diff options
Diffstat (limited to 'common/fpsensor/fpsensor_state.c')
| -rw-r--r-- | common/fpsensor/fpsensor_state.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/common/fpsensor/fpsensor_state.c b/common/fpsensor/fpsensor_state.c index 7618dbd859..82a548b8af 100644 --- a/common/fpsensor/fpsensor_state.c +++ b/common/fpsensor/fpsensor_state.c @@ -7,6 +7,7 @@ #include "cryptoc/util.h" #include "ec_commands.h" #include "fpsensor.h" +#include "fpsensor_crypto.h" #include "fpsensor_private.h" #include "fpsensor_state.h" #include "host_command.h" @@ -30,6 +31,13 @@ uint8_t fp_enc_buffer[FP_ALGORITHM_ENCRYPTED_TEMPLATE_SIZE] /* Salt used in derivation of positive match secret. */ uint8_t fp_positive_match_salt [FP_MAX_FINGER_COUNT][FP_POSITIVE_MATCH_SALT_BYTES]; + +struct positive_match_secret_state positive_match_secret_state = { + .template_matched = FP_NO_SUCH_TEMPLATE, + .readable = false, + .deadline.val = 0, +}; + /* Number of used templates */ uint32_t templ_valid; /* Bitmap of the templates with local modifications */ @@ -74,6 +82,7 @@ static void _fp_clear_context(void) always_memset(fp_buffer, 0, sizeof(fp_buffer)); always_memset(fp_enc_buffer, 0, sizeof(fp_enc_buffer)); always_memset(user_id, 0, sizeof(user_id)); + fp_disable_positive_match_secret(&positive_match_secret_state); for (idx = 0; idx < FP_MAX_FINGER_COUNT; idx++) fp_clear_finger_context(idx); } @@ -231,3 +240,72 @@ static enum ec_status fp_command_context(struct host_cmd_handler_args *args) return EC_RES_INVALID_PARAM; } DECLARE_HOST_COMMAND(EC_CMD_FP_CONTEXT, fp_command_context, EC_VER_MASK(1)); + +int fp_enable_positive_match_secret(uint32_t fgr, + struct positive_match_secret_state *state) +{ + timestamp_t now; + + if (state->readable) { + CPRINTS("Error: positive match secret already readable."); + fp_disable_positive_match_secret(state); + return EC_ERROR_UNKNOWN; + } + + now = get_time(); + state->template_matched = fgr; + state->readable = true; + state->deadline.val = now.val + (5 * SECOND); + return EC_SUCCESS; +} + +void fp_disable_positive_match_secret( + struct positive_match_secret_state *state) +{ + state->template_matched = FP_NO_SUCH_TEMPLATE; + state->readable = false; + state->deadline.val = 0; +} + +static enum ec_status fp_command_read_match_secret( + struct host_cmd_handler_args *args) +{ + const struct ec_params_fp_read_match_secret *params = args->params; + struct ec_response_fp_read_match_secret *response = args->response; + int8_t fgr = params->fgr; + timestamp_t now = get_time(); + struct positive_match_secret_state state_copy + = positive_match_secret_state; + + fp_disable_positive_match_secret(&positive_match_secret_state); + + if (fgr < 0 || fgr >= FP_MAX_FINGER_COUNT) { + CPRINTS("Invalid finger number %d", fgr); + return EC_RES_INVALID_PARAM; + } + if (timestamp_expired(state_copy.deadline, &now)) { + CPRINTS("Reading positive match secret disallowed: " + "deadline has passed."); + return EC_RES_TIMEOUT; + } + if (fgr != state_copy.template_matched || !state_copy.readable) { + CPRINTS("Positive match secret for finger %d is not meant to " + "be read now.", fgr); + return EC_RES_ACCESS_DENIED; + } + + if (derive_positive_match_secret(response->positive_match_secret, + fp_positive_match_salt[fgr]) + != EC_SUCCESS) { + CPRINTS("Failed to derive positive match secret for finger %d", + fgr); + /* Keep the template and encryption salt. */ + return EC_RES_ERROR; + } + CPRINTS("Derived positive match secret for finger %d", fgr); + args->response_size = sizeof(*response); + + return EC_RES_SUCCESS; +} +DECLARE_HOST_COMMAND(EC_CMD_FP_READ_MATCH_SECRET, fp_command_read_match_secret, + EC_VER_MASK(0)); |