Functions for serializing and deserializing elements.
int element_length_in_bytes(element_t e)
Returns the length in bytes the element e will take to represent
int element_to_bytes(unsigned char *data, element_t e)
Converts e to byte, writing the result in the buffer data. The number of bytes it will write can be determined from calling element_length_in_bytes(). Returns number of bytes written.
int element_from_bytes(element_t e, unsigned char *data)
Reads e from the buffer data, and returns the number of bytes read.
int element_to_bytes_x_only(unsigned char *data, element_t e)
Assumes e is a point on an elliptic curve. Writes the x-coordinate of e to the buffer data
int element_from_bytes_x_only(element_t e, unsigned char *data)
Assumes e is a point on an elliptic curve. Sets e to a point with x-coordinate represented by the buffer data. This is not unique. For each x-coordinate, there exist two different points, at least for the elliptic curves in PBC. (They are inverses of each other.)
int element_length_in_bytes_x_only(element_t e)
Assumes e is a point on an elliptic curve. Returns the length in bytes needed to hold the x-coordinate of e.
int element_to_bytes_compressed(unsigned char *data, element_t e)
If possible, outputs a compressed form of the element e to the buffer of bytes data. Currently only implemented for points on an elliptic curve.
int element_from_bytes_compressed(element_t e, unsigned char *data)
Sets element e to the element in compressed form in the buffer of bytes data. Currently only implemented for points on an elliptic curve.
int element_length_in_bytes_compressed(element_t e)
Returns the number of bytes needed to hold e in compressed form. Currently only implemented for points on an elliptic curve.
int element_item_count(element_t e)
For points, returns the number of coordinates. For polynomials, returns the number of coefficients. Otherwise returns zero.
element_t element_item(element_t e, int i)
For points, returns nth coordinate. For polynomials, returns coefficient of xn. Otherwise returns NULL. The element the return value points to may be modified.
element_t element_x(element_t a)
Equivalent to
element_item(a, 0).
element_t element_y(element_t a)
Equivalent to
element_item(a, 1).