commit cbe128b3e31814db820c3cf6ec35ad1ccb57adb2
author David Benjamin <davidben@google.com> Tue Apr 21 23:05:27 2020 -0400
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> Wed Apr 22 20:15:36 2020 +0000
tree 2cbfe99c86fabfe53b4810423454cfdf2b214c02
parent 13d09f0527c25ae7c088aeb84cbf27fde09d9a8d

Check for trailing data in TRUST_TOKEN_CLIENT_finish_issuance.

Change-Id: I2dec3ca3651c81e25370dfd7d10bd27c1803cc38
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/40847
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

crypto/trust_token/trust_token.c

diff --git a/crypto/trust_token/trust_token.c b/crypto/trust_token/trust_token.c
index 9826f42..08040f5 100644
--- a/crypto/trust_token/trust_token.c
+++ b/crypto/trust_token/trust_token.c
@@ -276,6 +276,11 @@
     }
   }
 
+  if (CBS_len(&in) != 0) {
+    OPENSSL_PUT_ERROR(TRUST_TOKEN, TRUST_TOKEN_R_DECODE_FAILURE);
+    goto err;
+  }
+
   sk_PMBTOKEN_PRETOKEN_pop_free(ctx->pretokens, PMBTOKEN_PRETOKEN_free);
   ctx->pretokens = NULL;
 

crypto/trust_token/trust_token_test.cc

diff --git a/crypto/trust_token/trust_token_test.cc b/crypto/trust_token/trust_token_test.cc
index 5ab3995..ce832db 100644
--- a/crypto/trust_token/trust_token_test.cc
+++ b/crypto/trust_token/trust_token_test.cc
@@ -182,6 +182,30 @@
   ASSERT_FALSE(tokens);
 }
 
+TEST_F(TrustTokenProtocolTest, ExtraDataIssuanceResponse) {
+  ASSERT_NO_FATAL_FAILURE(SetupContexts());
+
+  uint8_t *request = NULL, *response = NULL;
+  size_t request_len, response_len;
+  ASSERT_TRUE(TRUST_TOKEN_CLIENT_begin_issuance(client.get(), &request,
+                                                &request_len, 10));
+  bssl::UniquePtr<uint8_t> free_request(request);
+  uint8_t tokens_issued;
+  ASSERT_TRUE(TRUST_TOKEN_ISSUER_issue(issuer.get(), &response, &response_len,
+                                       &tokens_issued, request, request_len,
+                                       /*public_metadata=*/KeyID(0),
+                                       /*private_metadata=*/0,
+                                       /*max_issuance=*/10));
+  bssl::UniquePtr<uint8_t> free_response(response);
+  std::vector<uint8_t> response2(response, response + response_len);
+  response2.push_back(0);
+  size_t key_index;
+  bssl::UniquePtr<STACK_OF(TRUST_TOKEN)> tokens(
+      TRUST_TOKEN_CLIENT_finish_issuance(client.get(), &key_index,
+                                         response2.data(), response2.size()));
+  ASSERT_FALSE(tokens);
+}
+
 TEST_F(TrustTokenProtocolTest, TruncatedRedemptionRequest) {
   ASSERT_NO_FATAL_FAILURE(SetupContexts());