Does MD5 and SHA only contain alphanumeric characters? (i.e., from A to Z and 0 to 9, or do they exclude some characters?)
MD5 and SHA hashes in raw form are binary, however their common representation is a hex-encoded string, which contains characters [a-fA-F0-9]
.
So if this is what you meant, then characters G-Z, g-z are "excluded".
Another, less common, representation is Base64 encoding [0-9a-zA-Z+/].