Add special table formatting for Cipher.

Extracts a new file for JSON loading and cleans up a couple style issues.

Updates the support for GCM to 10+, it was available at least in that
version.

Bug: 35793879
Test: Manual inspection of output
Change-Id: I84f74fd14506cb36e0744a77c0223f5e3b86ca1b

4 files changed, 154 insertions, 20 deletions

diff --git a/tools/docs/crypto/crypto_docs.py b/tools/docs/crypto/crypto_docs.py
new file mode 100644
index 0000000000..d1f220dc87
--- /dev/null
+++ b/tools/docs/crypto/crypto_docs.py
@@ -0,0 +1,31 @@
+# Copyright (C) 2017 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+'''Utility functions for crypto doc updating tools.'''
+
+import json
+
+
+def load_json(filename):
+    '''Returns an object containing the JSON data from the provided file.'''
+    f = open(filename)
+    # JSON doesn't allow comments, but we have some header docs in our file,
+    # so strip comments out before parsing
+    stripped_contents = ''
+    for line in f:
+        if not line.strip().startswith('#'):
+            stripped_contents += line
+    data = json.loads(stripped_contents)
+    f.close()
+    return data
diff --git a/tools/docs/crypto/data/crypto_support.json b/tools/docs/crypto/data/crypto_support.json
index 8e6cc4f8de..0a32e5716f 100644
--- a/tools/docs/crypto/data/crypto_support.json
+++ b/tools/docs/crypto/data/crypto_support.json
@@ -224,7 +224,7 @@
         },
         {
           "name": "AES/GCM/NOPADDING",
-          "supported_api_levels": "21+"
+          "supported_api_levels": "10+"
         },
         {
           "name": "AES/OFB/ISO10126PADDING",
@@ -1227,5 +1227,5 @@
       "name": "TrustManagerFactory"
     }
   ],
-  "last_updated": "2017-03-16 10:29:21 UTC"
+  "last_updated": "2017-03-16 12:35:47 UTC"
 }
\ No newline at end of file
diff --git a/tools/docs/crypto/format_supported_algorithm_table.py b/tools/docs/crypto/format_supported_algorithm_table.py
index f07f9d9c5e..1460099078 100755
--- a/tools/docs/crypto/format_supported_algorithm_table.py
+++ b/tools/docs/crypto/format_supported_algorithm_table.py
@@ -20,9 +20,11 @@ Outputs HTML tables suitable for inclusion in the Android documentation that
 reflect the crypto algorithm support shown in the provided data file.
 """
 
-import json
+import operator
 import sys
 
+import crypto_docs
+
 
 def sort_by_name(seq):
     return sorted(seq, key=lambda x: x['name'])
@@ -32,7 +34,7 @@ def main():
     if len(sys.argv) < 2:
         print 'Must supply argument to data file.'
         sys.exit(1)
-    data = json.load(open(sys.argv[1]))
+    data = crypto_docs.load_json(sys.argv[1])
     categories = sort_by_name(data['categories'])
     print '<h2 id="SupportedAlgorithms">Supported Algorithms</h2>'
     print
@@ -42,25 +44,131 @@ def main():
                '<code>{name}</code></a></li>'.format(**category))
     print '</ul>'
     for category in categories:
-        print '''
+        if category['name'] == 'Cipher':
+            # We display ciphers in a four-column table to conserve space and
+            # so that it's more comprehensible.  To do this, we have to
+            # collapse all our ciphers into "equivalence classes" of a sort.
+
+            # First, collect the relevant data for each algorithm into a tuple.
+            # The mode and padding are in lists because we are going to collapse
+            # multiple tuples with those in later steps.
+            algorithms = sort_by_name(category['algorithms'])
+            tuples = []
+            for algorithm in algorithms:
+                name, mode, padding = algorithm['name'].split('/')
+                tuples.append((
+                    name,
+                    [mode],
+                    [padding],
+                    algorithm['supported_api_levels'],
+                    'deprecated' in algorithm and algorithm['deprecated']))
+            # Sort the tuples by all items except padding, then collapse
+            # items with all non-padding values the same (which will always be
+            # neighboring items) into a single item.
+            tuples.sort(key=operator.itemgetter(0, 1, 3, 4))
+            i = 0
+            while i < len(tuples) - 1:
+                if (tuples[i][0] == tuples[i+1][0]
+                    and tuples[i][1] == tuples[i+1][1]
+                    and tuples[i][3] == tuples[i+1][3]
+                    and tuples[i][4] == tuples[i+1][4]):
+                    tuples[i][2].extend(tuples[i+1][2])
+                    del tuples[i+1]
+                else:
+                    i += 1
+            # Do the same thing as above, but with modes.
+            tuples.sort(key=operator.itemgetter(0, 2, 3, 4))
+            i = 0
+            while i < len(tuples) - 1:
+                if (tuples[i][0] == tuples[i+1][0]
+                    and tuples[i][2] == tuples[i+1][2]
+                    and tuples[i][3] == tuples[i+1][3]
+                    and tuples[i][4] == tuples[i+1][4]):
+                    tuples[i][1].extend(tuples[i+1][1])
+                    del tuples[i+1]
+                else:
+                    i += 1
+            # Display the table with rowspans for those entries where all the
+            # items have the same algorithm, mode, etc
+            print '''
 <h3 id="Supported{name}">{name}</h3>
 <table>
   <thead>
     <th>Algorithm</th>
+    <th>Modes</th>
+    <th>Paddings</th>
     <th>Supported API Levels</th>
   </thead>
   <tbody>'''.format(**category)
-        algorithms = sort_by_name(category['algorithms'])
-        for algorithm in algorithms:
-            dep_class = ''
-            if 'deprecated' in algorithm and algorithm['deprecated']:
-                dep_class = ' class="deprecated"'
+            tuples.sort(key=operator.itemgetter(0, 4, 1, 2, 3))
+            i = 0
+            cur_deprecated = None
+            cur_algorithm = None
+            cur_mode = None
+            while i < len(tuples):
+                row = tuples[i]
+                if row[4] != cur_deprecated:
+                    cur_deprecated = row[4]
+                    cur_algorithm = None
+                    cur_mode = None
+                if cur_deprecated:
+                    print '    <tr class="deprecated">'
+                else:
+                    print '    <tr>'
+                if row[0] != cur_algorithm:
+                    cur_algorithm = row[0]
+                    cur_mode = None
+                    j = i + 1
+                    while (j < len(tuples)
+                           and tuples[j][4] == cur_deprecated
+                           and tuples[j][0] == cur_algorithm):
+                        j += 1
+                    rowspan = j - i
+                    if rowspan > 1:
+                        print '      <td rowspan="%d">%s</td>' % (rowspan, cur_algorithm)
+                    else:
+                        print '      <td>%s</td>' % cur_algorithm
+                if row[1] != cur_mode:
+                    cur_mode = row[1]
+                    j = i + 1
+                    while (j < len(tuples)
+                           and tuples[j][4] == cur_deprecated
+                           and tuples[j][0] == cur_algorithm
+                           and tuples[j][1] == cur_mode):
+                        j += 1
+                    rowspan = j - i
+                    modestring = '<br>'.join(cur_mode)
+                    if rowspan > 1:
+                        print '      <td rowspan="%d">%s</td>' % (rowspan, modestring)
+                    else:
+                        print '      <td>%s</td>' % modestring
+                print '      <td>%s</td>' % '<br>'.join(row[2])
+                print '      <td>%s</td>' % row[3]
+                print '    </tr>'
+                i += 1
             print '''
+  </tbody>
+</table>'''
+        else:
+            print '''
+<h3 id="Supported{name}">{name}</h3>
+<table>
+  <thead>
+    <th>Algorithm</th>
+    <th>Supported API Levels</th>
+  </thead>
+  <tbody>'''.format(**category)
+            algorithms = sort_by_name(category['algorithms'])
+            for algorithm in algorithms:
+                dep_class = ''
+                if 'deprecated' in algorithm and algorithm['deprecated']:
+                    dep_class = ' class="deprecated"'
+                print '''
     <tr{deprecated_class}>
       <td>{name}</td>
       <td>{supported_api_levels}</td>
     </tr>'''.format(deprecated_class=dep_class, **algorithm)
-        print '''
+            print '''
   </tbody>
 </table>'''
 
diff --git a/tools/docs/crypto/update_crypto_support.py b/tools/docs/crypto/update_crypto_support.py
index 7d7861f975..8d39cf8638 100755
--- a/tools/docs/crypto/update_crypto_support.py
+++ b/tools/docs/crypto/update_crypto_support.py
@@ -29,6 +29,8 @@ import datetime
 import json
 import sys
 
+import crypto_docs
+
 SUPPORTED_CATEGORIES = [
     'AlgorithmParameterGenerator',
     'AlgorithmParameters',
@@ -81,6 +83,7 @@ def normalize_name(name):
         name = name[:-1 * len("/PKCS7PADDING")] + "/PKCS5PADDING"
     return name
 
+
 def get_current_data(f):
     """Returns a map of the algorithms in the given input.
 
@@ -205,15 +208,7 @@ def main():
                         help='The JSON file to update')
     args = parser.parse_args()
 
-    f = open(args.file)
-    # JSON doesn't allow comments, but we have some header docs in our file,
-    # so strip comments out before parsing
-    stripped_contents = ''
-    for line in f:
-        if not line.strip().startswith('#'):
-            stripped_contents += line
-    prev_data = json.loads(stripped_contents)
-    f.close()
+    prev_data = crypto_docs.load_json(args.file)
 
     current_data = get_current_data(sys.stdin)