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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v3 11/22] x86/tpm.c: support extending PCRs of TPM2.0
On 30.05.2025 15:17, Sergii Dmytruk wrote:
> @@ -146,14 +156,15 @@ static inline bool is_tpm12(void)
> (tis_read32(TPM_STS_(0)) & TPM_FAMILY_MASK) == 0);
> }
>
> -/****************************** TPM1.2 specific
> *******************************/
> -#define TPM_ORD_Extend 0x00000014
> -#define TPM_ORD_SHA1Start 0x000000A0
> -#define TPM_ORD_SHA1Update 0x000000A1
> -#define TPM_ORD_SHA1CompleteExtend 0x000000A3
> +/****************************** TPM1.2 & TPM2.0
> *******************************/
>
> -#define TPM_TAG_RQU_COMMAND 0x00C1
> -#define TPM_TAG_RSP_COMMAND 0x00C4
> +/*
> + * TPM1.2 is required to support commands of up to 1101 bytes, vendors rarely
> + * go above that. Limit maximum size of block of data to be hashed to 1024.
> + *
> + * TPM2.0 should support hashing of at least 1024 bytes.
> + */
> +#define MAX_HASH_BLOCK 1024
>
> /* All fields of following structs are big endian. */
> struct tpm_cmd_hdr {
> @@ -168,6 +179,17 @@ struct tpm_rsp_hdr {
> uint32_t returnCode;
> } __packed;
>
> +/****************************** TPM1.2 specific
> *******************************/
> +
> +#define TPM_ORD_Extend 0x00000014
> +#define TPM_ORD_SHA1Start 0x000000A0
> +#define TPM_ORD_SHA1Update 0x000000A1
> +#define TPM_ORD_SHA1CompleteExtend 0x000000A3
> +
> +#define TPM_TAG_RQU_COMMAND 0x00C1
> +#define TPM_TAG_RSP_COMMAND 0x00C4
> +
> +/* All fields of following structs are big endian. */
> struct extend_cmd {
> struct tpm_cmd_hdr h;
> uint32_t pcrNum;
Can the previous patch please put these right in their final resting place?
> @@ -233,11 +255,6 @@ struct txt_ev_log_container_12 {
> };
>
> #ifdef __EARLY_SLAUNCH__
> -/*
> - * TPM1.2 is required to support commands of up to 1101 bytes, vendors rarely
> - * go above that. Limit maximum size of block of data to be hashed to 1024.
> - */
> -#define MAX_HASH_BLOCK 1024
> #define CMD_RSP_BUF_SIZE (sizeof(struct sha1_update_cmd) + MAX_HASH_BLOCK)
>
> union cmd_rsp {
> @@ -393,6 +410,400 @@ static void *create_log_event12(struct
> txt_ev_log_container_12 *evt_log,
>
> /************************** end of TPM1.2 specific
> ****************************/
>
> +/****************************** TPM2.0 specific
> *******************************/
> +
> +/*
> + * These constants are for TPM2.0 but don't have a distinct prefix to match
> + * names in the specification.
> + */
> +
> +#define TPM_HT_PCR 0x00
> +
> +#define TPM_RH_NULL 0x40000007
> +#define TPM_RS_PW 0x40000009
> +
> +#define HR_SHIFT 24
> +#define HR_PCR (TPM_HT_PCR << HR_SHIFT)
> +
> +#define TPM_ST_NO_SESSIONS 0x8001
> +#define TPM_ST_SESSIONS 0x8002
> +
> +#define TPM_ALG_SHA1 0x0004
> +#define TPM_ALG_SHA256 0x000b
> +#define TPM_ALG_NULL 0x0010
> +
> +#define TPM2_PCR_Extend 0x00000182
> +#define TPM2_PCR_HashSequenceStart 0x00000186
> +#define TPM2_PCR_SequenceUpdate 0x0000015C
> +#define TPM2_PCR_EventSequenceComplete 0x00000185
> +
> +#define PUT_BYTES(p, bytes, size) do { \
> + memcpy((p), (bytes), (size)); \
Preferably without the excess parentheses, much like you have it ...
> + (p) += (size); \
> + } while ( 0 )
> +
> +#define PUT_16BIT(p, data) do { \
> + *(uint16_t *)(p) = swap16(data); \
... e.g. in the function call here.
> + (p) += 2; \
> + } while ( 0 )
> +
> +/* All fields of following structs are big endian. */
> +struct tpm2_session_header {
> + uint32_t handle;
> + uint16_t nonceSize;
> + uint8_t nonce[0];
> + uint8_t attrs;
> + uint16_t hmacSize;
> + uint8_t hmac[0];
> +} __packed;
> +
> +struct tpm2_extend_cmd {
> + struct tpm_cmd_hdr h;
> + uint32_t pcrHandle;
> + uint32_t sessionHdrSize;
> + struct tpm2_session_header pcrSession;
> + uint32_t hashCount;
> + uint8_t hashes[0];
> +} __packed;
> +
> +struct tpm2_extend_rsp {
> + struct tpm_rsp_hdr h;
> +} __packed;
> +
> +struct tpm2_sequence_start_cmd {
> + struct tpm_cmd_hdr h;
> + uint16_t hmacSize;
> + uint8_t hmac[0];
> + uint16_t hashAlg;
> +} __packed;
> +
> +struct tpm2_sequence_start_rsp {
> + struct tpm_rsp_hdr h;
> + uint32_t sequenceHandle;
> +} __packed;
> +
> +struct tpm2_sequence_update_cmd {
> + struct tpm_cmd_hdr h;
> + uint32_t sequenceHandle;
> + uint32_t sessionHdrSize;
> + struct tpm2_session_header session;
> + uint16_t dataSize;
> + uint8_t data[0];
> +} __packed;
> +
> +struct tpm2_sequence_update_rsp {
> + struct tpm_rsp_hdr h;
> +} __packed;
> +
> +struct tpm2_sequence_complete_cmd {
> + struct tpm_cmd_hdr h;
> + uint32_t pcrHandle;
> + uint32_t sequenceHandle;
> + uint32_t sessionHdrSize;
> + struct tpm2_session_header pcrSession;
> + struct tpm2_session_header sequenceSession;
> + uint16_t dataSize;
> + uint8_t data[0];
> +} __packed;
> +
> +struct tpm2_sequence_complete_rsp {
> + struct tpm_rsp_hdr h;
> + uint32_t paramSize;
> + uint32_t hashCount;
> + uint8_t hashes[0];
> + /*
> + * Each hash is represented as:
> + * struct {
> + * uint16_t hashAlg;
> + * uint8_t hash[size of hashAlg];
> + * };
> + */
> +} __packed;
> +
> +/*
> + * These two structure are for convenience, they don't correspond to
> anything in
> + * any spec.
> + */
> +struct tpm2_log_hash {
> + uint16_t alg; /* TPM_ALG_* */
> + uint16_t size;
> + uint8_t *data; /* Non-owning reference to a buffer inside log entry. */
> +};
> +/* Should be more than enough for now and awhile in the future. */
> +#define MAX_HASH_COUNT 8
> +struct tpm2_log_hashes {
> + uint32_t count;
> + struct tpm2_log_hash hashes[MAX_HASH_COUNT];
> +};
> +
> +#ifdef __EARLY_SLAUNCH__
> +
> +union tpm2_cmd_rsp {
> + uint8_t b[sizeof(struct tpm2_sequence_update_cmd) + MAX_HASH_BLOCK];
> + struct tpm_cmd_hdr c;
> + struct tpm_rsp_hdr r;
> + struct tpm2_sequence_start_cmd start_c;
> + struct tpm2_sequence_start_rsp start_r;
> + struct tpm2_sequence_update_cmd update_c;
> + struct tpm2_sequence_update_rsp update_r;
> + struct tpm2_sequence_complete_cmd finish_c;
> + struct tpm2_sequence_complete_rsp finish_r;
> +};
> +
> +static uint32_t tpm2_hash_extend(unsigned loc, const uint8_t *buf,
> + unsigned size, unsigned pcr,
> + struct tpm2_log_hashes *log_hashes)
> +{
> + uint32_t seq_handle;
> + unsigned max_bytes = MAX_HASH_BLOCK;
> +
> + union tpm2_cmd_rsp cmd_rsp;
> + unsigned o_size;
> + unsigned i;
> + uint8_t *p;
> + uint32_t rc;
> +
> + cmd_rsp.start_c = (struct tpm2_sequence_start_cmd) {
> + .h.tag = swap16(TPM_ST_NO_SESSIONS),
> + .h.paramSize = swap32(sizeof(cmd_rsp.start_c)),
> + .h.ordinal = swap32(TPM2_PCR_HashSequenceStart),
> + .hashAlg = swap16(TPM_ALG_NULL), /* Compute all supported hashes. */
> + };
> +
> + request_locality(loc);
> +
> + o_size = sizeof(cmd_rsp);
> + send_cmd(loc, cmd_rsp.b, swap32(cmd_rsp.c.paramSize), &o_size);
> +
> + if ( cmd_rsp.r.tag == swap16(TPM_ST_NO_SESSIONS) &&
> + cmd_rsp.r.paramSize == swap32(10) )
> + {
> + rc = swap32(cmd_rsp.r.returnCode);
> + if ( rc != 0 )
> + goto error;
> + }
> +
> + seq_handle = swap32(cmd_rsp.start_r.sequenceHandle);
> +
> + while ( size > 64 )
> + {
> + if ( size < max_bytes )
> + max_bytes = size & ~(64 - 1);
> +
> + cmd_rsp.update_c = (struct tpm2_sequence_update_cmd) {
> + .h.tag = swap16(TPM_ST_SESSIONS),
> + .h.paramSize = swap32(sizeof(cmd_rsp.update_c) + max_bytes),
> + .h.ordinal = swap32(TPM2_PCR_SequenceUpdate),
> + .sequenceHandle = swap32(seq_handle),
> + .sessionHdrSize = swap32(sizeof(struct tpm2_session_header)),
> + .session.handle = swap32(TPM_RS_PW),
> + .dataSize = swap16(max_bytes),
> + };
> +
> + memcpy(cmd_rsp.update_c.data, buf, max_bytes);
> +
> + o_size = sizeof(cmd_rsp);
> + send_cmd(loc, cmd_rsp.b, swap32(cmd_rsp.c.paramSize), &o_size);
> +
> + if ( cmd_rsp.r.tag == swap16(TPM_ST_NO_SESSIONS) &&
> + cmd_rsp.r.paramSize == swap32(10) )
> + {
> + rc = swap32(cmd_rsp.r.returnCode);
> + if ( rc != 0 )
> + goto error;
> + }
> +
> + size -= max_bytes;
> + buf += max_bytes;
> + }
> +
> + cmd_rsp.finish_c = (struct tpm2_sequence_complete_cmd) {
> + .h.tag = swap16(TPM_ST_SESSIONS),
> + .h.paramSize = swap32(sizeof(cmd_rsp.finish_c) + size),
> + .h.ordinal = swap32(TPM2_PCR_EventSequenceComplete),
> + .pcrHandle = swap32(HR_PCR + pcr),
> + .sequenceHandle = swap32(seq_handle),
> + .sessionHdrSize = swap32(sizeof(struct tpm2_session_header)*2),
Why *2? Where to the two session headers go? (Also nit: blanks missing around
*.)
> + .pcrSession.handle = swap32(TPM_RS_PW),
> + .sequenceSession.handle = swap32(TPM_RS_PW),
> + .dataSize = swap16(size),
> + };
> +
> + memcpy(cmd_rsp.finish_c.data, buf, size);
> +
> + o_size = sizeof(cmd_rsp);
> + send_cmd(loc, cmd_rsp.b, swap32(cmd_rsp.c.paramSize), &o_size);
> +
> + if ( cmd_rsp.r.tag == swap16(TPM_ST_NO_SESSIONS) &&
> + cmd_rsp.r.paramSize == swap32(10) )
> + {
> + rc = swap32(cmd_rsp.r.returnCode);
> + if ( rc != 0 )
> + goto error;
> + }
> +
> + p = cmd_rsp.finish_r.hashes;
> + for ( i = 0; i < swap32(cmd_rsp.finish_r.hashCount); ++i )
> + {
> + unsigned j;
> + uint16_t hash_type;
> +
> + hash_type = swap16(*(uint16_t *)p);
> + p += sizeof(uint16_t);
> +
> + for ( j = 0; j < log_hashes->count; ++j )
> + {
> + struct tpm2_log_hash *hash = &log_hashes->hashes[j];
> + if ( hash->alg == hash_type )
> + {
> + memcpy(hash->data, p, hash->size);
> + p += hash->size;
> + break;
> + }
> + }
> +
> + if ( j == log_hashes->count )
> + /* Can't continue parsing without knowing hash size. */
> + break;
> + }
> +
> + rc = 0;
> +
> +error:
> + relinquish_locality(loc);
> + return rc;
> +}
> +
> +#else
> +
> +union tpm2_cmd_rsp {
> + /* Enough space for multiple hashes. */
> + uint8_t b[sizeof(struct tpm2_extend_cmd) + 1024];
> + struct tpm_cmd_hdr c;
> + struct tpm_rsp_hdr r;
> + struct tpm2_extend_cmd extend_c;
> + struct tpm2_extend_rsp extend_r;
> +};
> +
> +static uint32_t tpm20_pcr_extend(unsigned loc, uint32_t pcr_handle,
> + const struct tpm2_log_hashes *log_hashes)
> +{
> + union tpm2_cmd_rsp cmd_rsp;
> + unsigned o_size;
> + unsigned i;
> + uint8_t *p;
> +
> + cmd_rsp.extend_c = (struct tpm2_extend_cmd) {
> + .h.tag = swap16(TPM_ST_SESSIONS),
> + .h.ordinal = swap32(TPM2_PCR_Extend),
> + .pcrHandle = swap32(pcr_handle),
> + .sessionHdrSize = swap32(sizeof(struct tpm2_session_header)),
> + .pcrSession.handle = swap32(TPM_RS_PW),
> + .hashCount = swap32(log_hashes->count),
> + };
> +
> + p = cmd_rsp.extend_c.hashes;
> + for ( i = 0; i < log_hashes->count; ++i )
> + {
> + const struct tpm2_log_hash *hash = &log_hashes->hashes[i];
> +
> + if ( p + sizeof(uint16_t) + hash->size > &cmd_rsp.b[sizeof(cmd_rsp)]
> )
> + {
> + printk(XENLOG_ERR "Hit TPM message size implementation limit:
> %ld\n",
> + sizeof(cmd_rsp));
> + return -1;
> + }
> +
> + *(uint16_t *)p = swap16(hash->alg);
> + p += sizeof(uint16_t);
> +
> + memcpy(p, hash->data, hash->size);
> + p += hash->size;
> + }
> +
> + /* Fill in command size (size of the whole buffer). */
> + cmd_rsp.extend_c.h.paramSize = swap32(sizeof(cmd_rsp.extend_c) +
> + (p - cmd_rsp.extend_c.hashes)),
> +
> + o_size = sizeof(cmd_rsp);
> + send_cmd(loc, cmd_rsp.b, swap32(cmd_rsp.c.paramSize), &o_size);
> +
> + return swap32(cmd_rsp.r.returnCode);
> +}
> +
> +static bool tpm_supports_hash(unsigned loc, const struct tpm2_log_hash *hash)
> +{
> + uint32_t rc;
> + struct tpm2_log_hashes hashes = {
> + .count = 1,
> + .hashes[0] = *hash,
> + };
> +
> + /*
> + * This is a valid way of checking hash support, using it to not
> implement
> + * TPM2_GetCapability().
> + */
> + rc = tpm20_pcr_extend(loc, /*pcr_handle=*/TPM_RH_NULL, &hashes);
> +
> + return rc == 0;
> +}
> +
> +static uint32_t tpm2_hash_extend(unsigned loc, const uint8_t *buf,
> + unsigned size, unsigned pcr,
> + const struct tpm2_log_hashes *log_hashes)
> +{
> + uint32_t rc;
> + unsigned i;
> + struct tpm2_log_hashes supported_hashes = {0};
> +
> + request_locality(loc);
> +
> + for ( i = 0; i < log_hashes->count; ++i )
> + {
> + const struct tpm2_log_hash *hash = &log_hashes->hashes[i];
> + if ( !tpm_supports_hash(loc, hash) )
> + {
> + printk(XENLOG_WARNING "Skipped hash unsupported by TPM: %d\n",
> + hash->alg);
> + continue;
> + }
> +
> + if ( hash->alg == TPM_ALG_SHA1 )
> + {
> + sha1_hash(hash->data, buf, size);
> + }
> + else if ( hash->alg == TPM_ALG_SHA256 )
> + {
> + sha2_256_digest(hash->data, buf, size);
> + }
> + else
Is this really just "else", not "else if ( ... )"?
> + {
> + /* This is called "OneDigest" in TXT Software Development Guide.
> */
> + memset(hash->data, 0, size);
> + hash->data[0] = 1;
> + }
> +
> + if ( supported_hashes.count == MAX_HASH_COUNT )
> + {
> + printk(XENLOG_ERR "Hit hash count implementation limit: %d\n",
> + MAX_HASH_COUNT);
> + return -1;
This is an odd return value for a function returning uint32_t. And it's also ...
> @@ -419,6 +830,35 @@ void tpm_hash_extend(unsigned loc, unsigned pcr, const
> uint8_t *buf,
> {
> #ifndef __EARLY_SLAUNCH__
> printk(XENLOG_ERR "Extending PCR%u failed\n", pcr);
> +#endif
> + }
> + } else {
> + uint8_t sha1_digest[SHA1_DIGEST_SIZE];
> + uint8_t sha256_digest[SHA2_256_DIGEST_SIZE];
> + uint32_t rc;
> +
> + struct tpm2_log_hashes log_hashes = {
> + .count = 2,
> + .hashes = {
> + {
> + .alg = TPM_ALG_SHA1,
> + .size = SHA1_DIGEST_SIZE,
> + .data = sha1_digest,
> + },
> + {
> + .alg = TPM_ALG_SHA256,
> + .size = SHA2_256_DIGEST_SIZE,
> + .data = sha256_digest,
> + },
> + },
> + };
> +
> + rc = tpm2_hash_extend(loc, buf, size, pcr, &log_hashes);
> + if ( rc != 0 )
> + {
> +#ifndef __EARLY_SLAUNCH__
> + printk(XENLOG_ERR "Extending PCR%u failed with TPM error:
> 0x%08x\n",
> + pcr, rc);
... not exactly a TPM error.
Of course other comments given on the previous patch logically apply here (and
elsewhere) as well.
Jan
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