Merge remote-tracking branch 'origin/master' into topic/robin/dynamic-plugins-2.3

This commit is contained in:
Robin Sommer 2014-06-13 08:27:10 -07:00
commit ba7af428a7
133 changed files with 3382 additions and 1381 deletions

View file

@ -46,7 +46,7 @@ bool file_analysis::X509::EndOfFile()
::X509* ssl_cert = d2i_X509(NULL, &cert_char, cert_data.size());
if ( ! ssl_cert )
{
reporter->Error("Could not parse X509 certificate (fuid %s)", GetFile()->GetID().c_str());
reporter->Weird(fmt("Could not parse X509 certificate (fuid %s)", GetFile()->GetID().c_str()));
return false;
}
@ -88,7 +88,7 @@ RecordVal* file_analysis::X509::ParseCertificate(X509Val* cert_val)
{
::X509* ssl_cert = cert_val->GetCertificate();
char buf[256]; // we need a buffer for some of the openssl functions
char buf[2048]; // we need a buffer for some of the openssl functions
memset(buf, 0, sizeof(buf));
RecordVal* pX509Cert = new RecordVal(BifType::Record::X509::Certificate);
@ -96,14 +96,16 @@ RecordVal* file_analysis::X509::ParseCertificate(X509Val* cert_val)
pX509Cert->Assign(0, new Val((uint64) X509_get_version(ssl_cert) + 1, TYPE_COUNT));
i2a_ASN1_INTEGER(bio, X509_get_serialNumber(ssl_cert));
int len = BIO_read(bio, &(*buf), sizeof(buf));
int len = BIO_read(bio, buf, sizeof(buf));
pX509Cert->Assign(1, new StringVal(len, buf));
BIO_reset(bio);
X509_NAME_print_ex(bio, X509_get_subject_name(ssl_cert), 0, XN_FLAG_RFC2253);
len = BIO_gets(bio, &(*buf), sizeof(buf));
len = BIO_gets(bio, buf, sizeof(buf));
pX509Cert->Assign(2, new StringVal(len, buf));
BIO_reset(bio);
X509_NAME_print_ex(bio, X509_get_issuer_name(ssl_cert), 0, XN_FLAG_RFC2253);
len = BIO_gets(bio, &(*buf), sizeof(buf));
len = BIO_gets(bio, buf, sizeof(buf));
pX509Cert->Assign(3, new StringVal(len, buf));
BIO_free(bio);
@ -171,7 +173,7 @@ StringVal* file_analysis::X509::GetExtensionFromBIO(BIO* bio)
{
char tmp[120];
ERR_error_string_n(ERR_get_error(), tmp, sizeof(tmp));
reporter->Error("X509::GetExtensionFromBIO: %s", tmp);
reporter->Weird(fmt("X509::GetExtensionFromBIO: %s", tmp));
BIO_free_all(bio);
return 0;
}
@ -279,7 +281,7 @@ void file_analysis::X509::ParseBasicConstraints(X509_EXTENSION* ex)
}
else
reporter->Error("Certificate with invalid BasicConstraint. fuid %s", GetFile()->GetID().c_str());
reporter->Weird(fmt("Certificate with invalid BasicConstraint. fuid %s", GetFile()->GetID().c_str()));
}
void file_analysis::X509::ParseSAN(X509_EXTENSION* ext)
@ -289,7 +291,7 @@ void file_analysis::X509::ParseSAN(X509_EXTENSION* ext)
GENERAL_NAMES *altname = (GENERAL_NAMES*)X509V3_EXT_d2i(ext);
if ( ! altname )
{
reporter->Error("Could not parse subject alternative names. fuid %s", GetFile()->GetID().c_str());
reporter->Weird(fmt("Could not parse subject alternative names. fuid %s", GetFile()->GetID().c_str()));
return;
}
@ -309,7 +311,7 @@ void file_analysis::X509::ParseSAN(X509_EXTENSION* ext)
{
if ( ASN1_STRING_type(gen->d.ia5) != V_ASN1_IA5STRING )
{
reporter->Error("DNS-field does not contain an IA5String. fuid %s", GetFile()->GetID().c_str());
reporter->Weird(fmt("DNS-field does not contain an IA5String. fuid %s", GetFile()->GetID().c_str()));
continue;
}
@ -356,7 +358,7 @@ void file_analysis::X509::ParseSAN(X509_EXTENSION* ext)
else
{
reporter->Error("Weird IP address length %d in subject alternative name. fuid %s", gen->d.ip->length, GetFile()->GetID().c_str());
reporter->Weird(fmt("Weird IP address length %d in subject alternative name. fuid %s", gen->d.ip->length, GetFile()->GetID().c_str()));
continue;
}
}

View file

@ -43,9 +43,9 @@ event x509_extension%(f: fa_file, ext: X509::Extension%);
event x509_ext_basic_constraints%(f: fa_file, ext: X509::BasicConstraints%);
## Generated for the X509 subject alternative name extension seen in a certificate.
## This extension can be used to allow additional entities to be bound to the subject
## of the certificate. Usually it is used to specify one or multiple DNS names for
## which a certificate is valid.
## This extension can be used to allow additional entities to be bound to the
## subject of the certificate. Usually it is used to specify one or multiple DNS
## names for which a certificate is valid.
##
## f: The file.
##

View file

@ -5,6 +5,7 @@
#include <openssl/x509.h>
#include <openssl/asn1.h>
#include <openssl/x509_vfy.h>
#include <openssl/ocsp.h>
// This is the indexed map of X509 certificate stores.
static map<Val*, X509_STORE*> x509_stores;
@ -24,23 +25,92 @@ X509* d2i_X509_(X509** px, const u_char** in, int len)
}
// construct an error record
RecordVal* x509_error_record(uint64_t num, const char* reason)
RecordVal* x509_result_record(uint64_t num, const char* reason, Val* chainVector = 0)
{
RecordVal* rrecord = new RecordVal(BifType::Record::X509::Result);
rrecord->Assign(0, new Val(num, TYPE_COUNT));
rrecord->Assign(0, new Val(num, TYPE_INT));
rrecord->Assign(1, new StringVal(reason));
if ( chainVector )
rrecord->Assign(2, chainVector);
return rrecord;
}
X509_STORE* x509_get_root_store(TableVal* root_certs)
{
// If this certificate store was built previously, just reuse the old one.
if ( x509_stores.count(root_certs) > 0 )
return x509_stores[root_certs];
X509_STORE* ctx = X509_STORE_new();
ListVal* idxs = root_certs->ConvertToPureList();
// Build the validation store
for ( int i = 0; i < idxs->Length(); ++i )
{
Val* key = idxs->Index(i);
StringVal *sv = root_certs->Lookup(key)->AsStringVal();
assert(sv);
const uint8* data = sv->Bytes();
X509* x = d2i_X509_(NULL, &data, sv->Len());
if ( ! x )
{
builtin_error(fmt("Root CA error: %s", ERR_error_string(ERR_get_error(),NULL)));
return 0;
}
X509_STORE_add_cert(ctx, x);
X509_free(x);
}
delete idxs;
// Save the newly constructed certificate store into the cacheing map.
x509_stores[root_certs] = ctx;
return ctx;
}
// get all cretificates starting at the second one (assuming the first one is the host certificate)
STACK_OF(X509)* x509_get_untrusted_stack(VectorVal* certs_vec)
{
STACK_OF(X509)* untrusted_certs = sk_X509_new_null();
if ( ! untrusted_certs )
{
builtin_error(fmt("Untrusted certificate stack initialization error: %s", ERR_error_string(ERR_get_error(),NULL)));
return 0;
}
for ( int i = 1; i < (int) certs_vec->Size(); ++i ) // start at 1 - 0 is host cert
{
Val *sv = certs_vec->Lookup(i);
if ( ! sv )
continue;
// Fixme: check type
X509* x = ((file_analysis::X509Val*) sv)->GetCertificate();
if ( ! x )
{
sk_X509_free(untrusted_certs);
builtin_error(fmt("No certificate in opaque in stack"));
return 0;
}
sk_X509_push(untrusted_certs, x);
}
return untrusted_certs;
}
%%}
## Parses a certificate into an X509::Certificate structure.
##
## cert: The X509 certificicate opaque handle
## cert: The X509 certificate opaque handle.
##
## Returns: A X509::Certificate structure
## Returns: A X509::Certificate structure.
##
## .. bro:see:: x509_certificate x509_extension x509_ext_basic_constraints
## x509_ext_subject_alternative_name x509_verify
@ -55,13 +125,13 @@ function x509_parse%(cert: opaque of x509%): X509::Certificate
## Returns the string form of a certificate.
##
## cert: The X509 certificate opaque handle
## cert: The X509 certificate opaque handle.
##
## pem: A boolean that specifies if the certificate is returned
## in pem-form (true), or as the raw ASN1 encoded binary
## (false).
##
## Returns: X509 certificate as a string
## Returns: X509 certificate as a string.
##
## .. bro:see:: x509_certificate x509_extension x509_ext_basic_constraints
## x509_ext_subject_alternative_name x509_parse x509_verify
@ -86,6 +156,222 @@ function x509_get_certificate_string%(cert: opaque of x509, pem: bool &default=F
return ext_val;
%}
## Verifies an OCSP reply.
##
## certs: Specifies the certificate chain to use. Server certificate first.
##
## ocsp_reply: the ocsp reply to validate.
##
## root_certs: A list of root certificates to validate the certificate chain.
##
## verify_time: Time for the validity check of the certificates.
##
## Returns: A record of type X509::Result containing the result code of the
## verify operation.
##
## .. bro:see:: x509_certificate x509_extension x509_ext_basic_constraints
## x509_ext_subject_alternative_name x509_parse
## x509_get_certificate_string x509_verify
function x509_ocsp_verify%(certs: x509_opaque_vector, ocsp_reply: string, root_certs: table_string_of_string, verify_time: time &default=network_time()%): X509::Result
%{
RecordVal* rval = 0;
X509_STORE* ctx = x509_get_root_store(root_certs->AsTableVal());
if ( ! ctx )
return x509_result_record(-1, "Problem initializing root store");
VectorVal *certs_vec = certs->AsVectorVal();
if ( certs_vec->Size() < 1 )
{
reporter->Error("No certificates given in vector");
return x509_result_record(-1, "no certificates");
}
// host certificate
unsigned int index = 0; // to prevent overloading to 0pointer
Val *sv = certs_vec->Lookup(index);
if ( ! sv )
{
builtin_error("undefined value in certificate vector");
return x509_result_record(-1, "undefined value in certificate vector");
}
file_analysis::X509Val* cert_handle = (file_analysis::X509Val*) sv;
X509* cert = cert_handle->GetCertificate();
if ( ! cert )
{
builtin_error(fmt("No certificate in opaque"));
return x509_result_record(-1, "No certificate in opaque");
}
const unsigned char* start = ocsp_reply->Bytes();
STACK_OF(X509)* untrusted_certs = x509_get_untrusted_stack(certs_vec);
if ( ! untrusted_certs )
return x509_result_record(-1, "Problem initializing list of untrusted certificates");
// from here, always goto cleanup. Initialize all other required variables...
time_t vtime = (time_t) verify_time;
OCSP_BASICRESP *basic = 0;
OCSP_SINGLERESP *single = 0;
X509_STORE_CTX *csc = 0;
OCSP_CERTID *certid = 0;
int status = -1;
int out = -1;
int result = -1;
X509* issuer_certificate = 0;
OCSP_RESPONSE *resp = d2i_OCSP_RESPONSE(NULL, &start, ocsp_reply->Len());
if ( ! resp )
{
rval = x509_result_record(-1, "Could not parse OCSP response");
goto x509_ocsp_cleanup;
}
status = OCSP_response_status(resp);
if ( status != OCSP_RESPONSE_STATUS_SUCCESSFUL )
{
rval = x509_result_record(-2, OCSP_response_status_str(status));
goto x509_ocsp_cleanup;
}
basic = OCSP_response_get1_basic(resp);
if ( ! basic )
{
rval = x509_result_record(-1, "Could not parse OCSP response");
goto x509_ocsp_cleanup;
}
// the following code took me _forever_ to get right.
// The OCSP_basic_verify command takes a list of certificates. However (which is not immediately
// visible or understandable), those are only used to find the signer certificate. They are _not_
// used for chain building during the actual verification (this would be stupid). But - if we sneakily
// inject the certificates in the certificate list of the OCSP reply, they actually are used during
// the lookup.
// Yay.
issuer_certificate = 0;
for ( int i = 0; i < sk_X509_num(untrusted_certs); i++)
{
sk_X509_push(basic->certs, X509_dup(sk_X509_value(untrusted_certs, i)));
if ( X509_NAME_cmp(X509_get_issuer_name(cert), X509_get_subject_name(sk_X509_value(untrusted_certs, i))) )
issuer_certificate = sk_X509_value(untrusted_certs, i);
}
// Because we actually want to be able to give nice error messages that show why we were
// not able to verify the OCSP response - do our own verification logic first.
csc = X509_STORE_CTX_new();
X509_STORE_CTX_init(csc, ctx, sk_X509_value(basic->certs, 0), basic->certs);
X509_STORE_CTX_set_time(csc, 0, (time_t) verify_time);
X509_STORE_CTX_set_purpose(csc, X509_PURPOSE_OCSP_HELPER);
result = X509_verify_cert(csc);
if ( result != 1 )
{
const char *reason = X509_verify_cert_error_string((*csc).error);
rval = x509_result_record(result, X509_verify_cert_error_string((*csc).error));
goto x509_ocsp_cleanup;
}
out = OCSP_basic_verify(basic, NULL, ctx, 0);
if ( result < 1 )
{
rval = x509_result_record(out, ERR_error_string(ERR_get_error(),NULL));
goto x509_ocsp_cleanup;
}
// ok, now we verified the OCSP response. This means that we have a valid chain tying it
// to a root that we trust and that the signature also hopefully is valid. This does not yet
// mean that the ocsp response actually matches the certificate the server send us or that
// the OCSP response even says that the certificate is valid.
// let's start this out by checking that the response is actually for the certificate we want
// to validate and not for something completely unrelated that the server is trying to trick us
// into accepting.
if ( issuer_certificate )
certid = OCSP_cert_to_id(NULL, cert, issuer_certificate);
else
{
// issuer not in list sent by server, check store
X509_OBJECT obj;
int lookup = X509_STORE_get_by_subject(csc, X509_LU_X509, X509_get_subject_name(cert), &obj);
if ( lookup <= 0)
{
rval = x509_result_record(lookup, "Could not find issuer of host certificate");
goto x509_ocsp_cleanup;
}
certid = OCSP_cert_to_id(NULL, cert, obj.data.x509);
}
if ( ! certid )
{
rval = x509_result_record(-1, "Certificate ID construction failed");
goto x509_ocsp_cleanup;
}
// for now, assume we have one reply...
single = sk_OCSP_SINGLERESP_value(basic->tbsResponseData->responses, 0);
if ( ! single )
{
rval = x509_result_record(-1, "Could not lookup OCSP response information");
goto x509_ocsp_cleanup;
}
if ( ! OCSP_id_cmp(certid, single->certId) )
return x509_result_record(-1, "OCSP reply is not for host certificate");
// next - check freshness of proof...
if ( ! ASN1_GENERALIZEDTIME_check(single->thisUpdate) || ! ASN1_GENERALIZEDTIME_check(single->nextUpdate) )
{
rval = x509_result_record(-1, "OCSP reply contains invalid dates");
goto x509_ocsp_cleanup;
}
// now - nearly done. Check freshness and status code.
// There is a function to check the freshness of the ocsp reply in the ocsp code of OpenSSL. But - it only
// supports comparing it against the current time, not against arbitrary times. Hence it is kind of unusable
// for us...
// Well, we will do it manually.
if ( X509_cmp_time(single->thisUpdate, &vtime) > 0 )
rval = x509_result_record(-1, "OCSP reply specifies time in future");
else if ( X509_cmp_time(single->nextUpdate, &vtime) < 0 )
rval = x509_result_record(-1, "OCSP reply expired");
else if ( single->certStatus->type != V_OCSP_CERTSTATUS_GOOD )
rval = x509_result_record(-1, OCSP_cert_status_str(single->certStatus->type));
// if we have no error so far, we are done.
if ( !rval )
rval = x509_result_record(1, OCSP_cert_status_str(single->certStatus->type));
x509_ocsp_cleanup:
if ( untrusted_certs )
sk_X509_free(untrusted_certs);
if ( resp )
OCSP_RESPONSE_free(resp);
if ( basic )
OCSP_BASICRESP_free(basic);
if ( csc )
{
X509_STORE_CTX_cleanup(csc);
X509_STORE_CTX_free(csc);
}
if ( certid )
OCSP_CERTID_free(certid);
return rval;
%}
## Verifies a certificate.
##
@ -93,26 +379,29 @@ function x509_get_certificate_string%(cert: opaque of x509, pem: bool &default=F
## the given certificate against the root store given in *root_certs*.
## The host certificate has to be at index 0.
##
## root_certs: A list of root certificates to validate the certificate chain
## root_certs: A list of root certificates to validate the certificate chain.
##
## verify_time: Time for the validity check of the certificates.
##
## Returns: A record of type X509::Result containing the result code of the verify
## operation. In case of success also returns the full certificate chain.
## Returns: A record of type X509::Result containing the result code of the
## verify operation. In case of success also returns the full
## certificate chain.
##
## .. bro:see:: x509_certificate x509_extension x509_ext_basic_constraints
## x509_ext_subject_alternative_name x509_parse
## x509_get_certificate_string
## x509_get_certificate_string x509_ocsp_verify
function x509_verify%(certs: x509_opaque_vector, root_certs: table_string_of_string, verify_time: time &default=network_time()%): X509::Result
%{
X509_STORE* ctx = 0;
int i = 0;
X509_STORE* ctx = x509_get_root_store(root_certs->AsTableVal());
if ( ! ctx )
return x509_result_record(-1, "Problem initializing root store");
VectorVal *certs_vec = certs->AsVectorVal();
if ( certs_vec->Size() < 1 )
if ( ! certs_vec || certs_vec->Size() < 1 )
{
reporter->Error("No certificates given in vector");
return x509_error_record(-1, "no certificates");
return x509_result_record(-1, "no certificates");
}
// host certificate
@ -121,71 +410,20 @@ function x509_verify%(certs: x509_opaque_vector, root_certs: table_string_of_str
if ( !sv )
{
builtin_error("undefined value in certificate vector");
return x509_error_record(-1, "undefined value in certificate vector");
return x509_result_record(-1, "undefined value in certificate vector");
}
file_analysis::X509Val* cert_handle = (file_analysis::X509Val*) sv;
// If this certificate store was built previously, just reuse the old one.
if ( x509_stores.count(root_certs) > 0 )
ctx = x509_stores[root_certs];
if ( ! ctx ) // lookup to see if we have this one built already!
{
ctx = X509_STORE_new();
TableVal* root_certs2 = root_certs->AsTableVal();
ListVal* idxs = root_certs2->ConvertToPureList();
// Build the validation store
for ( i = 0; i < idxs->Length(); ++i )
{
Val* key = idxs->Index(i);
StringVal *sv = root_certs2->Lookup(key)->AsStringVal();
const uint8* data = sv->Bytes();
X509* x = d2i_X509_(NULL, &data, sv->Len());
if ( ! x )
{
builtin_error(fmt("Root CA error: %s", ERR_error_string(ERR_peek_last_error(),NULL)));
return x509_error_record((uint64) ERR_get_error(), ERR_error_string(ERR_peek_last_error(),NULL));
}
X509_STORE_add_cert(ctx, x);
}
delete idxs;
// Save the newly constructed certificate store into the cacheing map.
x509_stores[root_certs] = ctx;
}
X509* cert = cert_handle->GetCertificate();
if ( ! cert )
{
builtin_error(fmt("No certificate in opaque"));
return x509_error_record(-1, "No certificate in opaque");
return x509_result_record(-1, "No certificate in opaque");
}
STACK_OF(X509)* untrusted_certs = sk_X509_new_null();
STACK_OF(X509)* untrusted_certs = x509_get_untrusted_stack(certs_vec);
if ( ! untrusted_certs )
{
builtin_error(fmt("Untrusted certificate stack initialization error: %s", ERR_error_string(ERR_peek_last_error(),NULL)));
return x509_error_record((uint64) ERR_get_error(), ERR_error_string(ERR_peek_last_error(),NULL));
}
for ( i = 1; i < (int) certs_vec->Size(); ++i ) // start at 1 - 0 is host cert
{
Val *sv = certs_vec->Lookup(i);
// Fixme: check type
X509* x = ((file_analysis::X509Val*) sv)->GetCertificate();
if ( ! x )
{
sk_X509_free(untrusted_certs);
builtin_error(fmt("No certificate in opaque in stack"));
return x509_error_record(-1, "No certificate in opaque");
}
sk_X509_push(untrusted_certs, x);
}
return x509_result_record(-1, "Problem initializing list of untrusted certificates");
X509_STORE_CTX csc;
X509_STORE_CTX_init(&csc, ctx, cert, untrusted_certs);
@ -220,11 +458,8 @@ function x509_verify%(certs: x509_opaque_vector, root_certs: table_string_of_str
else
{
reporter->InternalWarning("OpenSSL returned null certificate");
for ( int j = i + 1; i < num_certs; ++j )
X509_free(sk_X509_value(chain, j));
break;
sk_X509_pop_free(chain, X509_free);
goto x509_verify_chainerror;
}
}
@ -237,13 +472,7 @@ x509_verify_chainerror:
sk_X509_free(untrusted_certs);
RecordVal* rrecord = new RecordVal(BifType::Record::X509::Result);
rrecord->Assign(0, new Val((uint64) csc.error, TYPE_COUNT));
rrecord->Assign(1, new StringVal(X509_verify_cert_error_string(csc.error)));
if ( chainVector )
rrecord->Assign(2, chainVector);
RecordVal* rrecord = x509_result_record(csc.error, X509_verify_cert_error_string(csc.error), chainVector);
return rrecord;
%}