diff --git a/include/psa/crypto.h b/include/psa/crypto.h index 3036d17b47..ea7d18d2bc 100644 --- a/include/psa/crypto.h +++ b/include/psa/crypto.h @@ -93,117 +93,10 @@ psa_status_t psa_crypto_init(void); /**@}*/ -/** \defgroup attributes Key attributes +/** \addtogroup attributes * @{ */ -/** The type of a structure containing key attributes. - * - * This is an opaque structure that can represent the metadata of a key - * object. Metadata that can be stored in attributes includes: - * - The location of the key in storage, indicated by its key identifier - * and its lifetime. - * - The key's policy, comprising usage flags and a specification of - * the permitted algorithm(s). - * - Information about the key itself: the key type and its size. - * - Implementations may define additional attributes. - * - * The actual key material is not considered an attribute of a key. - * Key attributes do not contain information that is generally considered - * highly confidential. - * - * An attribute structure can be a simple data structure where each function - * `psa_set_key_xxx` sets a field and the corresponding function - * `psa_get_key_xxx` retrieves the value of the corresponding field. - * However, implementations may report values that are equivalent to the - * original one, but have a different encoding. For example, an - * implementation may use a more compact representation for types where - * many bit-patterns are invalid or not supported, and store all values - * that it does not support as a special marker value. In such an - * implementation, after setting an invalid value, the corresponding - * get function returns an invalid value which may not be the one that - * was originally stored. - * - * An attribute structure may contain references to auxiliary resources, - * for example pointers to allocated memory or indirect references to - * pre-calculated values. In order to free such resources, the application - * must call psa_reset_key_attributes(). As an exception, calling - * psa_reset_key_attributes() on an attribute structure is optional if - * the structure has only been modified by the following functions - * since it was initialized or last reset with psa_reset_key_attributes(): - * - psa_set_key_id() - * - psa_set_key_lifetime() - * - psa_set_key_type() - * - psa_set_key_bits() - * - psa_set_key_usage_flags() - * - psa_set_key_algorithm() - * - * Before calling any function on a key attribute structure, the application - * must initialize it by any of the following means: - * - Set the structure to all-bits-zero, for example: - * \code - * psa_key_attributes_t attributes; - * memset(&attributes, 0, sizeof(attributes)); - * \endcode - * - Initialize the structure to logical zero values, for example: - * \code - * psa_key_attributes_t attributes = {0}; - * \endcode - * - Initialize the structure to the initializer #PSA_KEY_ATTRIBUTES_INIT, - * for example: - * \code - * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; - * \endcode - * - Assign the result of the function psa_key_attributes_init() - * to the structure, for example: - * \code - * psa_key_attributes_t attributes; - * attributes = psa_key_attributes_init(); - * \endcode - * - * A freshly initialized attribute structure contains the following - * values: - * - * - lifetime: #PSA_KEY_LIFETIME_VOLATILE. - * - key identifier: unspecified. - * - type: \c 0. - * - key size: \c 0. - * - usage flags: \c 0. - * - algorithm: \c 0. - * - * A typical sequence to create a key is as follows: - * -# Create and initialize an attribute structure. - * -# If the key is persistent, call psa_set_key_id(). - * Also call psa_set_key_lifetime() to place the key in a non-default - * location. - * -# Set the key policy with psa_set_key_usage_flags() and - * psa_set_key_algorithm(). - * -# Set the key type with psa_set_key_type(). - * Skip this step if copying an existing key with psa_copy_key(). - * -# When generating a random key with psa_generate_key() or deriving a key - * with psa_key_derivation_output_key(), set the desired key size with - * psa_set_key_bits(). - * -# Call a key creation function: psa_import_key(), psa_generate_key(), - * psa_key_derivation_output_key() or psa_copy_key(). This function reads - * the attribute structure, creates a key with these attributes, and - * outputs a handle to the newly created key. - * -# The attribute structure is now no longer necessary. - * You may call psa_reset_key_attributes(), although this is optional - * with the workflow presented here because the attributes currently - * defined in this specification do not require any additional resources - * beyond the structure itself. - * - * A typical sequence to query a key's attributes is as follows: - * -# Call psa_get_key_attributes(). - * -# Call `psa_get_key_xxx` functions to retrieve the attribute(s) that - * you are interested in. - * -# Call psa_reset_key_attributes() to free any resources that may be - * used by the attribute structure. - * - * Once a key has been created, it is impossible to change its attributes. - */ -typedef struct psa_key_attributes_s psa_key_attributes_t; - /** \def PSA_KEY_ATTRIBUTES_INIT * * This macro returns a suitable initializer for a key attribute structure diff --git a/include/psa/crypto_se_driver.h b/include/psa/crypto_se_driver.h index 3f3d7ca8dd..57d077c2e8 100644 --- a/include/psa/crypto_se_driver.h +++ b/include/psa/crypto_se_driver.h @@ -782,10 +782,6 @@ typedef struct { */ /**@{*/ -/* This type is documented in crypto.h. As far as drivers are concerned, - * this is an opaque type. */ -typedef struct psa_key_attributes_s psa_key_attributes_t; - /** \brief A function that allocates a slot for a key. * * \param[in,out] drv_context The driver context structure. diff --git a/include/psa/crypto_types.h b/include/psa/crypto_types.h index 7f0f38cddf..1944be4b26 100644 --- a/include/psa/crypto_types.h +++ b/include/psa/crypto_types.h @@ -133,6 +133,119 @@ typedef uint32_t psa_key_usage_t; /**@}*/ +/** \defgroup attributes Key attributes + * @{ + */ + +/** The type of a structure containing key attributes. + * + * This is an opaque structure that can represent the metadata of a key + * object. Metadata that can be stored in attributes includes: + * - The location of the key in storage, indicated by its key identifier + * and its lifetime. + * - The key's policy, comprising usage flags and a specification of + * the permitted algorithm(s). + * - Information about the key itself: the key type and its size. + * - Implementations may define additional attributes. + * + * The actual key material is not considered an attribute of a key. + * Key attributes do not contain information that is generally considered + * highly confidential. + * + * An attribute structure can be a simple data structure where each function + * `psa_set_key_xxx` sets a field and the corresponding function + * `psa_get_key_xxx` retrieves the value of the corresponding field. + * However, implementations may report values that are equivalent to the + * original one, but have a different encoding. For example, an + * implementation may use a more compact representation for types where + * many bit-patterns are invalid or not supported, and store all values + * that it does not support as a special marker value. In such an + * implementation, after setting an invalid value, the corresponding + * get function returns an invalid value which may not be the one that + * was originally stored. + * + * An attribute structure may contain references to auxiliary resources, + * for example pointers to allocated memory or indirect references to + * pre-calculated values. In order to free such resources, the application + * must call psa_reset_key_attributes(). As an exception, calling + * psa_reset_key_attributes() on an attribute structure is optional if + * the structure has only been modified by the following functions + * since it was initialized or last reset with psa_reset_key_attributes(): + * - psa_set_key_id() + * - psa_set_key_lifetime() + * - psa_set_key_type() + * - psa_set_key_bits() + * - psa_set_key_usage_flags() + * - psa_set_key_algorithm() + * + * Before calling any function on a key attribute structure, the application + * must initialize it by any of the following means: + * - Set the structure to all-bits-zero, for example: + * \code + * psa_key_attributes_t attributes; + * memset(&attributes, 0, sizeof(attributes)); + * \endcode + * - Initialize the structure to logical zero values, for example: + * \code + * psa_key_attributes_t attributes = {0}; + * \endcode + * - Initialize the structure to the initializer #PSA_KEY_ATTRIBUTES_INIT, + * for example: + * \code + * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; + * \endcode + * - Assign the result of the function psa_key_attributes_init() + * to the structure, for example: + * \code + * psa_key_attributes_t attributes; + * attributes = psa_key_attributes_init(); + * \endcode + * + * A freshly initialized attribute structure contains the following + * values: + * + * - lifetime: #PSA_KEY_LIFETIME_VOLATILE. + * - key identifier: unspecified. + * - type: \c 0. + * - key size: \c 0. + * - usage flags: \c 0. + * - algorithm: \c 0. + * + * A typical sequence to create a key is as follows: + * -# Create and initialize an attribute structure. + * -# If the key is persistent, call psa_set_key_id(). + * Also call psa_set_key_lifetime() to place the key in a non-default + * location. + * -# Set the key policy with psa_set_key_usage_flags() and + * psa_set_key_algorithm(). + * -# Set the key type with psa_set_key_type(). + * Skip this step if copying an existing key with psa_copy_key(). + * -# When generating a random key with psa_generate_key() or deriving a key + * with psa_key_derivation_output_key(), set the desired key size with + * psa_set_key_bits(). + * -# Call a key creation function: psa_import_key(), psa_generate_key(), + * psa_key_derivation_output_key() or psa_copy_key(). This function reads + * the attribute structure, creates a key with these attributes, and + * outputs a handle to the newly created key. + * -# The attribute structure is now no longer necessary. + * You may call psa_reset_key_attributes(), although this is optional + * with the workflow presented here because the attributes currently + * defined in this specification do not require any additional resources + * beyond the structure itself. + * + * A typical sequence to query a key's attributes is as follows: + * -# Call psa_get_key_attributes(). + * -# Call `psa_get_key_xxx` functions to retrieve the attribute(s) that + * you are interested in. + * -# Call psa_reset_key_attributes() to free any resources that may be + * used by the attribute structure. + * + * Once a key has been created, it is impossible to change its attributes. + */ +typedef struct psa_key_attributes_s psa_key_attributes_t; + +/**@}*/ + /** \defgroup derivation Key derivation * @{ */