+ int i, n;
+ const unsigned char *p;
+ next_io:
+ if (!(rctx->state & OHS_NOREAD))
+ {
+ n = BIO_read(rctx->io, rctx->iobuf, rctx->iobuflen);
+
+ if (n <= 0)
+ {
+ if (BIO_should_retry(rctx->io))
+ return -1;
+ return 0;
+ }
+
+ /* Write data to memory BIO */
+
+ if (BIO_write(rctx->mem, rctx->iobuf, n) != n)
+ return 0;
+ }
+
+ switch(rctx->state)
+ {
+
+ case OHS_ASN1_WRITE:
+ n = BIO_get_mem_data(rctx->mem, &p);
+
+ i = BIO_write(rctx->io,
+ p + (n - rctx->asn1_len), rctx->asn1_len);
+
+ if (i <= 0)
+ {
+ if (BIO_should_retry(rctx->io))
+ return -1;
+ rctx->state = OHS_ERROR;
+ return 0;
+ }
+
+ rctx->asn1_len -= i;
+
+ if (rctx->asn1_len > 0)
+ goto next_io;
+
+ rctx->state = OHS_ASN1_FLUSH;
+
+ (void)BIO_reset(rctx->mem);
+
+ case OHS_ASN1_FLUSH:
+
+ i = BIO_flush(rctx->io);
+
+ if (i > 0)
+ {
+ rctx->state = OHS_FIRSTLINE;
+ goto next_io;
+ }
+
+ if (BIO_should_retry(rctx->io))
+ return -1;
+
+ rctx->state = OHS_ERROR;
+ return 0;
+
+ case OHS_ERROR:
+ return 0;
+
+ case OHS_FIRSTLINE:
+ case OHS_HEADERS:
+
+ /* Attempt to read a line in */
+
+ next_line:
+ /* Due to &%^*$" memory BIO behaviour with BIO_gets we
+ * have to check there's a complete line in there before
+ * calling BIO_gets or we'll just get a partial read.
+ */
+ n = BIO_get_mem_data(rctx->mem, &p);
+ if ((n <= 0) || !memchr(p, '\n', n))
+ {
+ if (n >= rctx->iobuflen)
+ {
+ rctx->state = OHS_ERROR;
+ return 0;
+ }
+ goto next_io;
+ }
+ n = BIO_gets(rctx->mem, (char *)rctx->iobuf, rctx->iobuflen);
+
+ if (n <= 0)
+ {
+ if (BIO_should_retry(rctx->mem))
+ goto next_io;
+ rctx->state = OHS_ERROR;
+ return 0;
+ }
+
+ /* Don't allow excessive lines */
+ if (n == rctx->iobuflen)
+ {
+ rctx->state = OHS_ERROR;
+ return 0;
+ }
+
+ /* First line */
+ if (rctx->state == OHS_FIRSTLINE)
+ {
+ if (parse_http_line1((char *)rctx->iobuf))
+ {
+ rctx->state = OHS_HEADERS;
+ goto next_line;
+ }
+ else
+ {
+ rctx->state = OHS_ERROR;
+ return 0;
+ }
+ }
+ else
+ {
+ /* Look for blank line: end of headers */
+ for (p = rctx->iobuf; *p; p++)
+ {
+ if ((*p != '\r') && (*p != '\n'))
+ break;
+ }
+ if (*p)
+ goto next_line;
+
+ rctx->state = OHS_ASN1_HEADER;
+
+ }
+
+ /* Fall thru */
+
+
+ case OHS_ASN1_HEADER:
+ /* Now reading ASN1 header: can read at least 2 bytes which
+ * is enough for ASN1 SEQUENCE header and either length field
+ * or at least the length of the length field.
+ */
+ n = BIO_get_mem_data(rctx->mem, &p);
+ if (n < 2)
+ goto next_io;
+
+ /* Check it is an ASN1 SEQUENCE */
+ if (*p++ != (V_ASN1_SEQUENCE|V_ASN1_CONSTRUCTED))
+ {
+ rctx->state = OHS_ERROR;
+ return 0;
+ }
+
+ /* Check out length field */
+ if (*p & 0x80)
+ {
+ /* If MSB set on initial length octet we can now
+ * always read 6 octets: make sure we have them.
+ */
+ if (n < 6)
+ goto next_io;
+ n = *p & 0x7F;
+ /* Not NDEF or excessive length */
+ if (!n || (n > 4))
+ {
+ rctx->state = OHS_ERROR;
+ return 0;
+ }
+ p++;
+ rctx->asn1_len = 0;
+ for (i = 0; i < n; i++)
+ {
+ rctx->asn1_len <<= 8;
+ rctx->asn1_len |= *p++;
+ }
+
+ if (rctx->asn1_len > OCSP_MAX_REQUEST_LENGTH)
+ {
+ rctx->state = OHS_ERROR;
+ return 0;
+ }
+
+ rctx->asn1_len += n + 2;
+ }
+ else
+ rctx->asn1_len = *p + 2;
+
+ rctx->state = OHS_ASN1_CONTENT;
+
+ /* Fall thru */
+
+ case OHS_ASN1_CONTENT:
+ n = BIO_get_mem_data(rctx->mem, &p);
+ if (n < (int)rctx->asn1_len)
+ goto next_io;
+
+
+ *presp = d2i_OCSP_RESPONSE(NULL, &p, rctx->asn1_len);
+ if (*presp)
+ {
+ rctx->state = OHS_DONE;
+ return 1;
+ }
+
+ rctx->state = OHS_ERROR;
+ return 0;
+
+ break;
+
+ case OHS_DONE:
+ return 1;
+
+ }
+
+
+
+ return 0;
+
+