From: Samuel Thibault <samuel.thibault@ens-lyon.org>
To: Jason Andryuk <jandryuk@gmail.com>
Cc: xen-devel@lists.xenproject.org,
Daniel De Graaf <dgdegra@tycho.nsa.gov>,
Quan Xu <quan.xu0@gmail.com>
Subject: Re: [PATCH v2 09/13] vtpmmgr: Support GetRandom passthrough on TPM 2.0
Date: Thu, 6 May 2021 23:40:16 +0200 [thread overview]
Message-ID: <20210506214016.yt2df7y6xf5cbdzm@begin> (raw)
In-Reply-To: <20210506135923.161427-10-jandryuk@gmail.com>
Jason Andryuk, le jeu. 06 mai 2021 09:59:19 -0400, a ecrit:
> GetRandom passthrough currently fails when using vtpmmgr with a hardware
> TPM 2.0.
> vtpmmgr (8): INFO[VTPM]: Passthrough: TPM_GetRandom
> vtpm (12): vtpm_cmd.c:120: Error: TPM_GetRandom() failed with error code (30)
>
> When running on TPM 2.0 hardware, vtpmmgr needs to convert the TPM 1.2
> TPM_ORD_GetRandom into a TPM2 TPM_CC_GetRandom command. Besides the
> differing ordinal, the TPM 1.2 uses 32bit sizes for the request and
> response (vs. 16bit for TPM2).
>
> Place the random output directly into the tpmcmd->resp and build the
> packet around it. This avoids bouncing through an extra buffer, but the
> header has to be written after grabbing the random bytes so we have the
> number of bytes to include in the size.
>
> Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
> ---
> v2:
> Add bounds and size checks
> Whitespace fixup
> ---
> stubdom/vtpmmgr/marshal.h | 15 ++++++++
> stubdom/vtpmmgr/vtpm_cmd_handler.c | 61 +++++++++++++++++++++++++++++-
> 2 files changed, 75 insertions(+), 1 deletion(-)
>
> diff --git a/stubdom/vtpmmgr/marshal.h b/stubdom/vtpmmgr/marshal.h
> index dce19c6439..f1037a7976 100644
> --- a/stubdom/vtpmmgr/marshal.h
> +++ b/stubdom/vtpmmgr/marshal.h
> @@ -890,6 +890,15 @@ inline int sizeof_TPM_AUTH_SESSION(const TPM_AUTH_SESSION* auth) {
> return rv;
> }
>
> +static
> +inline int sizeof_TPM_RQU_HEADER(BYTE* ptr) {
> + int rv = 0;
> + rv += sizeof_UINT16(ptr);
> + rv += sizeof_UINT32(ptr);
> + rv += sizeof_UINT32(ptr);
> + return rv;
> +}
> +
> static
> inline BYTE* pack_TPM_RQU_HEADER(BYTE* ptr,
> TPM_TAG tag,
> @@ -920,8 +929,14 @@ inline int unpack3_TPM_RQU_HEADER(BYTE* ptr, UINT32* pos, UINT32 max,
> unpack3_UINT32(ptr, pos, max, ord);
> }
>
> +static
> +inline int sizeof_TPM_RQU_GetRandom(BYTE* ptr) {
> + return sizeof_TPM_RQU_HEADER(ptr) + sizeof_UINT32(ptr);
> +}
> +
> #define pack_TPM_RSP_HEADER(p, t, s, r) pack_TPM_RQU_HEADER(p, t, s, r)
> #define unpack_TPM_RSP_HEADER(p, t, s, r) unpack_TPM_RQU_HEADER(p, t, s, r)
> #define unpack3_TPM_RSP_HEADER(p, l, m, t, s, r) unpack3_TPM_RQU_HEADER(p, l, m, t, s, r)
> +#define sizeof_TPM_RSP_HEADER(p) sizeof_TPM_RQU_HEADER(p)
>
> #endif
> diff --git a/stubdom/vtpmmgr/vtpm_cmd_handler.c b/stubdom/vtpmmgr/vtpm_cmd_handler.c
> index 2ac14fae77..c879b24c13 100644
> --- a/stubdom/vtpmmgr/vtpm_cmd_handler.c
> +++ b/stubdom/vtpmmgr/vtpm_cmd_handler.c
> @@ -47,6 +47,7 @@
> #include "vtpm_disk.h"
> #include "vtpmmgr.h"
> #include "tpm.h"
> +#include "tpm2.h"
> #include "tpmrsa.h"
> #include "tcg.h"
> #include "mgmt_authority.h"
> @@ -772,6 +773,64 @@ static int vtpmmgr_permcheck(struct tpm_opaque *opq)
> return 1;
> }
>
> +TPM_RESULT vtpmmgr_handle_getrandom(struct tpm_opaque *opaque,
> + tpmcmd_t* tpmcmd)
> +{
> + TPM_RESULT status = TPM_SUCCESS;
> + TPM_TAG tag;
> + UINT32 size;
> + const int max_rand_size = TCPA_MAX_BUFFER_LENGTH -
> + sizeof_TPM_RQU_GetRandom(tpmcmd->req);
> + UINT32 rand_offset;
> + UINT32 rand_size;
> + TPM_COMMAND_CODE ord;
> + BYTE *p;
> +
> + if (tpmcmd->req_len != sizeof_TPM_RQU_GetRandom(tpmcmd->req)) {
> + status = TPM_BAD_PARAMETER;
> + tag = TPM_TAG_RQU_COMMAND;
> + goto abort_egress;
> + }
> +
> + p = unpack_TPM_RQU_HEADER(tpmcmd->req, &tag, &size, &ord);
> +
> + if (!hw_is_tpm2()) {
> + size = TCPA_MAX_BUFFER_LENGTH;
> + TPMTRYRETURN(TPM_TransmitData(tpmcmd->req, tpmcmd->req_len,
> + tpmcmd->resp, &size));
> + tpmcmd->resp_len = size;
> +
> + return TPM_SUCCESS;
> + }
> +
> + /* TPM_GetRandom req: <header><uint32 num bytes> */
> + unpack_UINT32(p, &rand_size);
> +
> + /* Returning fewer bytes is acceptable per the spec. */
> + if (rand_size > max_rand_size)
> + rand_size = max_rand_size;
> +
> + /* Call TPM2_GetRandom but return a TPM_GetRandom response. */
> + /* TPM_GetRandom resp: <header><uint32 num bytes><num random bytes> */
> + rand_offset = sizeof_TPM_RSP_HEADER(tpmcmd->resp) +
> + sizeof_UINT32(tpmcmd->resp);
> +
> + TPMTRYRETURN(TPM2_GetRandom(&rand_size, tpmcmd->resp + rand_offset));
> +
> + p = pack_TPM_RSP_HEADER(tpmcmd->resp, TPM_TAG_RSP_COMMAND,
> + rand_offset + rand_size, status);
> + p = pack_UINT32(p, rand_size);
> + tpmcmd->resp_len = rand_offset + rand_size;
> +
> + return status;
> +
> +abort_egress:
> + tpmcmd->resp_len = VTPM_COMMAND_HEADER_SIZE;
> + pack_TPM_RSP_HEADER(tpmcmd->resp, tag + 3, tpmcmd->resp_len, status);
> +
> + return status;
> +}
> +
> TPM_RESULT vtpmmgr_handle_cmd(
> struct tpm_opaque *opaque,
> tpmcmd_t* tpmcmd)
> @@ -842,7 +901,7 @@ TPM_RESULT vtpmmgr_handle_cmd(
> switch(ord) {
> case TPM_ORD_GetRandom:
> vtpmloginfo(VTPM_LOG_VTPM, "Passthrough: TPM_GetRandom\n");
> - break;
> + return vtpmmgr_handle_getrandom(opaque, tpmcmd);
> case TPM_ORD_PcrRead:
> vtpmloginfo(VTPM_LOG_VTPM, "Passthrough: TPM_PcrRead\n");
> // Quotes also need to be restricted to hide PCR values
> --
> 2.30.2
>
--
Samuel
<i8b4uUnderground> d-_-b
<BonyNoMore> how u make that inverted b?
<BonyNoMore> wait
<BonyNoMore> never mind
next prev parent reply other threads:[~2021-05-08 11:54 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-06 13:59 [PATCH v2 00/13] vtpmmgr: Some fixes - still incomplete Jason Andryuk
2021-05-06 13:59 ` [PATCH v2 01/13] docs: Warn about incomplete vtpmmgr TPM 2.0 support Jason Andryuk
2021-05-06 13:59 ` [PATCH v2 02/13] vtpmmgr: Print error code to aid debugging Jason Andryuk
2021-05-06 13:59 ` [PATCH v2 03/13] stubom: newlib: Enable C99 formats for %z Jason Andryuk
2021-05-06 13:59 ` [PATCH v2 04/13] vtpmmgr: Allow specifying srk_handle for TPM2 Jason Andryuk
2021-05-06 21:35 ` Samuel Thibault
2021-05-10 11:56 ` Daniel P. Smith
2021-05-06 13:59 ` [PATCH v2 05/13] vtpmmgr: Move vtpmmgr_shutdown Jason Andryuk
2021-05-07 15:48 ` Daniel P. Smith
2021-05-06 13:59 ` [PATCH v2 06/13] vtpmmgr: Flush transient keys on shutdown Jason Andryuk
2021-05-10 12:12 ` Daniel P. Smith
2021-05-06 13:59 ` [PATCH v2 07/13] vtpmmgr: Flush all transient keys Jason Andryuk
2021-05-10 12:19 ` Daniel P. Smith
2021-05-06 13:59 ` [PATCH v2 08/13] vtpmmgr: Shutdown more gracefully Jason Andryuk
2021-05-06 14:04 ` Jason Andryuk
2021-05-10 12:42 ` Daniel P. Smith
2021-05-06 13:59 ` [PATCH v2 09/13] vtpmmgr: Support GetRandom passthrough on TPM 2.0 Jason Andryuk
2021-05-06 21:40 ` Samuel Thibault [this message]
2021-05-10 12:51 ` Daniel P. Smith
2021-05-06 13:59 ` [PATCH v2 10/13] vtpmmgr: Remove bogus cast from TPM2_GetRandom Jason Andryuk
2021-05-06 21:41 ` Samuel Thibault
2021-05-10 13:03 ` Daniel P. Smith
2021-05-06 13:59 ` [PATCH v2 11/13] vtpmmgr: Fix owner_auth & srk_auth parsing Jason Andryuk
2021-05-06 21:41 ` Samuel Thibault
2021-05-10 13:18 ` Daniel P. Smith
2021-05-06 13:59 ` [PATCH v2 12/13] vtpmmgr: Check req_len before unpacking command Jason Andryuk
2021-05-06 21:42 ` Samuel Thibault
2021-05-10 13:32 ` Daniel P. Smith
2021-05-06 13:59 ` [PATCH v2 13/13] vtpm: Correct timeout units and command duration Jason Andryuk
2021-05-06 21:52 ` Samuel Thibault
2021-05-10 13:40 ` Daniel P. Smith
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