first commit

vendor/libssh2-sys/tests/run-security-regressions.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+# Run against the exact bundled libssh2 archive produced by the Cargo build.
+set -eu
+if [ "$#" -ne 1 ] || [ ! -f "$1" ]; then
+    echo "Usage: $0 /absolute/path/to/target/.../out/build/libssh2.a" >&2
+    exit 2
+fi
+test_root=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+test_temp=$(mktemp -d)
+trap 'rm -rf "$test_temp"' EXIT HUP INT TERM
+"${CC:-cc}" -std=c99 -O2 -DNDEBUG -Wall -Wextra -Werror \
+    -I"$test_root/../libssh2/include" \
+    "$test_root/security-regression.c" "$1" -lssl -lcrypto -lz \
+    -o "$test_temp/security-regression"
+"$test_temp/security-regression"

vendor/libssh2-sys/tests/security-regression.c

@@ -0,0 +1,73 @@
+/* Targeted runtime checks for the vendored libssh2 security backports.
+ * SPDX-License-Identifier: MIT
+ * This program deliberately supplies boundary lengths, without any network.
+ */
+#include <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <openssl/evp.h>
+#include "libssh2.h"
+
+/* Internal function from the statically linked, patched OpenSSL backend. */
+extern int _libssh2_cipher_crypt(EVP_CIPHER_CTX **ctx,
+                               const EVP_CIPHER *(*algo)(void),
+                               int encrypt, unsigned char *block,
+                               size_t blocksize, int firstlast);
+
+static int check_crypto_bounds(void)
+{
+    unsigned char buffer[EVP_MAX_BLOCK_LENGTH + 32];
+    unsigned char original[sizeof(buffer)];
+    size_t length;
+    memset(buffer, 0xa5, sizeof(buffer));
+    memcpy(original, buffer, sizeof(buffer));
+
+    /* A complete AES-GCM block requires 4 bytes of AAD plus a 16-byte tag.
+     * A null context makes an accidental call into OpenSSL fail immediately;
+     * a correct bounds check rejects these inputs before touching it. */
+    for(length = 0; length < 20; length++) {
+        if(_libssh2_cipher_crypt(NULL, EVP_aes_128_gcm, 0, buffer,
+                                 length, 3) != 1)
+            return 1;
+    }
+    if(_libssh2_cipher_crypt(NULL, EVP_aes_128_gcm, 0, buffer,
+                             sizeof(buffer), 3) != 1)
+        return 1;
+    if(_libssh2_cipher_crypt(NULL, EVP_aes_128_gcm, 0, buffer,
+                             SIZE_MAX, 3) != 1)
+        return 1;
+    return memcmp(buffer, original, sizeof(buffer)) != 0;
+}
+
+static int check_username_bounds(void)
+{
+    LIBSSH2_SESSION *session = libssh2_session_init();
+    int failure = 0;
+    if(!session)
+        return 1;
+    if(libssh2_userauth_list(session, "x", UINT_MAX) != NULL ||
+       libssh2_session_last_errno(session) != LIBSSH2_ERROR_PROTO)
+        failure = 1;
+    if(libssh2_userauth_password_ex(session, "x", UINT_MAX, "p", 1,
+                                   NULL) != LIBSSH2_ERROR_PROTO)
+        failure = 1;
+    libssh2_session_free(session);
+    return failure;
+}
+
+int main(void)
+{
+    int failure;
+    if(libssh2_init(0) != 0)
+        return 1;
+    failure = check_crypto_bounds() | check_username_bounds();
+    libssh2_exit();
+    if(failure) {
+        fputs("libssh2 security boundary regression failed\n", stderr);
+        return 1;
+    }
+    puts("libssh2 security boundaries: AES-GCM short/oversized blocks and overflowing username lengths PASS");
+    return 0;
+}