Export CBS_get_any_asn1_element.
Useful for parsing things when you don't know what tag to expect (e.g. a
CHOICE). Also allow its operands to be NULL, so that it can be used to skip
arbitrary elements.
Delete CBS_ASN1_ANY which wasn't doing anything.
Change-Id: I56413e68b4f2e13860ea3e55373d5830713d7e5c
Reviewed-on: https://boringssl-review.googlesource.com/1661
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/bytestring/cbs.c b/crypto/bytestring/cbs.c
index d6e9442..244daba 100644
--- a/crypto/bytestring/cbs.c
+++ b/crypto/bytestring/cbs.c
@@ -162,6 +162,12 @@
size_t *out_header_len) {
uint8_t tag, length_byte;
CBS header = *cbs;
+ CBS throwaway;
+
+ if (out == NULL) {
+ out = &throwaway;
+ }
+
if (!CBS_get_u8(&header, &tag) ||
!CBS_get_u8(&header, &length_byte)) {
return 0;
@@ -172,13 +178,17 @@
return 0;
}
- *out_tag = tag;
+ if (out_tag != NULL) {
+ *out_tag = tag;
+ }
size_t len;
if ((length_byte & 0x80) == 0) {
/* Short form length. */
len = ((size_t) length_byte) + 2;
- *out_header_len = 2;
+ if (out_header_len != NULL) {
+ *out_header_len = 2;
+ }
} else {
/* Long form length. */
const size_t num_bytes = length_byte & 0x7f;
@@ -210,7 +220,9 @@
return 0;
}
len += 2 + num_bytes;
- *out_header_len = 2 + num_bytes;
+ if (out_header_len != NULL) {
+ *out_header_len = 2 + num_bytes;
+ }
}
return CBS_get_bytes(cbs, out, len);
diff --git a/crypto/bytestring/internal.h b/crypto/bytestring/internal.h
index fd46aeb..b4ea7e5 100644
--- a/crypto/bytestring/internal.h
+++ b/crypto/bytestring/internal.h
@@ -22,15 +22,6 @@
#endif
-/* CBS_get_any_asn1_element sets |*out| to contain the next ASN.1 element from
- * |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to
- * the tag number and |*out_header_len| to the length of the ASN.1 header. If
- * the element has indefinite length then |*out| will only contain the header.
- *
- * Tag numbers greater than 31 are not supported. */
-int CBS_get_any_asn1_element(CBS *cbs, CBS *out, unsigned *out_tag,
- size_t *out_header_len);
-
/* CBS_asn1_ber_to_der reads an ASN.1 structure from |in|. If it finds
* indefinite-length elements then it attempts to convert the BER data to DER
* and sets |*out| and |*out_length| to describe a malloced buffer containing
diff --git a/include/openssl/bytestring.h b/include/openssl/bytestring.h
index a7507d8..6e18499 100644
--- a/include/openssl/bytestring.h
+++ b/include/openssl/bytestring.h
@@ -128,8 +128,6 @@
#define CBS_ASN1_CONSTRUCTED 0x20
#define CBS_ASN1_CONTEXT_SPECIFIC 0x80
-#define CBS_ASN1_ANY 0x10000
-
/* CBS_get_asn1 sets |*out| to the contents of DER-encoded, ASN.1 element (not
* including tag and length bytes) and advances |cbs| over it. The ASN.1
* element must match |tag_value|. It returns one on success and zero
@@ -142,6 +140,18 @@
* ASN.1 header bytes too. */
OPENSSL_EXPORT int CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned tag_value);
+/* CBS_get_any_asn1_element sets |*out| to contain the next ASN.1 element from
+ * |*cbs| (including header bytes) and advances |*cbs|. It sets |*out_tag| to
+ * the tag number and |*out_header_len| to the length of the ASN.1 header. If
+ * the element has indefinite length then |*out| will only contain the
+ * header. Each of |out|, |out_tag|, and |out_header_len| may be NULL to ignore
+ * the value.
+ *
+ * Tag numbers greater than 31 are not supported. */
+OPENSSL_EXPORT int CBS_get_any_asn1_element(CBS *cbs, CBS *out,
+ unsigned *out_tag,
+ size_t *out_header_len);
+
/* CBS_get_asn1_uint64 gets an ASN.1 INTEGER from |cbs| using |CBS_get_asn1|
* and sets |*out| to its value. It returns one on success and zero on error,
* where error includes the integer being negative, or too large to represent
