Element Import/Export

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.