halyssonJr commented on code in PR #3642: URL: https://github.com/apache/nuttx-apps/pull/3642#discussion_r3637920341
########## system/nxpkg/pkg_repo.c: ########## @@ -0,0 +1,612 @@ +/**************************************************************************** + * apps/system/nxpkg/pkg_repo.c + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the + * License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations + * under the License. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <ctype.h> +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <strings.h> +#include <unistd.h> + +#include <nuttx/config.h> + +#ifdef CONFIG_NETUTILS_WEBCLIENT +# include "netutils/webclient.h" +#endif + +#include "pkg.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/* Each webclient_perform() read/sink cycle costs a TCP receive plus an + * SD-card write call; at the old 512-byte size, a sub-1MB file like + * nxdoom's ~940KB ELF took ~1900 round trips and, in practice, close + * to two minutes to install - easily read as "stuck" with only a bare + * spinner for feedback. 4KB cuts that to ~230 round trips and lines + * up with typical SD card erase-block granularity, which also reduces + * write amplification. Still small enough to be a safe stack-local + * buffer against the 16KB (CLI) / 16KB (nxstore install worker) task + * stacks that call into this. + */ + +#define PKG_REPO_FETCH_BUFFER_SIZE 4096 + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +#ifdef CONFIG_NETUTILS_WEBCLIENT +struct pkg_fetch_context_s +{ + int fd; + size_t total; +}; +#endif + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +static int pkg_repo_copy_string(FAR char *buffer, size_t size, + FAR const char *value) +{ + int ret; + + ret = snprintf(buffer, size, "%s", value); + if (ret < 0) + { + return ret; + } + + return (size_t)ret >= size ? -ENAMETOOLONG : 0; +} + +static int pkg_repo_source_base(FAR char *buffer, size_t size, + FAR const char *source) +{ + FAR const char *slash; + size_t length; + + slash = strrchr(source, '/'); + if (slash == NULL) + { + return -EINVAL; + } + + length = (size_t)(slash - source); + if (length == 0) + { + length = 1; + } + + if (length >= size) + { + return -ENAMETOOLONG; + } + + memcpy(buffer, source, length); + buffer[length] = '\0'; + return 0; +} + +/**************************************************************************** + * Name: pkg_validate_artifact_relative + * + * Description: + * manifest->artifact is repo-relative content and gets spliced into a + * local filesystem path (or used to build a URL) unsanitized. Reject + * absolute paths outright - allowing them let a malicious index turn + * any local file with a known/predictable hash into an "installed" + * package, including making it executable - and reject any ".." path + * segment that would let the artifact escape the repo mirror directory. + * + ****************************************************************************/ + +static bool pkg_validate_artifact_relative(FAR const char *value) +{ + FAR const char *p; + + if (value == NULL || value[0] == '\0' || value[0] == '/') + { + return false; + } + + p = value; + while ((p = strstr(p, "..")) != NULL) + { + bool at_start = p == value || *(p - 1) == '/'; + bool at_end = p[2] == '\0' || p[2] == '/'; + + if (at_start && at_end) + { + return false; + } + + p++; + } + + return true; +} + +static int pkg_repo_read_source(FAR char *buffer, size_t size) +{ + char path[PATH_MAX]; + FAR char *text; + size_t length; + int ret; + + ret = pkg_store_format_repo_source_path(path, sizeof(path)); + if (ret < 0) + { + return ret; + } + + ret = pkg_store_read_text(path, &text); + if (ret < 0) + { + return ret; + } + + length = strlen(text); + while (length > 0 && isspace((unsigned char)text[length - 1])) + { + text[--length] = '\0'; + } + + ret = pkg_repo_copy_string(buffer, size, text); + pkg_free(text); + return ret; +} + +#ifdef CONFIG_NETUTILS_WEBCLIENT +static int pkg_repo_sink(FAR char **buffer, int offset, int datend, + FAR int *buflen, FAR void *arg) +{ + FAR struct pkg_fetch_context_s *ctx; + size_t remaining; + FAR char *cursor; + + UNUSED(buffer); + UNUSED(buflen); + + ctx = arg; + cursor = &(*buffer)[offset]; + remaining = (size_t)(datend - offset); + + /* Cap total downloaded bytes: an unbounded/malicious response could + * otherwise exhaust all SD-card space. Checked before writing more so + * the on-disk file never exceeds the cap even mid-chunk. + */ + + if (remaining > 0 && + (ctx->total > PKG_DOWNLOAD_MAX_SIZE || + remaining > PKG_DOWNLOAD_MAX_SIZE - ctx->total)) + { + return -EFBIG; + } + + ctx->total += remaining; + + while (remaining > 0) + { + ssize_t nwritten; + + nwritten = write(ctx->fd, cursor, remaining); + if (nwritten < 0) + { + if (errno == EINTR) + { + continue; + } + + return -errno; + } + + cursor += nwritten; + remaining -= (size_t)nwritten; + } + + return 0; +} + +static int pkg_repo_fetch_url(FAR const char *url, FAR const char *dest) +{ + struct pkg_fetch_context_s fetch; + struct webclient_context client; + char reason[64]; + char buffer[PKG_REPO_FETCH_BUFFER_SIZE]; + int ret; + + fetch.fd = open(dest, O_WRONLY | O_CREAT | O_TRUNC, 0644); + if (fetch.fd < 0) + { + return -errno; + } + + fetch.total = 0; + + webclient_set_defaults(&client); + client.method = "GET"; + client.url = url; + client.buffer = buffer; + client.buflen = sizeof(buffer); + client.sink_callback = pkg_repo_sink; + client.sink_callback_arg = &fetch; + client.http_reason = reason; + client.http_reason_len = sizeof(reason); + + ret = webclient_perform(&client); + if (ret < 0) + { + close(fetch.fd); + unlink(dest); + return ret; + } + + if (client.http_status / 100 != 2) + { + close(fetch.fd); + unlink(dest); + return -EPROTO; + } + + if (close(fetch.fd) < 0) + { + unlink(dest); + return -errno; + } + + return 0; +} +#endif + +static int pkg_resolve_relative_source(FAR char *buffer, size_t size, + FAR const char *relative) +{ + char source[PATH_MAX]; + char base[PATH_MAX]; + int ret; + + if (buffer == NULL || relative == NULL || relative[0] == '\0') + { + return -EINVAL; + } + + if (pkg_source_is_url(relative)) + { + return pkg_repo_copy_string(buffer, size, relative); + } + + if (!pkg_validate_artifact_relative(relative)) + { + return -EINVAL; + } + + ret = pkg_repo_read_source(source, sizeof(source)); + if (ret >= 0) + { + ret = pkg_repo_source_base(base, sizeof(base), source); + if (ret < 0) + { + return ret; + } + + ret = snprintf(buffer, size, "%s/%s", base, relative); + if (ret < 0) + { + return ret; + } + + return (size_t)ret >= size ? -ENAMETOOLONG : 0; + } + + ret = snprintf(buffer, size, "%s/%s", PKG_REPO_DIR, relative); + if (ret < 0) + { + return ret; + } + + return (size_t)ret >= size ? -ENAMETOOLONG : 0; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +bool pkg_source_is_url(FAR const char *source) +{ + if (source == NULL) + { + return false; + } + + return strncasecmp(source, "http://";, 7) == 0 || Review Comment: I recommend creating a macro and using `strlen` to return the number of characters. ``` #define PKG_REPO_HTTP "http://"; #define PKG_REPO_HTTPS "https://"; strncasecmp(source, PKG_REPO_HTTP, strlen(PKG_REPO_HTTP)) ``` -- This is an automated message from the Apache Git Service. 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