Add SecureRandom.base58

1 files changed, 21 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/core_ext/securerandom.rb b/activesupport/lib/active_support/core_ext/securerandom.rb
new file mode 100644
index 0000000000..394cc76b98
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/securerandom.rb
@@ -0,0 +1,21 @@
+module SecureRandom
+  BASE58_ALPHABET = ('0'..'9').to_a  + ('A'..'Z').to_a + ('a'..'z').to_a - ['0', 'O', 'I', 'l']
+  # SecureRandom.base58 generates a random base58 string.
+  #
+  # The argument _n_ specifies the length, of the random string to be generated.
+  #
+  # If _n_ is not specified or is nil, 16 is assumed. It may be larger in the future.
+  #
+  # The result may contain alphanumeric characters except 0, O, I and l
+  #
+  #   p SecureRandom.base58 #=> "4kUgL2pdQMSCQtjE"
+  #   p SecureRandom.base58(24) #=> "77TMHrHJFvFDwodq8w7Ev2m7"
+  #
+  def self.base58(n = 16)
+    SecureRandom.random_bytes(n).unpack("C*").map do |byte|
+      idx = byte % 64
+      idx = SecureRandom.random_number(58) if idx >= 58
+      BASE58_ALPHABET[idx]
+    end.join
+  end
+end