-"""
- Interface to OpenSSL object identifier database.
+"""
+Interface to OpenSSL object identifier database.
+
+It is primarily intended to deal with OIDs which are compiled into the
+database or defined in the openssl configuration files.
- It is primarily intended to deal with OIDs which are compiled into the
- database or defined in the openssl configuration files.
+But see create() function.
- But see create() function
+OpenSSL maintains database of OIDs, which contain long and short
+human-readable names, which correspond to Oid as well as canonical
+dotted-decimal representation, and links it to small integer, named
+numeric identifier or 'nid'. Most OpenSSL functions which deals with
+ASN.1 structures such as certificates or cryptographic messages,
+expect or return nids, but it is very bad idea to hardcode nids into
+your app, because it can change after mere recompilation of OpenSSL
+library.
+This module provides Oid object which represents entry to OpenSSL
+OID database.
"""
from ctypescrypto import libcrypto
from ctypes import c_char_p, c_void_p, c_int, create_string_buffer
+from ctypescrypto.exception import LibCryptoError
-__all__ = ['Oid','create','cleanup']
+__all__ = ['Oid', 'create', 'cleanup']
class Oid(object):
"""
- Represents an OID. It can be consturucted by textual
- representation like Oid("commonName") or Oid("CN"),
- dotted-decimal Oid("1.2.3.4") or using OpenSSL numeric
- identifer (NID), which is typically returned or required by
- OpenSSL API functions. If object is consturcted from textual
- representation which is not present in the database, it fails
- with ValueError
+ Represents an OID (ASN.1 Object identifier).
- attribute nid - contains object nid.
+ It can be consturucted by textual
+ representation like Oid("commonName") or Oid("CN"),
+ dotted-decimal Oid("1.2.3.4") or using OpenSSL numeric
+ identifer (NID), which is typically returned or required by
+ OpenSSL API functions. If object is consturcted from textual
+ representation which is not present in the database, it fails
+ with ValueError
+ attribute nid - contains object nid.
"""
- def __init__(self,value):
- " Object constuctor. Accepts string or integer"
- if isinstance(value,unicode):
- value=value.encode('ascii')
- if isinstance(value,str):
- self.nid=libcrypto.OBJ_txt2nid(value)
- if self.nid==0:
- raise ValueError("Cannot find object %s in the database"%(value))
- elif isinstance(value,(int,long)):
- cn=libcrypto.OBJ_nid2sn(value)
- if cn is None:
- raise ValueError("No such nid %d in the database"%(value))
- self.nid=value
+ def __init__(self, value):
+ """
+ Object constuctor. Accepts string, integer, or another Oid
+ object.
+
+ Integer should be OpenSSL numeric identifier (nid) as returned
+ by some libcrypto function or extracted from some libcrypto
+ structure
+ """
+ if isinstance(value, unicode):
+ value = value.encode('ascii')
+ if isinstance(value, str):
+ self.nid = libcrypto.OBJ_txt2nid(value)
+ if self.nid == 0:
+ raise ValueError("Cannot find object %s in the database" %
+ value)
+ elif isinstance(value, (int, long)):
+ short = libcrypto.OBJ_nid2sn(value)
+ if short is None:
+ raise ValueError("No such nid %d in the database" % value)
+ self.nid = value
+ elif isinstance(value, Oid):
+ self.nid = value.nid
else:
raise TypeError("Cannot convert this type to object identifier")
def __hash__(self):
- " Returns NID "
+ " Hash of object is equal to nid because Oids with same nid are same"
return self.nid
- def __cmp__(self,other):
+ def __cmp__(self, other):
" Compares NIDs of two objects "
- return self.nid-other.nid
+ return self.nid - other.nid
def __str__(self):
- " Default string representation of Oid is dotted-decimal"
+ " Default string representation of Oid is dotted-decimal "
return self.dotted()
def __repr__(self):
- return "Oid('%s')"%(self.dotted())
+ " Returns constructor call of Oid with dotted representation "
+ return "Oid('%s')" % (self.dotted())
def shortname(self):
" Returns short name if any "
return libcrypto.OBJ_nid2sn(self.nid)
return libcrypto.OBJ_nid2ln(self.nid)
def dotted(self):
" Returns dotted-decimal reperesentation "
- obj=libcrypto.OBJ_nid2obj(self.nid)
- buf=create_string_buffer(256)
- libcrypto.OBJ_obj2txt(buf,256,obj,1)
+ obj = libcrypto.OBJ_nid2obj(self.nid)
+ buf = create_string_buffer(256)
+ libcrypto.OBJ_obj2txt(buf, 256, obj, 1)
return buf.value
@staticmethod
def fromobj(obj):
"""
Creates an OID object from the pointer to ASN1_OBJECT c structure.
- Strictly for internal use
+ This method intended for internal use for submodules which deal
+ with libcrypto ASN1 parsing functions, such as x509 or CMS
"""
- nid=libcrypto.OBJ_obj2nid(obj)
- if nid==0:
- buf=create_string_buffer(80)
- l=libcrypto.OBJ_obj2txt(buf,80,obj,1)
- oid=create(buf[0:l],buf[0:l],buf[0:l])
+ nid = libcrypto.OBJ_obj2nid(obj)
+ if nid == 0:
+ buf = create_string_buffer(80)
+ dotted_len = libcrypto.OBJ_obj2txt(buf, 80, obj, 1)
+ dotted = buf[:dotted_len]
+ oid = create(dotted, dotted, dotted)
else:
- oid=Oid(nid)
+ oid = Oid(nid)
return oid
-def create(dotted,shortname,longname):
+def create(dotted, shortname, longname):
"""
- Creates new OID in the database
+ Creates new OID in the database
+
+ @param dotted - dotted-decimal representation of new OID
+ @param shortname - short name for new OID
+ @param longname - long name for new OID
+
+ @returns Oid object corresponding to new OID
- @param dotted - dotted-decimal representation of new OID
- @param shortname - short name for new OID
- @param longname - long name for new OID
+ This function should be used with exreme care. Whenever
+ possible, it is better to add new OIDs via OpenSSL configuration
+ file
- @returns Oid object corresponding to new OID
-
- This function should be used with exreme care. Whenever
- possible, it is better to add new OIDs via OpenSSL configuration
- file
+ Results of calling this function twice for same OIDor for
+ Oid alredy in database are undefined
- Results of calling this function twice for same OIDor for
- Oid alredy in database are undefined
"""
- nid=libcrypto.OBJ_create(dotted,shortname,longname)
+ nid = libcrypto.OBJ_create(dotted, shortname, longname)
if nid == 0:
raise LibCryptoError("Problem adding new OID to the database")
return Oid(nid)
def cleanup():
"""
- Removes all the objects, dynamically added by current
- application from database.
+ Removes all the objects, dynamically added by current
+ application from database.
"""
libcrypto.OBJ_cleanup()
-libcrypto.OBJ_nid2sn.restype=c_char_p
-libcrypto.OBJ_nid2ln.restype=c_char_p
-libcrypto.OBJ_nid2obj.restype=c_void_p
-libcrypto.OBJ_obj2txt.argtypes=(c_char_p,c_int,c_void_p,c_int)
-libcrypto.OBJ_txt2nid.argtupes=(c_char_p,)
-libcrypto.OBJ_create.argtypes=(c_char_p,c_char_p,c_char_p)
+libcrypto.OBJ_nid2sn.restype = c_char_p
+libcrypto.OBJ_nid2ln.restype = c_char_p
+libcrypto.OBJ_nid2obj.restype = c_void_p
+libcrypto.OBJ_obj2txt.argtypes = (c_char_p, c_int, c_void_p, c_int)
+libcrypto.OBJ_txt2nid.argtupes = (c_char_p, )
+libcrypto.OBJ_create.argtypes = (c_char_p, c_char_p, c_char_p)
projects / oss / ctypescrypto.git / blobdiff