discourse-gossamerhash/goss-gthash.rb

97 lines
2.4 KiB
Ruby

require 'digest'
# Constants
ITOA64 = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
def to64(value, length)
result = ""
length.times do
result << ITOA64[value & 0x3f]
value >>= 6
end
result
end
def gossamer_md5_crypt(password, legacy_hash)
# Extract the salt from the legacy hash
parts = legacy_hash.split('$')
salt = parts[2]
# Limit the salt to 8 characters
salt = salt[0, 8]
magic = "$GT$"
ctx = Digest::MD5.new
ctx.update(password)
ctx.update(magic)
ctx.update(salt)
final = Digest::MD5.new
final.update(password)
final.update(salt)
final.update(password)
final_digest = final.digest
password_length = password.length
while password_length > 0
ctx.update(final_digest[0, [password_length, 16].min])
password_length -= 16
end
password_length = password.length
while password_length > 0
if password_length & 1 != 0
ctx.update("\x00")
else
ctx.update(password[0, 1])
end
password_length >>= 1
end
final_digest = ctx.digest
1000.times do |i|
ctx1 = Digest::MD5.new
if i & 1 != 0
ctx1.update(password)
else
ctx1.update(final_digest)
end
ctx1.update(salt) if i % 3 != 0
ctx1.update(password) if i % 7 != 0
if i & 1 != 0
ctx1.update(final_digest)
else
ctx1.update(password)
end
final_digest = ctx1.digest
end
result = ''
result << to64((final_digest[0].ord << 16) | (final_digest[6].ord << 8) | final_digest[12].ord, 4)
result << to64((final_digest[1].ord << 16) | (final_digest[7].ord << 8) | final_digest[13].ord, 4)
result << to64((final_digest[2].ord << 16) | (final_digest[8].ord << 8) | final_digest[14].ord, 4)
result << to64((final_digest[3].ord << 16) | (final_digest[9].ord << 8) | final_digest[15].ord, 4)
result << to64((final_digest[4].ord << 16) | (final_digest[10].ord << 8) | final_digest[5].ord, 4)
result << to64(final_digest[11].ord, 2)
"#{magic}#{salt}$#{result}"
end
def verify_gossamer_password(password, legacy_hash)
generated_hash = gossamer_md5_crypt(password, legacy_hash)
generated_hash == legacy_hash
end
# Example usage
legacy_hash = "$GT$i5ZNZdfX$077FK6JU70HIr2pR1/uLP1"
password = "polyflex80"
resulting_hash = gossamer_md5_crypt(password, legacy_hash)
puts "Generated hash: #{resulting_hash}"
puts "Legacy hash: #{legacy_hash}"
puts "Password verification: #{verify_gossamer_password(password, legacy_hash)}"