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How is the MD2 hash function S-table constructed from Pi?

For fun, I'm learning more about cryptography and hashing. I'm implementing the MD2 hash function following RFC 1319 (https://www.rfc-editor.org/rfc/rfc1319). I'll preface by saying I know there are libraries, I know this is an old hash, and I do not intend to use this in anything real-world, so don't anyone freak out.

In learning about S-tables I notice MD2 uses an S-table based on Pi. What I don't understand, is how these numbers relate to Pi. And oddly, I can't find anywhere that describes it. The RFC just says:

This step uses a 256-byte "random" permutation constructed from the digits of pi.

In the reference code, there is the following comment:

Permutation of 0..255 constructed from the digits of pi. It gives a "random" nonlinear byte substitution operation.

Looking at the first few bytes:

41, 46, 67

I cannot see how you get these numbers from Pi. I've tried looking at the binary representation of Pi, and these numbers do not seem to match up with the first bytes of pi.

My usual Googling just leads me back to the RFC or other implementations which seem to copy the above comment exactly. No where can I find where the construction of this table from Pi is explained.

Answer*

Based on mikeazo's pseudocode, here's a fully working program in Python 3 that will generate the S-table:

    #!/usr/bin/env python3
    
    import io
    
    # We need 722 decimal digits of pi, including the integer part (3).
    pi = io.StringIO('3'
        '1415926535897932384626433832795028841971693993751058209749445923078164062'
        '8620899862803482534211706798214808651328230664709384460955058223172535940'
        '8128481117450284102701938521105559644622948954930381964428810975665933446'
        '1284756482337867831652712019091456485669234603486104543266482133936072602'
        '4914127372458700660631558817488152092096282925409171536436789259036001133'
        '0530548820466521384146951941511609433057270365759591953092186117381932611'
        '7931051185480744623799627495673518857527248912279381830119491298336733624'
        '4065664308602139494639522473719070217986094370277053921717629317675238467'
        '4818467669405132000568127145263560827785771342757789609173637178721468440'
        '901224953430146549585371050792279689258923542019956112129021960864034418')
    
    # Generate a pseudorandom integer in interval [0,n) using decimal
    # digits of pi (including the leading 3) as a seed.
    def pi_prng(n):
        while True:
            # based on n, decide how many of digits to work with
            if   n <=   10: x, y = int(pi.read(1)),   10
            elif n <=  100: x, y = int(pi.read(2)),  100
            elif n <= 1000: x, y = int(pi.read(3)), 1000
            else: raise ValueError(f'Given value of n ({n}) is too big!')
    
            # Compute the largest integer multiple of n not larger than y.
            # If x is smaller than that, we can safely return it modulo n,
            # otherwise we need to try again to avoid modulo bias.
            if x < (n * (y // n)): return x % n
    
    # Fischer-Yates/Durstenfeld shuffling algorithm, except counting up
    # XXX Does counting up bias the results?
    S = list(range(256))
    for i in range(1,256):
        # generate pseudorandom j such that 0 ≤ j ≤ i
        j = pi_prng(i+1)
        S[j], S[i] = S[i], S[j]
    
    # Print the S-table as shown on Wikipedia.
    for i in range(16):
        prefix = '{ ' if i ==  0 else '  '
        suffix = ' }' if i == 15 else ','
        row = S[i*16:i*16+16]
        print(prefix + ', '.join(map(lambda s: '0x%02X' % s, row)) + suffix)

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