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MastersThesis/TIIGER_TLS/PQ_TIIGER_TLS/sal/miracl-ubuntu22-11-04-24/includes/x509.cpp

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update tiigertls
2024-04-15 09:53:30 +00:00
/*
* Copyright (c) 2012-2020 MIRACL UK Ltd.
*
* This file is part of MIRACL Core
* (see https://github.com/miracl/core).
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* CORE X.509 Functions */
#include <stdio.h>
#include "core.h" // for octet support only
#include "x509.h"
// Some ASN.1 tags
#define ANY 0x00
#define SEQ 0x30
#define OID 0x06
#define INT 0x02
#define NUL 0x05
#define ZER 0x00
#define UTF 0x0C
#define UTC 0x17
#define GTM 0x18
#define LOG 0x01
#define BIT 0x03
#define OCT 0x04
#define STR 0x13
#define SET 0x31
#define IA5 0x16
#define EXT 0xA3
#define DNS 0x82
// Define some OIDs
// Elliptic Curve with SHA256
static unsigned char eccsha256[8] = {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x04, 0x03, 0x02};
static octet ECCSHA256 = {8, sizeof(eccsha256), (char *)eccsha256};
// Elliptic Curve with SHA384
static unsigned char eccsha384[8] = {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x04, 0x03, 0x03};
static octet ECCSHA384 = {8, sizeof(eccsha384), (char *)eccsha384};
// Elliptic Curve with SHA512
static unsigned char eccsha512[8] = {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x04, 0x03, 0x04};
static octet ECCSHA512 = {8, sizeof(eccsha512), (char *)eccsha512};
// EC Public Key - Elliptic curve public key cryptography
static unsigned char ecpk[7] = {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01};
static octet ECPK = {7, sizeof(ecpk), (char *)ecpk};
// ED25519 Public Key - Elliptic curve EdDSA (Ed25519) Signature
static unsigned char edpk25519[3] = {0x2B, 0x65, 0x70};
static octet EDPK25519 = {3, sizeof(edpk25519),(char *)edpk25519};
// ED448 Public Key - Elliptic curve EdDSA (Ed448) Signature
static unsigned char edpk448[3] = {0x2B, 0x65, 0x71};
static octet EDPK448 = {3, sizeof(edpk448),(char *)edpk448};
// C25519 curve
static unsigned char prime25519[9] = {0x2B, 0x06, 0x01, 0x04, 0x01, 0xDA, 0x47, 0x0F, 0x01}; /*****/
static octet PRIME25519 = {9, sizeof(prime25519), (char *)prime25519};
// NIST256 curve - (NIST) P-256
static unsigned char prime256v1[8] = {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07};
static octet PRIME256V1 = {8, sizeof(prime256v1), (char *)prime256v1};
// NIST384 curve
static unsigned char secp384r1[5] = {0x2B, 0x81, 0x04, 0x00, 0x22};
static octet SECP384R1 = {5, sizeof(secp384r1), (char *)secp384r1};
// NIST521 curve
static unsigned char secp521r1[5] = {0x2B, 0x81, 0x04, 0x00, 0x23};
static octet SECP521R1 = {5, sizeof(secp521r1), (char *)secp521r1};
// RSA Public Key - RSAES-PKCS1-v1_5
static unsigned char rsapk[9] = {0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01};
static octet RSAPK = {9, sizeof(rsapk), (char *)rsapk};
// RSA with SHA256
static unsigned char rsasha256[9] = {0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0b};
static octet RSASHA256 = {9, sizeof(rsasha256), (char *)rsasha256};
// RSA with SHA384
static unsigned char rsasha384[9] = {0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0c};
static octet RSASHA384 = {9, sizeof(rsasha384), (char *)rsasha384};
// RSA with SHA512
static unsigned char rsasha512[9] = {0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0d};
static octet RSASHA512 = {9, sizeof(rsasha512), (char *)rsasha512};
// DILITHIUM3
static unsigned char dilithium3[11] = {0x2b, 0x06, 0x01, 0x04, 0x01, 0x02, 0x82, 0x0B, 0x07, 0x06, 0x05};
static octet DILITHIUM3 = {11, sizeof(dilithium3), (char *)dilithium3};
// Cert details
// countryName
static unsigned char cn[3] = {0x55, 0x04, 0x06};
octet X509_CN = {3, sizeof(cn), (char *)cn};
// stateName
static char sn[3]= {0x55,0x04,0x08};
octet X509_SN= {3,sizeof(sn),sn};
// localName
static char ln[3]= {0x55,0x04,0x07};
octet X509_LN= {3,sizeof(ln),ln};
// orgName
static unsigned char on[3] = {0x55, 0x04, 0x0A};
octet X509_ON = {3, sizeof(on), (char *)on};
// unitName
static char un[3]= {0x55,0x04,0x0B};
octet X509_UN= {3,sizeof(un),un};
// myName
static char mn[3]= {0x55,0x04,0x03};
octet X509_MN= {3,sizeof(mn),mn};
// emailName
static unsigned char en[9] = {0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x09, 0x01};
octet X509_EN = {9, sizeof(en), (char *)en};
// Extensions
// Alt Name
static char an[3]={0x55,0x1D,0x11};
octet X509_AN = {3, sizeof(an),an};
// Key Usage
static char ku[3]={0x55,0x1d,0x0f};
octet X509_KU = {3,sizeof(ku),ku};
// Basic Constraints
static char bc[3]={0x55,0x1d,0x13};
octet X509_BC = {3,sizeof(bc),bc};
/* Check expected TAG and return ASN.1 field length. If tag=0 skip check. */
static int getalen(int tag, char *b, int j)
{
int len;
if (tag != 0 && (unsigned char)b[j] != tag) return -1; // not a valid tag
j++;
if ((unsigned char)b[j] == 0x81)
{
j++;
len = (unsigned char)b[j];
}
else if ((unsigned char)b[j] == 0x82)
{
j++;
len = 256 * b[j++];
len += (unsigned char)b[j];
}
else
{
len = (unsigned char)b[j];
if (len > 127) return -1;
}
return len;
}
/* jump over length field */
static int skip(int len)
{
if (len < 128) return 2;
if (len < 256) return 3;
return 4;
}
/* round length up to nearest 8-byte length */
static int bround(int len)
{
if (len % 8 == 0) return len;
return len + (8 - len % 8);
}
// Input private key in PKCS#8 format
// e.g. openssl req -x509 -nodes -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365
// e.g. openssl req -x509 -nodes -days 3650 -newkey ec:<(openssl ecparam -name prime256v1) -keyout key.pem -out ecdsacert.pem
// extract private key from uncompressed key.pem into octet
// For RSA octet = p|q|dp|dq|c where pk->len is multiple of 5
// For ECC octet = k
pktype X509_extract_private_key(octet *c,octet *pk)
{
int i, j, k, fin, len, rlen, flen, tlen, sj, ex;
char soid[12];
octet SOID = {0, sizeof(soid), soid};
pktype ret;
ret.type = 0;
ret.hash = 0;
j=0;
len = getalen(SEQ, c->val, j); // Check for expected SEQ clause, and get length
if (len < 0) return ret; // if not a SEQ clause, there is a problem, exit
j += skip(len); // skip over length to clause contents. Add len to skip clause
if (len + j != c->len) return ret;
len = getalen(INT, c->val, j);
if (len < 0) return ret;
j += skip(len) + len; // jump over serial number clause (if there is one)
len = getalen(SEQ, c->val, j);
if (len < 0) return ret;
j += skip(len);
// extract OID
len = getalen(OID, c->val, j);
if (len < 0) return ret;
j += skip(len);
fin = j + len;
if (len>SOID.max) return ret;
SOID.len = len;
for (i = 0; j < fin; j++)
SOID.val[i++] = c->val[j];
j=fin;
if (OCT_comp(&EDPK25519, &SOID))
{ // Its an Ed25519 key
len = getalen(OCT, c->val, j);
if (len < 0) return ret;
j += skip(len);
len = getalen(OCT, c->val, j);
if (len < 0) return ret;
j += skip(len);
rlen=32;
if (rlen>pk->max) return ret;
pk->len=rlen;
for (i=0;i<rlen-len;i++)
pk->val[i]=0;
for (i=rlen-len;i<rlen;i++)
pk->val[i]=c->val[j++];
ret.type = X509_ECD;
ret.curve = USE_ED25519;
}
if (OCT_comp(&EDPK448, &SOID))
{ // Its an Ed448 key
len = getalen(OCT, c->val, j);
if (len < 0) return ret;
j += skip(len);
len = getalen(OCT, c->val, j);
if (len < 0) return ret;
j += skip(len);
rlen=57;
if (rlen>pk->max) return ret;
pk->len=rlen;
for (i=0;i<rlen-len;i++)
pk->val[i]=0;
for (i=rlen-len;i<rlen;i++)
pk->val[i]=c->val[j++];
ret.type = X509_ECD;
ret.curve = USE_ED448;
}
if (OCT_comp(&DILITHIUM3, &SOID))
{ // Its a DILITHIUM3 key
len = getalen(OCT, c->val, j);
if (len < 0) return ret;
j += skip(len);
len = getalen(OCT, c->val, j);
if (len < 0) return ret;
j += skip(len);
tlen=len;
if (tlen>pk->max)
tlen=pk->max;
for (i=0;i<tlen;i++)
pk->val[i]=c->val[j++];
pk->len=tlen;
ret.type=X509_PQ;
ret.curve=8*tlen;
}
if (OCT_comp(&ECPK, &SOID))
{ // Its an ECC key
len = getalen(OID, c->val, j);
if (len < 0) return ret;
j += skip(len);
fin = j + len;
if (len>SOID.max) return ret;
SOID.len = len;
for (i = 0; j < fin; j++)
SOID.val[i++] = c->val[j];
j=fin;
len = getalen(OCT, c->val, j);
if (len < 0) return ret;
j += skip(len);
len = getalen(SEQ, c->val, j);
if (len < 0) return ret;
j += skip(len);
len = getalen(INT, c->val, j);
if (len < 0) return ret;
j += skip(len) + len; // jump over version
len = getalen(OCT, c->val, j);
if (len < 0) return ret;
j += skip(len);
ret.type = X509_ECC;
if (OCT_comp(&PRIME256V1, &SOID)) {
ret.curve = USE_NIST256;
rlen=32;
}
if (OCT_comp(&SECP384R1, &SOID)) {
ret.curve = USE_NIST384;
rlen=48;
}
if (OCT_comp(&SECP521R1, &SOID)) {
rlen=66;
ret.curve = USE_NIST521;
}
if (rlen>pk->max)
{
ret.curve=0;
return ret;
}
pk->len=rlen;
for (i=0;i<rlen-len;i++)
pk->val[i]=0;
for (i=rlen-len;i<rlen;i++)
pk->val[i]=c->val[j++];
}
if (OCT_comp(&RSAPK, &SOID))
{ // Its an RSA key
len = getalen(NUL, c->val, j);
if (len<0) return ret;
j += skip(len);
len = getalen(OCT, c->val, j);
if (len < 0) return ret;
j += skip(len);
len = getalen(SEQ, c->val, j);
if (len < 0) return ret;
j += skip(len);
len = getalen(INT, c->val, j);
if (len < 0) return ret;
j += skip(len) + len; // jump over version
len = getalen(INT, c->val, j);
if (len < 0) return ret;
j += skip(len) + len; // jump over n
len = getalen(INT, c->val, j);
if (len < 0) return ret;
j += skip(len) + len; // jump over e
len = getalen(INT, c->val, j);
if (len < 0) return ret;
j += skip(len) + len; // jump over d
len = getalen(INT, c->val, j);
if (len < 0) return ret;
j += skip(len); // get p
if (c->val[j] == 0)
{ // skip leading zero
j++;
len--;
}
rlen=bround(len);
if (5*rlen>pk->max)
return ret;
for (i=0;i<rlen-len;i++)
pk->val[i]=0;
for (i=rlen-len;i<rlen;i++)
pk->val[i]=c->val[j++];
flen=rlen; // should be same length for all
for (k=1;k<5;k++)
{
len = getalen(INT,c->val,j);
if (len<0) return ret;
j += skip(len); // get q,dp,dq,c
if (c->val[j] == 0)
{ // skip leading zero
j++;
len--;
}
rlen=bround(len);
if (rlen!=flen) return ret;
for (i=0;i<rlen-len;i++)
pk->val[i]=0;
for (i=rlen-len;i<rlen;i++)
pk->val[k*flen+i]=c->val[j++];
}
pk->len=5*flen;
ret.type = X509_RSA;
ret.curve = 16 * flen;
}
return ret;
}
// Input signed cert as octet, and extract signature
// Return 0 for failure, ECC for Elliptic Curve signature, RSA for RSA signature
// Note that signature type is not provided here - its the type of the public key that
// is used to verify it that matters, and which determines for example the curve to be used!
pktype X509_extract_cert_sig(octet *sc, octet *sig)
{
int i, j, k, fin, len, rlen, sj, ex;
char soid[12];
octet SOID = {0, sizeof(soid), soid};
pktype ret;
ret.type = 0;
ret.hash = 0;
j = 0;
len = getalen(SEQ, sc->val, j); // Check for expected SEQ clause, and get length
if (len < 0) return ret; // if not a SEQ clause, there is a problem, exit
j += skip(len); // skip over length to clause contents. Add len to skip clause
if (len + j != sc->len) return ret;
len = getalen(SEQ, sc->val, j);
if (len < 0) return ret;
j += skip(len) + len; // jump over cert to signature OID
len = getalen(SEQ, sc->val, j);
if (len < 0) return ret;
j += skip(len);
sj = j + len; // Needed to jump over signature OID
// dive in to extract OID
len = getalen(OID, sc->val, j);
if (len < 0) return ret;
j += skip(len);
fin = j + len;
if (len>SOID.max) return ret;
SOID.len = len;
for (i = 0; j < fin; j++)
SOID.val[i++] = sc->val[j];
// check OID here..
if (OCT_comp(&EDPK25519, &SOID))
{
ret.type = X509_ECD;
ret.hash = X509_H512;
}
if (OCT_comp(&EDPK448, &SOID))
{
ret.type = X509_ECD;
ret.hash = X509_SHAKE256;
}
if (OCT_comp(&ECCSHA256, &SOID))
{
ret.type = X509_ECC;
ret.hash = X509_H256;
}
if (OCT_comp(&ECCSHA384, &SOID))
{
ret.type = X509_ECC;
ret.hash = X509_H384;
}
if (OCT_comp(&ECCSHA512, &SOID))
{
ret.type = X509_ECC;
ret.hash = X509_H512;
}
if (OCT_comp(&RSASHA256, &SOID))
{
ret.type = X509_RSA;
ret.hash = X509_H256;
}
if (OCT_comp(&RSASHA384, &SOID))
{
ret.type = X509_RSA;
ret.hash = X509_H384;
}
if (OCT_comp(&RSASHA512, &SOID))
{
ret.type = X509_RSA;
ret.hash = X509_H512;
}
if (OCT_comp(&DILITHIUM3, &SOID))
{
ret.type = X509_PQ;
ret.hash = 0; // hash type is implicit
}
if (ret.type == 0) return ret; // unsupported type
j = sj; // jump out to signature
len = getalen(BIT, sc->val, j);
if (len < 0)
{
ret.type = 0;
return ret;
}
j += skip(len);
j++;
len--; // skip bit shift (hopefully 0!)
if (ret.type==X509_ECD)
{
if (len>sig->max)
{
ret.type=0;
return ret;
}
sig->len = len;
i = 0;
fin = j + len;
for (; j < fin; j++)
sig->val[i++] = sc->val[j];
if (ret.hash == X509_H512) ret.curve = USE_ED25519;
if (ret.hash == X509_SHAKE256) ret.curve = USE_ED448;
}
if (ret.type == X509_ECC)
{
// signature in the form (r,s)
len = getalen(SEQ, sc->val, j);
if (len < 0)
{
ret.type = 0;
return ret;
}
j += skip(len);
// pick up r part of signature
len = getalen(INT, sc->val, j);
if (len < 0)
{
ret.type = 0;
return ret;
}
j += skip(len);
if (sc->val[j] == 0)
{
// skip leading zero
j++;
len--;
}
rlen = bround(len);
ex = rlen - len;
if (2*rlen>sig->max)
{
ret.type=0;
return ret;
}
sig->len = 2 * rlen;
i = 0;
for (k = 0; k < ex; k++)
sig->val[i++] = 0;
fin = j + len;
for (; j < fin; j++)
sig->val[i++] = sc->val[j];
// pick up s part of signature
len = getalen(INT, sc->val, j);
if (len < 0)
{
ret.type = 0;
return ret;
}
j += skip(len);
if (sc->val[j] == 0)
{
// skip leading zeros
j++;
len--;
}
rlen = bround(len);
ex = rlen - len;
for (k = 0; k < ex; k++)
sig->val[i++] = 0;
fin = j + len;
for (; j < fin; j++)
sig->val[i++] = sc->val[j];
if (ret.hash == X509_H256) ret.curve = USE_NIST256;
if (ret.hash == X509_H384) ret.curve = USE_NIST384;
if (ret.hash == X509_H512) ret.curve = USE_NIST521;
}
if (ret.type == X509_RSA)
{
rlen = bround(len);
ex = rlen - len;
if (rlen>sig->max)
{
ret.type=0;
return ret;
}
sig->len = rlen;
i = 0;
for (k = 0; k < ex; k++)
sig->val[i++] = 0;
fin = j + len;
for (; j < fin; j++)
sig->val[i++] = sc->val[j];
ret.curve = 8*rlen;
}
if (ret.type == X509_PQ)
{
if (len>sig->max)
{
ret.type=0;
return ret;
}
sig->len = len;
fin = j + len;
for (i=0; j < fin; j++)
sig->val[i++] = sc->val[j];
ret.curve = 8*len;
}
return ret;
}
// Extract certificate from signed cert
int X509_extract_cert(octet *sc, octet *cert)
{
int i, j, fin, len, k;
j = 0;
len = getalen(SEQ, sc->val, j);
if (len < 0) return 0;
j += skip(len);
k = j;
len = getalen(SEQ, sc->val, j);
if (len < 0) return 0;
j += skip(len);
fin = j + len;
if (fin-k>cert->max) return 0;
cert->len = fin - k;
for (i = k; i < fin; i++) cert->val[i - k] = sc->val[i];
return 1;
}
// find index to start of ASN.1 raw public key, and return its length
int X509_find_public_key(octet *c,int *ptr)
{
int i, j, k, fin, len, sj;
j = 0;
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len);
if (len + j != c->len) return 0;
len = getalen(ANY, c->val, j);
if (len < 0) return 0;
j += skip(len) + len; //jump over version clause
len = getalen(INT, c->val, j);
if (len > 0) j += skip(len) + len; // jump over serial number clause (if there is one)
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len) + len; // jump over signature algorithm
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len) + len; // skip issuer
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len) + len; // skip validity
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len) + len; // skip subject
k=j;
len = getalen(SEQ, c->val, j); // look ahead to determine length
if (len < 0) return 0;
j += skip(len); //
fin=j+len;
*ptr=k;
return fin-k;
}
// get Public Key details from ASN.1 description
pktype X509_get_public_key(octet *c,octet *key)
{
int i, j, fin, len, sj, ptr;
char koid[12]; /*****/
octet KOID = {0, sizeof(koid), koid};
pktype ret;
ret.type = ret.hash = 0;
ret.curve = -1;
j=0;
len = getalen(SEQ, c->val, j);
if (len < 0) return ret;
j += skip(len); //
len = getalen(SEQ, c->val, j);
if (len < 0) return ret;
j += skip(len);
// ** Maybe dive in and check Public Key OIDs here?
// ecpublicKey & prime256v1, secp384r1 or secp521r1 for ECC
// rsapublicKey for RSA
sj = j + len;
len = getalen(OID, c->val, j);
if (len < 0) return ret;
j += skip(len);
fin = j + len;
if (len>KOID.max) return ret;
KOID.len = len;
for (i = 0; j < fin; j++)
KOID.val[i++] = c->val[j];
ret.type = 0;
if (OCT_comp(&ECPK, &KOID)) ret.type = X509_ECC;
if (OCT_comp(&EDPK25519, &KOID)) {ret.type = X509_ECD; ret.curve=USE_ED25519;}
if (OCT_comp(&EDPK448, &KOID)) {ret.type = X509_ECD; ret.curve=USE_ED448;}
if (OCT_comp(&RSAPK, &KOID)) ret.type = X509_RSA;
if (OCT_comp(&DILITHIUM3, &KOID)) ret.type = X509_PQ;
if (ret.type == 0) return ret;
if (ret.type == X509_ECC)
{
// which elliptic curve?
len = getalen(OID, c->val, j);
if (len < 0)
{
ret.type = 0;
return ret;
}
j += skip(len);
fin = j + len;
if (len>KOID.max)
{
ret.type=0;
return ret;
}
KOID.len = len;
for (i = 0; j < fin; j++)
KOID.val[i++] = c->val[j];
if (OCT_comp(&PRIME25519, &KOID)) ret.curve = USE_ED25519; /*****/
if (OCT_comp(&PRIME256V1, &KOID)) ret.curve = USE_NIST256;
if (OCT_comp(&SECP384R1, &KOID)) ret.curve = USE_NIST384;
if (OCT_comp(&SECP521R1, &KOID)) ret.curve = USE_NIST521;
}
j = sj; // skip to actual Public Key
len = getalen(BIT, c->val, j);
if (len < 0)
{
ret.type = 0;
return ret;
}
j += skip(len); //
j++;
len--; // skip bit shift (hopefully 0!)
// extract key
if (ret.type == X509_ECC || ret.type == X509_ECD || ret.type == X509_PQ)
{
if (len>key->max)
{
ret.type=0;
return ret;
}
key->len = len;
fin = j + len;
for (i = 0; j < fin; j++)
key->val[i++] = c->val[j];
}
if (ret.type == X509_PQ)
ret.curve=8*len;
if (ret.type == X509_RSA)
{
// Key is (modulus,exponent) - assume exponent is 65537
len = getalen(SEQ, c->val, j);
if (len < 0)
{
ret.type = 0;
return ret;
}
j += skip(len); //
len = getalen(INT, c->val, j); // get modulus
if (len < 0)
{
ret.type = 0;
return ret;
}
j += skip(len); //
if (c->val[j] == 0)
{
j++;
len--; // remove leading zero
}
if (len>key->max)
{
ret.type=0;
return ret;
}
key->len = len;
fin = j + len;
for (i = 0; j < fin; j++)
key->val[i++] = c->val[j];
ret.curve = 8 * len;
}
return ret;
}
// Extract Public Key from inside Certificate
pktype X509_extract_public_key(octet *c, octet *key)
{
int ptr=0;
int pklen=X509_find_public_key(c,&ptr);
octet CC={pklen,pklen,&c->val[ptr]};
return X509_get_public_key(&CC,key);
}
// Find pointer to main sections of cert, before extracting individual field
// Find index to issuer in cert, and its length
// This is the certificate DER encoded distinguished issuer name
int X509_find_issuer(octet *c,int *flen)
{
int j, len;
*flen=0;
j = 0;
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len);
if (len + j != c->len) return 0;
len = getalen(ANY, c->val, j);
if (len < 0) return 0;
j += skip(len) + len; //jump over version clause
len = getalen(INT, c->val, j);
if (len > 0) j += skip(len) + len; // jump over serial number clause (if there is one)
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len) + len; // jump over signature algorithm
len=getalen(SEQ,c->val,j);
*flen=len+skip(len); // length of issuer
return j;
}
// Find index to validity period
int X509_find_validity(octet *c)
{
int j, len;
j = X509_find_issuer(c,&len);
j+=len; // skip issuer
//len = getalen(SEQ, c->val, j);
//if (len < 0) return 0;
//j += skip(len) + len; // skip issuer
return j;
}
// Find index to subject in cert, and its length
// This is the certificate DER encoded distinguished subject name
int X509_find_subject(octet *c,int *flen)
{
int j, len;
*flen=0;
j = X509_find_validity(c);
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len) + len; // skip validity
len=getalen(SEQ,c->val,j);
*flen=len+skip(len);
return j;
}
int X509_self_signed(octet *c)
{
int i,m,slen,ilen;
int ksub=X509_find_subject(c,&slen);
int kiss=X509_find_issuer(c,&ilen);
if (slen!=ilen) return 0;
//int sublen=getalen(SEQ,c->val,ksub);
//int isslen=getalen(SEQ,c->val,kiss);
//if (isslen!=sublen) return 0;
//ksub+=skip(sublen);
//kiss+=skip(isslen);
for (i=m=0;i<slen;i++)
m|=c->val[i+ksub] - c->val[i+kiss];
if (m!=0) return 0;
return 1;
}
// NOTE: When extracting cert information, we actually return just an index to the data inside the cert, and maybe its length
// So no memory is assigned to store cert info. It is the callers responsibility to allocate such memory if required, and copy
// cert information into it.
// Find entity property indicated by SOID, given start of issuer or subject field. Return index in cert, flen=length of field
int X509_find_entity_property(octet *c, octet *SOID, int start, int *flen)
{
int i, j, k, fin, len, tlen;
char foid[50]; /*****/
octet FOID = {0, sizeof(foid), foid};
j = start;
tlen = getalen(SEQ, c->val, j);
if (tlen < 0) return 0;
j += skip(tlen);
for (k = j; j < k + tlen;)
{
// search for Owner OID
len = getalen(SET, c->val, j);
if (len < 0) return 0;
j += skip(len);
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len);
len = getalen(OID, c->val, j);
if (len < 0) return 0;
j += skip(len);
fin = j + len; // extract OID
if (len>FOID.max) return 0;
FOID.len = len;
for (i = 0; j < fin; j++)
FOID.val[i++] = c->val[j];
len = getalen(ANY, c->val, j); // get text, could be any type
if (len < 0) return 0;
j += skip(len);
if (OCT_comp(&FOID, SOID))
{
// if its the right one return
*flen = len;
return j;
}
j += len; // skip over it
}
*flen = 0; /*****/
return 0;
}
// Find start date of certificate validity period
int X509_find_start_date(octet *c, int start)
{
int j, len;
j = start;
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len);
len = getalen(UTC, c->val, j);
if (len < 0)
{ // could be generalised time
len = getalen(GTM, c->val, j);
if (len<0) return 0;
j += skip(len);
j += 2; // skip century
}
else j += skip(len);
return j;
}
// Find expiry date of certificate validity period
int X509_find_expiry_date(octet *c, int start)
{
int j, len;
j = start;
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len);
len = getalen(UTC, c->val, j);
if (len < 0)
{
len = getalen(GTM,c->val,j);
if (len<0) return 0;
}
j += skip(len) + len;
len = getalen(UTC, c->val, j);
if (len < 0)
{
len = getalen(GTM, c->val,j);
if (len<0) return 0;
j+=skip(len);
j+=2; // skip century
}
else j += skip(len);
return j;
}
int X509_find_extensions(octet *c)
{
int j, len;
j=X509_find_subject(c,&len);
j+=len; // skip subject
//len = getalen(SEQ, c->val, j);
//if (len<0) return 0;
//j += skip(len)+len; // skip subject
len = getalen(SEQ, c->val, j);
if (len<0) return 0;
j += skip(len)+len; // skip public key
if (j>=c->len) return 0;
return j;
}
int X509_find_extension(octet *c, octet *SOID, int start, int *flen)
{
int i, j, k, fin, len, tlen, nj;
char foid[50]; /*****/
octet FOID = {0, sizeof(foid), foid};
j = start;
tlen = getalen(EXT, c->val, j);
if (tlen < 0) return 0;
j += skip(tlen);
tlen = getalen(SEQ, c->val, j);
if (tlen < 0) return 0;
j += skip(tlen);
for (k = j; j < k + tlen;)
{
// search for Owner OID
len = getalen(SEQ, c->val, j);
if (len < 0) return 0;
j += skip(len); nj=j+len;
len = getalen(OID, c->val, j);
if (len < 0) return 0;
j += skip(len);
fin = j + len; // extract OID
if (len>FOID.max) return 0;
FOID.len = len;
for (i = 0; j < fin; j++)
FOID.val[i++] = c->val[j];
if (OCT_comp(&FOID, SOID))
{
// if its the right one return
*flen = nj-j;
return j;
}
j = nj; // skip over this extension
}
*flen = 0; /*****/
return 0;
}
// return 1 if name found, else 0, where name is URL
// input cert, and pointer to SAN extension
// Takes wild-card into consideration
int X509_find_alt_name(octet *c,int start,char *name)
{
int i,j,len,k,m,tlen,cmp,tag;
if (start==0) return 0;
j=start;
tlen = getalen(OCT, c->val, j);
if (tlen < 0) return 0;
j += skip(tlen);
tlen = getalen(SEQ, c->val, j);
if (tlen < 0) return 0;
j += skip(tlen);
for (k=j;j<k+tlen;)
{
tag=c->val[j]; tag&=0xff;
len = getalen(ANY, c->val, j);
if (len < 0) return 0;
j += skip(len); // ?? If its not dns, skip over it j+=len
if (tag!=DNS)
{ // only interested in URLs
j+=len;
continue;
}
cmp=1; m=0;
if (c->val[j]=='*')
{ // wildcard
j++; len--; // skip over *
while (name[m]!='.' && name[m]!=0) // advance to first .
m++;
}
for (i=0;i<len;i++)
{
if (name[m]==0)
{ // name has ended before comparison completed
cmp=0;
j++;
continue;
}
if (c->val[j++]!=name[m++]) // mismatch
cmp=0;
}
if (name[m]!=0) cmp=0; // name should have ended
if (cmp) return 1;
}
return 0;
}
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