work

1 files changed, 36 insertions, 10 deletions

diff --git a/app.py b/app.py
index 2177e9c..d573efc 100644
--- a/app.py
+++ b/app.py
@@ -1,6 +1,9 @@
 import binascii
 
 from flask import Flask, render_template, request, redirect, url_for
+from flask_wtf import FlaskForm
+from wtforms import StringField
+from wtforms.validators import DataRequired, Length, ValidationError
 
 from aesgcmanalysis import xor, gmac, gcm_encrypt, nonce_reuse_recover_secrets, gf128_to_bytes
 
@@ -10,18 +13,41 @@ app = Flask(__name__)
 def index():
     return render_template('index.html')
 
+def hex_check(form, field):
+    if len(field.data) % 2 != 0:
+        raise ValidationError(f'not valid hex; must have even length')
+    if not all(c in '1234567890abcdef' for c in field.data):
+        raise ValidationError(f'not valid hex; contains non-hex character')
+
+def not_equal_to(other):
+    def helper(form, field):
+        print(other, form['m1'], field)
+        if other not in form:
+            return
+        if form[other].data == field.data:
+            raise ValidationError(f'must not be equal to {other}')
+    return helper
+
+class NonceReuseForm(FlaskForm):
+    key = StringField('key', validators=[DataRequired(), Length(min=32, max=32), hex_check])
+    nonce = StringField('nonce', validators=[DataRequired(), Length(min=24, max=24), hex_check])
+    m1 = StringField('first message', validators=[DataRequired(), Length(min=1, max=64)])
+    m2 = StringField('second message', validators=[DataRequired(), Length(min=1, max=64), not_equal_to('m1')])
+    mf = StringField('forged message', validators=[DataRequired(), Length(min=1, max=64)])
+
 @app.route('/nonce-reuse', methods=['GET', 'POST'])
 def nonce_reuse():
-    key = nonce = c_forged = macs = None
-    m1 = m2 = mf = ''
-    if request.method == 'POST':
-        key = binascii.unhexlify(request.form['key'])
-        nonce = binascii.unhexlify(request.form['nonce'])
-        m1 = request.form['m1']
-        m2 = request.form['m2']
-        mf = request.form['mf']
-        c_forged, macs = solve(key, nonce, bytes(m1, 'ascii'), bytes(m2, 'ascii'), bytes(mf, 'ascii'))
-    return render_template('nonce-reuse.html', key=key, nonce=nonce, m1=m1, m2=m2, mf=mf, c_forged=c_forged, macs=macs)
+    form = NonceReuseForm(meta={'csrf': False})
+    key = nonce = None
+    m1 = m2 = mf = c_forged = ''
+    macs = None
+    if form.is_submitted():
+        key, nonce, m1, m2, mf = form.key.data, form.nonce.data, form.m1.data, form.m2.data, form.mf.data
+        if form.validate():
+            skey = binascii.unhexlify(key)
+            snonce = binascii.unhexlify(nonce)
+            c_forged, macs = solve(skey, snonce, bytes(m1, 'utf-8'), bytes(m2, 'utf-8'), bytes(mf, 'utf-8'))
+    return render_template('nonce-reuse.html', form=form, key=key, nonce=nonce, m1=m1, m2=m2, mf=mf, c_forged=c_forged, macs=macs)
 
 def solve(k, nonce, m1, m2, mf):
     aad1 = aad2 = b""