+import sha
+
+def bin2long(s):
+ return reduce( lambda x,y:(x<<8L)+y, map(ord, s))
+
+def long2bin(l):
+ res = ""
+ for byte in range(128):
+ res += chr((l >> (1024 - (byte + 1) * 8)) & 0xff)
+ return res
+
+def rsa_pub1024(src, mod):
+ return long2bin(pow(bin2long(src), 65537, bin2long(mod)))
+
+def decrypt_block(src, mod):
+ if len(src) != 128 and len(src) != 202:
+ return None
+ dest = rsa_pub1024(src[:128], mod)
+ hash = sha.new(dest[1:107])
+ if len(src) == 202:
+ hash.update(src[131:192])
+ result = hash.digest()
+ if result == dest[107:127]:
+ return dest
+ return None
+
+def validate_cert(cert, key):
+ buf = decrypt_block(cert[8:], key)
+ if buf is None:
+ return None
+ return buf[36:107] + cert[139:196]
+
+def read_random():
+ try:
+ fd = open("/dev/urandom", "r")
+ buf = fd.read(8)
+ fd.close()
+ return buf
+ except:
+ return None
\ No newline at end of file