BLAKE2b Hash¶

typedef struct cardano_blake2b_hash_t cardano_blake2b_hash_t¶

Represents a BLAKE2b hash.

This structure encapsulates the result of a BLAKE2b hashing operation, abstracting the underlying hash data. It is used throughout the Cardano system in various contexts, such as transaction identification, address generation, and cryptographic verification.

cardano_error_t cardano_blake2b_compute_hash(const byte_t *data, size_t data_length, size_t hash_length, cardano_blake2b_hash_t **hash)¶

Computes a BLAKE2b hash for the given data.

This function calculates the BLAKE2b hash of the specified input data and returns the hash result as a newly allocated cardano_blake2b_hash_t instance.

Example Usage:

byte_t data[] = { ... };
size_t data_length = sizeof(data);
cardano_blake2b_hash_t* hash = NULL;
cardano_error_t result = cardano_blake2b_compute_hash(data, data_length, CARDANO_BLAKE2B_HASH_SIZE_256, &hash);

if (result == CARDANO_SUCCESS)
{
  // Use the hash
  ...
  cardano_blake2b_hash_unref(&hash);
}
else
{
  // Handle error
}

Parameters:¶

const byte_t *data¶: [in] A pointer to the byte array containing the input data to hash.
size_t data_length¶: [in] The length of the input data array in bytes.
size_t hash_length¶: [in] The desired length of the resulting hash in bytes. Valid values depend on the specific BLAKE2b variant being used (e.g., 28 for BLAKE2b-224, 32 for BLAKE2b-256, 64 for BLAKE2b-512).
cardano_blake2b_hash_t **hash¶: [out] A pointer to a pointer to cardano_blake2b_hash_t that will be allocated and set to point to the newly created hash object on successful completion of the function.

Returns:¶

cardano_error_t indicating the success or failure of the hash computation. Returns CARDANO_SUCCESS on success, or an error code signifying the type of failure encountered during the hash computation.

cardano_error_t cardano_blake2b_hash_from_bytes(const byte_t *data, size_t data_length, cardano_blake2b_hash_t **hash)¶

Creates a BLAKE2b hash object from raw byte data.

This function takes a buffer of hash bytes and constructs a new BLAKE2b hash object.

Example Usage:

byte_t data[] = { ... };
size_t data_length = sizeof(data) / sizeof(byte_t);
cardano_blake2b_hash_t* hash = NULL;

cardano_error_t error = cardano_blake2b_hash_from_bytes(data, data_length, &hash);

if (error == CARDANO_SUCCESS)
{
  // Use the hash object for further operations
}

// Clean up
cardano_blake2b_hash_unref(hash);

Parameters:¶

const byte_t *data¶: [in] Pointer to the raw byte data of the hash.
size_t data_length¶: [in] The length of the data in bytes.
cardano_blake2b_hash_t **hash¶: [out] A pointer to a pointer to cardano_blake2b_hash_t where the address of the newly created hash object will be stored. The caller is responsible for managing the lifecycle of the created hash object, including its proper deallocation through the corresponding unreference or destruction function to prevent memory leaks.

Returns:¶

cardano_error_t Returns an error code indicating the status of the operation. On success, the function returns CARDANO_SUCCESS and hash is set to point to the newly created hash object. On failure, a non-zero error code is returned and the value pointed to by hash is set to NULL.

cardano_error_t cardano_blake2b_hash_from_hex(const char *hex, size_t hex_length, cardano_blake2b_hash_t **hash)¶

Creates a BLAKE2b hash object from hexadecimal string data.

This function takes a hexadecimal string representing hash data and constructs a new BLAKE2b hash object. The function is designed to parse the hexadecimal string input and convert it into the corresponding binary representation before creating the hash object.

Example Usage:

const char* hex_data = "abc123..."; // Hexadecimal representation of the data
size_t hex_length = strlen(hex_data);
cardano_blake2b_hash_t* hash = NULL;

cardano_error_t error = cardano_blake2b_hash_from_hex(hex_data, hex_length, &hash);

if (error == CARDANO_SUCCESS)
{
  // The hash object can now be used for further operations
}

// Clean up
cardano_blake2b_hash_unref(hash);

Parameters:¶

const char *hex¶: [in] Pointer to the hexadecimal string to be converted into a hash object.
size_t hex_length¶: [in] The length of the hexadecimal string in characters.
cardano_blake2b_hash_t **hash¶: [out] A pointer to a pointer to cardano_blake2b_hash_t where the address of the newly created hash object will be stored. The caller is responsible for managing the lifecycle of the created hash object, including its proper deallocation through the corresponding unreference or destruction function to prevent memory leaks.

Returns:¶

cardano_error_t Returns an error code indicating the status of the operation. On success, the function returns CARDANO_SUCCESS, and hash is set to point to the newly created hash object. On failure, a non-zero error code is returned, and the value pointed to by hash is set to NULL.

cardano_error_t cardano_blake2b_hash_from_cbor(cardano_cbor_reader_t *reader, cardano_blake2b_hash_t **blake2b_hash)¶

Creates a cardano_blake2b_hash_t from a CBOR reader.

This function parses CBOR data using a provided cardano_cbor_reader_t and constructs a cardano_blake2b_hash_t object. It assumes that the CBOR reader is set up correctly and that the CBOR data corresponds to the structure expected for a blake2b_hash.

Usage Example:

cardano_cbor_reader_t* reader = cardano_cbor_reader_new(cbor_data, data_size);
cardano_blake2b_hash_t* blake2b_hash = NULL;

cardano_error_t result = cardano_blake2b_hash_from_cbor(reader, &blake2b_hash);

if (result == CARDANO_SUCCESS)
{
  // Use the blake2b_hash

  // Once done, ensure to clean up and release the blake2b_hash
  cardano_blake2b_hash_unref(&blake2b_hash);
}
else
{
  const char* error = cardano_cbor_reader_get_last_error(reader);
  printf("Failed to decode blake2b_hash: %s\n", error);
}

cardano_cbor_reader_unref(&reader); // Cleanup the CBOR reader

Note

If the function fails, the last error can be retrieved by calling cardano_cbor_reader_get_last_error with the reader. The caller is responsible for freeing the created cardano_blake2b_hash_t object by calling cardano_blake2b_hash_unref when it is no longer needed.

Parameters:¶

cardano_cbor_reader_t *reader¶: [in] A pointer to an initialized cardano_cbor_reader_t that is ready to read the CBOR-encoded data.
cardano_blake2b_hash_t **blake2b_hash¶: [out] A pointer to a pointer of cardano_blake2b_hash_t that will be set to the address of the newly created blake2b_hash object upon successful decoding.

Returns:¶

A cardano_error_t value indicating the outcome of the operation. Returns CARDANO_SUCCESS if the object was successfully created, or an appropriate error code if an error occurred.

cardano_error_t cardano_blake2b_hash_to_cbor(const cardano_blake2b_hash_t *blake2b_hash, cardano_cbor_writer_t *writer)¶

Serializes protocol version into CBOR format using a CBOR writer.

This function serializes the given cardano_blake2b_hash_t object using a cardano_cbor_writer_t.

Usage Example:

cardano_blake2b_hash_t* blake2b_hash = ...;
cardano_cbor_writer_t* writer = cardano_cbor_writer_new();

if (writer)
{
  cardano_error_t result = cardano_blake2b_hash_to_cbor(blake2b_hash, writer);

  if (result == CARDANO_SUCCESS)
  {
    // Use the writer's buffer containing the serialized data
  }
  else
  {
    const char* error_message = cardano_cbor_writer_get_last_error(writer);
    printf("Serialization failed: %s\n", error_message);
  }

  cardano_cbor_writer_unref(&writer);
}

cardano_blake2b_hash_unref(&blake2b_hash);

Parameters:¶

const cardano_blake2b_hash_t *blake2b_hash¶: [in] A constant pointer to the cardano_blake2b_hash_t object that is to be serialized.
cardano_cbor_writer_t *writer¶: [out] A pointer to a cardano_cbor_writer_t where the CBOR serialized data will be written. The writer must already be initialized and ready to accept the data.

Returns:¶

Returns CARDANO_SUCCESS if the serialization is successful. If the blake2b_hash or writer is NULL, returns CARDANO_ERROR_POINTER_IS_NULL.

cardano_error_t cardano_blake2b_hash_to_cip116_json(const cardano_blake2b_hash_t *blake2b_hash, cardano_json_writer_t *writer)¶

Serializes a BLAKE2b-256 hash to CIP-116 JSON.

Writes exactly one JSON string (64 lowercase hex characters) to writer:

"0000000000000000000000000000000000000000000000000000000000000000"

Parameters:¶

const cardano_blake2b_hash_t *blake2b_hash¶: [in] The hash to serialize. Must not be NULL.
cardano_json_writer_t *writer¶: [inout] A valid JSON writer positioned where a value is expected. Must not be NULL.

Returns:¶

CARDANO_SUCCESS on success; an appropriate error code otherwise.

bool cardano_blake2b_hash_equals(const cardano_blake2b_hash_t *lhs, const cardano_blake2b_hash_t *rhs)¶

Compares two Blake2b hash objects for equality.

This function compares two Blake2b hash objects to determine if they are equal.

Usage Example:

cardano_blake2b_hash_t* hash1 = NULL;
cardano_blake2b_hash_t* hash2 = NULL;

// Assume hash1 and hash2 are initialized properly

bool are_equal = cardano_blake2b_hash_equals(hash1, hash2);

if (are_equal)
{
  printf("The hash objects are equal.\n");
}
else
{
  printf("The hash objects are not equal.\n");
}

// Clean up
cardano_blake2b_hash_unref(&hash1);
cardano_blake2b_hash_unref(&hash2);

Parameters:¶

const cardano_blake2b_hash_t *lhs¶: [in] Pointer to the first Blake2b hash object.
const cardano_blake2b_hash_t *rhs¶: [in] Pointer to the second Blake2b hash object.

Returns:¶

true if the hash objects are equal, false otherwise.

int32_t cardano_blake2b_hash_compare(const cardano_blake2b_hash_t *lhs, const cardano_blake2b_hash_t *rhs)¶

Compares two Blake2b hash objects.

This function compares two Blake2b hash objects and returns an integer indicating their relative order.

Usage Example:

cardano_blake2b_hash_t* hash1 = NULL;
cardano_blake2b_hash_t* hash2 = NULL;

// Assume hash1 and hash2 are initialized properly

int32_t comparison = cardano_blake2b_hash_compare(hash1, hash2);
if (comparison < 0)
{
  printf("hash1 is less than hash2.\n");
}
else if (comparison == 0)
{
  printf("hash1 is equal to hash2.\n");
}
else
{
  printf("hash1 is greater than hash2.\n");
}

// Clean up
cardano_blake2b_hash_unref(&hash1);
cardano_blake2b_hash_unref(&hash2);

Parameters:¶

const cardano_blake2b_hash_t *lhs¶: [in] Pointer to the first Blake2b hash object.
const cardano_blake2b_hash_t *rhs¶: [in] Pointer to the second Blake2b hash object.

Returns:¶

A negative value if lhs is less than rhs, zero if they are equal, and a positive value if lhs is greater than rhs.

void cardano_blake2b_hash_unref(cardano_blake2b_hash_t **hash)¶

Decrements the reference count of a BLAKE2b hash object.

This function is responsible for managing the lifecycle of a cardano_blake2b_hash_t object by decreasing its reference count. When the reference count reaches zero, the BLAKE2b hash is finalized; its associated resources are released, and its memory is deallocated.

Usage Example:

cardano_error_t result = cardano_blake2b_compute_hash(data, data_length, CARDANO_BLAKE2B_HASH_SIZE_256, &hash);

// Perform operations with the hash...

cardano_blake2b_hash_unref(&hash);
// At this point, hash is NULL and cannot be used.

Parameters:¶

cardano_blake2b_hash_t **hash¶: [inout] A pointer to the pointer of the BLAKE2b hash object. This double indirection allows the function to set the caller’s pointer to NULL, avoiding dangling pointer issues after the object has been freed.

void cardano_blake2b_hash_ref(cardano_blake2b_hash_t *hash)¶

Increases the reference count of the cardano_blake2b_hash_t object.

This function is used to manually increment the reference count of a BLAKE2b hash object, indicating that another part of the code has taken ownership of it. This ensures the object remains allocated and valid until all owners have released their reference by calling cardano_blake2b_hash_unref.

Usage Example:

// Assuming hash is a previously created BLAKE2b hash object

cardano_blake2b_hash_ref(hash);

// Now hash can be safely used elsewhere without worrying about premature deallocation

Note

Always ensure that for every call to cardano_blake2b_hash_ref there is a corresponding call to cardano_blake2b_hash_unref to prevent memory leaks.

Parameters:¶

cardano_blake2b_hash_t *hash¶: [inout] A pointer to the BLAKE2b hash object whose reference count is to be incremented.

size_t cardano_blake2b_hash_refcount(const cardano_blake2b_hash_t *hash)¶

Retrieves the current reference count of the cardano_blake2b_hash_t object.

This function returns the number of active references to a BLAKE2b hash object. It’s useful for debugging purposes or managing the lifecycle of the object in complex scenarios.

Usage Example:

// Assuming hash is a previously created BLAKE2b hash object

size_t ref_count = cardano_blake2b_hash_refcount(hash);

printf("Reference count: %zu\n", ref_count);

Warning

This function does not account for transitive references. A transitive reference occurs when an object holds a reference to another object, rather than directly to the cardano_blake2b_hash_t. As such, the reported count may not fully represent the total number of conceptual references in cases where such transitive relationships exist.

Parameters:¶

const cardano_blake2b_hash_t *hash¶: [inout] A pointer to the BLAKE2b hash object whose reference count is queried. The object must not be NULL.

Returns:¶

The number of active references to the specified BLAKE2b hash object. If the object is properly managed (i.e., every cardano_blake2b_hash_ref call is matched with a cardano_blake2b_hash_unref call), this count should reach zero right before the object is deallocated.

const byte_t *cardano_blake2b_hash_get_data(const cardano_blake2b_hash_t *blake2b_hash)¶

Retrieves a direct pointer to the internal data of a blake2b hash object.

This function provides access to the internal storage of the blake2b hash object, allowing for read-only operations on its contents. It is intended for situations where direct access to the data is necessary for performance or interoperability reasons.

Warning

The returned pointer provides raw, direct access to the blake2b hash object’s internal data. It must not be used to modify the buffer contents outside the API’s control, nor should it be deallocated using free or similar memory management functions. The lifecycle of the data pointed to by the returned pointer is managed by the blake2b hash object’s reference counting mechanism; therefore, the data remains valid as long as the blake2b hash object exists and has not been deallocated.

Parameters:¶

const cardano_blake2b_hash_t *blake2b_hash¶: [in] The blake2b hash instance from which to retrieve the internal data pointer. The blake2b hash must have been previously created and not yet deallocated.

Returns:¶

Returns a pointer to the internal data of the blake2b hash. If the blake2b hash instance is invalid, returns NULL. The returned pointer provides direct access to the blake2b hash’s contents and must be used in accordance with the warning above to avoid unintended consequences.

size_t cardano_blake2b_hash_get_bytes_size(const cardano_blake2b_hash_t *blake2b_hash)¶

Retrieves the size of the BLAKE2b hash object in bytes.

Parameters:¶

const cardano_blake2b_hash_t *blake2b_hash¶: [in] A pointer to the cardano_blake2b_hash_t object whose size is to be retrieved.

Returns:¶

The size of the BLAKE2b hash object in bytes. If the provided hash object is invalid or NULL, the function will return 0.

cardano_error_t cardano_blake2b_hash_to_bytes(const cardano_blake2b_hash_t *blake2b_hash, byte_t *hash, size_t hash_length)¶

Converts a BLAKE2b hash object into a raw byte array representation.

This function exports the contents of a given BLAKE2b hash object into a user-provided byte array.

Example Usage:

cardano_blake2b_hash_t* hash_obj = ...; // Assume hash_obj is previously created and valid
const size_t hash_size = cardano_blake2b_hash_get_bytes_size(hash_obj);
byte_t* hash_bytes = malloc(hash_size); // Allocate enough space for the hash

if (hash_bytes != NULL)
{
  cardano_error_t error = cardano_blake2b_hash_to_bytes(hash_obj, hash_bytes, hash_size);

  if (error == CARDANO_SUCCESS)
  {
    // The hash_bytes array now contains the hash object's bytes
  }

  // Remember to free the allocated memory when done
  free(hash_bytes);
}

Note: It is the caller’s responsibility to ensure that the hash array is correctly allocated and to free any allocated resources when no longer needed.

Parameters:¶

const cardano_blake2b_hash_t *blake2b_hash¶: [in] A pointer to the cardano_blake2b_hash_t object to be exported.
byte_t *hash¶: [out] A pointer to a byte array where the hash bytes will be stored. This array must be pre-allocated by the caller and be large enough to hold the entire hash value.
size_t hash_length¶: [in] The length of the hash array in bytes. This must be equal to or larger than the size of the hash object to avoid buffer overflow.

Returns:¶

cardano_error_t Returns an error code indicating the status of the operation. On success, the function returns CARDANO_SUCCESS and the hash array contains the byte representation of the hash object. On failure, a non-zero error code is returned. Possible failure reasons include invalid input parameters or a mismatch between hash_length and the actual size of the hash object.

size_t cardano_blake2b_hash_get_hex_size(const cardano_blake2b_hash_t *blake2b_hash)¶

Retrieves the size of the hexadecimal representation of a BLAKE2b hash object.

This function calculates the length of the string that would represent the BLAKE2b hash object in hexadecimal form. This is useful for allocating the correct amount of memory to store the hexadecimal representation of the hash.

Example Usage:

cardano_blake2b_hash_t* hash_obj = ...; // Assume hash_obj is previously created
size_t hex_size = cardano_blake2b_hash_get_hex_size(hash_obj);
char* hex_buffer = (char*)malloc(hex_size);

if (cardano_blake2b_hash_to_hex(hash_obj, hex_buffer, hex_size) == CARDANO_SUCCESS)
{
  // hex_buffer now contains the hexadecimal representation of the hash
}

free(hex_buffer);

Parameters:¶

const cardano_blake2b_hash_t *blake2b_hash¶: [in] A pointer to the cardano_blake2b_hash_t object whose hexadecimal size is to be retrieved.

Returns:¶

The size of the buffer needed to store the hexadecimal representation of the hash object, including the terminating null byte. If the provided hash object is invalid or NULL, the function will return 0.

cardano_error_t cardano_blake2b_hash_to_hex(const cardano_blake2b_hash_t *blake2b_hash, char *hex_hash, size_t hash_length)¶

Converts a BLAKE2b hash object into its hexadecimal string representation.

This function exports the hexadecimal string representation of the provided BLAKE2b hash object into a user-supplied buffer.

Example Usage:

cardano_blake2b_hash_t* hash_obj = ...; // Assume hash_obj is previously created
size_t hex_size = cardano_blake2b_hash_get_hex_size(hash_obj);
byte_t* hex_buffer = (byte_t*)malloc(hex_size);

if (cardano_blake2b_hash_to_hex(hash_obj, hex_buffer, hex_size) == CARDANO_SUCCESS)
{
 // hex_buffer now contains the hexadecimal representation of the hash
}

free(hex_buffer);

Parameters:¶

const cardano_blake2b_hash_t *blake2b_hash¶: [in] A pointer to the cardano_blake2b_hash_t object to be converted.
char *hex_hash¶: [out] A pointer to the buffer where the hexadecimal string representation of the hash will be stored. The buffer must be large enough to hold the hexadecimal representation of the hash, including the terminating null byte.
size_t hash_length¶: [in] The size of the buffer pointed to by hex_hash. This value should be at least twice the size of the hash object in bytes plus one for the terminating null byte, to accommodate the hexadecimal representation.

Returns:¶

cardano_error_t Returns an error code indicating the status of the operation. On success, the function returns CARDANO_SUCCESS, and the buffer pointed to by hex_hash is filled with the hexadecimal representation of the hash object. On failure, a non-zero error code is returned, which could indicate an invalid hash object, insufficient buffer size, or other errors.