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@InvoxiPlayGames
Created March 1, 2024 06:26
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rpcs3_prx_hash.py - implementation of RPCS3 prx hashing to help make patch files. wont work on every file but works for RB3Enhanced
import sys
import math
import hashlib
from elftools.elf.elffile import ELFFile
def cmod(a, b):
return abs(a)%abs(b)*(1-2*(a<0))
# referencing RPCS3(Nekotekina): https://github.com/RPCS3/rpcs3/blob/master/Utilities/StrFmt.cpp#L127
def base57(in_data):
# Precomputed tail sizes if input data is not a multiple of 8
tails = [0, 2, 3, 5, 6, 7, 9, 10]
alphabet = "0123456789ACEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
in_size = len(in_data)
# Get full output size
out_size = int(in_size / 8) * 11 + tails[in_size % 8]
out_string = bytearray(int(out_size))
# Each 8 bytes of input data produces 11 bytes of base57 output
for i in range(0, math.ceil(out_size / 11)):
data_off = i * 8
p = i * 11 # output offset
# If the remaining data is less than 8 bytes, pad it with zeroes
if in_size - data_off < 8:
value_be = in_data[data_off : data_off + (in_size - data_off)] + bytearray(in_size - data_off)
else:
value_be = in_data[data_off : data_off + 8]
# Convert from a big endian integer
value = int.from_bytes(value_be, byteorder='big')
for j in range (10, -1, -1):
if p + j < out_size:
out_string[p + j] = ord(alphabet[cmod(value, 57)])
value //= 57
return out_string.decode("utf-8")
def generate_hash(filename):
with open(filename, 'rb') as f:
elffile = ELFFile(f)
h = hashlib.sha1()
for seg in elffile.iter_segments():
if seg["p_type"] == "PT_LOAD":
h.update((1).to_bytes(4, byteorder='big'))
else:
h.update(seg["p_type"].to_bytes(4, byteorder='big'))
h.update(seg["p_flags"].to_bytes(4, byteorder='big'))
if seg["p_type"] == "PT_LOAD":
h.update(seg["p_vaddr"].to_bytes(8, byteorder='big'))
h.update(seg["p_memsz"].to_bytes(8, byteorder='big'))
h.update(seg.data())
return base57(h.digest())
if __name__ == '__main__':
if len(sys.argv) < 3:
print("rpcs3_prx_hash.py input.prx output.txt")
else:
with open(sys.argv[2], 'w', encoding='utf8') as f:
f.write("PRX-")
f.write(generate_hash(sys.argv[1]))
f.write("-0")
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