Add |BIO_read_asn1| to read a single ASN.1 object.
Android needs to be able to read a PKCS#7 blob from a Java
InputStream. This change adds |BIO_read_asn1| which reads a single
ASN.1 object from the start of a BIO without overreading.
Change-Id: I74776e686529c8e58af1c26a4909f9bd4e87b707
diff --git a/include/openssl/bio.h b/include/openssl/bio.h
index 66a72a1..8724657 100644
--- a/include/openssl/bio.h
+++ b/include/openssl/bio.h
@@ -339,6 +339,21 @@
* using human readable strings where possible. */
OPENSSL_EXPORT void BIO_print_errors(BIO *bio);
+/* BIO_read_asn1 reads a single ASN.1 object from |bio|. If successful it sets
+ * |*out| to be an allocated buffer (that should be freed with |OPENSSL_free|),
+ * |*out_size| to the length, in bytes, of that buffer and returns one.
+ * Otherwise it returns zero.
+ *
+ * If the length of the object is greater than |max_len| or 2^32 then the
+ * function will fail. Long-form tags are not supported. If the length of the
+ * object is indefinite the full contents of |bio| are read, unless it would be
+ * greater than |max_len|, in which case the function fails.
+ *
+ * If the function fails then some unknown amount of data may have been read
+ * from |bio|. */
+OPENSSL_EXPORT int BIO_read_asn1(BIO *bio, uint8_t **out, size_t *out_len,
+ size_t max_len);
+
/* Memory BIOs.
*
