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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v3 11/22] x86/tpm.c: support extending PCRs of TPM2.0
SHA1 and SHA256 are hard-coded here, but their support by the TPM is
checked. Addition of event log for TPM2.0 will generalize the code
further.
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@xxxxxxxxx>
---
xen/arch/x86/tpm.c | 464 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 452 insertions(+), 12 deletions(-)
diff --git a/xen/arch/x86/tpm.c b/xen/arch/x86/tpm.c
index 7fb19ce4fa..ed49fe3ccf 100644
--- a/xen/arch/x86/tpm.c
+++ b/xen/arch/x86/tpm.c
@@ -5,6 +5,7 @@
*/
#include <xen/sha1.h>
+#include <xen/sha2.h>
#include <xen/string.h>
#include <xen/types.h>
#include <asm/intel-txt.h>
@@ -31,6 +32,15 @@ struct slr_table *slaunch_get_slrt(void)
* other part of Xen. Providing implementation of builtin functions in this
* case is necessary if compiler chooses to not use an inline builtin.
*/
+void *(memset)(void *s, int c, size_t n)
+{
+ uint8_t *d = s;
+
+ while ( n-- )
+ *d++ = c;
+
+ return s;
+}
void *(memcpy)(void *dest, const void *src, size_t n)
{
const uint8_t *s = src;
@@ -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;
@@ -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)); \
+ (p) += (size); \
+ } while ( 0 )
+
+#define PUT_16BIT(p, data) do { \
+ *(uint16_t *)(p) = swap16(data); \
+ (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),
+ .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
+ {
+ /* 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;
+ }
+
+ supported_hashes.hashes[supported_hashes.count] = *hash;
+ ++supported_hashes.count;
+ }
+
+ rc = tpm20_pcr_extend(loc, HR_PCR + pcr, &supported_hashes);
+ relinquish_locality(loc);
+
+ return rc;
+}
+
+#endif /* __EARLY_SLAUNCH__ */
+
+/************************** end of TPM2.0 specific
****************************/
+
void tpm_hash_extend(unsigned loc, unsigned pcr, const uint8_t *buf,
unsigned size, uint32_t type, const uint8_t *log_data,
unsigned log_data_size)
@@ -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);
#endif
}
}
--
2.49.0
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