basic, generic sed script to sanitize things like AWS account numbers, IPv4 addresses, SSNs, TINs, etc. from text files, program output, etc.

sanitize.sed

#!/usr/bin/env -S sed -Ef

# Replace 12-digit strings (AWS Account IDs)
# 123456789012 => 123*********
s/([^0-9])([0-9]{3})[0-9]{9}([^0-9])/\1\2*********\3/g

# Replace Social Security Numbers (SSNs) with dashes => 
# 123-45-6789 => 123-**-****
s/([^0-9])([0-9]{3})-([0-9]{2})-([0-9]{4})([^0-9])/\1\2-**-****\5/g

# Replace Taxpayer ID Numbers (TINs) containing dashes
# 12-3456789 => 12-*******
s/([^0-9])([0-9]{2})-([0-9]{2})[0-9]{5}([^0-9])/\1\2-\3*****\4/g

# Replace SSNs / TINs not containing dashes
# 123456789 => 123******
s/(["'])([0-9]{3})([0-9]{9})\1/\1\2******\1/g

# Replace credit card numbers containing dashes
# 1234-5555-6666-7777 => 1234-****-****-****
s/([^0-9]*)([0-9]{4})-([0-9]{4})-([0-9]{4})-([0-9]{4})([^0-9]*)/\1\2-****-****-****\6/g

# Replace IPv4 addresses
# 123.45.67.8 => 123.***.***.8
s/\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b/\1.***.***.\4/g

To use:

# via pipe
cat /path/to/file | sanitize.sed

# via redirect
sanitize.sed < /path/to/file

# direct invocation
sanitize.sed /path/to/file