+ BIO_OK_CTX *ctx;
+ EVP_MD *md;
+ const EVP_MD **ppmd;
+ long ret = 1;
+ int i;
+ BIO *next;
+
+ ctx = BIO_get_data(b);
+ next = BIO_next(b);
+
+ switch (cmd) {
+ case BIO_CTRL_RESET:
+ ctx->buf_len = 0;
+ ctx->buf_off = 0;
+ ctx->buf_len_save = 0;
+ ctx->buf_off_save = 0;
+ ctx->cont = 1;
+ ctx->finished = 0;
+ ctx->blockout = 0;
+ ctx->sigio = 1;
+ ret = BIO_ctrl(next, cmd, num, ptr);
+ break;
+ case BIO_CTRL_EOF: /* More to read */
+ if (ctx->cont <= 0)
+ ret = 1;
+ else
+ ret = BIO_ctrl(next, cmd, num, ptr);
+ break;
+ case BIO_CTRL_PENDING: /* More to read in buffer */
+ case BIO_CTRL_WPENDING: /* More to read in buffer */
+ ret = ctx->blockout ? ctx->buf_len - ctx->buf_off : 0;
+ if (ret <= 0)
+ ret = BIO_ctrl(next, cmd, num, ptr);
+ break;
+ case BIO_CTRL_FLUSH:
+ /* do a final write */
+ if (ctx->blockout == 0)
+ if (!block_out(b))
+ return 0;
+
+ while (ctx->blockout) {
+ i = ok_write(b, NULL, 0);
+ if (i < 0) {
+ ret = i;
+ break;
+ }
+ }
+
+ ctx->finished = 1;
+ ctx->buf_off = ctx->buf_len = 0;
+ ctx->cont = (int)ret;
+
+ /* Finally flush the underlying BIO */
+ ret = BIO_ctrl(next, cmd, num, ptr);
+ break;
+ case BIO_C_DO_STATE_MACHINE:
+ BIO_clear_retry_flags(b);
+ ret = BIO_ctrl(next, cmd, num, ptr);
+ BIO_copy_next_retry(b);
+ break;
+ case BIO_CTRL_INFO:
+ ret = (long)ctx->cont;
+ break;
+ case BIO_C_SET_MD:
+ md = ptr;
+ if (!EVP_DigestInit_ex(ctx->md, md, NULL))
+ return 0;
+ BIO_set_init(b, 1);
+ break;
+ case BIO_C_GET_MD:
+ if (BIO_get_init(b)) {
+ ppmd = ptr;
+ *ppmd = EVP_MD_CTX_md(ctx->md);
+ } else
+ ret = 0;
+ break;
+ default:
+ ret = BIO_ctrl(next, cmd, num, ptr);
+ break;
+ }
+ return ret;
+}
+
+static long ok_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
+{
+ long ret = 1;
+ BIO *next;
+
+ next = BIO_next(b);
+
+ if (next == NULL)
+ return 0;
+
+ switch (cmd) {
+ default:
+ ret = BIO_callback_ctrl(next, cmd, fp);
+ break;
+ }
+
+ return ret;
+}
+
+static void longswap(void *_ptr, size_t len)
+{
+ const union {
+ long one;
+ char little;
+ } is_endian = {
+ 1
+ };
+
+ if (is_endian.little) {
+ size_t i;
+ unsigned char *p = _ptr, c;
+
+ for (i = 0; i < len; i += 4) {
+ c = p[0], p[0] = p[3], p[3] = c;
+ c = p[1], p[1] = p[2], p[2] = c;
+ }
+ }
+}
+
+static int sig_out(BIO *b)
+{
+ BIO_OK_CTX *ctx;
+ EVP_MD_CTX *md;
+ const EVP_MD *digest;
+ int md_size;
+ void *md_data;
+
+ ctx = BIO_get_data(b);
+ md = ctx->md;
+ digest = EVP_MD_CTX_md(md);
+ md_size = EVP_MD_size(digest);
+ md_data = EVP_MD_CTX_md_data(md);
+
+ if (ctx->buf_len + 2 * md_size > OK_BLOCK_SIZE)
+ return 1;
+
+ if (!EVP_DigestInit_ex(md, digest, NULL))
+ goto berr;
+ /*
+ * FIXME: there's absolutely no guarantee this makes any sense at all,
+ * particularly now EVP_MD_CTX has been restructured.
+ */
+ if (RAND_bytes(md_data, md_size) <= 0)
+ goto berr;
+ memcpy(&(ctx->buf[ctx->buf_len]), md_data, md_size);
+ longswap(&(ctx->buf[ctx->buf_len]), md_size);
+ ctx->buf_len += md_size;
+
+ if (!EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN)))
+ goto berr;
+ if (!EVP_DigestFinal_ex(md, &(ctx->buf[ctx->buf_len]), NULL))
+ goto berr;
+ ctx->buf_len += md_size;
+ ctx->blockout = 1;
+ ctx->sigio = 0;
+ return 1;
+ berr:
+ BIO_clear_retry_flags(b);
+ return 0;
+}
+
+static int sig_in(BIO *b)
+{
+ BIO_OK_CTX *ctx;
+ EVP_MD_CTX *md;
+ unsigned char tmp[EVP_MAX_MD_SIZE];
+ int ret = 0;
+ const EVP_MD *digest;
+ int md_size;
+ void *md_data;
+
+ ctx = BIO_get_data(b);
+ md = ctx->md;
+ digest = EVP_MD_CTX_md(md);
+ md_size = EVP_MD_size(digest);
+ md_data = EVP_MD_CTX_md_data(md);
+
+ if ((int)(ctx->buf_len - ctx->buf_off) < 2 * md_size)
+ return 1;
+
+ if (!EVP_DigestInit_ex(md, digest, NULL))
+ goto berr;
+ memcpy(md_data, &(ctx->buf[ctx->buf_off]), md_size);
+ longswap(md_data, md_size);
+ ctx->buf_off += md_size;
+
+ if (!EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN)))
+ goto berr;
+ if (!EVP_DigestFinal_ex(md, tmp, NULL))
+ goto berr;
+ ret = memcmp(&(ctx->buf[ctx->buf_off]), tmp, md_size) == 0;
+ ctx->buf_off += md_size;
+ if (ret == 1) {
+ ctx->sigio = 0;
+ if (ctx->buf_len != ctx->buf_off) {
+ memmove(ctx->buf, &(ctx->buf[ctx->buf_off]),
+ ctx->buf_len - ctx->buf_off);
+ }
+ ctx->buf_len -= ctx->buf_off;
+ ctx->buf_off = 0;
+ } else {
+ ctx->cont = 0;
+ }
+ return 1;
+ berr:
+ BIO_clear_retry_flags(b);
+ return 0;