package hacl-star

raw_to_compressed p converts a "raw" point p (64 bytes) to a "compressed" point (33 bytes).

raw_to_uncompressed p converts a "raw" point p (64 bytes) to an "uncompressed" point (65 bytes).

compressed_to_raw p attempts to convert a "compressed" point p (33 bytes) to a "raw" point (64 bytes) and returns it if successful.

uncompressed_to_raw p attempts to convert an "uncompressed" point p (65 bytes) to a "raw" point (64 bytes) and returns it if successful.

valid_sk sk checks if the contents of sk can be used as a secret key or as a signing secret. This is the case if:

• sk is 32 bytes long
• 0 < sk < the order of the curve

valid_pk pk checks if the contents of pk is a valid public key. This is the case if:

• pk is 64 bytes long (it is in the "raw" form)
• the first 32 bytes encode x and the last 32 bytes encode y such that (x, y) is on the curve and both x and y are greater than 0 and less than the order of the curve

secret_to_public sk checks if sk is a valid secret key and, if it is, returns its corresponding public key.

sign sk msg k attempts to sign the message msg with secret key sk and signing secret k and returns the signature if successful.

verify pk msg signature checks the signature of msg using public key pk and returns true if it is valid.

Versions of the ECDSA functions which work on low-S normalized signatures. These functions can be used when compatibility with libsecp256k1 is required.

Versions of these functions which write their output in a buffer passed in as an argument