From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=66.187.233.73; helo=mx1.redhat.com; envelope-from=lersek@redhat.com; receiver=edk2-devel@lists.01.org Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id ADAE72264A1E9 for ; Wed, 4 Apr 2018 03:32:38 -0700 (PDT) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 43D818182D06; Wed, 4 Apr 2018 10:32:37 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-120-114.rdu2.redhat.com [10.10.120.114]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1FA0210B2B39; Wed, 4 Apr 2018 10:32:35 +0000 (UTC) To: "Gao, Liming" , edk2-devel-01 Cc: "Wu, Jiaxin" , "Kinney, Michael D" , "Fu, Siyuan" References: <20180403145149.8925-1-lersek@redhat.com> <20180403145149.8925-3-lersek@redhat.com> <4A89E2EF3DFEDB4C8BFDE51014F606A14E1F1B10@SHSMSX104.ccr.corp.intel.com> From: Laszlo Ersek Message-ID: Date: Wed, 4 Apr 2018 12:32:35 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <4A89E2EF3DFEDB4C8BFDE51014F606A14E1F1B10@SHSMSX104.ccr.corp.intel.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 04 Apr 2018 10:32:37 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 04 Apr 2018 10:32:37 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'lersek@redhat.com' RCPT:'' Subject: Re: [PATCH 02/13] MdePkg/Include/Protocol/Tls.h: pack structures from the TLS RFC X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Apr 2018 10:32:39 -0000 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 04/03/18 17:08, Gao, Liming wrote: > Laszlo: > Could you use one pack to scope all structure definitions? I didn't do that originally because the affected structure definitions are spread out over a larger part of the code, intermixed with enums, #defines, and other structures, *and* it is not clear from the source code comments whether *all* of the structure definitions come from RFC 5246. Wherever the code comments did *not* indicate that a given structure came from the RFC, I didn't add packing either. Example structures for this: - EFI_TLS_VERSION - EFI_TLS_FRAGMENT_DATA Looking at these in more detail, I don't think either of them should be packed: - EfiTlsVersion / EFI_TLS_VERSION are used in TlsSetSessionData() [NetworkPkg/TlsDxe/TlsProtocol.c], and the constituent fields Major and Minor are passed individually to TlsSetVersion() [CryptoPkg/Library/TlsLib/TlsConfig.c]. So packing the structure is not necessary. - EFI_TLS_FRAGMENT_DATA contains a (VOID*) pointer, so it cannot be serialized to the wire by definition. And, it is used in TlsProcessPacket() [NetworkPkg/TlsDxe/TlsProtocol.c], and TlsEncryptPacket() / TlsDecryptPacket() [NetworkPkg/TlsDxe/TlsImpl.c], without any need for packing. Given that this protocol header file defines both packed and non-packed structures, without a very clear separation between them, I feel it is cleaner to use the pack #pragma for individual structures. If you disagree, then I think we should implement that "clear separation" in the header file first. Namely, move all the packed structures either after or before all the non-packed structures, and add a very visible comment that "all of the following structures come from RFC 5246 and need packing". Then we can use a single pack #pragma to cover them all. Thanks, Laszlo >> -----Original Message----- >> From: Laszlo Ersek [mailto:lersek@redhat.com] >> Sent: Tuesday, April 3, 2018 10:52 PM >> To: edk2-devel-01 >> Cc: Wu, Jiaxin ; Gao, Liming ; Kinney, Michael D ; Fu, >> Siyuan >> Subject: [PATCH 02/13] MdePkg/Include/Protocol/Tls.h: pack structures from the TLS RFC >> >> The structures defined in RFC 5246 are not to have any padding between >> fields or at the end; use the "pack" pragma as necessary. >> >> Cc: Jiaxin Wu >> Cc: Liming Gao >> Cc: Michael D Kinney >> Cc: Siyuan Fu >> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=915 >> Contributed-under: TianoCore Contribution Agreement 1.1 >> Signed-off-by: Laszlo Ersek >> --- >> MdePkg/Include/Protocol/Tls.h | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/MdePkg/Include/Protocol/Tls.h b/MdePkg/Include/Protocol/Tls.h >> index 2119f33c0f5b..dafaabcd2a8b 100644 >> --- a/MdePkg/Include/Protocol/Tls.h >> +++ b/MdePkg/Include/Protocol/Tls.h >> @@ -138,33 +138,37 @@ typedef enum { >> /// >> /// EFI_TLS_CIPHER >> /// Note: The definition of EFI_TLS_CIPHER definition is from "RFC 5246, A.4.1. >> /// Hello Messages". The value of EFI_TLS_CIPHER is from TLS Cipher >> /// Suite Registry of IANA. >> /// >> +#pragma pack (1) >> typedef struct { >> UINT8 Data1; >> UINT8 Data2; >> } EFI_TLS_CIPHER; >> +#pragma pack () >> >> /// >> /// EFI_TLS_COMPRESSION >> /// Note: The value of EFI_TLS_COMPRESSION definition is from "RFC 3749". >> /// >> typedef UINT8 EFI_TLS_COMPRESSION; >> >> /// >> /// EFI_TLS_EXTENSION >> /// Note: The definition of EFI_TLS_EXTENSION if from "RFC 5246 A.4.1. >> /// Hello Messages". >> /// >> +#pragma pack (1) >> typedef struct { >> UINT16 ExtensionType; >> UINT16 Length; >> UINT8 Data[1]; >> } EFI_TLS_EXTENSION; >> +#pragma pack () >> >> /// >> /// EFI_TLS_VERIFY >> /// Use either EFI_TLS_VERIFY_NONE or EFI_TLS_VERIFY_PEER, the last two options >> /// are 'ORed' with EFI_TLS_VERIFY_PEER if they are desired. >> /// >> @@ -191,35 +195,41 @@ typedef UINT32 EFI_TLS_VERIFY; >> >> /// >> /// EFI_TLS_RANDOM >> /// Note: The definition of EFI_TLS_RANDOM is from "RFC 5246 A.4.1. >> /// Hello Messages". >> /// >> +#pragma pack (1) >> typedef struct { >> UINT32 GmtUnixTime; >> UINT8 RandomBytes[28]; >> } EFI_TLS_RANDOM; >> +#pragma pack () >> >> /// >> /// EFI_TLS_MASTER_SECRET >> /// Note: The definition of EFI_TLS_MASTER_SECRET is from "RFC 5246 8.1. >> /// Computing the Master Secret". >> /// >> +#pragma pack (1) >> typedef struct { >> UINT8 Data[48]; >> } EFI_TLS_MASTER_SECRET; >> +#pragma pack () >> >> /// >> /// EFI_TLS_SESSION_ID >> /// Note: The definition of EFI_TLS_SESSION_ID is from "RFC 5246 A.4.1. Hello Messages". >> /// >> #define MAX_TLS_SESSION_ID_LENGTH 32 >> +#pragma pack (1) >> typedef struct { >> UINT16 Length; >> UINT8 Data[MAX_TLS_SESSION_ID_LENGTH]; >> } EFI_TLS_SESSION_ID; >> +#pragma pack () >> >> /// >> /// EFI_TLS_SESSION_STATE >> /// >> typedef enum { >> /// >> -- >> 2.14.1.3.gb7cf6e02401b >> >