Calculates the SHA-256 hash of the input and encodes it as base64. If the * output buffer is smaller than olm_sha256_length() then * olm_session_last_error() will be "OUTPUT_BUFFER_TOO_SMALL".
See Implementation
Calculates the SHA-256 hash of the input and encodes it as base64. If the * output buffer is smaller than olm_sha256_length() then * olm_session_last_error() will be "OUTPUT_BUFFER_TOO_SMALL".