def openssl_to_openssh()

in azurelinuxagent/common/osutil/gaia.py [0:0]

• 39 lines of code
• 8 McCabe index (conditional complexity)

    def openssl_to_openssh(self, input_file, output_file):
        cryptutil = CryptUtil(conf.get_openssl_cmd())
        ret, out = shellutil.run_get_output(
            conf.get_openssl_cmd() +
            " rsa -pubin -noout -text -in '" + input_file + "'")
        if ret != 0:
            raise OSUtilError('openssl failed with {0}'.format(ret))

        modulus = []
        exponent = []
        buf = None
        for line in out.split('\n'):
            if line.startswith('Modulus:'):
                buf = modulus
                buf.append(line)
                continue
            if line.startswith('Exponent:'):
                buf = exponent
                buf.append(line)
                continue
            if buf and line:
                buf.append(line.strip().replace(':', ''))

        def text_to_num(buf):
            if len(buf) == 1:
                return int(buf[0].split()[1])
            return int(''.join(buf[1:]), 16)

        n = text_to_num(modulus)
        e = text_to_num(exponent)

        keydata = bytearray()
        keydata.extend(struct.pack('>I', len('ssh-rsa')))
        keydata.extend(b'ssh-rsa')
        keydata.extend(struct.pack('>I', len(cryptutil.num_to_bytes(e))))
        keydata.extend(cryptutil.num_to_bytes(e))
        keydata.extend(struct.pack('>I', len(cryptutil.num_to_bytes(n)) + 1))
        keydata.extend(b'\0')
        keydata.extend(cryptutil.num_to_bytes(n))
        keydata_base64 = base64.b64encode(bytebuffer(keydata))
        fileutil.write_file(output_file,
                            ustr(b'ssh-rsa ' + keydata_base64 + b'\n',
                                 encoding='utf-8'))