Skip to content

[SECURITY] Randomness updates #4

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wiredfool wants to merge 3 commits into
base: master
Choose a base branch
from
Open

[SECURITY] Randomness updates #4

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
8cd5a66
Use pgcrypto's random bytes for cryptographically good random numbers
wiredfool Sep 30, 2022
dd5ca59
Constant time equality for the TOTP verify comparison
wiredfool Sep 30, 2022
1cc1d16
[SECURITY] Fix entropy
wiredfool Sep 30, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
131 changes: 55 additions & 76 deletions packages/totp/sql/launchql-totp--0.0.3.sql
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,46 +32,6 @@ BEGIN
END;
$EOFCODE$ LANGUAGE plpgsql STRICT IMMUTABLE;

CREATE FUNCTION totp.pad_secret ( input bytea, len int ) RETURNS bytea AS $EOFCODE$
DECLARE
output bytea;
orig_length int = octet_length(input);
BEGIN
IF (orig_length = len) THEN
RETURN input;
END IF;

-- create blank bytea size of new length
output = lpad('', len, 'x')::bytea;

FOR i IN 0 .. len-1 LOOP
output = set_byte(output, i, get_byte(input, i % orig_length));
END LOOP;

RETURN output;
END;
$EOFCODE$ LANGUAGE plpgsql IMMUTABLE;

CREATE FUNCTION totp.base32_to_hex ( input text ) RETURNS text AS $EOFCODE$
DECLARE
output text[];
decoded text = base32.decode(input);
len int = character_length(decoded);
hx text;
BEGIN

FOR i IN 1 .. len LOOP
hx = to_hex(ascii(substring(decoded from i for 1)))::text;
IF (character_length(hx) = 1) THEN
-- if it is odd number of digits, pad a 0 so it can later
hx = '0' || hx;
END IF;
output = array_append(output, hx);
END LOOP;

RETURN array_to_string(output, '');
END;
$EOFCODE$ LANGUAGE plpgsql IMMUTABLE;

CREATE FUNCTION totp.hotp ( key bytea, c int, digits int DEFAULT 6, hash text DEFAULT 'sha1' ) RETURNS text AS $EOFCODE$
DECLARE
Expand All @@ -84,56 +44,75 @@ BEGIN
END;
$EOFCODE$ LANGUAGE plpgsql IMMUTABLE;

CREATE FUNCTION totp.generate ( secret text, period int DEFAULT 30, digits int DEFAULT 6, time_from timestamptz DEFAULT now(), hash text DEFAULT 'sha1', encoding text DEFAULT 'base32', clock_offset int DEFAULT 0 ) RETURNS text AS $EOFCODE$

CREATE FUNCTION totp.generate ( secret bytea, period int DEFAULT 30, digits int DEFAULT 6, time_from timestamptz DEFAULT now(), hash text DEFAULT 'sha1', clock_offset int DEFAULT 0 ) RETURNS text AS $EOFCODE$
DECLARE
c int := FLOOR(EXTRACT(EPOCH FROM time_from) / period)::int + clock_offset;
key bytea;
BEGIN

IF (encoding = 'base32') THEN
key = ( '\x' || totp.base32_to_hex(secret) )::bytea;
ELSE
key = secret::bytea;
END IF;

RETURN totp.hotp(key, c, digits, hash);
RETURN totp.hotp(secret, c, digits, hash);
END;
$EOFCODE$ LANGUAGE plpgsql STABLE;

CREATE FUNCTION totp.verify ( secret text, check_totp text, period int DEFAULT 30, digits int DEFAULT 6, time_from timestamptz DEFAULT now(), hash text DEFAULT 'sha1', encoding text DEFAULT 'base32', clock_offset int DEFAULT 0 ) RETURNS boolean AS $EOFCODE$
SELECT totp.generate (
secret,
period,
digits,
time_from,
hash,
encoding,
clock_offset) = check_totp;
$EOFCODE$ LANGUAGE sql;

CREATE FUNCTION totp.url ( email text, totp_secret text, totp_interval int, totp_issuer text ) RETURNS text AS $EOFCODE$
$EOFCODE$ LANGUAGE plpgsql VOLATILE;


CREATE FUNCTION totp.constant_time_equal(a text, b text, minlength int DEFAULT 6) RETURNS boolean AS $EOFCODE$
-- Compare all of the individual characters of each string
-- minlength is optional, prevents timing attacks to discover the length of the string
-- Create a table of true/false for each individual character comparison
-- Count the true/false
-- Compare the count of true to the number of comparisons.
WITH maxlen AS (
SELECT max(s) AS l
FROM (VALUES (octet_length(a)),
(octet_length(b)),
(minlength)) AS val(s)
),
matches AS (
SELECT substring(a FROM ix for 1) = substring(b FROM ix for 1) AS eq
FROM (SELECT generate_series(1, (SELECT l FROM maxlen)) AS ix) AS series
),
counts AS (
SELECT count(*) AS ct, eq
FROM matches GROUP BY eq
)
SELECT (SELECT l FROM maxlen) = coalesce((SELECT ct FROM counts WHERE eq='t'), 0)

$EOFCODE$ language sql VOLATILE;

CREATE FUNCTION totp.verify ( secret bytea, check_totp text, period int DEFAULT 30, digits int DEFAULT 6, time_from timestamptz DEFAULT now(), hash text DEFAULT 'sha1', clock_offset int DEFAULT 0 ) RETURNS boolean AS $EOFCODE$
SELECT totp.constant_time_equal(
totp.generate (
secret,
period,
digits,
time_from,
hash,
clock_offset),
check_totp);
$EOFCODE$ LANGUAGE sql VOLATILE;

CREATE FUNCTION totp.url ( email text, totp_secret bytea, totp_interval int, totp_issuer text ) RETURNS text AS $EOFCODE$
SELECT
concat('otpauth://totp/', totp.urlencode (email), '?secret=', totp.urlencode (totp_secret), '&period=', totp.urlencode (totp_interval::text), '&issuer=', totp.urlencode (totp_issuer));
concat('otpauth://totp/',
totp.urlencode (email),
'?secret=',
totp.urlencode (base32.encode(totp_secret::text)),
'&period=',
totp.urlencode (totp_interval::text),
'&issuer=',
totp.urlencode (totp_issuer));
$EOFCODE$ LANGUAGE sql STRICT IMMUTABLE;

CREATE FUNCTION totp.random_base32 ( _length int DEFAULT 20 ) RETURNS text LANGUAGE sql AS $EOFCODE$
SELECT
string_agg(('{a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,2,3,4,5,6,7}'::text[])[ceil(random() * 32)], '')
FROM
generate_series(1, _length);
$EOFCODE$;

CREATE FUNCTION totp.generate_secret ( hash text DEFAULT 'sha1' ) RETURNS bytea AS $EOFCODE$
BEGIN
-- See https://tools.ietf.org/html/rfc4868#section-2.1.2
-- The optimal key length for HMAC is the block size of the algorithm
CASE
WHEN hash = 'sha1' THEN RETURN totp.random_base32(20); -- = 160 bits
WHEN hash = 'sha256' THEN RETURN totp.random_base32(32); -- = 256 bits
WHEN hash = 'sha512' THEN RETURN totp.random_base32(64); -- = 512 bits
WHEN hash = 'sha1' THEN RETURN gen_random_bytes(20); -- = 160 bits
WHEN hash = 'sha256' THEN RETURN gen_random_bytes(32); -- = 256 bits
WHEN hash = 'sha512' THEN RETURN gen_random_bytes(64); -- = 512 bits
ELSE
RAISE EXCEPTION 'Unsupported hash algorithm for OTP (see RFC6238/4226).';
RETURN NULL;
END CASE;
END;
$EOFCODE$ LANGUAGE plpgsql VOLATILE;
$EOFCODE$ LANGUAGE plpgsql VOLATILE;