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Allow a list of digests to be specified for a command.

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This commit is contained in:
Todd C. Miller
2020-03-11 11:17:52 -06:00
parent 8c08f5ef03
commit 4eca443246
19 changed files with 662 additions and 520 deletions
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90
plugins/sudoers/match_digest.c
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@@ -1,7 +1,7 @@
/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 1996, 1998-2005, 2007-2019
* Copyright (c) 1996, 1998-2005, 2007-2020
* Todd C. Miller <Todd.Miller@sudo.ws>
*
* Permission to use, copy, modify, and distribute this software for any
@@ -41,61 +41,81 @@
#include <unistd.h>
#include "sudoers.h"
#include "sudo_digest.h"
#include <gram.h>
bool
digest_matches(int fd, const char *file, const struct command_digest *digest)
digest_matches(int fd, const char *file, const struct command_digest_list *digests)
{
unsigned int digest_type = SUDO_DIGEST_INVALID;
unsigned char *file_digest = NULL;
unsigned char *sudoers_digest = NULL;
struct command_digest *digest;
bool matched = false;
size_t digest_len;
debug_decl(digest_matches, SUDOERS_DEBUG_MATCH);
if (fd == -1)
goto done;
file_digest = sudo_filedigest(fd, file, digest->digest_type, &digest_len);
if (lseek(fd, (off_t)0, SEEK_SET) == -1) {
sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO|SUDO_DEBUG_LINENO,
"unable to rewind digest fd");
if (TAILQ_EMPTY(digests)) {
/* No digest, no problem. */
debug_return_bool(true);
}
if (file_digest == NULL) {
/* Warning (if any) printed by sudo_filedigest() */
if (fd == -1) {
/* No file, no match. */
goto done;
}
/* Convert the command digest from ascii to binary. */
if ((sudoers_digest = malloc(digest_len)) == NULL) {
sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
goto done;
}
if (strlen(digest->digest_str) == digest_len * 2) {
/* Convert ascii hex to binary. */
unsigned int i;
for (i = 0; i < digest_len; i++) {
const int h = hexchar(&digest->digest_str[i + i]);
if (h == -1)
TAILQ_FOREACH(digest, digests, entries) {
/* Compute file digest if needed. */
if (digest->digest_type != digest_type) {
free(file_digest);
file_digest = sudo_filedigest(fd, file, digest->digest_type,
&digest_len);
if (lseek(fd, (off_t)0, SEEK_SET) == -1) {
sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO|SUDO_DEBUG_LINENO,
"unable to rewind digest fd");
}
if (file_digest == NULL) {
/* Warning (if any) printed by sudo_filedigest() */
goto done;
}
digest_type = digest->digest_type;
}
/* Convert the command digest from ascii to binary. */
if ((sudoers_digest = malloc(digest_len)) == NULL) {
sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
goto done;
}
if (strlen(digest->digest_str) == digest_len * 2) {
/* Convert ascii hex to binary. */
unsigned int i;
for (i = 0; i < digest_len; i++) {
const int h = hexchar(&digest->digest_str[i + i]);
if (h == -1)
goto bad_format;
sudoers_digest[i] = (unsigned char)h;
}
} else {
/* Convert base64 to binary. */
size_t len = base64_decode(digest->digest_str, sudoers_digest, digest_len);
if (len != digest_len) {
sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
"incorrect length for digest, expected %zu, got %zu",
digest_len, len);
goto bad_format;
sudoers_digest[i] = (unsigned char)h;
}
}
} else {
/* Convert base64 to binary. */
size_t len = base64_decode(digest->digest_str, sudoers_digest, digest_len);
if (len != digest_len) {
sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
"incorrect length for digest, expected %zu, got %zu",
digest_len, len);
goto bad_format;
if (memcmp(file_digest, sudoers_digest, digest_len) == 0) {
matched = true;
break;
}
}
if (memcmp(file_digest, sudoers_digest, digest_len) == 0) {
matched = true;
} else {
sudo_debug_printf(SUDO_DEBUG_DIAG|SUDO_DEBUG_LINENO,
"%s digest mismatch for %s, expecting %s",
digest_type_to_name(digest->digest_type), file, digest->digest_str);
free(sudoers_digest);
sudoers_digest = NULL;
}
goto done;