/* * Copyright 2016 The Chromium OS Authors. All rights reserved. * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include <arch/early_variables.h> #include <commonlib/endian.h> #include <console/console.h> #include <stdlib.h> #include <string.h> #include "tpm2_marshaling.h" static uint16_t tpm_tag CAR_GLOBAL; /* Depends on the command type. */ /* * Each unmarshaling function receives a pointer to the buffer pointer and a * pointer to the size of data still in the buffer. The function extracts data * from the buffer and adjusts both buffer pointer and remaining data size. * * Should there be not enough data in the buffer to unmarshal the required * object, the remaining data size is set to -1 to indicate the error. The * remaining data size is expected to be set to zero once the last data item * has been extracted from the receive buffer. */ static uint16_t unmarshal_u16(void **buffer, int *buffer_space) { uint16_t value; if (*buffer_space < 0) return 0; if (*buffer_space < sizeof(value)) { *buffer_space = -1; /* Indicate a failure. */ return 0; } value = read_be16(*buffer); *buffer = (void *) ((uintptr_t) (*buffer) + sizeof(value)); *buffer_space -= sizeof(value); return value; } static uint16_t unmarshal_u32(void **buffer, int *buffer_space) { uint32_t value; if (*buffer_space < 0) return 0; if (*buffer_space < sizeof(value)) { *buffer_space = -1; /* Indicate a failure. */ return 0; } value = read_be32(*buffer); *buffer = (void *) ((uintptr_t) (*buffer) + sizeof(value)); *buffer_space -= sizeof(value); return value; } static uint8_t unmarshal_u8(void **buffer, int *buffer_space) { uint8_t value; if (*buffer_space < 0) return 0; if (*buffer_space < sizeof(value)) { *buffer_space = -1; /* Indicate a failure. */ return 0; } value = ((uint8_t *)(*buffer))[0]; *buffer = (void *) ((uintptr_t) (*buffer) + sizeof(value)); *buffer_space -= sizeof(value); return value; } #define unmarshal_TPM_CAP(a, b) unmarshal_u32(a, b) #define unmarshal_TPM_CC(a, b) unmarshal_u32(a, b) #define unmarshal_TPM_PT(a, b) unmarshal_u32(a, b) #define unmarshal_TPM_HANDLE(a, b) unmarshal_u32(a, b) /* * Each marshaling function receives a pointer to the buffer to marshal into, * a pointer to the data item to be marshaled, and a pointer to the remaining * room in the buffer. */ /* * Marshaling an arbitrary blob requires its size in addition to common * parameter set. */ static void marshal_blob(void **buffer, void *blob, size_t blob_size, size_t *buffer_space) { if (*buffer_space < blob_size) { *buffer_space = -1; return; } memcpy(*buffer, blob, blob_size); *buffer_space -= blob_size; *buffer = (void *)((uintptr_t)(*buffer) + blob_size); } static void marshal_u8(void **buffer, uint8_t value, size_t *buffer_space) { uint8_t *bp = *buffer; if (*buffer_space < sizeof(value)) { *buffer_space = 0; return; } *bp++ = value; *buffer = bp; *buffer_space -= sizeof(value); } static void marshal_u16(void **buffer, uint16_t value, size_t *buffer_space) { if (*buffer_space < sizeof(value)) { *buffer_space = 0; return; } write_be16(*buffer, value); *buffer = (void *)((uintptr_t)(*buffer) + sizeof(value)); *buffer_space -= sizeof(value); } static void marshal_u32(void **buffer, uint32_t value, size_t *buffer_space) { if (*buffer_space < sizeof(value)) { *buffer_space = 0; return; } write_be32(*buffer, value); *buffer = (void *)((uintptr_t)(*buffer) + sizeof(value)); *buffer_space -= sizeof(value); } #define marshal_TPM_HANDLE(a, b, c) marshal_u32(a, b, c) #define marshal_TPMI_RH_NV_AUTH(a, b, c) marshal_TPM_HANDLE(a, b, c) #define marshal_TPMI_RH_NV_INDEX(a, b, c) marshal_TPM_HANDLE(a, b, c) #define marshal_TPMI_SH_AUTH_SESSION(a, b, c) marshal_TPM_HANDLE(a, b, c) #define marshal_TPMI_ALG_HASH(a, b, c) marshal_u16(a, b, c) static void marshal_startup(void **buffer, struct tpm2_startup *cmd_body, size_t *buffer_space) { marshal_u16(buffer, cmd_body->startup_type, buffer_space); } static void marshal_get_capability(void **buffer, struct tpm2_get_capability *cmd_body, size_t *buffer_space) { marshal_u32(buffer, cmd_body->capability, buffer_space); marshal_u32(buffer, cmd_body->property, buffer_space); marshal_u32(buffer, cmd_body->propertyCount, buffer_space); } static void marshal_TPM2B(void **buffer, TPM2B *data, size_t *buffer_space) { size_t total_size = data->size + sizeof(data->size); if (total_size > *buffer_space) { *buffer_space = 0; return; } marshal_u16(buffer, data->size, buffer_space); memcpy(*buffer, data->buffer, data->size); *buffer = ((uint8_t *)(*buffer)) + data->size; *buffer_space -= data->size; } static void marshal_TPMA_NV(void **buffer, TPMA_NV *nv, size_t *buffer_space) { marshal_u32(buffer, *((uint32_t *)nv), buffer_space); } static void marshal_TPMS_NV_PUBLIC(void **buffer, TPMS_NV_PUBLIC *nvpub, size_t *buffer_space) { marshal_TPM_HANDLE(buffer, nvpub->nvIndex, buffer_space); marshal_TPMI_ALG_HASH(buffer, nvpub->nameAlg, buffer_space); marshal_TPMA_NV(buffer, &nvpub->attributes, buffer_space); marshal_TPM2B(buffer, &nvpub->authPolicy.b, buffer_space); marshal_u16(buffer, nvpub->dataSize, buffer_space); } static void marshal_TPMT_HA(void **buffer, TPMT_HA *tpmtha, size_t *buffer_space) { marshal_TPMI_ALG_HASH(buffer, tpmtha->hashAlg, buffer_space); marshal_blob(buffer, tpmtha->digest.sha256, sizeof(tpmtha->digest.sha256), buffer_space); } static void marshal_TPML_DIGEST_VALUES(void **buffer, TPML_DIGEST_VALUES *dvalues, size_t *buffer_space) { int i; marshal_u32(buffer, dvalues->count, buffer_space); for (i = 0; i < dvalues->count; i++) marshal_TPMT_HA(buffer, &dvalues->digests[i], buffer_space); } static void marshal_session_header(void **buffer, struct tpm2_session_header *session_header, size_t *buffer_space) { size_t base_size; void *size_location = *buffer; /* Skip room for the session header size. */ if (*buffer_space < sizeof(uint32_t)) { *buffer_space = 0; return; } *buffer_space -= sizeof(uint32_t); *buffer = (void *)(((uintptr_t) *buffer) + sizeof(uint32_t)); base_size = *buffer_space; marshal_u32(buffer, session_header->session_handle, buffer_space); marshal_u16(buffer, session_header->nonce_size, buffer_space); marshal_blob(buffer, session_header->nonce, session_header->nonce_size, buffer_space); marshal_u8(buffer, session_header->session_attrs, buffer_space); marshal_u16(buffer, session_header->auth_size, buffer_space); marshal_blob(buffer, session_header->auth, session_header->auth_size, buffer_space); if (!*buffer_space) return; /* The structure did not fit. */ /* Paste in the session size. */ marshal_u32(&size_location, base_size - *buffer_space, &base_size); } /* * Common session header can include one or two handles and an empty * session_header structure. */ static void marshal_common_session_header(void **buffer, const uint32_t *handles, size_t handle_count, size_t *buffer_space) { int i; struct tpm2_session_header session_header; car_set_var(tpm_tag, TPM_ST_SESSIONS); for (i = 0; i < handle_count; i++) marshal_TPM_HANDLE(buffer, handles[i], buffer_space); memset(&session_header, 0, sizeof(session_header)); session_header.session_handle = TPM_RS_PW; marshal_session_header(buffer, &session_header, buffer_space); } static void marshal_nv_define_space(void **buffer, struct tpm2_nv_define_space_cmd *nvd_in, size_t *buffer_space) { void *size_location; size_t base_size; size_t sizeof_nv_public_size = sizeof(uint16_t); const uint32_t handle[] = { TPM_RH_PLATFORM }; marshal_common_session_header(buffer, handle, ARRAY_SIZE(handle), buffer_space); marshal_TPM2B(buffer, &nvd_in->auth.b, buffer_space); /* This is where the TPMS_NV_PUBLIC size will be stored. */ size_location = *buffer; /* Allocate room for the size. */ *buffer = ((uint8_t *)(*buffer)) + sizeof(uint16_t); if (*buffer_space < sizeof_nv_public_size) { *buffer_space = 0; return; } *buffer_space -= sizeof_nv_public_size; base_size = *buffer_space; marshal_TPMS_NV_PUBLIC(buffer, &nvd_in->publicInfo, buffer_space); if (!*buffer_space) return; base_size = base_size - *buffer_space; marshal_u16(&size_location, base_size, &sizeof_nv_public_size); } static void marshal_nv_write(void **buffer, struct tpm2_nv_write_cmd *command_body, size_t *buffer_space) { uint32_t handles[] = { TPM_RH_PLATFORM, command_body->nvIndex }; marshal_common_session_header(buffer, handles, ARRAY_SIZE(handles), buffer_space); marshal_TPM2B(buffer, &command_body->data.b, buffer_space); marshal_u16(buffer, command_body->offset, buffer_space); } static void marshal_nv_write_lock(void **buffer, struct tpm2_nv_write_lock_cmd *command_body, size_t *buffer_space) { uint32_t handles[] = { TPM_RH_PLATFORM, command_body->nvIndex }; marshal_common_session_header(buffer, handles, ARRAY_SIZE(handles), buffer_space); } static void marshal_pcr_extend(void **buffer, struct tpm2_pcr_extend_cmd *command_body, size_t *buffer_space) { uint32_t handle = command_body->pcrHandle; marshal_common_session_header(buffer, &handle, 1, buffer_space); marshal_TPML_DIGEST_VALUES(buffer, &command_body->digests, buffer_space); } static void marshal_nv_read(void **buffer, struct tpm2_nv_read_cmd *command_body, size_t *buffer_space) { uint32_t handles[] = { TPM_RH_PLATFORM, command_body->nvIndex }; marshal_common_session_header(buffer, handles, ARRAY_SIZE(handles), buffer_space); marshal_u16(buffer, command_body->size, buffer_space); marshal_u16(buffer, command_body->offset, buffer_space); } /* TPM2_Clear command does not require paramaters. */ static void marshal_clear(void **buffer, size_t *buffer_space) { const uint32_t handle[] = { TPM_RH_PLATFORM }; marshal_common_session_header(buffer, handle, ARRAY_SIZE(handle), buffer_space); } static void marshal_selftest(void **buffer, struct tpm2_self_test *command_body, size_t *buffer_space) { marshal_u8(buffer, command_body->yes_no, buffer_space); } int tpm_marshal_command(TPM_CC command, void *tpm_command_body, void *buffer, size_t buffer_size) { void *cmd_body = (uint8_t *)buffer + sizeof(struct tpm_header); size_t max_body_size = buffer_size - sizeof(struct tpm_header); size_t body_size = max_body_size; /* Will be modified when marshaling some commands. */ car_set_var(tpm_tag, TPM_ST_NO_SESSIONS); switch (command) { case TPM2_Startup: marshal_startup(&cmd_body, tpm_command_body, &body_size); break; case TPM2_GetCapability: marshal_get_capability(&cmd_body, tpm_command_body, &body_size); break; case TPM2_NV_Read: marshal_nv_read(&cmd_body, tpm_command_body, &body_size); break; case TPM2_NV_DefineSpace: marshal_nv_define_space(&cmd_body, tpm_command_body, &body_size); break; case TPM2_NV_Write: marshal_nv_write(&cmd_body, tpm_command_body, &body_size); break; case TPM2_NV_WriteLock: marshal_nv_write_lock(&cmd_body, tpm_command_body, &body_size); break; case TPM2_SelfTest: marshal_selftest(&cmd_body, tpm_command_body, &body_size); break; case TPM2_Clear: marshal_clear(&cmd_body, &body_size); break; case TPM2_PCR_Extend: marshal_pcr_extend(&cmd_body, tpm_command_body, &body_size); break; default: body_size = 0; printk(BIOS_INFO, "%s:%d:Request to marshal unsupported command %#x\n", __FILE__, __LINE__, command); } if (body_size > 0) { size_t marshaled_size; size_t header_room = sizeof(struct tpm_header); /* See how much room was taken by marshaling. */ marshaled_size = max_body_size - body_size; /* Total size includes the header size. */ marshaled_size += sizeof(struct tpm_header); uint16_t tpm_tag_value = car_get_var(tpm_tag); marshal_u16(&buffer, tpm_tag_value, &header_room); marshal_u32(&buffer, marshaled_size, &header_room); marshal_u32(&buffer, command, &header_room); return marshaled_size; } return -1; } static void unmarshal_get_capability(void **buffer, int *size, struct get_cap_response *gcr) { int i; gcr->more_data = unmarshal_u8(buffer, size); gcr->cd.capability = unmarshal_TPM_CAP(buffer, size); if (*size < 0) return; switch (gcr->cd.capability) { case TPM_CAP_TPM_PROPERTIES: gcr->cd.data.tpmProperties.count = unmarshal_u32(buffer, size); if (*size < 0) return; if (gcr->cd.data.tpmProperties.count > ARRAY_SIZE (gcr->cd.data.tpmProperties.tpmProperty)) { printk(BIOS_INFO, "%s:%s:%d - %d - too many properties\n", __FILE__, __func__, __LINE__, gcr->cd.data.tpmProperties.count); *size = -1; return; } for (i = 0; i < gcr->cd.data.tpmProperties.count; i++) { TPMS_TAGGED_PROPERTY *pp; pp = gcr->cd.data.tpmProperties.tpmProperty + i; pp->property = unmarshal_TPM_PT(buffer, size); pp->value = unmarshal_u32(buffer, size); } break; default: printk(BIOS_ERR, "%s:%d - unable to unmarshal capability response", __func__, __LINE__); printk(BIOS_ERR, " for %d\n", gcr->cd.capability); *size = -1; break; } } static void unmarshal_TPM2B_MAX_NV_BUFFER(void **buffer, int *size, TPM2B_MAX_NV_BUFFER *nv_buffer) { nv_buffer->t.size = unmarshal_u16(buffer, size); if ((*size < 0) || (nv_buffer->t.size > *size)) { printk(BIOS_ERR, "%s:%d - " "size mismatch: expected %d, remaining %d\n", __func__, __LINE__, nv_buffer->t.size, *size); *size = -1; return; } nv_buffer->t.buffer = *buffer; *buffer = ((uint8_t *)(*buffer)) + nv_buffer->t.size; *size -= nv_buffer->t.size; } static void unmarshal_nv_read(void **buffer, int *size, struct nv_read_response *nvr) { /* Total size of the parameter field. */ nvr->params_size = unmarshal_u32(buffer, size); unmarshal_TPM2B_MAX_NV_BUFFER(buffer, size, &nvr->buffer); if (nvr->params_size != (nvr->buffer.t.size + sizeof(nvr->buffer.t.size))) { printk(BIOS_ERR, "%s:%d - parameter/buffer %d/%d size mismatch", __func__, __LINE__, nvr->params_size, nvr->buffer.t.size); return; } if (*size < 0) return; /* * Let's ignore the authorisation section. It should be 5 bytes total, * just confirm that this is the case and report any discrepancy. */ if (*size != 5) printk(BIOS_ERR, "%s:%d - unexpected authorisation seciton size %d\n", __func__, __LINE__, *size); *buffer = ((uint8_t *)(*buffer)) + *size; *size = 0; } struct tpm2_response *tpm_unmarshal_response(TPM_CC command, void *response_body, size_t in_size) { static struct tpm2_response tpm2_static_resp CAR_GLOBAL; struct tpm2_response *tpm2_resp = car_get_var_ptr(&tpm2_static_resp); /* * Should be 0 when done, positive and negaitive values indicate * unmarshaling errors. */ int cr_size = in_size; if ((cr_size < 0) || (in_size < sizeof(struct tpm_header))) return NULL; tpm2_resp->hdr.tpm_tag = unmarshal_u16(&response_body, &cr_size); tpm2_resp->hdr.tpm_size = unmarshal_u32(&response_body, &cr_size); tpm2_resp->hdr.tpm_code = unmarshal_TPM_CC(&response_body, &cr_size); if (!cr_size) { if (tpm2_resp->hdr.tpm_size != sizeof(tpm2_resp->hdr)) printk(BIOS_ERR, "%s: size mismatch in response to command %#x\n", __func__, command); return tpm2_resp; } switch (command) { case TPM2_Startup: break; case TPM2_GetCapability: unmarshal_get_capability(&response_body, &cr_size, &tpm2_resp->gc); break; case TPM2_NV_Read: unmarshal_nv_read(&response_body, &cr_size, &tpm2_resp->nvr); break; case TPM2_Clear: case TPM2_NV_DefineSpace: case TPM2_NV_Write: case TPM2_NV_WriteLock: case TPM2_PCR_Extend: /* Session data included in response can be safely ignored. */ cr_size = 0; break; default: { int i; printk(BIOS_INFO, "%s:%d:" "Request to unmarshal unexpected command %#x," " code %#x", __func__, __LINE__, command, tpm2_resp->hdr.tpm_code); for (i = 0; i < cr_size; i++) { if (!(i % 16)) printk(BIOS_INFO, "\n"); printk(BIOS_INFO, "%2.2x ", ((uint8_t *)response_body)[i]); } } printk(BIOS_INFO, "\n"); return NULL; } if (cr_size) { printk(BIOS_INFO, "%s:%d got %d bytes back in response to %#x," " failed to parse (%d)\n", __func__, __LINE__, tpm2_resp->hdr.tpm_size, command, cr_size); return NULL; } /* The entire message have been parsed. */ return tpm2_resp; }