This is useful for creating a message hash and achieving domain separation
through an application-specific tag. This function returns
SHA256(SHA256(tag)||SHA256(tag)||msg). Therefore, tagged hash
implementations optimized for a specific tag can precompute the SHA256 state
after hashing the tag hashes.
Returns 0 if the arguments are invalid and 1 otherwise.
Args: ctx: pointer to a context object
Out: hash32: pointer to a 32-byte array to store the resulting hash
In: tag: pointer to an array containing the tag
taglen: length of the tag array
msg: pointer to an array containing the message
msglen: length of the message array
Compute a tagged hash as defined in BIP-340.
This is useful for creating a message hash and achieving domain separation through an application-specific tag. This function returns SHA256(SHA256(tag)||SHA256(tag)||msg). Therefore, tagged hash implementations optimized for a specific tag can precompute the SHA256 state after hashing the tag hashes.
Returns 0 if the arguments are invalid and 1 otherwise. Args: ctx: pointer to a context object Out: hash32: pointer to a 32-byte array to store the resulting hash In: tag: pointer to an array containing the tag taglen: length of the tag array msg: pointer to an array containing the message msglen: length of the message array