diff options
| -rwxr-xr-x | Lib/base64.py | 90 |
1 files changed, 14 insertions, 76 deletions
diff --git a/Lib/base64.py b/Lib/base64.py index 90b5273..c5a7ca7 100755 --- a/Lib/base64.py +++ b/Lib/base64.py @@ -2,95 +2,33 @@ # version). # Parameters set by RFX-XXXX. -MAXLINESIZE = 76 # Excluding the CRLF -INVAR = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/' -PAD = '=' +# +# Modified 04-Oct-95 by Jack to use binascii module -# Check that I typed that string correctly... -if len(INVAR) <> 64: raise RuntimeError, 'wrong INVAR string!?!?' +import binascii -# Compute the inverse table, for decode(). -inverse = {} -for i in range(64): inverse[INVAR[i]] = i -del i -inverse[PAD] = 0 +MAXLINESIZE = 76 # Excluding the CRLF +MAXBINSIZE = (MAXLINESIZE/4)*3 # Encode a file. def encode(input, output): - line = '' - BUFSIZE = 8192 - leftover = '' while 1: - s = input.read(BUFSIZE) + s = input.read(MAXBINSIZE) if not s: break - s = leftover + s - i = 0 - while i+3 <= len(s): - quad = makequad(s[i:i+3]) - i = i+3 - if len(line) + 4 > MAXLINESIZE: - output.write(line + '\n') - line = '' - line = line + quad - leftover = s[i:] - if leftover: - quad = makeshortquad(leftover) - if len(line) + 4 > MAXLINESIZE: - output.write(line + '\n') - line = '' - line = line + quad - if line: - output.write(line + '\n') - -def makequad(s): # Return the quad for a 3 character string - x = ord(s[0])*0x10000 + ord(s[1])*0x100 + ord(s[2]) - x, c4 = divmod(x, 64) - x, c3 = divmod(x, 64) - c1, c2 = divmod(x, 64) - return INVAR[c1] + INVAR[c2] +INVAR[c3] + INVAR[c4] - -def makeshortquad(s): # Return the quad value for a 1 or 2 character string - n = len(s) - while len(s) < 3: - s = s + '\0' - quad = makequad(s) - if n == 2: - quad = quad[:3] + PAD - elif n == 1: - quad = quad[:2] + 2*PAD - return quad + while len(s) < MAXBINSIZE: + ns = input.read(MAXBINSIZE-len(s)) + if not ns: break + s = s + ns + line = binascii.b2a_base64(s) + output.write(line) # Decode a file. def decode(input, output): - BUFSIZE = 8192 - bits, n, bytes, prev = 0, 0, '', '' while 1: line = input.readline() if not line: break - for c in line: - if inverse.has_key(c): - bits = bits*64 + inverse[c] - n = n+6 - if n == 24: - triplet = decodequad(bits) - if c == PAD: - if prev == PAD: - triplet = triplet[:1] - else: - triplet = triplet[:2] - bits, n = 0, 0 - bytes = bytes + triplet - if len(bytes) > BUFSIZE: - output.write(bytes[:BUFSIZE]) - bytes = bytes[BUFSIZE:] - prev = c - if bytes: - output.write(bytes) - -def decodequad(bits): # Turn 24 bits into 3 characters - bits, c3 = divmod(bits, 256) - c1, c2 = divmod(bits, 256) - return chr(c1) + chr(c2) + chr(c3) + s = binascii.a2b_base64(line) + output.write(s) def encodestring(s): import StringIO |