ClamAV is an open source (GPLv2) anti-virus toolkit.
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clamav/libclamav/crypto.c

958 lines
19 KiB

/*
* Copyright (C) 2014 Cisco and/or its affiliates. All rights reserved.
*
* Author: Shawn Webb
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#ifdef _WIN32
#include <io.h>
#endif
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
#include <fcntl.h>
#if !defined(_WIN32)
#include <unistd.h>
#endif
#include <openssl/ssl.h>
#include <openssl/err.h>
#include "libclamav/crypto.h"
#include "clamav.h"
#include "default.h"
#include "others.h"
#include "libclamav/conv.h"
#include "libclamav/str.h"
#if defined(_WIN32)
char * strptime(const char *buf, const char *fmt, struct tm *tm);
#endif
#if !defined(MIN)
#define MIN(x,y) ((x)<(y)?(x):(y))
#endif
int cl_initialize_crypto(void)
{
SSL_load_error_strings();
SSL_library_init();
OpenSSL_add_all_digests();
OpenSSL_add_all_algorithms();
OpenSSL_add_all_ciphers();
ERR_load_crypto_strings();
return 0;
}
void cl_cleanup_crypto(void)
{
EVP_cleanup();
}
unsigned char *cl_hash_data(char *alg, const void *buf, size_t len, unsigned char *obuf, unsigned int *olen)
{
EVP_MD_CTX ctx;
unsigned char *ret;
size_t mdsz;
const EVP_MD *md;
unsigned int i;
size_t cur;
md = EVP_get_digestbyname(alg);
if (!(md))
return NULL;
mdsz = EVP_MD_size(md);
ret = (obuf != NULL) ? obuf : (unsigned char *)malloc(mdsz);
if (!(ret))
return NULL;
if (!EVP_DigestInit(&ctx, md)) {
if (!(obuf))
free(ret);
if ((olen))
*olen = 0;
return NULL;
}
cur=0;
while (cur < len) {
size_t todo = MIN(EVP_MD_block_size(md), len-cur);
if (!EVP_DigestUpdate(&ctx, (void *)(((unsigned char *)buf)+cur), todo)) {
if (!(obuf))
free(ret);
if ((olen))
*olen = 0;
return NULL;
}
cur += todo;
}
if (!EVP_DigestFinal(&ctx, ret, &i)) {
if (!(obuf))
free(ret);
if ((olen))
*olen = 0;
return NULL;
}
EVP_MD_CTX_cleanup(&ctx);
if ((olen))
*olen = i;
return ret;
}
unsigned char *cl_hash_file_fd(int fd, char *alg, unsigned int *olen)
{
EVP_MD_CTX ctx;
const EVP_MD *md;
unsigned char *res;
md = EVP_get_digestbyname(alg);
if (!(md))
return NULL;
if (!EVP_DigestInit(&ctx, md)) {
return NULL;
}
res = cl_hash_file_fd_ctx(&ctx, fd, olen);
return res;
}
unsigned char *cl_hash_file_fd_ctx(EVP_MD_CTX *ctx, int fd, unsigned int *olen)
{
unsigned char *buf;
unsigned char *hash;
int mdsz;
unsigned int hashlen;
struct stat sb;
unsigned int blocksize;
#ifdef _WIN32
int nread;
#else
ssize_t nread;
#endif
mdsz = EVP_MD_CTX_size(ctx);
if (fstat(fd, &sb) < 0) {
return NULL;
}
#ifdef _WIN32
blocksize = 8192;
#else
blocksize = sb.st_blksize;
#endif
buf = (unsigned char *)malloc(blocksize);
if (!(buf)) {
return NULL;
}
hash = (unsigned char *)malloc(mdsz);
if (!(hash)) {
free(buf);
return NULL;
}
#ifdef _WIN32
while ((nread = _read(fd, buf, blocksize)) > 0) {
#else
while ((nread = read(fd, buf, blocksize)) > 0) {
#endif
if (!EVP_DigestUpdate(ctx, buf, nread)) {
free(buf);
free(hash);
return NULL;
}
}
if (!EVP_DigestFinal(ctx, hash, &hashlen)) {
free(hash);
free(buf);
return NULL;
}
EVP_MD_CTX_cleanup(&ctx);
if ((olen))
*olen = hashlen;
free(buf);
return hash;
}
unsigned char *cl_hash_file_fp(FILE *fp, char *alg, unsigned int *olen)
{
return cl_hash_file_fd(fileno(fp), alg, olen);
}
unsigned char *cl_sha256(const void *buf, size_t len, unsigned char *obuf, unsigned int *olen)
{
return cl_hash_data("sha256", buf, len, obuf, olen);
}
unsigned char *cl_sha1(const void *buf, size_t len, unsigned char *obuf, unsigned int *olen)
{
return cl_hash_data("sha1", buf, len, obuf, olen);
}
int cl_verify_signature_hash(EVP_PKEY *pkey, char *alg, unsigned char *sig, unsigned int siglen, unsigned char *digest)
{
EVP_MD_CTX ctx;
const EVP_MD *md;
size_t mdsz;
md = EVP_get_digestbyname(alg);
if (!(md))
return -1;
mdsz = EVP_MD_size(md);
if (!EVP_VerifyInit(&ctx, md)) {
return -1;
}
if (!EVP_VerifyUpdate(&ctx, digest, mdsz)) {
return -1;
}
if (EVP_VerifyFinal(&ctx, sig, siglen, pkey) != 0) {
return -1;
}
return 0;
}
int cl_verify_signature_fd(EVP_PKEY *pkey, char *alg, unsigned char *sig, unsigned int siglen, int fd)
{
EVP_MD_CTX ctx;
const EVP_MD *md;
size_t mdsz;
unsigned char *digest;
digest = cl_hash_file_fd(fd, alg, NULL);
if (!(digest))
return -1;
md = EVP_get_digestbyname(alg);
if (!(md))
return -1;
mdsz = EVP_MD_size(md);
if (!EVP_VerifyInit(&ctx, md)) {
free(digest);
return -1;
}
if (!EVP_VerifyUpdate(&ctx, digest, mdsz)) {
free(digest);
return -1;
}
if (EVP_VerifyFinal(&ctx, sig, siglen, pkey) != 0) {
free(digest);
return -1;
}
free(digest);
return 0;
}
int cl_verify_signature(EVP_PKEY *pkey, char *alg, unsigned char *sig, unsigned int siglen, unsigned char *data, size_t datalen, int decode)
{
EVP_MD_CTX ctx;
const EVP_MD *md;
size_t mdsz;
unsigned char *digest;
if (decode) {
unsigned char *newsig;
size_t newsiglen;
newsig = (unsigned char *)cl_base64_decode((char *)sig, siglen, NULL, &newsiglen);
if (!(newsig))
return -1;
sig = newsig;
siglen = newsiglen;
}
digest = cl_hash_data(alg, data, datalen, NULL, NULL);
if (!(digest)) {
if (decode)
free(sig);
return -1;
}
md = EVP_get_digestbyname(alg);
if (!(md)) {
free(digest);
if (decode)
free(sig);
return -1;
}
mdsz = EVP_MD_size(md);
if (!EVP_VerifyInit(&ctx, md)) {
free(digest);
if (decode)
free(sig);
return -1;
}
if (!EVP_VerifyUpdate(&ctx, digest, mdsz)) {
free(digest);
if (decode)
free(sig);
return -1;
}
if (EVP_VerifyFinal(&ctx, sig, siglen, pkey) != 0) {
free(digest);
if (decode)
free(sig);
return -1;
}
if (decode)
free(sig);
free(digest);
return 0;
}
int cl_verify_signature_hash_x509_keyfile(char *x509path, char *alg, unsigned char *sig, unsigned int siglen, unsigned char *digest)
{
X509 *x509;
FILE *fp;
int res;
fp = fopen(x509path, "r");
if (!(fp)) {
return -1;
}
x509 = PEM_read_X509(fp, NULL, NULL, NULL);
if (!(x509)) {
fclose(fp);
return -1;
}
fclose(fp);
res = cl_verify_signature_hash_x509(x509, alg, sig, siglen, digest);
X509_free(x509);
return res;
}
int cl_verify_signature_fd_x509_keyfile(char *x509path, char *alg, unsigned char *sig, unsigned int siglen, int fd)
{
X509 *x509;
FILE *fp;
int res;
fp = fopen(x509path, "r");
if (!(fp)) {
return -1;
}
x509 = PEM_read_X509(fp, NULL, NULL, NULL);
if (!(x509)) {
fclose(fp);
return -1;
}
fclose(fp);
res = cl_verify_signature_fd_x509(x509, alg, sig, siglen, fd);
X509_free(x509);
return res;
}
int cl_verify_signature_x509_keyfile(char *x509path, char *alg, unsigned char *sig, unsigned int siglen, unsigned char *data, size_t datalen, int decode)
{
X509 *x509;
FILE *fp;
int res;
fp = fopen(x509path, "r");
if (!(fp)) {
return -1;
}
x509 = PEM_read_X509(fp, NULL, NULL, NULL);
if (!(x509)) {
fclose(fp);
return -1;
}
fclose(fp);
res = cl_verify_signature_x509(x509, alg, sig, siglen, data, datalen, decode);
X509_free(x509);
return res;
}
int cl_verify_signature_hash_x509(X509 *x509, char *alg, unsigned char *sig, unsigned int siglen, unsigned char *digest)
{
EVP_PKEY *pkey;
int res;
pkey = X509_get_pubkey(x509);
if (!(pkey))
return -1;
res = cl_verify_signature_hash(pkey, alg, sig, siglen, digest);
EVP_PKEY_free(pkey);
return res;
}
int cl_verify_signature_fd_x509(X509 *x509, char *alg, unsigned char *sig, unsigned int siglen, int fd)
{
EVP_PKEY *pkey;
int res;
pkey = X509_get_pubkey(x509);
if (!(pkey))
return -1;
res = cl_verify_signature_fd(pkey, alg, sig, siglen, fd);
EVP_PKEY_free(pkey);
return res;
}
int cl_verify_signature_x509(X509 *x509, char *alg, unsigned char *sig, unsigned int siglen, unsigned char *data, size_t datalen, int decode)
{
EVP_PKEY *pkey;
int res;
pkey = X509_get_pubkey(x509);
if (!(pkey))
return -1;
res = cl_verify_signature(pkey, alg, sig, siglen, data, datalen, decode);
EVP_PKEY_free(pkey);
return res;
}
unsigned char *cl_sign_data_keyfile(char *keypath, char *alg, unsigned char *hash, unsigned int *olen, int encode)
{
FILE *fp;
EVP_PKEY *pkey;
unsigned char *res;
fp = fopen(keypath, "r");
if (!(fp)) {
return NULL;
}
pkey = PEM_read_PrivateKey(fp, NULL, NULL, NULL);
if (!(pkey)) {
fclose(fp);
return NULL;
}
fclose(fp);
res = cl_sign_data(pkey, alg, hash, olen, encode);
EVP_PKEY_free(pkey);
return res;
}
unsigned char *cl_sign_data(EVP_PKEY *pkey, char *alg, unsigned char *hash, unsigned int *olen, int encode)
{
EVP_MD_CTX ctx;
const EVP_MD *md;
unsigned int siglen;
unsigned char *sig;
md = EVP_get_digestbyname(alg);
if (!(md))
return NULL;
sig = (unsigned char *)calloc(1, EVP_PKEY_size(pkey));
if (!(sig)) {
free(hash);
return NULL;
}
if (!EVP_SignInit(&ctx, md)) {
free(sig);
free(hash);
return NULL;
}
if (!EVP_SignUpdate(&ctx, hash, EVP_MD_size(md))) {
free(sig);
free(hash);
return NULL;
}
if (!EVP_SignFinal(&ctx, sig, &siglen, pkey)) {
free(sig);
free(hash);
return NULL;
}
if (encode) {
unsigned char *newsig = (unsigned char *)cl_base64_encode(sig, siglen);
if (!(newsig)) {
free(sig);
free(hash);
return NULL;
}
free(sig);
sig = newsig;
siglen = (unsigned int)strlen((const char *)newsig);
}
free(hash);
*olen = siglen;
return sig;
}
unsigned char *cl_sign_file_fd(int fd, EVP_PKEY *pkey, char *alg, unsigned int *olen, int encode)
{
unsigned char *hash, *res;
unsigned int hashlen;
hash = cl_hash_file_fd(fd, alg, &hashlen);
if (!(hash)) {
return NULL;
}
res = cl_sign_data(pkey, alg, hash, olen, encode);
free(hash);
return res;
}
unsigned char *cl_sign_file_fp(FILE *fp, EVP_PKEY *pkey, char *alg, unsigned int *olen, int encode)
{
return cl_sign_file_fd(fileno(fp), pkey, alg, olen, encode);
}
EVP_PKEY *cl_get_pkey_file(char *keypath)
{
EVP_PKEY *pkey;
FILE *fp;
fp = fopen(keypath, "r");
if (!(fp))
return NULL;
if (!(pkey = PEM_read_PrivateKey(fp, NULL, NULL, NULL))) {
fclose(fp);
return NULL;
}
fclose(fp);
return pkey;
}
X509 *cl_get_x509_from_mem(void *data, unsigned int len)
{
X509 *cert;
BIO *cbio;
cbio = BIO_new_mem_buf(data, len);
if (!(cbio))
return NULL;
cert = PEM_read_bio_X509(cbio, NULL, 0, NULL);
BIO_free(cbio);
return cert;
}
int cl_validate_certificate_chain_ts_dir(char *tsdir, char *certpath)
{
char **authorities=NULL, **t, *fullpath;
size_t nauths = 0;
int res;
DIR *dp;
struct dirent *dirent;
#if defined(HAVE_READDIR_R_3) || defined(HAVE_READDIR_R_2)
union {
struct dirent d;
char b[offsetof(struct dirent, d_name) + NAME_MAX + 1];
} result;
#endif
dp = opendir(tsdir);
if (!(dp))
return CL_EOPEN;
#if defined(HAVE_READDIR_R_3)
while (!readdir_r(dp, &result.d, &dirent) && dirent) {
#elif defined(HAVE_READDIR_R_2)
while ((dirent = (struct dirent *)readdir_r(dp, &result.d))) {
#else
while ((dirent = readdir(dp))) {
#endif
if (dirent->d_name[0] == '.')
continue;
if (!cli_strbcasestr(dirent->d_name, ".crt"))
continue;
t = (char **)realloc(authorities, sizeof(char **) * (nauths + 1));
if (!(t)) {
if (nauths) {
while (nauths > 0)
free(authorities[--nauths]);
free(authorities);
return -1;
}
}
authorities = t;
authorities[nauths] = (char *)malloc(strlen(tsdir) + strlen(dirent->d_name) + 2);
if (!authorities[nauths]) {
if (nauths) {
while (nauths > 0)
free(authorities[nauths--]);
free(authorities[0]);
free(authorities);
return -1;
}
}
sprintf(authorities[nauths], "%s"PATHSEP"%s", tsdir, dirent->d_name);
nauths++;
}
t = (char **)realloc(authorities, sizeof(char **) * (nauths + 1));
if (!(t)) {
if (nauths) {
while (nauths > 0)
free(authorities[--nauths]);
free(authorities);
return -1;
}
}
authorities = t;
authorities[nauths] = NULL;
closedir(dp);
res = cl_validate_certificate_chain(authorities, NULL, certpath);
while (nauths > 0)
free(authorities[--nauths]);
free(authorities);
return res;
}
int cl_validate_certificate_chain(char **authorities, char *crlpath, char *certpath)
{
X509_STORE *store=NULL;
X509_STORE_CTX *store_ctx;
X509_LOOKUP *lookup=NULL;
X509_CRL *crl=NULL;
X509_VERIFY_PARAM *param=NULL;
X509 *cert;
unsigned long i;
int res;
store = X509_STORE_new();
if (!(store)) {
return -1;
}
X509_STORE_set_flags(store, 0);
lookup = X509_STORE_add_lookup(store, X509_LOOKUP_file());
if (!(lookup)) {
X509_STORE_free(store);
return -1;
}
if ((crlpath)) {
crl = cl_load_crl(crlpath);
if (!(crl)) {
X509_STORE_free(store);
return -1;
}
X509_STORE_add_crl(store, crl);
param = X509_VERIFY_PARAM_new();
if ((param)) {
X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_CRL_CHECK);
X509_STORE_set1_param(store, param);
} else {
X509_STORE_free(store);
X509_CRL_free(crl);
return -1;
}
}
/* Support multi-tiered setups */
for (i=0; authorities[i]; i++) {
if (!X509_LOOKUP_load_file(lookup, authorities[i], X509_FILETYPE_PEM)) {
X509_STORE_free(store);
if ((crl))
X509_CRL_free(crl);
if ((param))
X509_VERIFY_PARAM_free(param);
return -1;
}
}
lookup = X509_STORE_add_lookup(store, X509_LOOKUP_hash_dir());
if (!(lookup)) {
X509_STORE_free(store);
if ((crl))
X509_CRL_free(crl);
if ((param))
X509_VERIFY_PARAM_free(param);
return -1;
}
X509_LOOKUP_add_dir(lookup, NULL, X509_FILETYPE_DEFAULT);
store_ctx = X509_STORE_CTX_new();
if (!(store_ctx)) {
X509_STORE_free(store);
if ((crl))
X509_CRL_free(crl);
if ((param))
X509_VERIFY_PARAM_free(param);
return -1;
}
cert = cl_load_cert(certpath);
if (!(cert)) {
X509_STORE_CTX_free(store_ctx);
X509_STORE_free(store);
if ((crl))
X509_CRL_free(crl);
if ((param))
X509_VERIFY_PARAM_free(param);
return -1;
}
if (!X509_STORE_CTX_init(store_ctx, store, cert, NULL)) {
X509_STORE_CTX_free(store_ctx);
X509_STORE_free(store);
if ((crl))
X509_CRL_free(crl);
if ((param))
X509_VERIFY_PARAM_free(param);
X509_free(cert);
return -1;
}
res = X509_verify_cert(store_ctx);
X509_STORE_CTX_free(store_ctx);
if ((crl))
X509_CRL_free(crl);
if ((param))
X509_VERIFY_PARAM_free(param);
X509_STORE_free(store);
X509_free(cert);
return (res > 0);
}
X509 *cl_load_cert(const char *certpath)
{
X509 *cert;
BIO *bio;
bio = BIO_new(BIO_s_file());
if (!(bio))
return NULL;
if (BIO_read_filename(bio, certpath) != 1) {
BIO_free(bio);
return NULL;
}
cert = PEM_read_bio_X509_AUX(bio, NULL, NULL, NULL);
BIO_free(bio);
return cert;
}
struct tm *cl_ASN1_GetTimeT(ASN1_TIME *timeobj)
{
struct tm *t;
char* str;
size_t i = 0;
const char *fmt;
time_t localt;
#ifdef _WIN32
struct tm localtm, *ltm;
#else
struct tm localtm;
#endif
if (!(timeobj) || !(timeobj->data))
return NULL;
str = (char *)(timeobj->data);
if (strlen(str) < 12)
return NULL;
t = (struct tm *)calloc(1, sizeof(struct tm));
if (!(t))
return NULL;
if (timeobj->type == V_ASN1_UTCTIME) {
/* two digit year */
fmt = "%y%m%d%H%M%S";
if (str[3] == '0') {
str[2] = '0';
str[3] = '9';
} else {
str[3]--;
}
}
else if (timeobj->type == V_ASN1_GENERALIZEDTIME) {
/* four digit year */
fmt = "%Y%m%d%H%M%S";
if (str[5] == '0') {
str[4] = '0';
str[5] = '9';
} else {
str[5]--;
}
}
if (!strptime(str, fmt, t)) {
free(t);
return NULL;
}
/* Convert to local time */
localt = time(NULL);
#ifdef _WIN32
ltm = localtime(&localt);
memcpy((void *)(&localtm), (void *)ltm, sizeof(struct tm));
#else
localtime_r(&localt, &localtm);
#endif
t->tm_isdst = localtm.tm_isdst;
return t;
}
X509_CRL *cl_load_crl(const char *file)
{
X509_CRL *x=NULL;
FILE *fp;
struct tm *tm;
time_t crltime;
if (!(file))
return NULL;
fp = fopen(file, "r");
if (!(fp))
return NULL;
x = PEM_read_X509_CRL(fp, NULL, NULL, NULL);
fclose(fp);
if ((x)) {
tm = cl_ASN1_GetTimeT(x->crl->nextUpdate);
if (!(tm)) {
X509_CRL_free(x);
return NULL;
}
#if !defined(_WIN32)
if (timegm(tm) < time(NULL)) {
X509_CRL_free(x);
free(tm);
return NULL;
}
#endif
free(tm);
}
return x;
}