(Tcl) Generating Repeatable Random Data for Testing/Debugging

Demonstrates how to use the Fortuna PRNG to generate random-looking but repeatable non-random data for the purpose of testing and debugging.

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load ./chilkat.dll

# All Chilkat classes can be unlocked at once at the beginning of a program
# by calling UnlockBundle.  It requires a Bundle unlock code.
set chilkatGlob [new_CkGlobal]

set success [CkGlobal_UnlockBundle $chilkatGlob "Anything for 30-day trial."]
if {$success != 1} then {
    puts [CkGlobal_lastErrorText $chilkatGlob]
    delete_CkGlobal $chilkatGlob
    exit
}

set fortuna [new_CkPrng]

# Normally an application would seed the PRNG with entropy from
# some real random source.  However, sometimes we want the same
# random sequence of bytes for testing and debugging purposes.
# This a reason why GetEntropy and AddEntropy are two different methods.
# An application could omit the call to GetEntropy, and instead pass
# non-random data to AddEntropy. For example:

# Seed the PRNG with non-entropy, so we get a repeatable sequence.
# Note: AddEntropy can be called any number of times.
set success [CkPrng_AddEntropy $fortuna "01020304" "hex"]
set success [CkPrng_AddEntropy $fortuna "hello world" "ascii"]

# Generate some random data:
set strRandHex [CkPrng_genRandom $fortuna 16 "hex"]
set strRandBase64 [CkPrng_genRandom $fortuna 22 "base64"]
set strRandBase58 [CkPrng_genRandom $fortuna 32 "base58"]

puts "hex random bytes: $strRandHex"
puts "base64 random bytes: $strRandBase64"
puts "base58 random bytes: $strRandBase58"

# Try it again with a different object to verify that the same results are obtained:
set fortuna2 [new_CkPrng]

set success [CkPrng_AddEntropy $fortuna2 "01020304" "hex"]
set success [CkPrng_AddEntropy $fortuna2 "hello world" "ascii"]

set strRandHex [CkPrng_genRandom $fortuna2 16 "hex"]
set strRandBase64 [CkPrng_genRandom $fortuna2 22 "base64"]
set strRandBase58 [CkPrng_genRandom $fortuna2 32 "base58"]

puts "hex random bytes: $strRandHex"
puts "base64 random bytes: $strRandBase64"
puts "base58 random bytes: $strRandBase58"

delete_CkGlobal $chilkatGlob
delete_CkPrng $fortuna
delete_CkPrng $fortuna2