decode base64: invalid input
That version will not decode (by default) lines with separators, yet the encoder does that by default. (Newer versions don't have this problem.)
One solution:
base64 -w 0 foo.zip | base64 -d > foo2.zip
Alternate:
base64 foo.zip | base64 -di > foo2.zip
The -i option stands for (from the man page):
-i, --ignore-garbage When decoding, ignore non-alphabet characters.[...]Decoding require compliant input by default, use --ignore-garbage toattempt to recover from non-alphabet characters (such as newlines)