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Diffstat (limited to 'libparc/parc/security/parc_KeyId.h')
| -rwxr-xr-x | libparc/parc/security/parc_KeyId.h | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/libparc/parc/security/parc_KeyId.h b/libparc/parc/security/parc_KeyId.h new file mode 100755 index 00000000..daa2a2fe --- /dev/null +++ b/libparc/parc/security/parc_KeyId.h @@ -0,0 +1,348 @@ +/* + * Copyright (c) 2017 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/** + * @file parc_KeyId.h + * @ingroup security + * @brief Represent a key by an octet string + * + * A KeyId is a hash digest used to identify a key. These are used as key entries in hash-table + * based key stores that cache raw keys. Instead of transferring raw keys, parties may exchange + * KeyIds used to index into key stores for constant-time key retrieval. This exchange + * expects that the raw key will be present in the key store. If not, the lookup will fail. + * Consequently, KeyIds are not used to encapsulate or transfer raw keys. + * + */ +#include <parc/algol/parc_Buffer.h> +#include <parc/algol/parc_BufferComposer.h> + +#ifndef libparc_parc_KeyId_h +#define libparc_parc_KeyId_h + +struct parc_keyid; +/** + * @typedef PARCKeyId + * @brief A KeyId is a hash digest used to identify a key. + */ + +typedef struct parc_keyid PARCKeyId; + +/** + * @def parcKeyId_OptionalAssertValid + * Optional validation of the given instance. + * + * Define `PARCLibrary_DISABLE_VALIDATION` to disable validation. + */ +#ifdef PARCLibrary_DISABLE_VALIDATION +# define parcKeyId_OptionalAssertValid(_instance_) +#else +# define parcKeyId_OptionalAssertValid(_instance_) parcKeyId_AssertValid(_instance_) +#endif + +/** + * Create a `PARCKeyId` from the given pre-computed-key identifier. + * + * A reference to the given identifer is created and the caller is responsible for releasing the remaining references. + * + * @param [in] preComputedKeyId A pointer to a `PARCBuffer` instance containing the pre-computed-key identifier. + * @return A pointer to an allocated `PARCKeyId` that must be released via `parcKeyId_Release`. + * + * Example: + * @code + * { + * PARCBuffer *keybits = parcBuffer_Wrap("Hello", 5, 0, 5); + * PARCKeyId *keyid = parcKeyId_Create(keybits); + * parcBuffer_Release(&keybits); + * // do something with keyid + * parcKeyId_Release(&keyid); + * } + * @endcode + */ +PARCKeyId *parcKeyId_Create(PARCBuffer *preComputedKeyId); + +/** + * Increase the number of references to a `PARCKeyId`. + * + * Note that new `PARCKeyId` is not created, + * only that the given `PARCKeyId` reference count is incremented. + * Discard the reference by invoking `parcKeyId_Release`. + * + * @param [in] instance A pointer to the instance of `PARCKeyId`. + * @return The value of the input parameter @p instance. + * + * Example: + * @code + * { + * PARCBuffer *buffer = parcBuffer_Wrap("Hello", 5, 0, 5); + * PARCKeyId *instance = parcKeyId_CreateFromByteBuffer(buffer); + * parcBuffer_Release(&buffer); + * + * PARCKeyId *reference = parcKeyId_Acquire(instance); + * + * parcKeyId_Release(&instance); + * parcKeyId_Release(&reference); + * } + * @endcode + * + * @see parcKeyId + */ +PARCKeyId *parcKeyId_Acquire(const PARCKeyId *instance); + +/** + * Assert a valid PARCKeyId instance. + * + * @param [in] keyId A pointer to a `PARCKeyId` instance. + * + * Example: + * @code + * { + * PARCBuffer *buffer = parcBuffer_Wrap("Hello", 5, 0, 5); + * PARCKeyId *instance = parcKeyId_CreateFromByteBuffer(buffer); + * parcBuffer_Release(&buffer); + * + * parcKeyId_AssertValid(&instance); + * parcKeyId_Release(&instance); + * } + * @endcode + * @see parcKeyId_OptionalAssertValid + */ +void parcKeyId_AssertValid(const PARCKeyId *keyId); + +/** + * Create a copy of the KeyId from the specified `PARCKeyId` instance. + * + * A deep copy is performed, acquiring handles to objects when needed. + * + * @param [in] original A pointer to a `PARCKeyId` instance containing the pre-computerd-key identifier. + * @return A pointer to a newly allocated `PARCKeyId` that must be released via `parcKeyId_Release`. + * + * Example: + * @code + * { + * PARCBuffer *keybits = parcBuffer_Wrap("Hello", 5, 0, 5); + * PARCKeyId *keyid = parcKeyId_Create(keybits); + * parcBuffer_Release(&keybits); + * // do something with keyid + * parcKeyId_Release(&keyid); + * } + * @endcode + */ +PARCKeyId *parcKeyId_Copy(const PARCKeyId *original); + +/** + * Release a previously acquired reference to the specified instance, + * decrementing the reference count for the instance. + * + * The pointer to the instance is set to NULL as a side-effect of this function. + * + * If the invocation causes the last reference to the instance to be released, + * the instance is deallocated and the instance's implementation will perform + * additional cleanup and release other privately held references. + * + * @param [in,out] object A pointer to a pointer to the `PARCKeyId` instance to release. + * + * Example: + * @code + * { + * PARCBuffer *buffer = parcBuffer_Wrap("Hello", 5, 0, 5); + * PARCKeyId *instance = parcKeyId_CreateFromByteBuffer(buffer); + * parcBuffer_Release(&buffer); + * + * parcKeyId_Release(&instance); + * } + * @endcode + */ +void parcKeyId_Release(PARCKeyId **object); + +/** + * Determine if two `PARCKeyId` instances are equal. + * + * Two `PARCKeyId` instances are equal if, and only if, + * + * The following equivalence relations on non-null `PARCKeyId` instances are maintained: + * + * * It is reflexive: for any non-null reference value x, `parcKeyId_Equals(x, x)` + * must return true. + * + * * It is symmetric: for any non-null reference values x and y, + * `parcKeyId_Equals(x, y)` must return true if and only if + * `parcKeyId_Equals(y, x)` returns true. + * + * * It is transitive: for any non-null reference values x, y, and z, if + * `parcKeyId_Equals(x, y)` returns true and + * `parcKeyId_Equals(y, z)` returns true, + * then `parcKeyId_Equals(x, z)` must return true. + * + * * It is consistent: for any non-null reference values x and y, multiple + * invocations of `parcKeyId_Equals(x, y)` consistently return true or + * consistently return false. + * + * * For any non-null reference value x, `parcKeyId_Equals(x, NULL)` must + * return false. + * + * @param a A pointer to a `PARCKeyId` instance. + * @param b A pointer to a `PARCKeyId` instance. + * @return true if the two `PARCKeyId` instances are equal. + * + * Example: + * @code + * { + * PARCKeyId *a = parcKeyId_Create(...); + * PARCKeyId *b = parcKeyId_Create(...); + * + * if (parcKeyId_Equals(a, b)) { + * // equal + * } else { + * // unequal + * } + * } + * @endcode + */ +bool parcKeyId_Equals(const PARCKeyId *a, const PARCKeyId *b); + +/** + * Get the digest bytes of a `PARCKeyId` instance; + * + * @param [in] keyid A pointer to a `PARCKeyId` instance. + * + * @return A pointer to a (shared) {@link PARCBuffer} instance containing the digest bytes of the `PARCKeyId`. + * + * Example: + * @code + * { + * PARCBuffer *buffer = parcBuffer_Wrap("Hello", 5, 0, 5); + * PARCKeyId *instance = parcKeyId_CreateFromByteBuffer(buffer); + * PARCBuffer *bytes = parcKeyId_GetKeyId(instance); + * // use or display the bytes buffer as needed + * } + * @endcode + */ +const PARCBuffer *parcKeyId_GetKeyId(const PARCKeyId *keyid); + +/** + * Returns a hash code value for the given instance. + * + * The general contract of `parcKeyId_HashCode` is: + * + * Whenever it is invoked on the same instance more than once during an + * execution of an application, + * the {@link parcKeyId_HashCode} function must consistently return the same value, + * provided no information used in a corresponding {@link parcKeyId_Equals} + * comparisons on the instance is modified. + * + * This value need not remain consistent from one execution of an application to + * another execution of the same application. + * If two instances are equal according to the {@link parcKeyId_Equals} function, + * then calling the {@link parcKeyId_HashCode} function on each of the two instances must + * produce the same integer result. + * + * It is not required that if two instances are unequal according to the + * {@link parcKeyId_Equals} function, + * then calling the {@link parcKeyId_HashCode} + * method on each of the two objects must produce distinct integer results. + * + * @param [in] keyid A pointer to the `PARCKeyId` instance. + * + * @return The hashcode for the given instance. + * + * Example: + * @code + * { + * PARCKeyId *x = parcKeyId_Create(...); + * uint32_t hashValue = parcKeyId_HashCode(array); + * parcKeyId_Release(&x); + * } + * @endcode + */ +PARCHashCode parcKeyId_HashCode(const PARCKeyId *keyid); + +/** + * Compute a non-cryptographic hash of a `PARCKeyId` instance from a void pointer. + * + * This is useful for use in {@link PARCHashCodeTable}. + * + * @param [in] keyId A pointer to the instance to be hashed + * + * @return A 32-bit non-cryptographic hash of the instance. + * + * Example: + * @code + * { + * PARCKeyId *x = parcKeyId_Create(...); + * uint32_t hash = parcKeyId_HashCode((void*)x); + * // use the hash to index into a table, or something else + * } + * @endcode + * + * @see parcKeyId_HashCode + */ +PARCHashCode parcKeyId_HashCodeFromVoid(const void *keyId); + +/** + * Append a representation of the specified instance to the given + * {@link PARCBufferComposer}. + * + * @param [in] keyId A pointer to a `PARCKeyId` instance. + * @param [in] composer A pointer to a `PARCBufferComposer` instance. + * + * @return NULL Cannot allocate memory. + * @return non-NULL The given `PARCBufferComposer`. + * + * Example: + * @code + * { + * PARCBufferComposer *result = parcBufferComposer_Create(); + * + * parcKeyId_BuildString(instance, result); + * + * char *string = parcBuffer_ToString(parcBufferComposer_ProduceBuffer(result)); + * printf("Hello: %s\n", string); + * parcMemory_Deallocate((void **)&string); + * + * parcBufferComposer_Release(&result); + * } + * @endcode + */ +PARCBufferComposer *parcKeyId_BuildString(const PARCKeyId *keyId, PARCBufferComposer *composer); + +/** + * Produce a null-terminated string representation of the specified instance. + * + * The non-null result must be freed by the caller via {@link parcMemory_Deallocate}. + * + * @param [in] instance A pointer to the instance. + * + * @return NULL Cannot allocate memory. + * @return non-NULL A pointer to an allocated, + * null-terminated C string that must be deallocated via {@link parcMemory_Deallocate}. + * + * Example: + * @code + * { + * PARCKeyId *instance = parcKeyId_Create(...); + * + * char *string = parcKeyId_ToString(instance); + * + * printf("Hello: %s\n", string); + * parcMemory_Deallocate((void **)&string); + * + * parcKeyId_Release(&instance); + * } + * @endcode + * + * @see parcKeyId_BuildString + */ +char *parcKeyId_ToString(const PARCKeyId *instance); +#endif // libparc_parc_KeyId_h |