From be728cba83fda33925d1c0f901aaa1054c88c14d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Deuc=D0=B5?= <shurd@sasktel.net>
Date: Thu, 22 Feb 2024 22:09:46 -0500
Subject: [PATCH] Read SSH packet headers into a fixed buffer in the session
info
Previously, it was read into a local variable, and in the case of a
partial read, everything would go to hell and SSH would hang.
"Luckily" this was very hard to trigger.
---
3rdp/build/GNUmakefile | 3 +-
3rdp/build/cl-fix-ssh-header-read.patch | 87 +++++++++++++++++++++++++
2 files changed, 89 insertions(+), 1 deletion(-)
create mode 100644 3rdp/build/cl-fix-ssh-header-read.patch
diff --git a/3rdp/build/GNUmakefile b/3rdp/build/GNUmakefile
index cd73d947ab..efe18687c3 100644
--- a/3rdp/build/GNUmakefile
+++ b/3rdp/build/GNUmakefile
@@ -90,7 +90,7 @@ $(CRYPT_SRC): | $(3RDPSRCDIR)
$(CRYPT_IDIR): | $(3RDPODIR)
$(QUIET)$(IFNOTEXIST) mkdir $(CRYPT_IDIR)
-$(CRYPTLIB_BUILD): $(3RDP_ROOT)/dist/cryptlib.zip $(3RDP_ROOT)/build/cl-fix-test-select.patch $(3RDP_ROOT)/build/cl-terminal-params.patch $(3RDP_ROOT)/build/cl-mingw32-static.patch $(3RDP_ROOT)/build/cl-ranlib.patch $(3RDP_ROOT)/build/cl-win32-noasm.patch $(3RDP_ROOT)/build/cl-zz-country.patch $(3RDP_ROOT)/build/cl-algorithms.patch $(3RDP_ROOT)/build/cl-allow-duplicate-ext.patch $(3RDP_ROOT)/build/cl-macosx-minver.patch $(3RDP_ROOT)/build/cl-posix-me-gently.patch $(3RDP_ROOT)/build/cl-PAM-noprompts.patch $(3RDP_ROOT)/build/cl-zlib.patch $(3RDP_ROOT)/build/cl-Dynamic-linked-static-lib.patch $(3RDP_ROOT)/build/cl-SSL-fix.patch $(3RDP_ROOT)/build/cl-bigger-maxattribute.patch $(3RDP_ROOT)/build/cl-endian.patch $(3RDP_ROOT)/build/cl-vcxproj.patch $(3RDP_ROOT)/build/cl-mingw-vcver.patch $(3RDP_ROOT)/build/cl-win32-build-fix.patch $(3RDP_ROOT)/build/cl-no-odbc.patch $(3RDP_ROOT)/build/cl-noasm-defines.patch $(3RDP_ROOT)/build/cl-bn-noasm64-fix.patch $(3RDP_ROOT)/build/cl-prefer-ECC.patch $(3RDP_ROOT)/build/cl-prefer-ECC-harder.patch $(3RDP_ROOT)/build/cl-clear-GCM-flag.patch $(3RDP_ROOT)/build/cl-use-ssh-ctr.patch $(3RDP_ROOT)/build/cl-ssl-suite-blocksizes.patch $(3RDP_ROOT)/build/cl-no-tpm.patch $(3RDP_ROOT)/build/cl-no-via-aes.patch $(3RDP_ROOT)/build/cl-fix-ssh-ecc-ephemeral.patch $(3RDP_ROOT)/build/cl-just-use-cc.patch $(3RDP_ROOT)/build/cl-no-safe-stack.patch $(3RDP_ROOT)/build/cl-allow-pkcs12.patch $(3RDP_ROOT)/build/cl-openbsd-threads.patch $(3RDP_ROOT)/build/cl-allow-none-auth.patch $(3RDP_ROOT)/build/cl-mingw-add-m32.patch $(3RDP_ROOT)/build/cl-poll-not-select.patch $(3RDP_ROOT)/build/cl-good-sockets.patch $(3RDP_ROOT)/build/cl-moar-objects.patch $(3RDP_ROOT)/build/cl-server-term-support.patch $(3RDP_ROOT)/build/cl-add-pubkey-attribute.patch $(3RDP_ROOT)/build/cl-allow-ssh-auth-retries.patch $(3RDP_ROOT)/build/cl-fix-ssh-channel-close.patch $(3RDP_ROOT)/build/cl-vt-lt-2005-always-defined.patch $(3RDP_ROOT)/build/cl-no-pie.patch $(3RDP_ROOT)/build/cl-no-testobjs.patch $(3RDP_ROOT)/build/cl-win32-lean-and-mean.patch $(3RDP_ROOT)/build/cl-thats-not-asm.patch $(3RDP_ROOT)/build/cl-make-channels-work.patch $(3RDP_ROOT)/build/cl-allow-ssh-2.0-go.patch $(3RDP_ROOT)/build/cl-read-timeout-every-time.patch $(3RDP_ROOT)/build/cl-allow-servercheck-pubkeys.patch $(3RDP_ROOT)/build/cl-pass-after-pubkey.patch $(3RDP_ROOT)/build/cl-ssh-list-ctr-modes.patch $(3RDP_ROOT)/build/cl-double-delete-fine-on-close.patch $(3RDP_ROOT)/build/cl-handle-unsupported-pubkey.patch $(3RDP_ROOT)/build/cl-add-patches-info.patch $(3RDP_ROOT)/build/cl-netbsd-hmac-symbol.patch $(3RDP_ROOT)/build/cl-netbsd-no-getfsstat.patch GNUmakefile $(3RDP_ROOT)/build/cl-remove-march.patch $(3RDP_ROOT)/build/cl-add-win64.patch $(3RDP_ROOT)/build/cl-fix-mb-w-conv-warnings.patch | $(CRYPT_SRC) $(CRYPT_IDIR)
+$(CRYPTLIB_BUILD): $(3RDP_ROOT)/dist/cryptlib.zip $(3RDP_ROOT)/build/cl-fix-test-select.patch $(3RDP_ROOT)/build/cl-terminal-params.patch $(3RDP_ROOT)/build/cl-mingw32-static.patch $(3RDP_ROOT)/build/cl-ranlib.patch $(3RDP_ROOT)/build/cl-win32-noasm.patch $(3RDP_ROOT)/build/cl-zz-country.patch $(3RDP_ROOT)/build/cl-algorithms.patch $(3RDP_ROOT)/build/cl-allow-duplicate-ext.patch $(3RDP_ROOT)/build/cl-macosx-minver.patch $(3RDP_ROOT)/build/cl-posix-me-gently.patch $(3RDP_ROOT)/build/cl-PAM-noprompts.patch $(3RDP_ROOT)/build/cl-zlib.patch $(3RDP_ROOT)/build/cl-Dynamic-linked-static-lib.patch $(3RDP_ROOT)/build/cl-SSL-fix.patch $(3RDP_ROOT)/build/cl-bigger-maxattribute.patch $(3RDP_ROOT)/build/cl-endian.patch $(3RDP_ROOT)/build/cl-vcxproj.patch $(3RDP_ROOT)/build/cl-mingw-vcver.patch $(3RDP_ROOT)/build/cl-win32-build-fix.patch $(3RDP_ROOT)/build/cl-no-odbc.patch $(3RDP_ROOT)/build/cl-noasm-defines.patch $(3RDP_ROOT)/build/cl-bn-noasm64-fix.patch $(3RDP_ROOT)/build/cl-prefer-ECC.patch $(3RDP_ROOT)/build/cl-prefer-ECC-harder.patch $(3RDP_ROOT)/build/cl-clear-GCM-flag.patch $(3RDP_ROOT)/build/cl-use-ssh-ctr.patch $(3RDP_ROOT)/build/cl-ssl-suite-blocksizes.patch $(3RDP_ROOT)/build/cl-no-tpm.patch $(3RDP_ROOT)/build/cl-no-via-aes.patch $(3RDP_ROOT)/build/cl-fix-ssh-ecc-ephemeral.patch $(3RDP_ROOT)/build/cl-just-use-cc.patch $(3RDP_ROOT)/build/cl-no-safe-stack.patch $(3RDP_ROOT)/build/cl-allow-pkcs12.patch $(3RDP_ROOT)/build/cl-openbsd-threads.patch $(3RDP_ROOT)/build/cl-allow-none-auth.patch $(3RDP_ROOT)/build/cl-mingw-add-m32.patch $(3RDP_ROOT)/build/cl-poll-not-select.patch $(3RDP_ROOT)/build/cl-good-sockets.patch $(3RDP_ROOT)/build/cl-moar-objects.patch $(3RDP_ROOT)/build/cl-server-term-support.patch $(3RDP_ROOT)/build/cl-add-pubkey-attribute.patch $(3RDP_ROOT)/build/cl-allow-ssh-auth-retries.patch $(3RDP_ROOT)/build/cl-fix-ssh-channel-close.patch $(3RDP_ROOT)/build/cl-vt-lt-2005-always-defined.patch $(3RDP_ROOT)/build/cl-no-pie.patch $(3RDP_ROOT)/build/cl-no-testobjs.patch $(3RDP_ROOT)/build/cl-win32-lean-and-mean.patch $(3RDP_ROOT)/build/cl-thats-not-asm.patch $(3RDP_ROOT)/build/cl-make-channels-work.patch $(3RDP_ROOT)/build/cl-allow-ssh-2.0-go.patch $(3RDP_ROOT)/build/cl-read-timeout-every-time.patch $(3RDP_ROOT)/build/cl-allow-servercheck-pubkeys.patch $(3RDP_ROOT)/build/cl-pass-after-pubkey.patch $(3RDP_ROOT)/build/cl-ssh-list-ctr-modes.patch $(3RDP_ROOT)/build/cl-double-delete-fine-on-close.patch $(3RDP_ROOT)/build/cl-handle-unsupported-pubkey.patch $(3RDP_ROOT)/build/cl-add-patches-info.patch $(3RDP_ROOT)/build/cl-netbsd-hmac-symbol.patch $(3RDP_ROOT)/build/cl-netbsd-no-getfsstat.patch GNUmakefile $(3RDP_ROOT)/build/cl-remove-march.patch $(3RDP_ROOT)/build/cl-add-win64.patch $(3RDP_ROOT)/build/cl-fix-mb-w-conv-warnings.patch $(3RDP_ROOT)/build/cl-fix-ssh-header-read.patch | $(CRYPT_SRC) $(CRYPT_IDIR)
@echo Creating $@ ...
$(QUIET)-rm -rf $(CRYPT_SRC)/*
$(QUIET)unzip -oa $(3RDPDISTDIR)/cryptlib.zip -d $(CRYPT_SRC)
@@ -157,6 +157,7 @@ $(CRYPTLIB_BUILD): $(3RDP_ROOT)/dist/cryptlib.zip $(3RDP_ROOT)/build/cl-fix-test
$(QUIET)patch -b -p0 -d $(CRYPT_SRC) < cl-netbsd-no-getfsstat.patch
$(QUIET)patch -b -p0 -d $(CRYPT_SRC) < cl-add-win64.patch
$(QUIET)patch -b -p0 -d $(CRYPT_SRC) < cl-fix-mb-w-conv-warnings.patch
+ $(QUIET)patch -b -p0 -d $(CRYPT_SRC) < cl-fix-ssh-header-read.patch
$(QUIET)perl -pi.bak -e 's/^(#define CRYPTLIB_VERSION.*)$$/"$$1\n#define CRYPTLIB_PATCHES \"" . (chomp($$val = `cat cl-*.patch | if (which md5sum > \/dev\/null 2>&1); then md5sum; else md5; fi`), $$val) . "\""/e' $(CRYPT_SRC)/cryptlib.h
ifeq ($(os),win32)
$(QUIET)cd $(CRYPT_SRC) && env - PATH="$(PATH)" CC="$(CC)" AR="$(AR)" RANLIB="$(RANLIB)" make directories
diff --git a/3rdp/build/cl-fix-ssh-header-read.patch b/3rdp/build/cl-fix-ssh-header-read.patch
new file mode 100644
index 0000000000..358bf57870
--- /dev/null
+++ b/3rdp/build/cl-fix-ssh-header-read.patch
@@ -0,0 +1,87 @@
+--- session/session.h.orig 2024-02-22 21:46:07.919870000 -0500
++++ session/session.h 2024-02-22 21:54:28.395535000 -0500
+@@ -370,6 +370,12 @@
+ BUFFER_FIXED( KEYID_SIZE ) \
+ BYTE authUserNameHash[ KEYID_SIZE + 8 ];/* Hashed userID */
+ /* SSH_AUTHTYPE_TYPE */ int authType; /* Authentication method */
++
++ /* If a header is only partially read, cryptlib takes a shit because
++ it's in a local variable. Store it in the session data instead. */
++ BUFFER_FIXED( 20 ) \
++ BYTE headerBuffer[ 20 + 8 ];
++ int headerBufferUsed;
+ } SSH_INFO;
+ #endif /* USE_SSH */
+
+--- session/ssh2_rd.c.orig 2023-06-15 04:35:42.000000000 -0400
++++ session/ssh2_rd.c 2024-02-22 21:57:48.805525000 -0500
+@@ -407,7 +407,6 @@
+ const SSH_PROTOSTATE_TYPE protocolState )
+ {
+ STREAM stream;
+- BYTE headerBuffer[ LENGTH_SIZE + MIN_PACKET_SIZE + 8 ];
+ const BOOLEAN isHandshake = \
+ ( protocolState == SSH_PROTOSTATE_HANDSHAKE || \
+ protocolState == SSH_PROTOSTATE_AUTH ) ? TRUE : FALSE;
+@@ -460,13 +459,13 @@
+ conditions due to buggy SSH implementations, to handle these we
+ check the return code as well as the returned data to see if we
+ need to process it specially */
+- status = readFixedHeaderAtomic( sessionInfoPtr, headerBuffer,
++ status = readFixedHeaderAtomic( sessionInfoPtr, sshInfo->headerBuffer,
+ headerByteCount );
+ if( status == CRYPT_ERROR_READ || cryptStatusOK( status ) )
+ {
+ const int localStatus = \
+ checkHandshakePacketStatus( sessionInfoPtr, status,
+- headerBuffer, headerByteCount,
++ sshInfo->headerBuffer, headerByteCount,
+ expectedType );
+ if( cryptStatusError( localStatus ) )
+ status = localStatus;
+@@ -474,11 +473,12 @@
+ }
+ else
+ {
+- status = readFixedHeader( sessionInfoPtr, headerBuffer,
+- headerByteCount );
++ status = readFixedHeader( sessionInfoPtr, sshInfo->headerBuffer + sshInfo->headerBufferUsed,
++ headerByteCount - sshInfo->headerBufferUsed );
+ }
+ if( cryptStatusError( status ) )
+ return( status );
++ sshInfo->headerBufferUsed = 0;
+
+ /* If we're in the data-processing stage (i.e. it's a post-handshake
+ data packet read) exception conditions need to be handled specially
+@@ -500,8 +500,8 @@
+ of the message we decrypt */
+ if( isSecureRead )
+ {
+- void *payloadPtr = useETM ? headerBuffer + LENGTH_SIZE : \
+- headerBuffer;
++ void *payloadPtr = useETM ? sshInfo->headerBuffer + LENGTH_SIZE : \
++ sshInfo->headerBuffer;
+
+ /* If we're using EtM then we have to preserve a copy of the
+ ciphertext so that we can MAC it later */
+@@ -541,7 +541,7 @@
+ larger than the (remaining) data that we've already read. For
+ this case we need to check that the data payload is at least as
+ long as the minimum-length packet */
+- sMemConnect( &stream, headerBuffer, headerByteCount );
++ sMemConnect( &stream, sshInfo->headerBuffer, headerByteCount );
+ status = length = readUint32( &stream );
+ static_assert( SSH_HEADER_REMAINDER_SIZE == MIN_PACKET_SIZE - \
+ LENGTH_SIZE, \
+@@ -598,8 +598,8 @@
+ from the stream above but have to manually extract it here */
+ static_assert( LENGTH_SIZE + 1 + ID_SIZE <= MIN_PACKET_SIZE,
+ "Header length calculation" );
+- sshInfo->padLength = headerBuffer[ LENGTH_SIZE ];
+- sshInfo->packetType = headerBuffer[ LENGTH_SIZE + 1 ];
++ sshInfo->padLength = sshInfo->headerBuffer[ LENGTH_SIZE ];
++ sshInfo->packetType = sshInfo->headerBuffer[ LENGTH_SIZE + 1 ];
+ if( sshInfo->padLength < SSH2_MIN_PADLENGTH_SIZE || \
+ sshInfo->padLength > 255 )
+ {
--
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