Data commit

Task/RSA-code/V-(Vlang)/rsa-code.v

@@ -0,0 +1,92 @@
+/*import math.big
+fn main() {
+    //var bb, ptn, etn, dtn big.Int
+    pt := "Rosetta Code"
+    println("Plain text:            $pt")
+
+    // a key set big enough to hold 16 bytes of plain text in
+    // a single block (to simplify the example) and also big enough
+    // to demonstrate efficiency of modular exponentiation.
+    n := big.integer_from_string("9516311845790656153499716760847001433441357")?
+    e := big.integer_from_string("65537")?
+    d := big.integer_from_string("5617843187844953170308463622230283376298685")?
+
+    mut ptn := big.zero_int
+    // convert plain text to a number
+    for b in pt.bytes() {
+        bb := big.integer_from_i64(i64(b))
+        ptn = ptn.lshift(8).bitwise_or(bb)
+    }
+    if ptn >= n {
+        println("Plain text message too long")
+        return
+    }
+    println("Plain text as a number:$ptn")
+
+    // encode a single number
+    etn := ptn.big_mod_pow(e,n)
+    println("Encoded:               $etn")
+
+    // decode a single number
+    mut dtn := etn.big_mod_pow(d,n)
+    println("Decoded:               $dtn")
+
+    // convert number to text
+    mut db := [16]u8{}
+    mut dx := 16
+    bff := big.integer_from_int(0xff)
+    for dtn.bit_len() > 0 {
+        dx--
+        bb := dtn.bitwise_and(bff)
+        db[dx] = u8(i64(bb.int()))
+        dtn = dtn.rshift(8)
+        println('${db[0..].bytestr()} ${dtn.bit_len()}')
+    }
+    println("Decoded number as text: ${db[dx..].bytestr()}")
+}*/
+
+import math.big
+fn main() {
+    //var bb, ptn, etn, dtn big.Int
+    pt := "Hello World"
+    println("Plain text:            $pt")
+
+    // a key set big enough to hold 16 bytes of plain text in
+    // a single block (to simplify the example) and also big enough
+    // to demonstrate efficiency of modular exponentiation.
+    n := big.integer_from_string("9516311845790656153499716760847001433441357")?
+    e := big.integer_from_string("65537")?
+    d := big.integer_from_string("5617843187844953170308463622230283376298685")?
+
+    mut ptn := big.zero_int
+    // convert plain text to a number
+    for b in pt.bytes() {
+        bb := big.integer_from_i64(i64(b))
+        ptn = ptn.lshift(8).bitwise_or(bb)
+    }
+    if ptn >= n {
+        println("Plain text message too long")
+        return
+    }
+    println("Plain text as a number:$ptn")
+
+    // encode a single number
+    etn := ptn.big_mod_pow(e,n)
+    println("Encoded:               $etn")
+
+    // decode a single number
+    mut dtn := etn.big_mod_pow(d,n)
+    println("Decoded:               $dtn")
+
+    // convert number to text
+    mut db := [16]u8{}
+    mut dx := 16
+    bff := big.integer_from_int(0xff)
+    for dtn.bit_len() > 0 {
+        dx--
+        bb := dtn.bitwise_and(bff)
+        db[dx] = u8(i64(bb.int()))
+        dtn = dtn.rshift(8)
+    }
+    println("Decoded number as text: ${db[dx..].bytestr()}")
+}