Add CBB_add_asn1_[u]int64_with_tag.
CBB_add_asn1_uint64 doesn't work if you're encoding an implicitly-tagged
INTEGER. Take a leaf from Go cryptobyte and add a "with tag" variant,
rather than a "contents" variant, which is a little more convenient to
use. It also avoids us having to decide how to name the contents field.
Change-Id: I6072e55017230c513577c44c5a7ed86e778255b3
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/54685
Reviewed-by: Bob Beck <bbe@google.com>
Commit-Queue: Bob Beck <bbe@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Auto-Submit: David Benjamin <davidben@google.com>
diff --git a/crypto/bytestring/bytestring_test.cc b/crypto/bytestring/bytestring_test.cc
index b6b716e..27aae79 100644
--- a/crypto/bytestring/bytestring_test.cc
+++ b/crypto/bytestring/bytestring_test.cc
@@ -862,12 +862,28 @@
EXPECT_EQ(0, is_negative);
EXPECT_TRUE(CBS_is_unsigned_asn1_integer(&child));
- bssl::ScopedCBB cbb;
- ASSERT_TRUE(CBB_init(cbb.get(), 0));
- ASSERT_TRUE(CBB_add_asn1_uint64(cbb.get(), test.value));
- ASSERT_TRUE(CBB_finish(cbb.get(), &out, &len));
- bssl::UniquePtr<uint8_t> scoper(out);
- EXPECT_EQ(Bytes(test.encoding, test.encoding_len), Bytes(out, len));
+ {
+ bssl::ScopedCBB cbb;
+ ASSERT_TRUE(CBB_init(cbb.get(), 0));
+ ASSERT_TRUE(CBB_add_asn1_uint64(cbb.get(), test.value));
+ ASSERT_TRUE(CBB_finish(cbb.get(), &out, &len));
+ bssl::UniquePtr<uint8_t> scoper(out);
+ EXPECT_EQ(Bytes(test.encoding, test.encoding_len), Bytes(out, len));
+ }
+
+ {
+ // Overwrite the tag.
+ bssl::ScopedCBB cbb;
+ ASSERT_TRUE(CBB_init(cbb.get(), 0));
+ ASSERT_TRUE(CBB_add_asn1_uint64_with_tag(cbb.get(), test.value,
+ CBS_ASN1_CONTEXT_SPECIFIC | 1));
+ ASSERT_TRUE(CBB_finish(cbb.get(), &out, &len));
+ bssl::UniquePtr<uint8_t> scoper(out);
+ std::vector<uint8_t> expected(test.encoding,
+ test.encoding + test.encoding_len);
+ expected[0] = 0x81;
+ EXPECT_EQ(Bytes(expected), Bytes(out, len));
+ }
}
for (const ASN1InvalidUint64Test &test : kASN1InvalidUint64Tests) {
@@ -952,12 +968,28 @@
EXPECT_EQ(test.value < 0, !!is_negative);
EXPECT_EQ(test.value >= 0, !!CBS_is_unsigned_asn1_integer(&child));
- bssl::ScopedCBB cbb;
- ASSERT_TRUE(CBB_init(cbb.get(), 0));
- ASSERT_TRUE(CBB_add_asn1_int64(cbb.get(), test.value));
- ASSERT_TRUE(CBB_finish(cbb.get(), &out, &len));
- bssl::UniquePtr<uint8_t> scoper(out);
- EXPECT_EQ(Bytes(test.encoding, test.encoding_len), Bytes(out, len));
+ {
+ bssl::ScopedCBB cbb;
+ ASSERT_TRUE(CBB_init(cbb.get(), 0));
+ ASSERT_TRUE(CBB_add_asn1_int64(cbb.get(), test.value));
+ ASSERT_TRUE(CBB_finish(cbb.get(), &out, &len));
+ bssl::UniquePtr<uint8_t> scoper(out);
+ EXPECT_EQ(Bytes(test.encoding, test.encoding_len), Bytes(out, len));
+ }
+
+ {
+ // Overwrite the tag.
+ bssl::ScopedCBB cbb;
+ ASSERT_TRUE(CBB_init(cbb.get(), 0));
+ ASSERT_TRUE(CBB_add_asn1_int64_with_tag(cbb.get(), test.value,
+ CBS_ASN1_CONTEXT_SPECIFIC | 1));
+ ASSERT_TRUE(CBB_finish(cbb.get(), &out, &len));
+ bssl::UniquePtr<uint8_t> scoper(out);
+ std::vector<uint8_t> expected(test.encoding,
+ test.encoding + test.encoding_len);
+ expected[0] = 0x81;
+ EXPECT_EQ(Bytes(expected), Bytes(out, len));
+ }
}
for (const ASN1InvalidInt64Test &test : kASN1InvalidInt64Tests) {
diff --git a/crypto/bytestring/cbb.c b/crypto/bytestring/cbb.c
index 6ce20ad..100c713 100644
--- a/crypto/bytestring/cbb.c
+++ b/crypto/bytestring/cbb.c
@@ -503,13 +503,16 @@
}
int CBB_add_asn1_uint64(CBB *cbb, uint64_t value) {
- CBB child;
- int started = 0;
+ return CBB_add_asn1_uint64_with_tag(cbb, value, CBS_ASN1_INTEGER);
+}
- if (!CBB_add_asn1(cbb, &child, CBS_ASN1_INTEGER)) {
+int CBB_add_asn1_uint64_with_tag(CBB *cbb, uint64_t value, unsigned tag) {
+ CBB child;
+ if (!CBB_add_asn1(cbb, &child, tag)) {
return 0;
}
+ int started = 0;
for (size_t i = 0; i < 8; i++) {
uint8_t byte = (value >> 8*(7-i)) & 0xff;
if (!started) {
@@ -538,8 +541,12 @@
}
int CBB_add_asn1_int64(CBB *cbb, int64_t value) {
+ return CBB_add_asn1_int64_with_tag(cbb, value, CBS_ASN1_INTEGER);
+}
+
+int CBB_add_asn1_int64_with_tag(CBB *cbb, int64_t value, unsigned tag) {
if (value >= 0) {
- return CBB_add_asn1_uint64(cbb, value);
+ return CBB_add_asn1_uint64_with_tag(cbb, (uint64_t)value, tag);
}
uint8_t bytes[sizeof(int64_t)];
@@ -551,7 +558,7 @@
}
CBB child;
- if (!CBB_add_asn1(cbb, &child, CBS_ASN1_INTEGER)) {
+ if (!CBB_add_asn1(cbb, &child, tag)) {
return 0;
}
for (int i = start; i >= 0; i--) {
diff --git a/include/openssl/bytestring.h b/include/openssl/bytestring.h
index 1d47f60..33a417c 100644
--- a/include/openssl/bytestring.h
+++ b/include/openssl/bytestring.h
@@ -557,11 +557,23 @@
// error.
OPENSSL_EXPORT int CBB_add_asn1_uint64(CBB *cbb, uint64_t value);
+// CBB_add_asn1_uint64_with_tag behaves like |CBB_add_asn1_uint64| but uses
+// |tag| as the tag instead of INTEGER. This is useful if the INTEGER type uses
+// implicit tagging.
+OPENSSL_EXPORT int CBB_add_asn1_uint64_with_tag(CBB *cbb, uint64_t value,
+ unsigned tag);
+
// CBB_add_asn1_int64 writes an ASN.1 INTEGER into |cbb| using |CBB_add_asn1|
// and writes |value| in its contents. It returns one on success and zero on
// error.
OPENSSL_EXPORT int CBB_add_asn1_int64(CBB *cbb, int64_t value);
+// CBB_add_asn1_int64_with_tag behaves like |CBB_add_asn1_int64| but uses |tag|
+// as the tag instead of INTEGER. This is useful if the INTEGER type uses
+// implicit tagging.
+OPENSSL_EXPORT int CBB_add_asn1_int64_with_tag(CBB *cbb, int64_t value,
+ unsigned tag);
+
// CBB_add_asn1_octet_string writes an ASN.1 OCTET STRING into |cbb| with the
// given contents. It returns one on success and zero on error.
OPENSSL_EXPORT int CBB_add_asn1_octet_string(CBB *cbb, const uint8_t *data,
