Industry standard for parsing out IP addresses from a text document regex
can you give me some kind of formula that is an industry standard to parse out ip addresses of a txt document. it can be complete or partial obfuscation/redaction
ChatGPT said:
Thought for 21s
Yep — the “industry standard” way to do this is:
- Use a regex to find candidates (fast, works in grep/sed/ripgrep/etc.)
- Optionally validate candidates (best practice) with a real IP parser (e.g., Python’s
ipaddress) to avoid weird false-positives.
Below are solid, widely-used patterns and redaction variants.
IPv4 extraction (strict 0–255 per octet)
Regex (PCRE / most engines):
\b(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\.){3}(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\b
If you also want optional :port:
\b(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\.){3}(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\b(?::\d{1,5})?
IPv6 extraction (practical + common forms)
IPv6 regex can get very long if you try to perfectly cover every compressed form. The common industry approach is “good-enough extraction + validation”.
Good extraction regex (covers most real-world IPv6 you’ll see, including :: compression):
\b(?:[0-9A-Fa-f]{1,4}:){1,7}[0-9A-Fa-f]{1,4}\b|\b(?:[0-9A-Fa-f]{1,4}:){1,7}:\b|\b:(?::[0-9A-Fa-f]{1,4}){1,7}\b
If you also want bracketed IPv6 with optional port (common in URLs/logs: [2001:db8::1]:443):
\[(?:[0-9A-Fa-f:]+)\](?::\d{1,5})?
(Then validate the inside of the brackets.)
Redaction / obfuscation patterns
A) Full redaction (replace any IPv4 with a token)
Match (IPv4 strict):
\b(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\.){3}(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\b
Replace with:
[REDACTED_IP]
B) Partial IPv4 redaction (keep /24, hide last octet)
Match + capture first 3 octets:
\b((?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d))\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\b
Replace with:
$1.xxx
(Some tools use \1 instead of $1.)
C) Partial IPv6 redaction (keep prefix, hide the rest)
For IPv6, regex-only redaction gets messy because of compression (::). The clean way is:
- extract candidate IPv6 tokens (regex),
- normalize/validate (e.g., expand/compress),
- then redact by prefix length (like keeping first 4 hextets).
If you must do regex-only, keep it simple and accept imperfections:
- Replace anything that looks IPv6-ish with
[REDACTED_IPV6]using a broad pattern like:
\b[0-9A-Fa-f:]{2,}\b
…but this will overmatch (timestamps, hashes, etc.), so validation is recommended.
Best-practice note (why validation matters)
Even “strict” regex can still pick up things you don’t want in edge cases (IDs, version strings, etc.). The standard robust workflow is:
- Regex → candidate tokens
- Validate → confirm it’s a real IP
- Redact/transform → consistent output
If you tell me what tool you’re using (grep/sed, Python, Node, Go, etc.), I’ll give you the exact one-liner / function you can drop in, including IPv4+IPv6 and your preferred redaction style.
You said:
Python
ChatGPT said:
Thought for 1m 43s
Here’s a solid “industry standard” Python approach: regex for candidate matches + ipaddress for real validation, with optional redaction/obfuscation (full token, partial, or deterministic hashing).
#!/usr/bin/env python3
import re
import sys
import argparse
import ipaddress
import hashlib
from collections import Counter
# --- Candidate patterns (broad enough to catch real-world logs, then validated) ---
# [IPv6]:port (common in URLs/logs)
RE_V6_BRACKET = r"\[(?P<v6b>[0-9A-Fa-f:]{2,})\](?P<pb>:\d{1,5})?"
# IPv6 with embedded IPv4 (e.g., ::ffff:192.0.2.1) — no port here
RE_V6V4 = r"(?<![0-9A-Fa-f:])(?P<v6v4>(?:[0-9A-Fa-f]{0,4}:){1,6}\d{1,3}(?:\.\d{1,3}){3})(?![0-9A-Fa-f:])"
# IPv4 with optional :port
RE_V4 = r"(?P<v4>\b\d{1,3}(?:\.\d{1,3}){3}\b)(?P<p4>:\d{1,5})?"
# Practical IPv6 (most forms incl :: compression) — no port here
RE_V6 = (
r"(?<![0-9A-Fa-f:])"
r"(?P<v6>"
r"(?:[0-9A-Fa-f]{1,4}:){1,7}[0-9A-Fa-f]{1,4}|"
r"(?:[0-9A-Fa-f]{1,4}:){1,7}:|"
r":(?::[0-9A-Fa-f]{1,4}){1,7}"
r")"
r"(?![0-9A-Fa-f:])"
)
CANDIDATE_RE = re.compile(
f"{RE_V6_BRACKET}|{RE_V6V4}|{RE_V4}|{RE_V6}"
)
def _validate_ip(s: str):
try:
return ipaddress.ip_address(s)
except ValueError:
return None
def iter_ips_from_line(line: str, ipv4_only=False, ipv6_only=False):
for m in CANDIDATE_RE.finditer(line):
addr = None
if m.group("v6b"):
addr = m.group("v6b")
elif m.group("v6v4"):
addr = m.group("v6v4")
elif m.group("v4"):
addr = m.group("v4")
elif m.group("v6"):
addr = m.group("v6")
ip = _validate_ip(addr) if addr else None
if not ip:
continue
if ipv4_only and ip.version != 4:
continue
if ipv6_only and ip.version != 6:
continue
yield ip
def obfuscate_ip(ip, style: str, salt: str | None, ipv6_hextets: int):
s = ip.compressed
if style == "token":
return "[IP]"
if style in ("keep24", "keep16"):
if ip.version == 4:
a, b, c, d = s.split(".")
if style == "keep24":
return f"{a}.{b}.{c}.xxx" # invalid on purpose (redacted)
else:
return f"{a}.{b}.xxx.xxx" # invalid on purpose (redacted)
# IPv6: keep N hextets, redact the rest as "xxxx" (invalid on purpose)
parts = ip.exploded.split(":") # 8 hextets
n = max(1, min(8, ipv6_hextets))
return ":".join(parts[:n] + ["xxxx"] * (8 - n))
if style == "hash":
if not salt:
raise ValueError("--salt is required for style=hash")
h = hashlib.sha256((salt + "|" + s).encode("utf-8")).hexdigest()
return f"[IP:{h[:12]}]" # short deterministic pseudonym
raise ValueError(f"Unknown style: {style}")
def redact_line(line: str, style: str, salt: str | None, ipv6_hextets: int,
ipv4_only=False, ipv6_only=False):
def repl(m: re.Match):
full = m.group(0)
# figure out address + preserve port/brackets if present
if m.group("v6b"):
addr = m.group("v6b")
port = m.group("pb") or ""
ip = _validate_ip(addr)
if not ip:
return full
if ipv4_only and ip.version != 4:
return full
if ipv6_only and ip.version != 6:
return full
obf = obfuscate_ip(ip, style, salt, ipv6_hextets)
return f"[{obf}]{port}"
if m.group("v4"):
addr = m.group("v4")
port = m.group("p4") or ""
ip = _validate_ip(addr)
if not ip:
return full
if ipv6_only and ip.version != 4:
return full
obf = obfuscate_ip(ip, style, salt, ipv6_hextets)
return f"{obf}{port}"
addr = m.group("v6v4") or m.group("v6")
ip = _validate_ip(addr)
if not ip:
return full
if ipv4_only and ip.version != 4:
return full
if ipv6_only and ip.version != 6:
return full
return obfuscate_ip(ip, style, salt, ipv6_hextets)
return CANDIDATE_RE.sub(repl, line)
def main():
ap = argparse.ArgumentParser(description="Extract / count / redact IPs in a text file (IPv4 + IPv6).")
ap.add_argument("input", help="Input file path, or '-' for stdin")
ap.add_argument("--mode", choices=["extract", "count", "redact"], default="extract")
ap.add_argument("--out", help="Output file for redact mode (default: stdout)")
ap.add_argument("--ipv4-only", action="store_true")
ap.add_argument("--ipv6-only", action="store_true")
ap.add_argument("--style", choices=["token", "keep24", "keep16", "hash"], default="token",
help="Redaction style (for --mode redact).")
ap.add_argument("--ipv6-hextets", type=int, default=4,
help="How many IPv6 hextets to keep for keep24/keep16 (default: 4).")
ap.add_argument("--salt", help="Salt for deterministic hashing (required for --style hash).")
ap.add_argument("--top", type=int, default=50, help="Top N for count mode (default: 50).")
args = ap.parse_args()
src = sys.stdin if args.input == "-" else open(args.input, "r", encoding="utf-8", errors="replace")
if args.mode == "extract":
seen = set()
for line in src:
for ip in iter_ips_from_line(line, args.ipv4_only, args.ipv6_only):
seen.add(ip.compressed)
for ip in sorted(seen):
print(ip)
elif args.mode == "count":
c = Counter()
for line in src:
for ip in iter_ips_from_line(line, args.ipv4_only, args.ipv6_only):
c[ip.compressed] += 1
for ip, n in c.most_common(args.top):
print(f"{n}\t{ip}")
else: # redact
out = open(args.out, "w", encoding="utf-8") if args.out else sys.stdout
for line in src:
out.write(
redact_line(
line,
style=args.style,
salt=args.salt,
ipv6_hextets=args.ipv6_hextets,
ipv4_only=args.ipv4_only,
ipv6_only=args.ipv6_only,
)
)
if args.out:
out.close()
if args.input != "-":
src.close()
if __name__ == "__main__":
main()
Examples
Extract unique IPs:
python3 ip_parse.py /path/to/log.txt
Count top IPs:
python3 ip_parse.py /path/to/log.txt --mode count --top 25
Redact everything to a token:
python3 ip_parse.py /path/to/log.txt --mode redact --style token --out redacted.txt
Redact IPv4 to /24-ish (keep first 3 octets), IPv6 keep first 4 hextets:
python3 ip_parse.py /path/to/log.txt --mode redact --style keep24 --out redacted.txt
Deterministic “same IP → same pseudonym” hashing:
python3 ip_parse.py /path/to/log.txt --mode redact --style hash --salt "my_secret_salt" --out redacted.txt
If you tell me what your input looks like (plain logs? UFW blocks? Nginx access logs?), I can tune the patterns to catch edge cases (like weird delimiters, CSV fields, quoted JSON, etc.) while staying strict on false positives.
You said:
that's awesome! make an infographic for my blog my question of this subject matter and your solutions