Data update

Task/RSA-code/Pluto/rsa-code.pluto

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+require "bignum"
+require "table2"
+
+local pt = "Rosetta Code"
+print($"Plain text:            : {pt}")
+local n = bigint.new("9516311845790656153499716760847001433441357")
+local e = bigint.new("65537")
+local d = bigint.new("5617843187844953170308463622230283376298685")
+local ptn = bigint.zero
+-- Convert plain text to a number.
+for {pt:byte(1, #pt)} as b do
+    ptn = bigint.bor(bigint.shl(ptn, 8), bigint.new(b))
+end
+if ptn >= n then
+    print("Plain text message too long")
+    os.exit(1)
+end
+print($"Plain text as a number : {ptn}")
+
+-- Encode a single number.
+local etn = bigint.modpow(ptn, e, n)
+print($"Encoded                : {etn}")
+
+-- Decode a single number.
+local dtn = bigint.modpow(etn, d, n)
+print($"Decoded                : {dtn}")
+
+-- Convert number to text.
+local db = table.rep(16, 0)
+local dx = 16
+local bff = bigint.new(255)
+while dtn:bitlength() > 0 do
+    db[dx] = bigint.toplain(bigint.band(dtn, bff))
+    dx -= 1
+    dtn = bigint.shr(dtn, 8)
+end
+local s = ""
+for i = dx + 1, 16 do s ..= string.char(db[i]) end
+print($"Decoded number as text : {s}")