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Diffstat (limited to 'libparc/parc/security/parc_CryptoHash.h')
| -rwxr-xr-x | libparc/parc/security/parc_CryptoHash.h | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/libparc/parc/security/parc_CryptoHash.h b/libparc/parc/security/parc_CryptoHash.h new file mode 100755 index 00000000..d0312d9e --- /dev/null +++ b/libparc/parc/security/parc_CryptoHash.h @@ -0,0 +1,234 @@ +/* + * 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_CryptoHash.h + * @ingroup security + * + * @brief PARCDigest holds a cryptographic digest, which is comprised + * the bytes of the digest and the algorithm used for the digest. + * + */ +#ifndef libparc_parc_CryptoHash_h +#define libparc_parc_CryptoHash_h + +#include <parc/algol/parc_Buffer.h> +#include <parc/security/parc_CryptoHashType.h> + +struct parc_crypto_hash; +typedef struct parc_crypto_hash PARCCryptoHash; + +/** + * Create a Digest holding the type and digest buffer. + * + * Creates a new reference to the given PARCBuffer `digest`. + * + * @param [in] digestType The type of hash digest algorithm used to compute this digest. + * @param [in] digestBuffer The actual hash digest instance. + * + * @return A newly allocated `PARCCryptoHash` instance that must be freed via `parcCryptoHash_Release()` + * + * Example: + * @code + * { + * PARCBuffer *digestBuffer = ... + * PARCCryptoHash *digest = parcCryptoHash_Create(PARCCryptoHashType_SHA256, digestBuffer); + * ... + * parcCryptoHash_Release(&digest); + * } + * @endcode + */ +PARCCryptoHash *parcCryptoHash_Create(PARCCryptoHashType digestType, const PARCBuffer *digestBuffer); + +/** + * Increase the number of references to a `PARCCryptoHash` instance. + * + * Note that a new `PARCCryptoHash` is not created, + * only that the given `PARCCryptoHash` reference count is incremented. + * Discard the reference by invoking {@link parcCryptoHash_Release}. + * + * @param [in] hash A pointer to the original instance. + * @return The value of the input parameter @p instance. + * + * Example: + * @code + * { + * PARCCryptoHash *x = ... + * PARCCryptoHash *x2 = parcCryptoHash_Acquire(x); + * + * parcCryptoHash_Release(&x); + * parcCryptoHash_Release(&x2); + * } + * @endcode + * + * @see {@link parcCryptoHash_Release} + */ +PARCCryptoHash *parcCryptoHash_Acquire(const PARCCryptoHash *hash); + +/** + * 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] hashP A pointer to a pointer to the instance to release. + * + * Example: + * @code + * { + * PARCCryptoHash *x = ... + * + * parcCryptoHash_Release(&x); + * } + * @endcode + * + * @see {@link parcCryptoHash_Acquire} + */ +void parcCryptoHash_Release(PARCCryptoHash **hashP); + +/** + * Create a digest, copying the buffer. + * + * @param [in] digestType The type of hash digest algorithm used to compute this digest. + * @param [in] buffer Pointer to array containing the raw digest bytes. + * @param [in] length Length of the digest byte array. + * + * @return A newly allocated `PARCCryptoHash` instance that must be freed via `parcCryptoHash_Release()` + * + * Example: + * @code + * { + * size_t bufferLen = 32; + * uint8_t *buffer = ... + * PARCCryptoHash *digest = parcCryptoHash_Create(PARCCryptoHashType_SHA256, buffer, bufferLen); + * ... + * parcCryptoHash_Release(&digest); + * // free the raw buffer as needed + * } + * @endcode + */ +PARCCryptoHash *parcCryptoHash_CreateFromArray(PARCCryptoHashType digestType, const void *buffer, size_t length); + +/** + * Destroy the specified `PARCCryptoHash` instance. + * + * @param [in,out] parcDigestPtr Pointer to the instance to be destroyed. + * + * Example: + * @code + * { + * PARCBuffer *buffer = ... + * PARCCryptoHash *digest = parcCryptoHash_Create(PARCCryptoHashType_SHA256, buffer); + * ... + * parcCryptoHash_Release(&digest); + * } + * @endcode + */ +void parcCryptoHash_Release(PARCCryptoHash **parcDigestPtr); + +/** + * Returns the digest algorithm, of type `PARCCryptoHashType`. + * + * @param [in] parcDigest The `PARCCryptoHash` instance being examined. + * + * @return A `PARCCryptoHashType` value. + * + * Example: + * @code + * { + * PARCBuffer *buffer = ... + * PARCCryptoHash *digest = parcCryptoHash_Create(PARCCryptoHashType_SHA256, buffer); + * PARCCryptoHashType type = parcCryptoHash_GetDigestType(digest); + * // type will be PARCCryptoHashType_SHA256 + * ... + * parcCryptoHash_Release(&digest); + * } + * @endcode + */ +PARCCryptoHashType parcCryptoHash_GetDigestType(const PARCCryptoHash *parcDigest); + +/** + * Returnes the digest buffer, copy if you will destroy + * + * Returns the inner digest buffer. You must copy it if you will make + * changes or destroy it. + * + * @param [in] cryptoHash The `PARCCryptoHash` instance being examined. + * + * @return A `PARCBuffer` instance containing the raw hash digest. + * + * Example: + * @code + * { + * PARCBuffer *buffer = ... + * PARCCryptoHash *digest = parcCryptoHash_Create(PARCCryptoHashType_SHA256, buffer); + * PARCBuffer *rawDigest = parcCryptoHash_GetDigest(digest); + * // use the raw digest as necessary + * ... + * parcCryptoHash_Release(&digest); + * } + * @endcode + */ +PARCBuffer *parcCryptoHash_GetDigest(const PARCCryptoHash *cryptoHash); + +/** + * Determine if two PARCCryptoHash instances are equal. + * + * The following equivalence relations on non-null `PARCCryptoHash` instances are maintained: + * + * * It is reflexive: for any non-null reference value x, `parcCryptoHash_Equals(x, x)` must return true. + * + * * It is symmetric: for any non-null reference values x and y, `parcCryptoHash_Equals(x, y)` must return true if and only if + * parcCryptoHash_Equals(y x) returns true. + * + * * It is transitive: for any non-null reference values x, y, and z, if + * `parcCryptoHash_Equals(x, y)` returns true and + * `parcCryptoHash_Equals(y, z)` returns true, + * then `parcCryptoHash_Equals(x, z)` must return true. + * + * * It is consistent: for any non-null reference values x and y, multiple invocations of `parcCryptoHash_Equals(x, y)` + * consistently return true or consistently return false. + * + * * For any non-null reference value x, `parcCryptoHash_Equals(x, NULL)` must return false. + * + * @param [in] a A pointer to a PARCCryptoHash instance. + * @param [in] b A pointer to a PARCCryptoHash instance. + * + * @return True if the given PARCCryptoHash instances are equal, false otherwise. + * + * Example: + * @code + * { + * PARCBuffer *buffer = ... + * PARCCryptoHash *orig = parcCryptoHash_Create(PARCCryptoHashType_SHA256, buffer); + * PARCCryptoHash *copy = parcCryptoHash_Create(PARCCryptoHashType_SHA256, buffer); + * + * if (parcCryptoHash_Equals(orig, copy)) { + * // true + * } else { + * // false + * } + * + * parcCryptoHash_Release(&orig); + * parcCryptoHash_Release(©); + * } + * @endcode + */ +bool parcCryptoHash_Equals(const PARCCryptoHash *a, const PARCCryptoHash *b); +#endif // libparc_parc_CryptoHash_h |