Is the algorithm known to produce all theoretically possible hash values? Imagine a simple algorithm that should hash a string to a number 0-3, but due to an e

Is the algorithm known to produce all theoretically possible hash values? Imagine a simple algorithm that should hash a string to a number 0-3, but due to an extra condition it actually cannot produce "3", pseudocode: ``` Sum = sumOfAsciiCodeOfString(input); Rest = Sum % 4; Return Rest === 3 ? 2 : Rest; ``` Or due to a bug (replace `% 4` with `% 3`). Can we prove that md5 doesn't suffer from such issues and it actually can output ffffffffffff or deaddeaddeaddead ?