Clean up ssh_rsa_key_util.py.

reused some functions from keyczar.util

1 files changed, 12 insertions, 40 deletions

diff --git a/ssh_rsa_key_util.py b/ssh_rsa_key_util.py
index 11d322e..e4cd5ba 100644
--- a/ssh_rsa_key_util.py
+++ b/ssh_rsa_key_util.py
@@ -1,6 +1,7 @@
 import base64
 import struct
 import filecmp
+from keyczar import util
 
 # need pyasn for DER parsing and generating
 from pyasn1.type import univ
@@ -13,7 +14,6 @@ def read_int(buffer, i):
     i += 4
     return (l, i)
 
-
 def read_chunk(buffer, i):
     "Read chunk from buffer."
 
@@ -29,34 +29,6 @@ def read_chunk(buffer, i):
     i += l
     return (s, i)
 
-
-def unpack_bigint(buffer):
-    "Turn binary chunk into integer."
-
-    v = 0
-    for c in buffer:
-        v *= 256
-        v += ord(c)
-
-    return v
-
-
-def pack_bigint(v):
-    "Pack integer into binary chunk."
-
-    chunk = ''
-    rest = v
-    while rest:
-        chunk = chr(rest % 256) + chunk
-        rest //= 256
-
-    # add a zero byte if the highest bit is 1, so it won't be negative
-    if ord(chunk[0]) & 128:
-        chunk = chr(0) + chunk
-
-    return chunk
-
-
 def read_rsa_pub(filename):
     """Read RSA public key file. Structure:
 
@@ -76,15 +48,14 @@ def read_rsa_pub(filename):
 
     # grab e
     (s, i) = read_chunk(raw, i)
-    e = unpack_bigint(s)
-
+    #e = unpack_bigint(s)
+    e = util.BytesToLong(s)
     # grab n
     (s, i) = read_chunk(raw, i)
-    n = unpack_bigint(s)
-
+    #n = unpack_bigint(s)
+    n = util.BytesToLong(s)
     return (n, e, host)
 
-
 def write_rsa_pub(filename, n, e, host):
     """Write RSA public key file. Structure:
 
@@ -93,8 +64,11 @@ def write_rsa_pub(filename, n, e, host):
        base64data: [7]ssh-rsa[len][e-data][len][n-data]
     """
 
-    e_str = pack_bigint(e)
-    n_str = pack_bigint(n)
+    #e_str = pack_bigint(e)
+    #n_str = pack_bigint(n)
+    e_str = util.BigIntToBytes(e)
+    n_str = util.BigIntToBytes(n)
+    
     # pack e and n properly into the raw data
     raw = struct.pack('!I7sI{0:d}sI{1:d}s'.format(len(e_str), len(n_str)), 7, 'ssh-rsa',
                                         len(e_str), e_str, len(n_str), n_str)
@@ -102,7 +76,6 @@ def write_rsa_pub(filename, n, e, host):
     content = "ssh-rsa {0!s} {1!s}\n".format(base64.b64encode(raw), host)
     file(filename, 'w').write(content)
 
-
 def read_rsa_pri(filename):
     """Read RSA private key file. Structure:
 
@@ -136,7 +109,6 @@ def read_rsa_pri(filename):
 
     return (n, e, d, p, q, e1, e2, c)
 
-
 def write_rsa_pri(filename, n, e, d, p, q, e1, e2, c):
     """Write RSA private key file. Structure:
 
@@ -184,9 +156,9 @@ def write_rsa_pri(filename, n, e, d, p, q, e1, e2, c):
     chopped = [data[i:i + width] for i in xrange(0, len(data), width)]
     # assemble file content
     content = """-----BEGIN RSA PRIVATE KEY-----
-%s
+{0}
 -----END RSA PRIVATE KEY-----
-""" % '\n'.join(chopped)
+""".format('\n'.join(chopped))
     file(filename, 'w').write(content)
 
 if __name__ == '__main__' :