X-Git-Url: http://wagner.pp.ru/gitweb/?a=blobdiff_plain;f=ctypescrypto%2Fx509.py;h=dd4cba2b1c13b403359e98c4e1ca02b36158e7f0;hb=92df3e73921ba7b8756bfab1af4189dab7cc610e;hp=28c587c1673e879c6a5263cdc967695fe7dd5128;hpb=7c390cd3c8d93a8fb5f1a769fa61c59c0bf9bdd0;p=oss%2Fctypescrypto.git diff --git a/ctypescrypto/x509.py b/ctypescrypto/x509.py index 28c587c..dd4cba2 100644 --- a/ctypescrypto/x509.py +++ b/ctypescrypto/x509.py @@ -1,65 +1,570 @@ -from ctypes import c_void_p +""" +Implements interface to openssl X509 and X509Store structures, +I.e allows to load, analyze and verify certificates. + +X509Store objects are also used to verify other signed documets, +such as CMS, OCSP and timestamps. +""" + + + +from ctypes import c_void_p,create_string_buffer,c_long,c_int,POINTER,c_char_p,Structure,cast from ctypescrypto.bio import Membio +from ctypescrypto.pkey import PKey +from ctypescrypto.oid import Oid from ctypescrypto.exception import LibCryptoError -from crypescrypto import libcrypto +from ctypescrypto import libcrypto +from datetime import datetime +try: + from pytz import utc +except ImportError: + from datetime import timedelta,tzinfo + ZERO=timedelta(0) + class UTC(tzinfo): + """tzinfo object for UTC. + If no pytz is available, we would use it. + """ -class X509Name: - def __init__(self,ptr): - self.ptr=ptr - def __del__(self): - libcrypto.X509_NAME_free(self.ptr) - def __str__(self): + def utcoffset(self, dt): + return ZERO - def __len__(self): - return libcrypto.X509_NAME_entry_count(self.ptr) + def tzname(self, dt): + return "UTC" + + def dst(self, dt): + return ZERO + + utc=UTC() + +__all__ = ['X509Error','X509Name','X509Store','StackOfX509'] + +class _validity(Structure): + """ ctypes representation of X509_VAL structure + needed to access certificate validity period, because openssl + doesn't provide fuctions for it - only macros + """ + _fields_ = [('notBefore',c_void_p),('notAfter',c_void_p)] - def __getattr__(self,key): - - def __setattr__(self,key,val): +class _cinf(Structure): + """ ctypes representtion of X509_CINF structure + neede to access certificate data, which are accessable only + via macros + """ + _fields_ = [('version',c_void_p), + ('serialNumber',c_void_p), + ('sign_alg',c_void_p), + ('issuer',c_void_p), + ('validity',POINTER(_validity)), + ('subject',c_void_p), + ('pubkey',c_void_p), + ('issuerUID',c_void_p), + ('subjectUID',c_void_p), + ('extensions',c_void_p), + ] -class X509_extlist: - def __init__(self,ptr): - self.ptr=ptr +class _x509(Structure): + """ + ctypes represntation of X509 structure needed + to access certificate data which are accesable only via + macros, not functions + """ + _fields_ = [('cert_info',POINTER(_cinf)), + ('sig_alg',c_void_p), + ('signature',c_void_p), + # There are a lot of parsed extension fields there + ] +_px509 = POINTER(_x509) + +class X509Error(LibCryptoError): + """ + Exception, generated when some openssl function fail + during X509 operation + """ + pass + + +class X509Name(object): + """ + Class which represents X.509 distinguished name - typically + a certificate subject name or an issuer name. + + Now used only to represent information, extracted from the + certificate. Potentially can be also used to build DN when creating + certificate signing request + """ + # XN_FLAG_SEP_COMMA_PLUS & ASN1_STRFLG_UTF8_CONVERT + PRINT_FLAG=0x10010 + ESC_MSB=4 + def __init__(self,ptr=None,copy=False): + """ + Creates a X509Name object + @param ptr - pointer to X509_NAME C structure (as returned by some OpenSSL functions + @param copy - indicates that this structure have to be freed upon object destruction + """ + if ptr is not None: + self.ptr=ptr + self.need_free=copy + self.writable=False + else: + self.ptr=libcrypto.X509_NAME_new() + self.need_free=True + self.writable=True def __del__(self): - libcrypto.X509_NAME_free(self.ptr) + """ + Frees if neccessary + """ + if self.need_free: + libcrypto.X509_NAME_free(self.ptr) def __str__(self): - + """ + Produces an ascii representation of the name, escaping all symbols > 0x80 + Probably it is not what you want, unless your native language is English + """ + b=Membio() + libcrypto.X509_NAME_print_ex(b.bio,self.ptr,0,self.PRINT_FLAG | self.ESC_MSB) + return str(b) + def __unicode__(self): + """ + Produces unicode representation of the name. + """ + b=Membio() + libcrypto.X509_NAME_print_ex(b.bio,self.ptr,0,self.PRINT_FLAG) + return unicode(b) def __len__(self): + """ + return number of components in the name + """ return libcrypto.X509_NAME_entry_count(self.ptr) + def __cmp__(self,other): + """ + Compares X509 names + """ + return libcrypto.X509_NAME_cmp(self.ptr,other.ptr) + def __eq__(self,other): + return libcrypto.X509_NAME_cmp(self.ptr,other.ptr)==0 - def __getattr__(self,key): - - def __setattr__(self,key,val): + def __getitem__(self,key): + if isinstance(key,Oid): + # Return first matching field + idx=libcrypto.X509_NAME_get_index_by_NID(self.ptr,key.nid,-1) + if idx<0: + raise KeyError("Key not found "+str(Oid)) + entry=libcrypto.X509_NAME_get_entry(self.ptr,idx) + s=libcrypto.X509_NAME_ENTRY_get_data(entry) + b=Membio() + libcrypto.ASN1_STRING_print_ex(b.bio,s,self.PRINT_FLAG) + return unicode(b) + elif isinstance(key,(int,long)): + # Return OID, string tuple + entry=libcrypto.X509_NAME_get_entry(self.ptr,key) + if entry is None: + raise IndexError("name entry index out of range") + oid=Oid.fromobj(libcrypto.X509_NAME_ENTRY_get_object(entry)) + s=libcrypto.X509_NAME_ENTRY_get_data(entry) + b=Membio() + libcrypto.ASN1_STRING_print_ex(b.bio,s,self.PRINT_FLAG) + return (oid,unicode(b)) + else: + raise TypeError("X509 NAME can be indexed by Oids or integers only") + def __setitem__(self,key,val): + if not self.writable: + raise ValueError("Attempt to modify constant X509 object") + else: + raise NotImplementedError + def __delitem__(self,key): + if not self.writable: + raise ValueError("Attempt to modify constant X509 object") + else: + raise NotImplementedError - +class _x509_ext(Structure): + """ Represens C structure X509_EXTENSION """ + _fields_=[("object",c_void_p), + ("critical",c_int), + ("value",c_void_p)] +class X509_EXT(object): + """ Python object which represents a certificate extension """ + def __init__(self,ptr,copy=False): + """ Initializes from the pointer to X509_EXTENSION. + If copy is True, creates a copy, otherwise just + stores pointer. + """ + if copy: + self.ptr=libcrypto.X509_EXTENSION_dup(ptr) + else: + self.ptr=cast(ptr,POINTER(_x509_ext)) + def __del__(self): + libcrypto.X509_EXTENSION_free(self.ptr) + def __str__(self): + b=Membio() + libcrypto.X509V3_EXT_print(b.bio,self.ptr,0x20010,0) + return str(b) + def __unicode__(self): + b=Membio() + libcrypto.X509V3_EXT_print(b.bio,self.ptr,0x20010,0) + return unicode(b) + @property + def oid(self): + return Oid.fromobj(self.ptr[0].object) + @property + def critical(self): + return self.ptr[0].critical >0 +class _X509extlist(object): + """ + Represents list of certificate extensions + """ + def __init__(self,cert): + self.cert=cert + def __len__(self): + return libcrypto.X509_get_ext_count(self.cert.cert) + def __getitem__(self,item): + p=libcrypto.X509_get_ext(self.cert.cert,item) + if p is None: + raise IndexError + return X509_EXT(p,True) + def find(self,oid): + """ + Return list of extensions with given Oid + """ + if not isinstance(oid,Oid): + raise TypeError("Need crytypescrypto.oid.Oid as argument") + found=[] + l=-1 + end=len(self) + while True: + l=libcrypto.X509_get_ext_by_NID(self.cert.cert,oid.nid,l) + if l>=end or l<0: + break + found.append(self[l]) + return found + def find_critical(self,crit=True): + """ + Return list of critical extensions (or list of non-cricital, if + optional second argument is False + """ + if crit: + flag=1 + else: + flag=0 + found=[] + end=len(self) + l=-1 + while True: + l=libcrypto.X509_get_ext_by_critical(self.cert.cert,flag,l) + if l>=end or l<0: + break + found.append(self[l]) + return found -class X509: - def __init__(self,ptr): - self.cert = ptr +class X509(object): + """ + Represents X.509 certificate. + """ + def __init__(self,data=None,ptr=None,format="PEM"): + """ + Initializes certificate + @param data - serialized certificate in PEM or DER format. + @param ptr - pointer to X509, returned by some openssl function. + mutually exclusive with data + @param format - specifies data format. "PEM" or "DER", default PEM + """ + if ptr is not None: + if data is not None: + raise TypeError("Cannot use data and ptr simultaneously") + self.cert = ptr + elif data is None: + raise TypeError("data argument is required") + else: + b=Membio(data) + if format == "PEM": + self.cert=libcrypto.PEM_read_bio_X509(b.bio,None,None,None) + else: + self.cert=libcrypto.d2i_X509_bio(b.bio,None) + if self.cert is None: + raise X509Error("error reading certificate") + self.extensions=_X509extlist(self) def __del__(self): + """ + Frees certificate object + """ libcrypto.X509_free(self.cert) def __str__(self): """ Returns der string of the certificate """ + b=Membio() + if libcrypto.i2d_X509_bio(b.bio,self.cert)==0: + raise X509Error("error serializing certificate") + return str(b) + def __repr__(self): + """ Returns valid call to the constructor """ + return "X509(data="+repr(str(self))+",format='DER')" + @property def pubkey(self): - """ Returns EVP PKEy object of certificate public key""" - return PKey(libcrypto.X509_get_pubkey(self.cert,False) - def verify(self,key): - """ Verify self on given issuer key """ - def frompem(s): - """ Create X509 object from pem string """ - def fromder(s): - """ Create X509 object from der string """ + """EVP PKEy object of certificate public key""" + return PKey(ptr=libcrypto.X509_get_pubkey(self.cert,False)) + def verify(self,store=None,chain=[],key=None): + """ + Verify self. Supports verification on both X509 store object + or just public issuer key + @param store X509Store object. + @param chain - list of X509 objects to add into verification + context.These objects are untrusted, but can be used to + build certificate chain up to trusted object in the store + @param key - PKey object with open key to validate signature + + parameters store and key are mutually exclusive. If neither + is specified, attempts to verify self as self-signed certificate + """ + if store is not None and key is not None: + raise X509Error("key and store cannot be specified simultaneously") + if store is not None: + ctx=libcrypto.X509_STORE_CTX_new() + if ctx is None: + raise X509Error("Error allocating X509_STORE_CTX") + if chain is not None and len(chain)>0: + ch=StackOfX509(chain) + else: + ch=None + if libcrypto.X509_STORE_CTX_init(ctx,store.store,self.cert,ch) < 0: + raise X509Error("Error allocating X509_STORE_CTX") + res= libcrypto.X509_verify_cert(ctx) + libcrypto.X509_STORE_CTX_free(ctx) + return res>0 + else: + if key is None: + if self.issuer != self.subject: + # Not a self-signed certificate + return False + key = self.pubkey + res = libcrypto.X509_verify(self.cert,key.key) + if res < 0: + raise X509Error("X509_verify failed") + return res>0 + + @property def subject(self): + """ X509Name for certificate subject name """ return X509Name(libcrypto.X509_get_subject_name(self.cert)) + @property def issuer(self): + """ X509Name for certificate issuer name """ return X509Name(libcrypto.X509_get_issuer_name(self.cert)) + @property def serial(self): - return - + """ Serial number of certificate as integer """ + asnint=libcrypto.X509_get_serialNumber(self.cert) + b=Membio() + libcrypto.i2a_ASN1_INTEGER(b.bio,asnint) + return int(str(b),16) + @property + def version(self): + """ certificate version as integer. Really certificate stores 0 for + version 1 and 2 for version 3, but we return 1 and 3 """ + asn1int=cast(self.cert,_px509)[0].cert_info[0].version + return libcrypto.ASN1_INTEGER_get(asn1int)+1 + @property def startDate(self): + """ Certificate validity period start date """ + # Need deep poke into certificate structure (x)->cert_info->validity->notBefore + global utc + asn1date=cast(self.cert,_px509)[0].cert_info[0].validity[0].notBefore + b=Membio() + libcrypto.ASN1_TIME_print(b.bio,asn1date) + return datetime.strptime(str(b),"%b %d %H:%M:%S %Y %Z").replace(tzinfo=utc) + @property + def endDate(self): + """ Certificate validity period end date """ + # Need deep poke into certificate structure (x)->cert_info->validity->notAfter + global utc + asn1date=cast(self.cert,_px509)[0].cert_info[0].validity[0].notAfter + b=Membio() + libcrypto.ASN1_TIME_print(b.bio,asn1date) + return datetime.strptime(str(b),"%b %d %H:%M:%S %Y %Z").replace(tzinfo=utc) + def check_ca(self): + """ Returns True if certificate is CA certificate """ + return libcrypto.X509_check_ca(self.cert)>0 +class X509Store(object): + """ + Represents trusted certificate store. Can be used to lookup CA + certificates to verify - def endDate(self); + @param file - file with several certificates and crls + to load into store + @param dir - hashed directory with certificates and crls + @param default - if true, default verify location (directory) + is installed - def extensions(self): + """ + def __init__(self,file=None,dir=None,default=False): + """ + Creates X509 store and installs lookup method. Optionally initializes + by certificates from given file or directory. + """ + # + # Todo - set verification flags + # + self.store=libcrypto.X509_STORE_new() + if self.store is None: + raise X509Error("allocating store") + lookup=libcrypto.X509_STORE_add_lookup(self.store,libcrypto.X509_LOOKUP_file()) + if lookup is None: + raise X509Error("error installing file lookup method") + if (file is not None): + if not libcrypto.X509_LOOKUP_ctrl(lookup,1,file,1,None)>0: + raise X509Error("error loading trusted certs from file "+file) + lookup=libcrypto.X509_STORE_add_lookup(self.store,libcrypto.X509_LOOKUP_hash_dir()) + if lookup is None: + raise X509Error("error installing hashed lookup method") + if dir is not None: + if not libcrypto.X509_LOOKUP_ctrl(lookup,2,dir,1,None)>0: + raise X509Error("error adding hashed trusted certs dir "+dir) + if default: + if not libcrypto.X509_LOOKUP_ctrl(lookup,2,None,3,None)>0: + raise X509Error("error adding default trusted certs dir ") + def add_cert(self,cert): + """ + Explicitely adds certificate to set of trusted in the store + @param cert - X509 object to add + """ + if not isinstance(cert,X509): + raise TypeError("cert should be X509") + libcrypto.X509_STORE_add_cert(self.store,cert.cert) + def add_callback(self,callback): + """ + Installs callback function, which would receive detailed information + about verified ceritificates + """ + raise NotImplementedError + def setflags(self,flags): + """ + Set certificate verification flags. + @param flags - integer bit mask. See OpenSSL X509_V_FLAG_* constants + """ + libcrypto.X509_STORE_set_flags(self.store,flags) + def setpurpose(self,purpose): + """ + Sets certificate purpose which verified certificate should match + @param purpose - number from 1 to 9 or standard strind defined in Openssl + possible strings - sslcient,sslserver, nssslserver, smimesign,smimeencrypt, crlsign, any,ocsphelper + """ + if isinstance(purpose,str): + purp_no=X509_PURPOSE_get_by_sname(purpose) + if purp_no <=0: + raise X509Error("Invalid certificate purpose '"+purpose+"'") + elif isinstance(purpose,int): + purp_no = purpose + if libcrypto.X509_STORE_set_purpose(self.store,purp_no)<=0: + raise X509Error("cannot set purpose") + def setdepth(self,depth): + """ + Sets the verification depth i.e. max length of certificate chain + which is acceptable + """ + libcrypto.X509_STORE_set_depth(self.store,depth) + def settime(self, time): + """ + Set point in time used to check validity of certificates for + Time can be either python datetime object or number of seconds + sinse epoch + """ + if isinstance(time,datetime.datetime) or isinstance(time,datetime.date): + d=int(time.strftime("%s")) + elif isinstance(time,int): + pass + else: + raise TypeError("datetime.date, datetime.datetime or integer is required as time argument") + raise NotImplementedError +class StackOfX509(object): + """ + Implements OpenSSL STACK_OF(X509) object. + It looks much like python container types + """ + def __init__(self,certs=None,ptr=None,disposable=True): + """ + Create stack + @param certs - list of X509 objects. If specified, read-write + stack is created and populated by these certificates + @param ptr - pointer to OpenSSL STACK_OF(X509) as returned by + some functions + @param disposable - if True, stack created from object, returned + by function is copy, and can be modified and need to be + freeid. If false, it is just pointer into another + structure i.e. CMS_ContentInfo + """ + if ptr is None: + self.need_free = True + self.ptr=libcrypto.sk_new_null() + if certs is not None: + for crt in certs: + self.append(crt) + elif certs is not None: + raise ValueError("cannot handle certs an ptr simultaneously") + else: + self.need_free = disposable + self.ptr=ptr + def __len__(self): + return libcrypto.sk_num(self.ptr) + def __getitem__(self,index): + if index <0 or index>=len(self): + raise IndexError + p=libcrypto.sk_value(self.ptr,index) + return X509(ptr=libcrypto.X509_dup(p)) + def __setitem__(self,index,value): + if not self.need_free: + raise ValueError("Stack is read-only") + if index <0 or index>=len(self): + raise IndexError + if not isinstance(value,X509): + raise TypeError('StackOfX508 can contain only X509 objects') + p=libcrypto.sk_value(self.ptr,index) + libcrypto.sk_set(self.ptr,index,libcrypto.X509_dup(value.cert)) + libcrypto.X509_free(p) + def __delitem__(self,index): + if not self.need_free: + raise ValueError("Stack is read-only") + if index <0 or index>=len(self): + raise IndexError + p=libcrypto.sk_delete(self.ptr,index) + libcrypto.X509_free(p) + def __del__(self): + if self.need_free: + libcrypto.sk_pop_free(self.ptr,libcrypto.X509_free) + def append(self,value): + if not self.need_free: + raise ValueError("Stack is read-only") + if not isinstance(value,X509): + raise TypeError('StackOfX508 can contain only X509 objects') + libcrypto.sk_push(self.ptr,libcrypto.X509_dup(value.cert)) +libcrypto.i2a_ASN1_INTEGER.argtypes=(c_void_p,c_void_p) +libcrypto.ASN1_STRING_print_ex.argtypes=(c_void_p,c_void_p,c_long) +libcrypto.ASN1_TIME_print.argtypes=(c_void_p,c_void_p) +libcrypto.ASN1_INTEGER_get.argtypes=(c_void_p,) +libcrypto.ASN1_INTEGER_get.restype=c_long +libcrypto.X509_get_serialNumber.argtypes=(c_void_p,) +libcrypto.X509_get_serialNumber.restype=c_void_p +libcrypto.X509_NAME_ENTRY_get_object.restype=c_void_p +libcrypto.X509_NAME_ENTRY_get_object.argtypes=(c_void_p,) +libcrypto.OBJ_obj2nid.argtypes=(c_void_p,) +libcrypto.X509_NAME_get_entry.restype=c_void_p +libcrypto.X509_NAME_get_entry.argtypes=(c_void_p,c_int) +libcrypto.X509_STORE_new.restype=c_void_p +libcrypto.X509_STORE_add_lookup.restype=c_void_p +libcrypto.X509_STORE_add_lookup.argtypes=(c_void_p,c_void_p) +libcrypto.X509_LOOKUP_file.restype=c_void_p +libcrypto.X509_LOOKUP_hash_dir.restype=c_void_p +libcrypto.X509_LOOKUP_ctrl.restype=c_int +libcrypto.X509_LOOKUP_ctrl.argtypes=(c_void_p,c_int,c_char_p,c_long,POINTER(c_char_p)) +libcrypto.X509_EXTENSION_dup.argtypes=(c_void_p,) +libcrypto.X509_EXTENSION_dup.restype=POINTER(_x509_ext) +libcrypto.X509V3_EXT_print.argtypes=(c_void_p,POINTER(_x509_ext),c_long,c_int) +libcrypto.X509_get_ext.restype=c_void_p +libcrypto.X509_get_ext.argtypes=(c_void_p,c_int) +libcrypto.X509V3_EXT_print.argtypes=(c_void_p,POINTER(_x509_ext),c_long,c_int) +libcrypto.sk_set.argtypes=(c_void_p,c_int,c_void_p) +libcrypto.sk_set.restype=c_void_p +libcrypto.sk_value.argtypes=(c_void_p,c_int) +libcrypto.sk_value.restype=c_void_p +libcrypto.X509_dup.restype=c_void_p +libcrypto.sk_new_null.restype=c_void_p +libcrypto.X509_dup.argtypes=(c_void_p,)