unsigned long *signature_len)
{
    int ret;
    unsigned char *sig;
    unsigned int sig_len;

    sig_len = RSA_size(rsactx);
    sig = LIBSSH2_ALLOC(session, sig_len);

    if (!sig) {
        return -1;
    }

    ret = RSA_sign(NID_sha1, hash, hash_len, sig, &sig_len, rsactx);

    if (!ret) {
        LIBSSH2_FREE(session, sig);
        return -1;
    }

    *signature = sig;
    *signature_len = sig_len;

    return 0;
}

static voidpf
libssh2_comp_method_zlib_alloc(voidpf opaque, uInt items, uInt size)
{
    LIBSSH2_SESSION *session = (LIBSSH2_SESSION *) opaque;

    return (voidpf) LIBSSH2_ALLOC(session, items * size);
}

/* {{{ libssh2_comp_method_zlib_init
 * All your bandwidth are belong to us (so save some)
 */
static int
libssh2_comp_method_zlib_init(LIBSSH2_SESSION * session, int compress,
                              void **abstract)
{
    z_stream *strm;
    int status;

    strm = LIBSSH2_ALLOC(session, sizeof(z_stream));
    if (!strm) {
        libssh2_error(session, LIBSSH2_ERROR_ALLOC,
                      "Unable to allocate memory for zlib compression/decompression",
                      0);
        return -1;
    }
    memset(strm, 0, sizeof(z_stream));

    strm->opaque = (voidpf) session;
    strm->zalloc = (alloc_func) libssh2_comp_method_zlib_alloc;
    strm->zfree = (free_func) libssh2_comp_method_zlib_free;
    if (compress) {
        /* deflate */
        status = deflateInit(strm, Z_DEFAULT_COMPRESSION);
    } else {
        /* inflate */
        status = inflateInit(strm);
    }

    if (status != Z_OK) {
        LIBSSH2_FREE(session, strm);
        return -1;
    }
    *abstract = strm;

    return 0;
}

/* {{{ libssh2_publickey_packet_receive
 * Read a packet from the subsystem
 */
static int libssh2_publickey_packet_receive(LIBSSH2_PUBLICKEY *pkey, unsigned char **data, unsigned long *data_len)
{
	LIBSSH2_CHANNEL *channel = pkey->channel;
	LIBSSH2_SESSION *session = channel->session;
	unsigned char buffer[4];
	unsigned long packet_len;
	unsigned char *packet;

	if (libssh2_channel_read(channel, buffer, 4) != 4) {
		libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_PROTOCOL, "Invalid response from publickey subsystem", 0);
		return -1;
	}

	packet_len = libssh2_ntohu32(buffer);
	packet = LIBSSH2_ALLOC(session, packet_len);
	if (!packet) {
		libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate publickey response buffer", 0);
		return -1;
	}

	if (libssh2_channel_read(channel, packet, packet_len) != packet_len) {
		libssh2_error(session, LIBSSH2_ERROR_SOCKET_TIMEOUT, "Timeout waiting for publickey subsystem response packet", 0);
		LIBSSH2_FREE(session, packet);
		return -1;
	}

	*data = packet;
	*data_len = packet_len;

	return 0;
}

static unsigned char *
gen_publickey_from_rsa(LIBSSH2_SESSION *session, RSA *rsa,
                       size_t *key_len)
{
    int            e_bytes, n_bytes;
    unsigned long  len;
    unsigned char* key;
    unsigned char* p;

    e_bytes = BN_num_bytes(rsa->e) + 1;
    n_bytes = BN_num_bytes(rsa->n) + 1;

    /* Key form is "ssh-rsa" + e + n. */
    len = 4 + 7 + 4 + e_bytes + 4 + n_bytes;

    key = LIBSSH2_ALLOC(session, len);
    if (key == NULL) {
        return NULL;
    }

    /* Process key encoding. */
    p = key;

    _libssh2_htonu32(p, 7);  /* Key type. */
    p += 4;
    memcpy(p, "ssh-rsa", 7);
    p += 7;

    p = write_bn(p, rsa->e, e_bytes);
    p = write_bn(p, rsa->n, n_bytes);

    *key_len = (size_t)(p - key);
    return key;
}

static int
agent_transact_unix(LIBSSH2_AGENT *agent, agent_transaction_ctx_t transctx)
{
    unsigned char buf[4];
    int rc;

    /* Send the length of the request */
    if (transctx->state == agent_NB_state_request_created) {
        _libssh2_htonu32(buf, transctx->request_len);
        rc = send(agent->fd, buf, sizeof buf, 0);
        if (rc < 0) {
            if (errno == EAGAIN)
                return LIBSSH2_ERROR_EAGAIN;
            return -1;
        }
        transctx->state = agent_NB_state_request_length_sent;
    }

    /* Send the request body */
    if (transctx->state == agent_NB_state_request_length_sent) {
        rc = send(agent->fd, transctx->request,
                  transctx->request_len, 0);
        if (rc < 0) {
            if (errno == EAGAIN)
                return LIBSSH2_ERROR_EAGAIN;
            return -1;
        }
        transctx->state = agent_NB_state_request_sent;
    }

    /* Receive the length of a response */
    if (transctx->state == agent_NB_state_request_sent) {
        rc = recv(agent->fd, buf, sizeof buf, 0);
        if (rc < 0) {
            if (errno == EAGAIN)
                return LIBSSH2_ERROR_EAGAIN;
            return -1;
        }
        transctx->response_len = _libssh2_ntohu32(buf);
        transctx->response = LIBSSH2_ALLOC(agent->session,
                                           transctx->response_len);
        if (!transctx->response) {
            return LIBSSH2_ERROR_ALLOC;
        }
        transctx->state = agent_NB_state_response_length_received;
    }

    /* Receive the response body */
    if (transctx->state == agent_NB_state_response_length_received) {
        rc = recv(agent->fd, transctx->response, transctx->response_len, 0);
        if (rc < 0) {
            if (errno == EAGAIN)
                return LIBSSH2_ERROR_EAGAIN;
            return -1;
        }
        transctx->state = agent_NB_state_response_received;
    }

    return 0;
}

int
_libssh2_rsa_sha1_sign(LIBSSH2_SESSION * session,
                       libssh2_rsa_ctx * rsactx,
                       const unsigned char *hash,
                       size_t hash_len,
                       unsigned char **signature, size_t *signature_len)
{
    gcry_sexp_t sig_sexp;
    gcry_sexp_t data;
    int rc;
    const char *tmp;
    size_t size;

    if(hash_len != SHA_DIGEST_LENGTH) {
        return -1;
    }

    if(gcry_sexp_build(&data, NULL,
                        "(data (flags pkcs1) (hash sha1 %b))",
                        hash_len, hash)) {
        return -1;
    }

    rc = gcry_pk_sign(&sig_sexp, data, rsactx);

    gcry_sexp_release(data);

    if(rc != 0) {
        return -1;
    }

    data = gcry_sexp_find_token(sig_sexp, "s", 0);
    if(!data) {
        return -1;
    }

    tmp = gcry_sexp_nth_data(data, 1, &size);
    if(!tmp) {
        return -1;
    }

    if(tmp[0] == '\0') {
        tmp++;
        size--;
    }

    *signature = LIBSSH2_ALLOC(session, size);
    if(!*signature) {
        return -1;
    }
    memcpy(*signature, tmp, size);
    *signature_len = size;

    return rc;
}

static unsigned char *
gen_publickey_from_dsa(LIBSSH2_SESSION* session, DSA *dsa,
                       size_t *key_len)
{
    int            p_bytes, q_bytes, g_bytes, k_bytes;
    unsigned long  len;
    unsigned char *key;
    unsigned char *p;

    const BIGNUM * p_bn;
    const BIGNUM * q;
    const BIGNUM * g;
    const BIGNUM * pub_key;
#ifdef HAVE_OPAQUE_STRUCTS
    DSA_get0_pqg(dsa, &p_bn, &q, &g);
#else
    p_bn = dsa->p;
    q = dsa->q;
    g = dsa->g;
#endif

#ifdef HAVE_OPAQUE_STRUCTS
    DSA_get0_key(dsa, &pub_key, NULL);
#else
    pub_key = dsa->pub_key;
#endif
    p_bytes = BN_num_bytes(p_bn) + 1;
    q_bytes = BN_num_bytes(q) + 1;
    g_bytes = BN_num_bytes(g) + 1;
    k_bytes = BN_num_bytes(pub_key) + 1;

    /* Key form is "ssh-dss" + p + q + g + pub_key. */
    len = 4 + 7 + 4 + p_bytes + 4 + q_bytes + 4 + g_bytes + 4 + k_bytes;

    key = LIBSSH2_ALLOC(session, len);
    if(key == NULL) {
        return NULL;
    }

    /* Process key encoding. */
    p = key;

    _libssh2_htonu32(p, 7);  /* Key type. */
    p += 4;
    memcpy(p, "ssh-dss", 7);
    p += 7;

    p = write_bn(p, p_bn, p_bytes);
    p = write_bn(p, q, q_bytes);
    p = write_bn(p, g, g_bytes);
    p = write_bn(p, pub_key, k_bytes);

    *key_len = (size_t)(p - key);
    return key;
}

static int
gen_publickey_from_dsa_evp(LIBSSH2_SESSION *session,
                           unsigned char **method,
                           size_t *method_len,
                           unsigned char **pubkeydata,
                           size_t *pubkeydata_len,
                           EVP_PKEY *pk)
{
    DSA*           dsa = NULL;
    unsigned char* key;
    unsigned char* method_buf = NULL;
    size_t  key_len;

    _libssh2_debug(session,
                   LIBSSH2_TRACE_AUTH,
                   "Computing public key from DSA private key envelop");

    dsa = EVP_PKEY_get1_DSA(pk);
    if (dsa == NULL) {
        /* Assume memory allocation error... what else could it be ? */
        goto __alloc_error;
    }

    method_buf = LIBSSH2_ALLOC(session, 7);  /* ssh-dss. */
    if (method_buf == NULL) {
        goto __alloc_error;
    }

    key = gen_publickey_from_dsa(session, dsa, &key_len);
    if (key == NULL) {
        goto __alloc_error;
    }
    DSA_free(dsa);

    memcpy(method_buf, "ssh-dss", 7);
    *method         = method_buf;
    *method_len     = 7;
    *pubkeydata     = key;
    *pubkeydata_len = key_len;
    return 0;

  __alloc_error:
    if (dsa != NULL) {
        DSA_free(dsa);
    }
    if (method_buf != NULL) {
        LIBSSH2_FREE(session, method_buf);
    }

    _libssh2_error(session,
                   LIBSSH2_ERROR_ALLOC,
                   "Unable to allocate memory for private key data");
    return -1;
}

/* {{{ proto libssh2_userauth_list
 * List authentication methods
 * Will yield successful login if "none" happens to be allowable for this user
 * Not a common configuration for any SSH server though
 * username should be NULL, or a null terminated string
 */
LIBSSH2_API char *libssh2_userauth_list(LIBSSH2_SESSION *session, const char *username, unsigned int username_len)
{
	unsigned char reply_codes[3] = { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, 0 };
	unsigned long data_len = username_len + 31; /* packet_type(1) + username_len(4) + service_len(4) + service(14)"ssh-connection" +
												   method_len(4) + method(4)"none" */
	unsigned long methods_len;
	unsigned char *data, *s;

	s = data = LIBSSH2_ALLOC(session, data_len);
	if (!data) {
		libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for userauth_list", 0);
		return NULL;
	}

	*(s++) = SSH_MSG_USERAUTH_REQUEST;
	libssh2_htonu32(s, username_len);				s += 4;
	if (username) {
		memcpy(s, username, username_len);			s += username_len;
	}

	libssh2_htonu32(s, 14);							s += 4;
	memcpy(s, "ssh-connection", 14);				s += 14;

	libssh2_htonu32(s, 4);							s += 4;
	memcpy(s, "none", 4);							s += 4;

	if (libssh2_packet_write(session, data, data_len)) {
		libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-none request", 0);
		LIBSSH2_FREE(session, data);
		return NULL;
	}
	LIBSSH2_FREE(session, data);

	if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
		return NULL;
	}

	if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
		/* Wow, who'dve thought... */
		LIBSSH2_FREE(session, data);
		session->state |= LIBSSH2_STATE_AUTHENTICATED;
		return NULL;
	}

	methods_len = libssh2_ntohu32(data + 1);
	memcpy(data, data + 5, methods_len);
	data[methods_len] = '\0';
#ifdef LIBSSH2_DEBUG_USERAUTH
	_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Permitted auth methods: %s", data);
#endif
	return (char *)data;
}

/*
 * libssh2_knownhost_init
 *
 * Init a collection of known hosts. Returns the pointer to a collection.
 *
 */
LIBSSH2_API LIBSSH2_KNOWNHOSTS *
libssh2_knownhost_init(LIBSSH2_SESSION *session)
{
    LIBSSH2_KNOWNHOSTS *knh =
        LIBSSH2_ALLOC(session, sizeof(struct _LIBSSH2_KNOWNHOSTS));

    if(!knh)
        return NULL;

    knh->session = session;

    _libssh2_list_init(&knh->head);

    return knh;
}