Files
w3m/istream.c
Rene Kita cab914ef48 Fix manipulation of ASN1_STRING
Take the correct type from ASN1_STRING_get0_data() to fix a warning.
IA5Strings are ASCII, we do not need to care about signedness.

Since the pointer returned by ASN1_STRING_get0_data() points to internal
memory of the ASN1_STRING we are not allowed to manipulate the data.
Also it is not guaranteed that the data is null terminated. Copy the
data to our own buffer and make sure it is null terminated before using
it.
2021-09-13 10:04:49 +02:00

772 lines
18 KiB
C

/* $Id: istream.c,v 1.27 2010/07/18 13:43:23 htrb Exp $ */
#include "fm.h"
#include "myctype.h"
#include "istream.h"
#include <signal.h>
#ifdef USE_SSL
#include <openssl/x509v3.h>
#endif
#ifdef __MINGW32_VERSION
#include <winsock.h>
#endif
#define uchar unsigned char
#define STREAM_BUF_SIZE 8192
#define SSL_BUF_SIZE 1536
#define MUST_BE_UPDATED(bs) ((bs)->stream.cur==(bs)->stream.next)
#define POP_CHAR(bs) ((bs)->iseos?'\0':(bs)->stream.buf[(bs)->stream.cur++])
static void basic_close(int *handle);
static int basic_read(int *handle, char *buf, int len);
static void file_close(struct io_file_handle *handle);
static int file_read(struct io_file_handle *handle, char *buf, int len);
static int str_read(Str handle, char *buf, int len);
#ifdef USE_SSL
static void ssl_close(struct ssl_handle *handle);
static int ssl_read(struct ssl_handle *handle, char *buf, int len);
#endif
static int ens_read(struct ens_handle *handle, char *buf, int len);
static void ens_close(struct ens_handle *handle);
static void memchop(char *p, int *len);
static void
do_update(BaseStream base)
{
int len;
base->stream.cur = base->stream.next = 0;
len = (*base->read) (base->handle, base->stream.buf, base->stream.size);
if (len <= 0)
base->iseos = TRUE;
else
base->stream.next += len;
}
static int
buffer_read(StreamBuffer sb, char *obuf, int count)
{
int len = sb->next - sb->cur;
if (len > 0) {
if (len > count)
len = count;
bcopy((const void *)&sb->buf[sb->cur], obuf, len);
sb->cur += len;
}
return len;
}
static void
init_buffer(BaseStream base, char *buf, int bufsize)
{
StreamBuffer sb = &base->stream;
sb->size = bufsize;
sb->cur = 0;
sb->buf = NewWithoutGC_N(uchar, bufsize);
if (buf) {
memcpy(sb->buf, buf, bufsize);
sb->next = bufsize;
}
else {
sb->next = 0;
}
base->iseos = FALSE;
}
static void
init_base_stream(BaseStream base, int bufsize)
{
init_buffer(base, NULL, bufsize);
}
static void
init_str_stream(BaseStream base, Str s)
{
init_buffer(base, s->ptr, s->length);
}
InputStream
newInputStream(int des)
{
InputStream stream;
if (des < 0)
return NULL;
stream = NewWithoutGC(union input_stream);
init_base_stream(&stream->base, STREAM_BUF_SIZE);
stream->base.type = IST_BASIC;
stream->base.handle = NewWithoutGC(int);
*(int *)stream->base.handle = des;
stream->base.read = (int (*)())basic_read;
stream->base.close = (void (*)())basic_close;
return stream;
}
InputStream
newFileStream(FILE * f, void (*closep) ())
{
InputStream stream;
if (f == NULL)
return NULL;
stream = NewWithoutGC(union input_stream);
init_base_stream(&stream->base, STREAM_BUF_SIZE);
stream->file.type = IST_FILE;
stream->file.handle = NewWithoutGC(struct io_file_handle);
stream->file.handle->f = f;
if (closep)
stream->file.handle->close = closep;
else
stream->file.handle->close = (void (*)())fclose;
stream->file.read = (int (*)())file_read;
stream->file.close = (void (*)())file_close;
return stream;
}
InputStream
newStrStream(Str s)
{
InputStream stream;
if (s == NULL)
return NULL;
stream = NewWithoutGC(union input_stream);
init_str_stream(&stream->base, s);
stream->str.type = IST_STR;
stream->str.handle = NULL;
stream->str.read = (int (*)())str_read;
stream->str.close = NULL;
return stream;
}
#ifdef USE_SSL
InputStream
newSSLStream(SSL * ssl, int sock)
{
InputStream stream;
if (sock < 0)
return NULL;
stream = NewWithoutGC(union input_stream);
init_base_stream(&stream->base, SSL_BUF_SIZE);
stream->ssl.type = IST_SSL;
stream->ssl.handle = NewWithoutGC(struct ssl_handle);
stream->ssl.handle->ssl = ssl;
stream->ssl.handle->sock = sock;
stream->ssl.read = (int (*)())ssl_read;
stream->ssl.close = (void (*)())ssl_close;
return stream;
}
#endif
InputStream
newEncodedStream(InputStream is, char encoding)
{
InputStream stream;
if (is == NULL || (encoding != ENC_QUOTE && encoding != ENC_BASE64 &&
encoding != ENC_UUENCODE))
return is;
stream = NewWithoutGC(union input_stream);
init_base_stream(&stream->base, STREAM_BUF_SIZE);
stream->ens.type = IST_ENCODED;
stream->ens.handle = NewWithoutGC(struct ens_handle);
stream->ens.handle->is = is;
stream->ens.handle->pos = 0;
stream->ens.handle->encoding = encoding;
growbuf_init_without_GC(&stream->ens.handle->gb);
stream->ens.read = (int (*)())ens_read;
stream->ens.close = (void (*)())ens_close;
return stream;
}
int
ISclose(InputStream stream)
{
MySignalHandler(*prevtrap) ();
if (stream == NULL || stream->base.close == NULL ||
stream->base.type & IST_UNCLOSE)
return -1;
prevtrap = mySignal(SIGINT, SIG_IGN);
stream->base.close (stream->base.handle);
mySignal(SIGINT, prevtrap);
xfree(stream->base.stream.buf);
xfree(stream);
return 0;
}
int
ISgetc(InputStream stream)
{
BaseStream base;
if (stream == NULL)
return '\0';
base = &stream->base;
if (!base->iseos && MUST_BE_UPDATED(base))
do_update(base);
return POP_CHAR(base);
}
int
ISundogetc(InputStream stream)
{
StreamBuffer sb;
if (stream == NULL)
return -1;
sb = &stream->base.stream;
if (sb->cur > 0) {
sb->cur--;
return 0;
}
return -1;
}
Str
StrISgets2(InputStream stream, char crnl)
{
struct growbuf gb;
if (stream == NULL)
return NULL;
growbuf_init(&gb);
ISgets_to_growbuf(stream, &gb, crnl);
return growbuf_to_Str(&gb);
}
void
ISgets_to_growbuf(InputStream stream, struct growbuf *gb, char crnl)
{
BaseStream base = &stream->base;
StreamBuffer sb = &base->stream;
int i;
gb->length = 0;
while (!base->iseos) {
if (MUST_BE_UPDATED(base)) {
do_update(base);
continue;
}
if (crnl && gb->length > 0 && gb->ptr[gb->length - 1] == '\r') {
if (sb->buf[sb->cur] == '\n') {
GROWBUF_ADD_CHAR(gb, '\n');
++sb->cur;
}
break;
}
for (i = sb->cur; i < sb->next; ++i) {
if (sb->buf[i] == '\n' || (crnl && sb->buf[i] == '\r')) {
++i;
break;
}
}
growbuf_append(gb, &sb->buf[sb->cur], i - sb->cur);
sb->cur = i;
if (gb->length > 0 && gb->ptr[gb->length - 1] == '\n')
break;
}
growbuf_reserve(gb, gb->length + 1);
gb->ptr[gb->length] = '\0';
return;
}
#ifdef unused
int
ISread(InputStream stream, Str buf, int count)
{
int len;
if (count + 1 > buf->area_size) {
char *newptr = GC_MALLOC_ATOMIC(count + 1);
memcpy(newptr, buf->ptr, buf->length);
newptr[buf->length] = '\0';
buf->ptr = newptr;
buf->area_size = count + 1;
}
len = ISread_n(stream, buf->ptr, count);
buf->length = (len > 0) ? len : 0;
buf->ptr[buf->length] = '\0';
return (len > 0) ? 1 : 0;
}
#endif
int
ISread_n(InputStream stream, char *dst, int count)
{
int len, l;
BaseStream base;
if (stream == NULL || count <= 0)
return -1;
if ((base = &stream->base)->iseos)
return 0;
len = buffer_read(&base->stream, dst, count);
if (MUST_BE_UPDATED(base)) {
l = (*base->read) (base->handle, &dst[len], count - len);
if (l <= 0) {
base->iseos = TRUE;
} else {
len += l;
}
}
return len;
}
int
ISfileno(InputStream stream)
{
if (stream == NULL)
return -1;
switch (IStype(stream) & ~IST_UNCLOSE) {
case IST_BASIC:
return *(int *)stream->base.handle;
case IST_FILE:
return fileno(stream->file.handle->f);
#ifdef USE_SSL
case IST_SSL:
return stream->ssl.handle->sock;
#endif
case IST_ENCODED:
return ISfileno(stream->ens.handle->is);
default:
return -1;
}
}
int
ISeos(InputStream stream)
{
BaseStream base = &stream->base;
if (!base->iseos && MUST_BE_UPDATED(base))
do_update(base);
return base->iseos;
}
#ifdef USE_SSL
static Str accept_this_site;
void
ssl_accept_this_site(char *hostname)
{
if (hostname)
accept_this_site = Strnew_charp(hostname);
else
accept_this_site = NULL;
}
static int
ssl_match_cert_ident(char *ident, int ilen, char *hostname)
{
/* RFC2818 3.1. Server Identity
* Names may contain the wildcard
* character * which is considered to match any single domain name
* component or component fragment. E.g., *.a.com matches foo.a.com but
* not bar.foo.a.com. f*.com matches foo.com but not bar.com.
*/
int hlen = strlen(hostname);
int i, c;
/* Is this an exact match? */
if ((ilen == hlen) && strncasecmp(ident, hostname, hlen) == 0)
return TRUE;
for (i = 0; i < ilen; i++) {
if (ident[i] == '*' && ident[i + 1] == '.') {
while ((c = *hostname++) != '\0')
if (c == '.')
break;
i++;
}
else {
if (ident[i] != *hostname++)
return FALSE;
}
}
return *hostname == '\0';
}
static Str
ssl_check_cert_ident(X509 * x, char *hostname)
{
int i;
Str ret = NULL;
int match_ident = FALSE;
/*
* All we need to do here is check that the CN matches.
*
* From RFC2818 3.1 Server Identity:
* If a subjectAltName extension of type dNSName is present, that MUST
* be used as the identity. Otherwise, the (most specific) Common Name
* field in the Subject field of the certificate MUST be used. Although
* the use of the Common Name is existing practice, it is deprecated and
* Certification Authorities are encouraged to use the dNSName instead.
*/
i = X509_get_ext_by_NID(x, NID_subject_alt_name, -1);
if (i >= 0) {
X509_EXTENSION *ex;
STACK_OF(GENERAL_NAME) * alt;
ex = X509_get_ext(x, i);
alt = X509V3_EXT_d2i(ex);
if (alt) {
int n;
GENERAL_NAME *gn;
X509V3_EXT_METHOD *method;
Str seen_dnsname = NULL;
n = sk_GENERAL_NAME_num(alt);
for (i = 0; i < n; i++) {
gn = sk_GENERAL_NAME_value(alt, i);
if (gn->type == GEN_DNS) {
#if (OPENSSL_VERSION_NUMBER < 0x10100000L) || defined(LIBRESSL_VERSION_NUMBER)
unsigned char *sn = ASN1_STRING_data(gn->d.ia5);
#else
const unsigned char *sn = ASN1_STRING_get0_data(gn->d.ia5);
#endif
int sl = ASN1_STRING_length(gn->d.ia5);
/*
* sn is a pointer to internal data and not guaranteed to
* be null terminated. Ensure we have a null terminated
* string that we can modify.
*/
char *asn = GC_MALLOC(sl + 1);
if (!asn)
exit(1);
bcopy(sn, asn, sl);
asn[sl] = '\0';
if (!seen_dnsname)
seen_dnsname = Strnew();
/* replace \0 to make full string visible to user */
if (sl != strlen(asn)) {
int i;
for (i = 0; i < sl; ++i) {
if (!asn[i])
asn[i] = '!';
}
}
Strcat_m_charp(seen_dnsname, asn, " ", NULL);
if (sl == strlen(asn) /* catch \0 in SAN */
&& ssl_match_cert_ident(asn, sl, hostname))
break;
}
}
method = X509V3_EXT_get(ex);
sk_GENERAL_NAME_free(alt);
if (i < n) /* Found a match */
match_ident = TRUE;
else if (seen_dnsname)
/* FIXME: gettextize? */
ret = Sprintf("Bad cert ident from %s: dNSName=%s", hostname,
seen_dnsname->ptr);
}
}
if (match_ident == FALSE && ret == NULL) {
X509_NAME *xn;
char buf[2048];
int slen;
xn = X509_get_subject_name(x);
slen = X509_NAME_get_text_by_NID(xn, NID_commonName, buf, sizeof(buf));
if ( slen == -1)
/* FIXME: gettextize? */
ret = Strnew_charp("Unable to get common name from peer cert");
else if (slen != strlen(buf)
|| !ssl_match_cert_ident(buf, strlen(buf), hostname)) {
/* replace \0 to make full string visible to user */
if (slen != strlen(buf)) {
int i;
for (i = 0; i < slen; ++i) {
if (!buf[i])
buf[i] = '!';
}
}
/* FIXME: gettextize? */
ret = Sprintf("Bad cert ident %s from %s", buf, hostname);
}
}
return ret;
}
Str
ssl_get_certificate(SSL * ssl, char *hostname)
{
BIO *bp;
X509 *x;
X509_NAME *xn;
char *p;
int len;
Str s;
char buf[2048];
Str amsg = NULL;
Str emsg;
char *ans;
if (ssl == NULL)
return NULL;
x = SSL_get_peer_certificate(ssl);
if (x == NULL) {
if (accept_this_site
&& strcasecmp(accept_this_site->ptr, hostname) == 0)
ans = "y";
else {
/* FIXME: gettextize? */
emsg = Strnew_charp("No SSL peer certificate: accept? (y/n)");
ans = inputAnswer(emsg->ptr);
}
if (ans && TOLOWER(*ans) == 'y')
/* FIXME: gettextize? */
amsg = Strnew_charp
("Accept SSL session without any peer certificate");
else {
/* FIXME: gettextize? */
char *e = "This SSL session was rejected "
"to prevent security violation: no peer certificate";
disp_err_message(e, FALSE);
free_ssl_ctx();
return NULL;
}
if (amsg)
disp_err_message(amsg->ptr, FALSE);
ssl_accept_this_site(hostname);
/* FIXME: gettextize? */
s = amsg ? amsg : Strnew_charp("valid certificate");
return s;
}
#ifdef USE_SSL_VERIFY
/* check the cert chain.
* The chain length is automatically checked by OpenSSL when we
* set the verify depth in the ctx.
*/
if (ssl_verify_server) {
long verr;
if ((verr = SSL_get_verify_result(ssl))
!= X509_V_OK) {
const char *em = X509_verify_cert_error_string(verr);
if (accept_this_site
&& strcasecmp(accept_this_site->ptr, hostname) == 0)
ans = "y";
else {
/* FIXME: gettextize? */
emsg = Sprintf("%s: accept? (y/n)", em);
ans = inputAnswer(emsg->ptr);
}
if (ans && TOLOWER(*ans) == 'y') {
/* FIXME: gettextize? */
amsg = Sprintf("Accept unsecure SSL session: "
"unverified: %s", em);
}
else {
/* FIXME: gettextize? */
char *e =
Sprintf("This SSL session was rejected: %s", em)->ptr;
disp_err_message(e, FALSE);
free_ssl_ctx();
return NULL;
}
}
}
#endif
emsg = ssl_check_cert_ident(x, hostname);
if (emsg != NULL) {
if (accept_this_site
&& strcasecmp(accept_this_site->ptr, hostname) == 0)
ans = "y";
else {
Str ep = Strdup(emsg);
if (ep->length > COLS - 16)
Strshrink(ep, ep->length - (COLS - 16));
Strcat_charp(ep, ": accept? (y/n)");
ans = inputAnswer(ep->ptr);
}
if (ans && TOLOWER(*ans) == 'y') {
/* FIXME: gettextize? */
amsg = Strnew_charp("Accept unsecure SSL session:");
Strcat(amsg, emsg);
}
else {
/* FIXME: gettextize? */
char *e = "This SSL session was rejected "
"to prevent security violation";
disp_err_message(e, FALSE);
free_ssl_ctx();
return NULL;
}
}
if (amsg)
disp_err_message(amsg->ptr, FALSE);
ssl_accept_this_site(hostname);
/* FIXME: gettextize? */
s = amsg ? amsg : Strnew_charp("valid certificate");
Strcat_charp(s, "\n");
xn = X509_get_subject_name(x);
if (X509_NAME_get_text_by_NID(xn, NID_commonName, buf, sizeof(buf)) == -1)
Strcat_charp(s, " subject=<unknown>");
else
Strcat_m_charp(s, " subject=", buf, NULL);
xn = X509_get_issuer_name(x);
if (X509_NAME_get_text_by_NID(xn, NID_commonName, buf, sizeof(buf)) == -1)
Strcat_charp(s, ": issuer=<unknown>");
else
Strcat_m_charp(s, ": issuer=", buf, NULL);
Strcat_charp(s, "\n\n");
bp = BIO_new(BIO_s_mem());
X509_print(bp, x);
len = (int)BIO_ctrl(bp, BIO_CTRL_INFO, 0, (char *)&p);
Strcat_charp_n(s, p, len);
BIO_free_all(bp);
X509_free(x);
return s;
}
#endif
/* Raw level input stream functions */
static void
basic_close(int *handle)
{
#ifdef __MINGW32_VERSION
closesocket(*(int *)handle);
#else
close(*(int *)handle);
#endif
xfree(handle);
}
static int
basic_read(int *handle, char *buf, int len)
{
#ifdef __MINGW32_VERSION
return recv(*(int *)handle, buf, len, 0);
#else
return read(*(int *)handle, buf, len);
#endif
}
static void
file_close(struct io_file_handle *handle)
{
handle->close(handle->f);
xfree(handle);
}
static int
file_read(struct io_file_handle *handle, char *buf, int len)
{
return fread(buf, 1, len, handle->f);
}
static int
str_read(Str handle, char *buf, int len)
{
return 0;
}
#ifdef USE_SSL
static void
ssl_close(struct ssl_handle *handle)
{
close(handle->sock);
if (handle->ssl)
SSL_free(handle->ssl);
xfree(handle);
}
static int
ssl_read(struct ssl_handle *handle, char *buf, int len)
{
int status;
if (handle->ssl) {
#ifdef USE_SSL_VERIFY
for (;;) {
status = SSL_read(handle->ssl, buf, len);
if (status > 0)
break;
switch (SSL_get_error(handle->ssl, status)) {
case SSL_ERROR_WANT_READ:
case SSL_ERROR_WANT_WRITE: /* reads can trigger write errors; see SSL_get_error(3) */
continue;
default:
break;
}
break;
}
#else /* if !defined(USE_SSL_VERIFY) */
status = SSL_read(handle->ssl, buf, len);
#endif /* !defined(USE_SSL_VERIFY) */
}
else
status = read(handle->sock, buf, len);
return status;
}
#endif /* USE_SSL */
static void
ens_close(struct ens_handle *handle)
{
ISclose(handle->is);
growbuf_clear(&handle->gb);
xfree(handle);
}
static int
ens_read(struct ens_handle *handle, char *buf, int len)
{
if (handle->pos == handle->gb.length) {
char *p;
struct growbuf gbtmp;
ISgets_to_growbuf(handle->is, &handle->gb, TRUE);
if (handle->gb.length == 0)
return 0;
if (handle->encoding == ENC_BASE64)
memchop(handle->gb.ptr, &handle->gb.length);
else if (handle->encoding == ENC_UUENCODE) {
if (handle->gb.length >= 5 &&
!strncmp(handle->gb.ptr, "begin", 5))
ISgets_to_growbuf(handle->is, &handle->gb, TRUE);
memchop(handle->gb.ptr, &handle->gb.length);
}
growbuf_init_without_GC(&gbtmp);
p = handle->gb.ptr;
if (handle->encoding == ENC_QUOTE)
decodeQP_to_growbuf(&gbtmp, &p);
else if (handle->encoding == ENC_BASE64)
decodeB_to_growbuf(&gbtmp, &p);
else if (handle->encoding == ENC_UUENCODE)
decodeU_to_growbuf(&gbtmp, &p);
growbuf_clear(&handle->gb);
handle->gb = gbtmp;
handle->pos = 0;
}
if (len > handle->gb.length - handle->pos)
len = handle->gb.length - handle->pos;
memcpy(buf, &handle->gb.ptr[handle->pos], len);
handle->pos += len;
return len;
}
static void
memchop(char *p, int *len)
{
char *q;
for (q = p + *len; q > p; --q) {
if (q[-1] != '\n' && q[-1] != '\r')
break;
}
if (q != p + *len)
*q = '\0';
*len = q - p;
return;
}