#!/usr/bin/env python3

import argparse
import datetime
import hashlib
import os
import shutil
import struct
import subprocess
import sys

sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
from generated_offsets import *


# Default / Architectural Options

ARCHITECTURE = "amd64"

SSAFRAMESIZE = PAGESIZE

DEFAULT_ENCLAVE_SIZE = '256M'
DEFAULT_THREAD_NUM = 4
enclave_heap_min = DEFAULT_HEAP_MIN


# Utilities

ZERO_PAGE = bytes(PAGESIZE)


def roundup(addr):
    remaining = addr % PAGESIZE
    if remaining:
        return addr + (PAGESIZE - remaining)
    return addr


def rounddown(addr):
    return addr - addr % PAGESIZE


def parse_size(s):
    scale = 1
    if s.endswith("K"):
        scale = 1024
    if s.endswith("M"):
        scale = 1024 * 1024
    if s.endswith("G"):
        scale = 1024 * 1024 * 1024
    if scale != 1:
        s = s[:-1]
    return int(s, 0) * scale


# Reading / Writing Manifests

def read_manifest(filename):
    manifest = dict()
    manifest_layout = []
    with open(filename, "r") as f:
        for line in f.readlines():
            if line == "":
                manifest_layout.append((None, None))
                break

            pound = line.find("#")
            if pound != -1:
                comment = line[pound:].strip()
                line = line[:pound]
            else:
                comment = None

            line = line.strip()
            equal = line.find("=")
            if equal != -1:
                key = line[:equal].strip()
                manifest[key] = line[equal + 1:].strip()
            else:
                key = None

            manifest_layout.append((key, comment))

    return (manifest, manifest_layout)


def output_manifest(filename, manifest, manifest_layout):
    with open(filename, 'w') as f:
        written = []

        for (key, comment) in manifest_layout:
            line = ''
            if key is not None:
                line += key + ' = ' + manifest[key]
                written.append(key)
            if comment is not None:
                if line != '':
                    line += ' '
                line += comment
            f.write(line)
            f.write('\n')

        f.write('\n')
        f.write("# Generated by Graphene\n")
        f.write('\n')

        for key in sorted(manifest):
            if key not in written:
                f.write("%s = %s\n" % (key, manifest[key]))


# Loading Enclave Attributes

def get_enclave_attributes(manifest):
    sgx_flags = {
        'FLAG_DEBUG': struct.pack("<Q", SGX_FLAGS_DEBUG),
        'FLAG_MODE64BIT': struct.pack("<Q", SGX_FLAGS_MODE64BIT),
    }

    sgx_xfrms = {
        'XFRM_LEGACY': struct.pack("<Q", SGX_XFRM_LEGACY),
        'XFRM_AVX': struct.pack("<Q", SGX_XFRM_AVX),
        'XFRM_AVX512': struct.pack("<Q", SGX_XFRM_AVX512),
        'XFRM_MPX': struct.pack("<Q", SGX_XFRM_MPX),
    }

    sgx_miscs = {
        'MISC_EXINFO': struct.pack("<L", SGX_MISCSELECT_EXINFO),
    }

    default_attributes = {
        'FLAG_DEBUG',
        'XFRM_LEGACY',
    }

    if ARCHITECTURE == 'amd64':
        default_attributes.add('FLAG_MODE64BIT')

    manifest_options = {
        'debug'          : 'FLAG_DEBUG',
        'require_avx'    : 'XFRM_AVX',
        'require_avx512' : 'XFRM_AVX512',
        'enable_mpx'     : 'XFRM_MPX',
        'support_exinfo' : 'MISC_EXINFO',
    }

    attributes = default_attributes

    for opt in manifest_options:
        key = 'sgx.' + opt
        if key in manifest:
            if manifest[key] == '1':
                attributes.add(manifest_options[opt])
            else:
                attributes.discard(manifest_options[opt])

    flags_raw = struct.pack("<Q", 0)
    xfrms_raw = struct.pack("<Q", 0)
    miscs_raw = struct.pack("<L", 0)

    for attr in attributes:
        if attr in sgx_flags:
            flags_raw = bytes([a | b for a, b in
                               zip(flags_raw, sgx_flags[attr])])
        if attr in sgx_xfrms:
            xfrms_raw = bytes([a | b for a, b in
                               zip(xfrms_raw, sgx_xfrms[attr])])
        if attr in sgx_miscs:
            miscs_raw = bytes([a | b for a, b in
                               zip(miscs_raw, sgx_miscs[attr])])

    return flags_raw, xfrms_raw, miscs_raw


# Generate Checksums / Measurement

def resolve_uri(uri, check_exist=True):
    orig_uri = uri
    if uri.startswith('file:'):
        target = os.path.normpath(uri[5:])
    else:
        target = os.path.normpath(uri)
    if check_exist and not os.path.exists(target):
        raise Exception(
            'Cannot resolve ' + orig_uri + ' or the file does not exist.')
    return target


def get_checksum(file):
    digest = hashlib.sha256()
    with open(file, 'rb') as f:
        digest.update(f.read())
    return digest.digest()


def get_trusted_files(manifest, args):
    targets = dict()

    if 'exec' in args:
        targets['exec'] = (args['exec'], resolve_uri(args['exec']))

    if 'loader.preload' in manifest:
        i = 0
        preloads = []
        for uri in str.split(manifest['loader.preload'], ','):
            targets['preload' + str(i)] = (uri, resolve_uri(uri))
            preloads.append(uri)
            i += 1

    for (key, val) in manifest.items():
        if not key.startswith('sgx.trusted_files.'):
            continue
        key = key[len('sgx.trusted_files.'):]
        if key in targets:
            raise Exception(
                'repeated key in manifest: sgx.trusted_files.' + key)
        targets[key] = (val, resolve_uri(val))

    for (key, val) in targets.items():
        (uri, target) = val
        checksum = get_checksum(target).hex()
        targets[key] = (uri, target, checksum)

    return targets


def get_trusted_children(manifest):
    targets = dict()

    for (key, val) in manifest.items():
        if not key.startswith('sgx.trusted_children.'):
            continue
        key = key[len('sgx.trusted_children.'):]
        if key in targets:
            raise Exception(
                'repeated key in manifest: sgx.trusted_children.' + key)

        target = resolve_uri(val)
        if not target.endswith('.sig'):
            target += '.sig'
        sig = open(target, 'rb').read()[
            SGX_ARCH_SIGSTRUCT_ENCLAVE_HASH:
            SGX_ARCH_SIGSTRUCT_ENCLAVE_HASH + SGX_ARCH_HASH_SIZE].hex()
        targets[key] = (val, target, sig)

    return targets


# Populate Enclave Memory

PAGEINFO_R = 0x1
PAGEINFO_W = 0x2
PAGEINFO_X = 0x4
PAGEINFO_TCS = 0x100
PAGEINFO_REG = 0x200


def get_loadcmds(filename):
    loadcmds = []
    p = subprocess.Popen(['readelf', '-l', '-W', filename],
                         stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    while True:
        line = p.stdout.readline()
        if not line:
            break
        line = line.decode()
        stripped = line.strip()
        if not stripped.startswith('LOAD'):
            continue
        tokens = stripped.split()
        if len(tokens) < 6:
            continue
        if len(tokens) >= 7 and tokens[7] == "E":
            tokens[6] += tokens[7]
        prot = 0
        for t in tokens[6]:
            if t == "R":
                prot = prot | 4
            if t == "W":
                prot = prot | 2
            if t == "E":
                prot = prot | 1

        loadcmds.append((int(tokens[1][2:], 16),  # offset
                         int(tokens[2][2:], 16),  # addr
                         int(tokens[4][2:], 16),  # filesize
                         int(tokens[5][2:], 16),  # memsize
                         prot))
    p.wait()
    if p.returncode != 0:
        return None
    return loadcmds


class MemoryArea:
    def __init__(self, desc, file=None, content=None, addr=None, size=None,
                 flags=None, measure=True):
        self.desc = desc
        self.file = file
        self.content = content
        self.addr = addr
        self.size = size
        self.flags = flags
        self.is_binary = False
        self.measure = measure

        if file:
            loadcmds = get_loadcmds(file)
            if loadcmds:
                mapaddr = 0xffffffffffffffff
                mapaddr_end = 0
                for (_, addr_, _, memsize, _) in loadcmds:
                    if rounddown(addr_) < mapaddr:
                        mapaddr = rounddown(addr_)
                    if roundup(addr_ + memsize) > mapaddr_end:
                        mapaddr_end = roundup(addr_ + memsize)

                self.is_binary = True
                self.size = mapaddr_end - mapaddr
                if mapaddr > 0:
                    self.addr = mapaddr
            else:
                self.size = os.stat(file).st_size

        if self.addr is not None:
            self.addr = rounddown(self.addr)
        if self.size is not None:
            self.size = roundup(self.size)


def get_memory_areas(attr, args):
    areas = []
    areas.append(
        MemoryArea('ssa',
                   size=attr['thread_num'] * SSAFRAMESIZE * SSAFRAMENUM,
                   flags=PAGEINFO_R | PAGEINFO_W | PAGEINFO_REG))
    areas.append(MemoryArea('tcs', size=attr['thread_num'] * TCS_SIZE,
                            flags=PAGEINFO_TCS))
    areas.append(MemoryArea('tls', size=attr['thread_num'] * PAGESIZE,
                            flags=PAGEINFO_R | PAGEINFO_W | PAGEINFO_REG))

    for _ in range(attr['thread_num']):
        areas.append(MemoryArea('stack', size=ENCLAVE_STACK_SIZE,
                                flags=PAGEINFO_R | PAGEINFO_W | PAGEINFO_REG))

    areas.append(MemoryArea('pal', file=args['libpal'], flags=PAGEINFO_REG))

    if 'exec' in args:
        areas.append(MemoryArea('exec', file=args['exec'],
                                flags=PAGEINFO_W | PAGEINFO_REG))
    return areas


def find_areas(areas, desc):
    return [area for area in areas if area.desc == desc]


def find_area(areas, desc, allow_none=False):
    matching = find_areas(areas, desc)

    if not matching and allow_none:
        return None

    if len(matching) != 1:
        raise KeyError(
            "Could not find exactly one MemoryArea '{}'".format(desc))

    return matching[0]


def entry_point(elf_path):
    env = os.environ
    env['LC_ALL'] = 'C'
    out = subprocess.check_output(
        ['readelf', '-l', '--', elf_path], env=env)
    for line in out.splitlines():
        line = line.decode()
        if line.startswith("Entry point "):
            return int(line[12:], 0)
    raise ValueError("Could not find entry point of elf file")


def baseaddr():
    if enclave_heap_min == 0:
        return ENCLAVE_HIGH_ADDRESS
    return 0


def gen_area_content(attr, areas):
    manifest_area = find_area(areas, 'manifest')
    exec_area = find_area(areas, 'exec', True)
    pal_area = find_area(areas, 'pal')
    ssa_area = find_area(areas, 'ssa')
    tcs_area = find_area(areas, 'tcs')
    tls_area = find_area(areas, 'tls')
    stacks = find_areas(areas, 'stack')

    tcs_data = bytearray(tcs_area.size)

    def set_tcs_field(t, offset, pack_fmt, value):
        struct.pack_into(pack_fmt, tcs_data, t * TCS_SIZE + offset, value)

    tls_data = bytearray(tls_area.size)

    def set_tls_field(t, offset, value):
        struct.pack_into('<Q', tls_data, t * PAGESIZE + offset, value)

    enclave_heap_max = pal_area.addr - MEMORY_GAP

    # Sanity check that we measure everything except the heap which is zeroed
    # on enclave startup.
    for area in areas:
        if (area.addr + area.size <= enclave_heap_min or
                area.addr >= enclave_heap_max or area is exec_area):
            if not area.measure:
                raise ValueError("Memory area, which is not the heap, "
                                 "is not measured")
        elif area.desc != 'free':
            raise ValueError("Unexpected memory area is in heap range")

    for t in range(0, attr['thread_num']):
        ssa_offset = ssa_area.addr + SSAFRAMESIZE * SSAFRAMENUM * t
        ssa = baseaddr() + ssa_offset
        set_tcs_field(t, TCS_OSSA, '<Q', ssa_offset)
        set_tcs_field(t, TCS_NSSA, '<L', SSAFRAMENUM)
        set_tcs_field(t, TCS_OENTRY, '<Q',
                      pal_area.addr + entry_point(pal_area.file))
        set_tcs_field(t, TCS_OGSBASGX, '<Q', tls_area.addr + PAGESIZE * t)
        set_tcs_field(t, TCS_FSLIMIT, '<L', 0xfff)
        set_tcs_field(t, TCS_GSLIMIT, '<L', 0xfff)

        set_tls_field(t, SGX_COMMON_SELF,
                      tls_area.addr + PAGESIZE * t + baseaddr())
        set_tls_field(t, SGX_ENCLAVE_SIZE, attr['enclave_size'])
        set_tls_field(t, SGX_TCS_OFFSET, tcs_area.addr + TCS_SIZE * t)
        set_tls_field(t, SGX_INITIAL_STACK_OFFSET,
                      stacks[t].addr + stacks[t].size)
        set_tls_field(t, SGX_SSA, ssa)
        set_tls_field(t, SGX_GPR, ssa + SSAFRAMESIZE - SGX_GPR_SIZE)
        set_tls_field(t, SGX_MANIFEST_SIZE,
                      os.stat(manifest_area.file).st_size)
        set_tls_field(t, SGX_HEAP_MIN, baseaddr() + enclave_heap_min)
        set_tls_field(t, SGX_HEAP_MAX, baseaddr() + enclave_heap_max)
        if exec_area is not None:
            set_tls_field(t, SGX_EXEC_ADDR, baseaddr() + exec_area.addr)
            set_tls_field(t, SGX_EXEC_SIZE, exec_area.size)

    tcs_area.content = tcs_data
    tls_area.content = tls_data


def populate_memory_areas(attr, areas):
    populating = attr['enclave_size']

    for area in areas:
        if area.addr is not None:
            continue

        area.addr = populating - area.size
        if area.addr < enclave_heap_min:
            raise Exception("Enclave size is not large enough")
        if area.desc == 'exec':
            populating = area.addr
        else:
            populating = area.addr - MEMORY_GAP

    free_areas = []
    for area in areas:
        if area.addr + area.size < populating:
            addr = area.addr + area.size
            flags = PAGEINFO_R | PAGEINFO_W | PAGEINFO_X | PAGEINFO_REG
            free_areas.append(
                MemoryArea('free', addr=addr, size=populating - addr,
                           flags=flags, measure=False))
            populating = area.addr

    if populating > enclave_heap_min:
        flags = PAGEINFO_R | PAGEINFO_W | PAGEINFO_X | PAGEINFO_REG
        free_areas.append(
            MemoryArea('free', addr=enclave_heap_min,
                       size=populating - enclave_heap_min, flags=flags,
                       measure=False))

    gen_area_content(attr, areas)

    return areas + free_areas


def generate_measurement(attr, areas):

    def do_ecreate(digest, size):
        data = struct.pack("<8sLQ44s", b"ECREATE", SSAFRAMESIZE // PAGESIZE,
                           size, b"")
        digest.update(data)

    def do_eadd(digest, offset, flags):
        data = struct.pack("<8sQQ40s", b"EADD", offset, flags, b"")
        digest.update(data)

    def do_eextend(digest, offset, content):
        if len(content) != 256:
            raise ValueError("Exactly 256 bytes expected")

        data = struct.pack("<8sQ48s", b"EEXTEND", offset, b"")
        digest.update(data)
        digest.update(content)

    def include_page(digest, offset, flags, content, measure):
        if len(content) != PAGESIZE:
            raise ValueError("Exactly one page expected")

        do_eadd(digest, offset, flags)
        if measure:
            for i in range(0, PAGESIZE, 256):
                do_eextend(digest, offset + i, content[i:i + 256])

    mrenclave = hashlib.sha256()
    do_ecreate(mrenclave, attr['enclave_size'])

    def print_area(addr, size, flags, desc, measured):
        if flags & PAGEINFO_REG:
            type_ = 'REG'
        if flags & PAGEINFO_TCS:
            type_ = 'TCS'
        prot = ['-', '-', '-']
        if flags & PAGEINFO_R:
            prot[0] = 'R'
        if flags & PAGEINFO_W:
            prot[1] = 'W'
        if flags & PAGEINFO_X:
            prot[2] = 'X'
        prot = ''.join(prot)

        desc = '(' + desc + ')'
        if measured:
            desc += ' measured'

        if size == PAGESIZE:
            print("    %016x [%s:%s] %s" % (addr, type_, prot, desc))
        else:
            print("    %016x-%016lx [%s:%s] %s" %
                  (addr, addr + size, type_, prot, desc))

    def load_file(digest, f, offset, addr, filesize, memsize, desc, flags):
        f_addr = rounddown(offset)
        m_addr = rounddown(addr)
        m_size = roundup(addr + memsize) - m_addr

        print_area(m_addr, m_size, flags, desc, True)

        for pg in range(m_addr, m_addr + m_size, PAGESIZE):
            start = pg - m_addr + f_addr
            end = start + PAGESIZE
            start_zero = b""
            if start < offset:
                if offset - start >= PAGESIZE:
                    start_zero = ZERO_PAGE
                else:
                    start_zero = bytes(offset - start)
            end_zero = b""
            if end > offset + filesize:
                if end - offset - filesize >= PAGESIZE:
                    end_zero = ZERO_PAGE
                else:
                    end_zero = bytes(end - offset - filesize)
            start += len(start_zero)
            end -= len(end_zero)
            if start < end:
                f.seek(start)
                data = f.read(end - start)
            else:
                data = b""
            if len(start_zero + data + end_zero) != PAGESIZE:
                raise Exception("wrong calculation")

            include_page(digest, pg, flags, start_zero + data + end_zero, True)

    for area in areas:
        if area.file:
            with open(area.file, 'rb') as f:
                if area.is_binary:
                    loadcmds = get_loadcmds(area.file)
                    if loadcmds:
                        mapaddr = 0xffffffffffffffff
                        for (offset, addr, filesize, memsize,
                             prot) in loadcmds:
                            if rounddown(addr) < mapaddr:
                                mapaddr = rounddown(addr)
                    baseaddr_ = area.addr - mapaddr
                    for (offset, addr, filesize, memsize, prot) in loadcmds:
                        flags = area.flags
                        if prot & 4:
                            flags = flags | PAGEINFO_R
                        if prot & 2:
                            flags = flags | PAGEINFO_W
                        if prot & 1:
                            flags = flags | PAGEINFO_X

                        if flags & PAGEINFO_X:
                            desc = 'code'
                        else:
                            desc = 'data'
                        load_file(mrenclave, f, offset, baseaddr_ + addr,
                                  filesize, memsize, desc, flags)
                else:
                    load_file(mrenclave, f, 0, area.addr,
                              os.stat(area.file).st_size, area.size,
                              area.desc, area.flags)
        else:
            for a in range(area.addr, area.addr + area.size, PAGESIZE):
                data = ZERO_PAGE
                if area.content is not None:
                    start = a - area.addr
                    end = start + PAGESIZE
                    data = area.content[start:end]

                include_page(mrenclave, a, area.flags, data, area.measure)

            print_area(area.addr, area.size, area.flags, area.desc,
                       area.measure)

    return mrenclave.digest()


def generate_sigstruct(attr, args, mrenclave):
    """Generate Sigstruct."""
    today = datetime.date.today()

    # field format: (offset, type, value)
    fields = {
        'header': (SGX_ARCH_SIGSTRUCT_HEADER,
                   "<4L", 0x00000006, 0x000000e1, 0x00010000, 0x00000000),
        'vendor': (SGX_ARCH_SIGSTRUCT_VENDOR, "<L", 0x00000000),
        'date': (SGX_ARCH_SIGSTRUCT_DATE,
                 "<HBB", today.year, today.month, today.day),
        'header2': (SGX_ARCH_SIGSTRUCT_HEADER2,
                    "<4L", 0x00000101, 0x00000060, 0x00000060, 0x00000001),
        'swdefined': (SGX_ARCH_SIGSTRUCT_SWDEFINED, "<L", 0x00000000),

        'miscs': (SGX_ARCH_SIGSTRUCT_MISCSELECT, "4s", attr['miscs']),
        'miscmask': (SGX_ARCH_SIGSTRUCT_MISCSELECT_MASK, "4s", attr['miscs']),
        'attrs': (SGX_ARCH_SIGSTRUCT_ATTRIBUTES,
                  "8s8s", attr['flags'], attr['xfrms']),
        'attrmask': (SGX_ARCH_SIGSTRUCT_ATTRIBUTES_MASK,
                     "8s8s", attr['flags'], attr['xfrms']),
        'mrenclave': (SGX_ARCH_SIGSTRUCT_ENCLAVE_HASH, "32s", mrenclave),
        'isvprodid': (SGX_ARCH_SIGSTRUCT_ISVPRODID, "<H", attr['isvprodid']),
        'isvsvn': (SGX_ARCH_SIGSTRUCT_ISVSVN, "<H", attr['isvsvn']),
    }

    sign_buffer = bytearray(128 + 128)

    for field in fields.values():
        if field[0] >= SGX_ARCH_SIGSTRUCT_MISCSELECT:
            struct.pack_into(field[1], sign_buffer,
                             field[0] - SGX_ARCH_SIGSTRUCT_MISCSELECT + 128,
                             *field[2:])
        else:
            struct.pack_into(field[1], sign_buffer, field[0], *field[2:])

    p = subprocess.Popen(
        ['openssl', 'rsa', '-modulus', '-in', args['key'], '-noout'],
        stdout=subprocess.PIPE)
    modulus_out = p.communicate()[0]
    modulus = bytes.fromhex(modulus_out[8:8+SGX_ARCH_KEY_SIZE*2].decode())
    modulus = bytes(reversed(modulus))

    p = subprocess.Popen(
        ['openssl', 'sha256', '-binary', '-sign', args['key']],
        stdin=subprocess.PIPE, stdout=subprocess.PIPE)
    signature = p.communicate(sign_buffer)[0]
    signature = signature[::-1]

    modulus_int = int.from_bytes(modulus, byteorder='little')
    signature_int = int.from_bytes(signature, byteorder='little')

    tmp1 = signature_int * signature_int
    q1_int = tmp1 // modulus_int
    tmp2 = tmp1 % modulus_int
    q2_int = tmp2 * signature_int // modulus_int

    q1 = q1_int.to_bytes(384, byteorder='little')
    q2 = q2_int.to_bytes(384, byteorder='little')

    fields.update({
        'modulus': (SGX_ARCH_SIGSTRUCT_MODULUS, "384s", modulus),
        'exponent': (SGX_ARCH_SIGSTRUCT_EXPONENT, "<L", 3),
        'signature': (SGX_ARCH_SIGSTRUCT_SIGNATURE, "384s", signature),

        'q1': (SGX_ARCH_SIGSTRUCT_Q1, "384s", q1),
        'q2': (SGX_ARCH_SIGSTRUCT_Q2, "384s", q2),
    })

    buffer = bytearray(SGX_ARCH_SIGSTRUCT_SIZE)

    for field in fields.values():
        struct.pack_into(field[1], buffer, field[0], *field[2:])

    return buffer

# Main Program

argparser = argparse.ArgumentParser()
argparser.add_argument('--output', '-output', metavar='OUTPUT',
                       type=str, required=True,
                       help='Output .manifest.sgx file '
                            '(manifest augmented with autogenerated fields)')
argparser.add_argument('--libpal', '-libpal', metavar='LIBPAL',
                       type=str, required=True,
                       help='Input libpal file '
                            '(required as part of the enclave measurement)')
argparser.add_argument('--key', '-key', metavar='KEY',
                       type=str, required=True,
                       help='specify signing key(.pem) file')
argparser.add_argument('--manifest', '-manifest', metavar='MANIFEST',
                       type=str, required=True,
                       help='Input .manifest file '
                            '(user-prepared manifest template)')
argparser.add_argument('--exec', '-exec', metavar='EXEC',
                       type=str, required=False,
                       help='Input executable file '
                            '(required as part of the enclave measurement)')


def parse_args(args):
    args = argparser.parse_args(args)
    args_dict = {
        'output': args.output,
        'libpal': args.libpal,
        'key': args.key,
        'manifest': args.manifest,
    }
    if args.exec is not None:
        args_dict['exec'] = args.exec

    return args_dict


def main(args=None):
    args = parse_args(args)

    (manifest, manifest_layout) = read_manifest(args['manifest'])

    if 'exec' not in args:
        if 'loader.exec' in manifest:
            exec_url = manifest['loader.exec']
            if exec_url[:5] != 'file:':
                print("executable must be a local file", file=sys.stderr)
                return -1

            args['exec'] = os.path.join(os.path.dirname(args['manifest']),
                                        exec_url[5:])

    args['root'] = os.path.dirname(os.path.abspath(args['output']))

    if 'sgx.sigfile' in manifest:
        args['sigfile'] = resolve_uri(manifest['sgx.sigfile'], False)
    else:
        sigfile = args['output']
        for ext in ['.manifest.sgx', '.manifest']:
            if sigfile.endswith(ext):
                sigfile = sigfile[:-len(ext)]
                break
        args['sigfile'] = sigfile + '.sig'
        manifest['sgx.sigfile'] = 'file:' + os.path.basename(args['sigfile'])

    # Get attributes from manifest
    attr = dict()
    parse_int = lambda s: int(s, 0)

    for key, default, parse in [
            ('enclave_size', DEFAULT_ENCLAVE_SIZE, parse_size),
            ('thread_num', str(DEFAULT_THREAD_NUM), parse_int),
            ('isvprodid', '0', parse_int),
            ('isvsvn', '0', parse_int),
    ]:
        attr[key] = parse(manifest.setdefault('sgx.' + key, default))

    (attr['flags'], attr['xfrms'], attr['miscs']) = get_enclave_attributes(
        manifest)

    print("Attributes:")
    print("    size:      %d" % attr['enclave_size'])
    print("    threadnum: %d" % attr['thread_num'])
    print("    isvprodid: %d" % attr['isvprodid'])
    print("    isvsvn:    %d" % attr['isvsvn'])
    print("    flags:     %016x" % int.from_bytes(attr['flags'],
                                                  byteorder='big'))
    print("    xfrms:     %016x" % int.from_bytes(attr['xfrms'],
                                                  byteorder='big'))
    print("    miscs:     %08x" % int.from_bytes(attr['miscs'],
                                                 byteorder='big'))

    # Check client info for remote attestation (if sgx.ra_client.spid is provided)
    print("Attestation:")
    if 'sgx.ra_client_spid' in manifest and manifest['sgx.ra_client_spid']:
        print("    spid:     " + manifest['sgx.ra_client_spid'])
        if 'sgx.ra_client_key' in manifest and manifest['sgx.ra_client_key']:
            print("    key:   " + manifest['sgx.ra_client_key'])
        else:
            print("    *** sgx.ra_client_key not specified ***")
            return -1
        if 'sgx.ra_client_linkable' in manifest:
            print("    linkable: " + manifest['sgx.ra_client_linkable'])
        else:
            print("    linkable: 0")
    else:
        print("    *** Client info is not specified. Graphene will not perform"
              " remote attestation before execution. Please provide"
              " sgx.ra_client_spid and sgx.ra_client_key in the manifest. ***")

    # Get trusted checksums and measurements
    print("Trusted files:")
    for key, val in get_trusted_files(manifest, args).items():
        (uri, _, checksum) = val
        print("    %s %s" % (checksum, uri))
        manifest['sgx.trusted_checksum.' + key] = checksum

    print("Trusted children:")
    for key, val in get_trusted_children(manifest).items():
        (uri, _, mrenclave) = val
        print("    %s %s" % (mrenclave, uri))
        manifest['sgx.trusted_mrenclave.' + key] = mrenclave

    # Try populate memory areas
    memory_areas = get_memory_areas(attr, args)

    if any([a.addr is not None for a in memory_areas]):
        manifest['sgx.static_address'] = '1'
    else:
        global enclave_heap_min
        enclave_heap_min = 0

    # Add manifest at the top
    shutil.copy2(args['manifest'], args['output'])
    output_manifest(args['output'], manifest, manifest_layout)

    memory_areas = [
        MemoryArea('manifest', file=args['output'],
                   flags=PAGEINFO_R | PAGEINFO_REG)
        ] + memory_areas

    memory_areas = populate_memory_areas(attr, memory_areas)

    print("Memory:")
    # Generate measurement
    mrenclave = generate_measurement(attr, memory_areas)
    print("Measurement:")
    print("    %s" % mrenclave.hex())

    # Generate sigstruct
    open(args['sigfile'], 'wb').write(
        generate_sigstruct(attr, args, mrenclave))
    return 0


if __name__ == "__main__":
    sys.exit(main())