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Correct keymaster1 documentation.

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Bug: 22291207
Change-Id: I130d2ab2110321dc2228d41a154750da3a3f0b75
This commit is contained in:
Shawn Willden 2015-07-08 09:57:16 -06:00
parent f9df59a7ff
commit 70335f3d30
2 changed files with 65 additions and 96 deletions
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158
include/hardware/keymaster1.h
View file

@ -250,11 +250,8 @@ struct keymaster1_device {
* of useful keys are:
*
* - KM_TAG_ALGORITHM;
* - KM_TAG_PURPOSE;
* - KM_TAG_USER_ID or KM_TAG_ALL_USERS;
* - KM_TAG_USER_AUTH_ID or KM_TAG_NO_AUTH_REQUIRED;
* - KM_TAG_APPLICATION_ID or KM_TAG_ALL_APPLICATIONS; and
* - KM_TAG_ORIGINATION_EXPIRE_DATETIME
* - KM_TAG_PURPOSE; and
* - (KM_TAG_USER_SECURE_ID and KM_TAG_USER_AUTH_TYPE) or KM_TAG_NO_AUTH_REQUIRED.
*
* KM_TAG_AUTH_TIMEOUT should generally be specified unless KM_TAG_NO_AUTH_REQUIRED is present,
* or the user will have to authenticate for every use.
@ -262,25 +259,11 @@ struct keymaster1_device {
* KM_TAG_BLOCK_MODE, KM_TAG_PADDING, KM_TAG_MAC_LENGTH and KM_TAG_DIGEST must be specified for
* algorithms that require them.
*
* The following tags will take default values if unspecified:
*
* - KM_TAG_KEY_SIZE defaults to a recommended key size for the specified algorithm.
*
* - KM_TAG_USAGE_EXPIRE_DATETIME defaults to the value of KM_TAG_ORIGINATION_EXPIRE_DATETIME.
*
* - KM_TAG_ACTIVE_DATETIME will default to the value of KM_TAG_CREATION_DATETIME
*
* - KM_TAG_ROOT_OF_TRUST will default to the current root of trust.
*
* - KM_TAG_{RSA|DSA|DH}_* will default to values appropriate for the specified key size.
*
* The following tags may not be specified; their values will be provided by the implementation.
*
* - KM_TAG_ORIGIN,
*
* - KM_TAG_ROLLBACK_RESISTANT,
*
* - KM_TAG_CREATION_DATETIME,
* - KM_TAG_CREATION_DATETIME
*
* \param[in] dev The keymaster device structure.
*
@ -288,12 +271,11 @@ struct keymaster1_device {
*
* \param[in] params_count Length of \p params.
*
* \param[out] key_blob returns the generated key. If \p key_blob is NULL, no key is generated,
* but the characteristics of the key that would be generated are returned. The caller assumes
* ownership key_blob->key_material and must free() it.
* \param[out] key_blob returns the generated key. \p key_blob must not be NULL. The caller
* assumes ownership key_blob->key_material and must free() it.
*
* \param[out] characteristics returns the characteristics of the key that was, or would be,
* generated, if non-NULL. The caller assumes ownership, and the object must be freed with
* \param[out] characteristics returns the characteristics of the key that was, generated, if
* non-NULL. If non-NULL, the caller assumes ownership and must deallocate with
* keymaster_free_characteristics(). Note that KM_TAG_ROOT_OF_TRUST, KM_TAG_APPLICATION_ID and
* KM_TAG_APPLICATION_DATA are never returned.
*/
@ -303,11 +285,13 @@ struct keymaster1_device {
keymaster_key_characteristics_t** characteristics);
/**
* Returns the characteristics of the specified key, or NULL if the key_blob is invalid
* (implementations must fully validate the integrity of the key). client_id and app_data must
* be the ID and data provided when the key was generated or imported. Those values are not
* included in the returned characteristics. Caller assumes ownership of the allocated
* characteristics object, which must be deallocated with keymaster_free_characteristics().
* Returns the characteristics of the specified key, or KM_ERROR_INVALID_KEY_BLOB if the
* key_blob is invalid (implementations must fully validate the integrity of the key).
* client_id and app_data must be the ID and data provided when the key was generated or
* imported, or empty if KM_TAG_APPLICATION_ID and/or KM_TAG_APPLICATION_DATA were not provided
* during generation. Those values are not included in the returned characteristics. The
* caller assumes ownership of the allocated characteristics object, which must be deallocated
* with keymaster_free_characteristics().
*
* Note that KM_TAG_ROOT_OF_TRUST, KM_TAG_APPLICATION_ID and KM_TAG_APPLICATION_DATA are never
* returned.
@ -332,38 +316,26 @@ struct keymaster1_device {
* Imports a key, or key pair, returning a key blob and/or a description of the key.
*
* Most key import parameters are defined as keymaster tag/value pairs, provided in "params".
* See keymaster_tag_t for the full list. Some values that are always required for import of
* useful keys are:
* See keymaster_tag_t for the full list. Values that are always required for import of useful
* keys are:
*
* - KM_TAG_PURPOSE;
*
* - KM_TAG_USER_ID
*
* - KM_TAG_USER_AUTH_ID;
*
* - KM_TAG_APPLICATION_ID or KM_TAG_ALL_APPLICATIONS;
*
* - KM_TAG_PRIVKEY_EXPIRE_DATETIME.
* - KM_TAG_ALGORITHM;
* - KM_TAG_PURPOSE; and
* - (KM_TAG_USER_SECURE_ID and KM_TAG_USER_AUTH_TYPE) or KM_TAG_NO_AUTH_REQUIRED.
*
* KM_TAG_AUTH_TIMEOUT should generally be specified. If unspecified, the user will have to
* authenticate for every use, unless KM_TAG_USER_AUTH_ID is set to
* KM_NO_AUTHENTICATION_REQUIRED.
* authenticate for every use.
*
* The following tags will take default values if unspecified:
*
* - KM_TAG_PUBKEY_EXPIRE_DATETIME will default to the value for KM_TAG_PRIVKEY_EXPIRE_DATETIME.
*
* - KM_TAG_ACTIVE_DATETIME will default to the value of KM_TAG_CREATION_DATETIME
*
* - KM_TAG_ROOT_OF_TRUST will default to the current root of trust.
* - KM_TAG_KEY_SIZE will default to the size of the key provided.
* - KM_TAG_RSA_PUBLIC_EXPONENT will default to the value in the key provided (for RSA keys)
*
* The following tags may not be specified; their values will be provided by the implementation.
*
* - KM_TAG_ORIGIN,
*
* - KM_TAG_ROLLBACK_RESISTANT,
*
* - KM_TAG_CREATION_DATETIME,
* - KM_TAG_CREATION_DATETIME
*
* \param[in] dev The keymaster device structure.
*
@ -378,7 +350,9 @@ struct keymaster1_device {
*
* \param[out] characteristics Used to return the characteristics of the imported key. May be
* NULL, in which case no characteristics will be returned. If non-NULL, the caller assumes
* ownership and must deallocate with keymaster_free_characteristics().
* ownership and must deallocate with keymaster_free_characteristics(). Note that
* KM_TAG_ROOT_OF_TRUST, KM_TAG_APPLICATION_ID and
* KM_TAG_APPLICATION_DATA are never returned.
*/
keymaster_error_t (*import_key)(const struct keymaster1_device* dev,
const keymaster_key_param_set_t* params,
@ -439,37 +413,40 @@ struct keymaster1_device {
*
* It is critical that each call to begin() be paired with a subsequent call to finish() or
* abort(), to allow the keymaster implementation to clean up any internal operation state.
* Failure to do this will leak internal state space or other internal resources and will
* Failure to do this may leak internal state space or other internal resources and may
* eventually cause begin() to return KM_ERROR_TOO_MANY_OPERATIONS when it runs out of space for
* operations.
* operations. Any result other than KM_ERROR_OK from begin(), update() or finish() implicitly
* aborts the operation, in which case abort() need not be called (and will return
* KM_ERROR_INVALID_OPERATION_HANDLE if called).
*
* \param[in] dev The keymaster device structure.
*
* \param[in] purpose The purpose of the operation, one of KM_PURPOSE_ENCRYPT,
* KM_PURPOSE_DECRYPT, KM_PURPOSE_SIGN or KM_PURPOSE_VERIFY. Note that for AEAD modes,
* encryption and decryption imply signing and verification, respectively.
* encryption and decryption imply signing and verification, respectively, but should be
* specified as KM_PURPOSE_ENCRYPT and KM_PURPOSE_DECRYPT.
*
* \param[in] key The key to be used for the operation. \p key must have a purpose compatible
* with \p purpose and all of its usage requirements must be satisfied, or begin() will return
* an appropriate error code.
*
* \param[in] params Additional parameters for the operation. This is typically used to provide
* client ID information, with tags KM_TAG_APPLICATION_ID and KM_TAG_APPLICATION_DATA. If the
* client information associated with the key is not provided, begin() will fail and return
* KM_ERROR_INVALID_KEY_BLOB. For operations that require a nonce or IV, this must contain a
* tag KM_TAG_NONCE. For AEAD operations KM_TAG_CHUNK_SIZE is specified here.
* \param[in] in_params Additional parameters for the operation. This is typically used to
* provide authentication data, with KM_TAG_AUTH_TOKEN. If KM_TAG_APPLICATION_ID or
* KM_TAG_APPLICATION_DATA were provided during generation, they must be provided here, or the
* operation will fail with KM_ERROR_INVALID_KEY_BLOB. For operations that require a nonce or
* IV, on keys that were generated with KM_TAG_CALLER_NONCE, in_params may contain a tag
* KM_TAG_NONCE. For AEAD operations KM_TAG_CHUNK_SIZE is specified here.
*
* \param[in] params_count The number of entries in \p params.
*
* \param[out] out_params Array of output parameters. The caller takes ownership of the output
* parametes array and must free it. out_params may be set to NULL if no output parameters are
* expected. If NULL, and output paramaters are generated, begin() will return
* \param[out] out_params Output parameters. Used to return additional data from the operation
* initialization, notably to return the IV or nonce from operations that generate an IV or
* nonce. The caller takes ownership of the output parameters array and must free it with
* keymaster_free_param_set(). out_params may be set to NULL if no output parameters are
* expected. If out_params is NULL, and output paramaters are generated, begin() will return
* KM_ERROR_OUTPUT_PARAMETER_NULL.
*
* \param[out] out_params_count The length of out_params.
*
* \param[out] operation_handle The newly-created operation handle which must be passed to
* update(), finish() or abort().
* update(), finish() or abort(). If operation_handle is NULL, begin() will return
* KM_ERROR_OUTPUT_PARAMETER_NULL.
*/
keymaster_error_t (*begin)(const struct keymaster1_device* dev, keymaster_purpose_t purpose,
const keymaster_key_blob_t* key,
@ -483,37 +460,37 @@ struct keymaster1_device {
*
* If operation_handle is invalid, update() will return KM_ERROR_INVALID_OPERATION_HANDLE.
*
* Not all of the data provided in the data buffer may be consumed. update() will return the
* amount consumed in *data_consumed. The caller should provide the unconsumed data in a
* update() may not consume all of the data provided in the data buffer. update() will return
* the amount consumed in *data_consumed. The caller should provide the unconsumed data in a
* subsequent call.
*
* \param[in] dev The keymaster device structure.
*
* \param[in] operation_handle The operation handle returned by begin().
*
* \param[in] params Additional parameters for the operation. For AEAD modes, this is used to
* specify KM_TAG_ADDITIONAL_DATA.
*
* \param[in] params_count Length of \p params.
* \param[in] in_params Additional parameters for the operation. For AEAD modes, this is used
* to specify KM_TAG_ADDITIONAL_DATA. Note that additional data may be provided in multiple
* calls to update(), but only until input data has been provided.
*
* \param[in] input Data to be processed, per the parameters established in the call to begin().
* Note that update() may or may not consume all of the data provided. See \p data_consumed.
*
* \param[in] input_length Length of \p input.
* Note that update() may or may not consume all of the data provided. See \p input_consumed.
*
* \param[out] input_consumed Amount of data that was consumed by update(). If this is less
* than the amount provided, the caller should provide the remainder in a subsequent call to
* update().
*
* \param[out] out_params Output parameters. Used to return additional data from the operation
* The caller takes ownership of the output parameters array and must free it with
* keymaster_free_param_set(). out_params may be set to NULL if no output parameters are
* expected. If out_params is NULL, and output paramaters are generated, begin() will return
* KM_ERROR_OUTPUT_PARAMETER_NULL.
*
* \param[out] output The output data, if any. The caller assumes ownership of the allocated
* buffer. If output is NULL then NO input data is consumed and no output is produced, but
* *output_length is set to an estimate of the size that would have been produced by this
* update() and a subsequent finish().
* buffer. output must not be NULL.
*
* \param[out] output_length The length of the output buffer.
*
* Note that update() may not provide any output, in which case *output_length will be zero, and
* *output may be either NULL or zero-length (so the caller should always free() it).
* Note that update() may not provide any output, in which case output->data_length will be
* zero, and output->data may be either NULL or zero-length (so the caller should always free()
* it).
*/
keymaster_error_t (*update)(const struct keymaster1_device* dev,
keymaster_operation_handle_t operation_handle,
@ -522,8 +499,7 @@ struct keymaster1_device {
keymaster_key_param_set_t* out_params, keymaster_blob_t* output);
/**
* Finalizes a cryptographic operation begun with begin() and invalidates operation_handle
* (except in the insufficient buffer case, detailed below).
* Finalizes a cryptographic operation begun with begin() and invalidates \p operation_handle.
*
* \param[in] dev The keymaster device structure.
*
@ -531,20 +507,14 @@ struct keymaster1_device {
* invalidated.
*
* \param[in] params Additional parameters for the operation. For AEAD modes, this is used to
* specify KM_TAG_ADDITIONAL_DATA.
*
* \param[in] params_count Length of \p params.
* specify KM_TAG_ADDITIONAL_DATA, but only if no input data was provided to update().
*
* \param[in] signature The signature to be verified if the purpose specified in the begin()
* call was KM_PURPOSE_VERIFY.
*
* \param[in] signature_length The length of \p signature.
*
* \param[out] output The output data, if any. The caller assumes ownership of the allocated
* buffer.
*
* \param[out] output_length The length of the output buffer.
*
* If the operation being finished is a signature verification or an AEAD-mode decryption and
* verification fails then finish() will return KM_ERROR_VERIFICATION_FAILED.
*/
@ -556,7 +526,7 @@ struct keymaster1_device {
/**
* Aborts a cryptographic operation begun with begin(), freeing all internal resources and
* invalidating operation_handle.
* invalidating \p operation_handle.
*/
keymaster_error_t (*abort)(const struct keymaster1_device* dev,
keymaster_operation_handle_t operation_handle);

3
include/hardware/keymaster_defs.h
View file

@ -115,8 +115,7 @@ typedef enum {
KM_TAG_CREATION_DATETIME = KM_DATE | 701, /* Key creation time */
KM_TAG_ORIGIN = KM_ENUM | 702, /* keymaster_key_origin_t. */
KM_TAG_ROLLBACK_RESISTANT = KM_BOOL | 703, /* Whether key is rollback-resistant. */
KM_TAG_ROOT_OF_TRUST = KM_BYTES | 704, /* Root of trust ID. Empty array means usable by all
roots. */
KM_TAG_ROOT_OF_TRUST = KM_BYTES | 704, /* Root of trust ID. */
/* Tags used only to provide data to or receive data from operations */
KM_TAG_ASSOCIATED_DATA = KM_BYTES | 1000, /* Used to provide associated data for AEAD modes. */