feat(lexers): add ASCII armored

AUTHORS

@@ -201,6 +201,7 @@ Other contributors, listed alphabetically, are:
 * Robert Simmons -- Standard ML lexer
 * Kirill Simonov -- YAML lexer
 * Corbin Simpson -- Monte lexer
+* Ville Skyttä -- ASCII armored lexer
 * Alexander Smishlajev -- Visual FoxPro lexer
 * Steve Spigarelli -- XQuery lexer
 * Jerome St-Louis -- eC lexer

pygments/lexers/_mapping.py

@@ -41,6 +41,7 @@
     'AppleScriptLexer': ('pygments.lexers.scripting', 'AppleScript', ('applescript',), ('*.applescript',), ()),
     'ArduinoLexer': ('pygments.lexers.c_like', 'Arduino', ('arduino',), ('*.ino',), ('text/x-arduino',)),
     'ArrowLexer': ('pygments.lexers.arrow', 'Arrow', ('arrow',), ('*.arw',), ()),
+    'AscLexer': ('pygments.lexers.asc', 'ASCII armored', ('asc', 'pem'), ('*.asc', '*.pem', 'id_dsa', 'id_ecdsa', 'id_ecdsa_sk', 'id_ed25519', 'id_ed25519_sk', 'id_rsa'), (['application/pgp-keys', 'application/pgp-encrypted', 'application/pgp-signature'],)),
     'AspectJLexer': ('pygments.lexers.jvm', 'AspectJ', ('aspectj',), ('*.aj',), ('text/x-aspectj',)),
     'AsymptoteLexer': ('pygments.lexers.graphics', 'Asymptote', ('asymptote', 'asy'), ('*.asy',), ('text/x-asymptote',)),
     'AugeasLexer': ('pygments.lexers.configs', 'Augeas', ('augeas',), ('*.aug',), ()),

pygments/lexers/asc.py

@@ -0,0 +1,49 @@
+"""
+    pygments.lexers.asc
+    ~~~~~~~~~~~~~~~~~~~
+
+    Lexer for various ASCII armored files.
+
+    :copyright: Copyright 2021 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+import re
+
+from pygments.lexer import RegexLexer, bygroups
+from pygments.token import Comment, Generic, Name, Operator, Text, String
+
+__all__ = ['AscLexer']
+
+
+class AscLexer(RegexLexer):
+    """
+    Lexer for ASCII armored files, containing `-----BEGIN/END ...-----` wrapped base64 data.
+    """
+    name = 'ASCII armored'
+    aliases = ['asc', 'pem']
+    filenames = [
+        '*.asc',  # PGP; *.gpg, *.pgp, and *.sig too, but those can be binary
+        '*.pem',  # X.509; *.cer, *.crt, *.csr, and key etc too, but those can be binary
+        'id_dsa', 'id_ecdsa', 'id_ecdsa_sk', 'id_ed25519', 'id_ed25519_sk', 'id_rsa',  # SSH private keys
+    ]
+    mimetypes = ['application/pgp-keys', 'application/pgp-encrypted', 'application/pgp-signature'],
+
+    flags = re.MULTILINE
+
+    tokens = {
+        'root': [
+            (r'\s+', Text),
+            (r'^-----BEGIN [^\n]+-----$', Generic.Heading, 'data'),
+            (r'\S+', Comment),
+        ],
+        'data': [
+            (r'\s+', Text),
+            (r'^([^:]+)(:)([ \t]+)(.*)', bygroups(Name.Attribute, Operator, Text, String)),
+            (r'^-----END [^\n]+-----$', Generic.Heading, 'root'),
+            (r'\S+', String),
+        ],
+    }
+
+    def analyse_text(text):
+        if re.search(r'^-----BEGIN [^\n]+-----\r?\n', text):
+            return True