scripts/generate-cipherinfo.py: ensure output is consistently sorted.

This ensures that the output of the script is consistently sorted.
This commit uses the integer value of the literal cipher suite value.

This will make future diffs from output of the script much easier to read.

1 files changed, 23 insertions, 2 deletions

diff --git a/scripts/generate-cipherinfo.py b/scripts/generate-cipherinfo.py
index ace0013f2..9dc1393cf 100755
--- a/scripts/generate-cipherinfo.py
+++ b/scripts/generate-cipherinfo.py
@@ -24,6 +24,24 @@ from xml.dom import minidom
 
 IETF_TLS_PARAMETERS_WWW = "https://www.ietf.org/assignments/tls-parameters/tls-parameters.xml"
 
+def integerFromIdent(ident):
+	'''
+		Parses a TLS cipher suite identifier from the IETF TLS cipher suite registry.
+		The cipher suite identifier is represented as a string of hex-encoded byte values
+		separated by commas.
+
+		This function consumes the byte sequence and converts it into an unsigned integer.
+	'''
+	hexVals = ident.split(',')
+	nbytes = len(hexVals)
+	if nbytes > 3:
+		raise Exception("unexpected amount of bytes")
+	outVal = 0
+	for idx, val in enumerate(hexVals):
+		intVal = int(val, base=16)
+		outVal |= ((intVal & 0xff) << (((nbytes - 1) - idx) * 8))
+	return outVal
+
 def rfcNameLut():
 	lut = {}
 
@@ -244,6 +262,7 @@ def main():
 		# XXX: should SRP be marked as forward_secret?
 
 		output.append({
+			'sort_order': integerFromIdent(ident),
 			'identifier': ident,
 			'openssl_name': osslname,
 			'rfc_name': rfcname,
@@ -266,6 +285,7 @@ def main():
 		for key in lut.keys():
 			if not key in added_ids:
 				output.append({
+					'sort_order': integerFromIdent(key),
 					'identifier': key,
 					'openssl_name': None,
 					'rfc_name': lut[key],
@@ -280,6 +300,7 @@ def main():
 					'export': None,
 					'forward_secret': None
 				})
+	sortedOutput = sorted(output, key=lambda meta: meta['sort_order'])
 
 	output_c = True
 	if output_c:
@@ -292,7 +313,7 @@ def main():
 		print('// will cause a preprocessor error. Oops!')
 		print('#error Please verify this file is correct')
 		print('static const SSLCipherInfo cipher_info_lookup_table[] = {')
-		for entry in output:
+		for entry in sortedOutput:
 			print('\t{')
 			print('\t\t// openssl_name')
 			print('\t\t{0},'.format(Cstr(entry["openssl_name"])))
@@ -309,7 +330,7 @@ def main():
 			print('\t},')
 		print('};')
 	else:
-		print(json.dumps(output, sort_keys=True, indent=4, separators=(',', ': ')))
+		print(json.dumps(sortedOutput, sort_keys=True, indent=4, separators=(',', ': ')))
 
 if __name__ == '__main__':
 	main()