Implement CUP signing in UpdateClient.
BUG=583027
Review URL: https://codereview.chromium.org/1685323002
Cr-Commit-Position: refs/heads/master@{#375930}
diff --git a/components/update_client/client_update_protocol_ecdsa.cc b/components/update_client/client_update_protocol_ecdsa.cc
index 499ece73..8479ceb 100644
--- a/components/update_client/client_update_protocol_ecdsa.cc
+++ b/components/update_client/client_update_protocol_ecdsa.cc
@@ -5,6 +5,7 @@
#include "components/update_client/client_update_protocol_ecdsa.h"
#include "base/logging.h"
+#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_piece.h"
@@ -14,6 +15,8 @@
#include "crypto/sha2.h"
#include "crypto/signature_verifier.h"
+namespace update_client {
+
namespace {
// This is the algorithm ID for ECDSA with SHA-256. Parameters are ABSENT.
@@ -46,7 +49,7 @@
reinterpret_cast<const char*>(&vec.front()), vec.size()));
}
-bool ParseETagHeader(const base::StringPiece& etag_header_value,
+bool ParseETagHeader(const base::StringPiece& etag_header_value_in,
std::vector<uint8_t>* ecdsa_signature_out,
std::vector<uint8_t>* request_hash_out) {
DCHECK(ecdsa_signature_out);
@@ -55,6 +58,20 @@
// The ETag value is a UTF-8 string, formatted as "S:H", where:
// * S is the ECDSA signature in DER-encoded ASN.1 form, converted to hex.
// * H is the SHA-256 hash of the observed request body, standard hex format.
+ // A Weak ETag is formatted as W/"S:H". This function treats it the same as a
+ // strong ETag.
+ base::StringPiece etag_header_value(etag_header_value_in);
+
+ // Remove the weak prefix, then remove the begin and the end quotes.
+ const char kWeakETagPrefix[] = "W/";
+ if (etag_header_value.starts_with(kWeakETagPrefix))
+ etag_header_value.remove_prefix(arraysize(kWeakETagPrefix) - 1);
+ if (etag_header_value.size() >= 2 && etag_header_value.starts_with("\"") &&
+ etag_header_value.ends_with("\"")) {
+ etag_header_value.remove_prefix(1);
+ etag_header_value.remove_suffix(1);
+ }
+
const base::StringPiece::size_type delim_pos = etag_header_value.find(':');
if (delim_pos == base::StringPiece::npos || delim_pos == 0 ||
delim_pos == etag_header_value.size() - 1)
@@ -188,3 +205,5 @@
static_cast<int>(signed_message_hash.size()));
return verifier.VerifyFinal();
}
+
+} // namespace update_client
