Added support for loading public keys from OpenSSL

1 files changed, 35 insertions, 0 deletions

diff --git a/rsa/asn1.py b/rsa/asn1.py
new file mode 100644
index 0000000..706e6cf
--- /dev/null
+++ b/rsa/asn1.py
@@ -0,0 +1,35 @@
+'''ASN.1 definitions.
+
+Not all ASN.1-handling code use these definitions, but when it does, they should be here.
+'''
+
+from pyasn1.type import univ, namedtype, tag
+
+class PubKeyHeader(univ.Sequence):
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType('oid', univ.ObjectIdentifier()),
+        namedtype.NamedType('parameters', univ.Null()),
+    )
+
+class OpenSSLPubKey(univ.Sequence):
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType('header', PubKeyHeader()),
+        
+        # This little hack (the implicit tag) allows us to get a Bit String as Octet String
+        namedtype.NamedType('key', univ.OctetString().subtype(
+                                          implicitTag=tag.Tag(tagClass=0, tagFormat=0, tagId=3))),
+    )
+
+
+class AsnPubKey(univ.Sequence):
+    '''ASN.1 contents of DER encoded public key:
+    
+    RSAPublicKey ::= SEQUENCE {
+         modulus           INTEGER,  -- n
+         publicExponent    INTEGER,  -- e
+    '''
+
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType('modulus', univ.Integer()),
+        namedtype.NamedType('publicExponent', univ.Integer()),
+    )