commit 56aaf164acd67eaa3e1c21fde31e328a96f85a13
author David Benjamin <davidben@google.com> Fri Nov 24 12:36:51 2017 -0500
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> Mon Nov 27 18:38:50 2017 +0000
tree c5481b186887eccff124902d0af644c02ec268fe
parent 27bc0f26c8d132df04f5b0b173aefeb8aaa13c33

Pretty-print large INTEGERs and ENUMERATEDs in hex.

This avoids taking quadratic time to pretty-print certificates with
excessively large integer fields. Very large integers aren't any more
readable in decimal than hexadecimal anyway, and the i2s_* functions
will parse either form.

Found by libFuzzer.

Change-Id: Id586cd1b0eef8936d38ff50433ae7c819f0054f3
Reviewed-on: https://boringssl-review.googlesource.com/23424
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>

crypto/x509/x509_test.cc

diff --git a/crypto/x509/x509_test.cc b/crypto/x509/x509_test.cc
index cd4e61d..b4cecca 100644
--- a/crypto/x509/x509_test.cc
+++ b/crypto/x509/x509_test.cc
@@ -26,6 +26,7 @@
 #include <openssl/pem.h>
 #include <openssl/pool.h>
 #include <openssl/x509.h>
+#include <openssl/x509v3.h>
 
 #include "../internal.h"
 
@@ -996,3 +997,41 @@
               std::string(reinterpret_cast<const char *>(contents), len));
   }
 }
+
+TEST(X509Test, PrettyPrintIntegers) {
+  static const char *kTests[] = {
+      // Small numbers are pretty-printed in decimal.
+      "0",
+      "-1",
+      "1",
+      "42",
+      "-42",
+      "256",
+      "-256",
+      // Large numbers are pretty-printed in hex to avoid taking quadratic time.
+      "0x0123456789",
+      "-0x0123456789",
+  };
+  for (const char *in : kTests) {
+    SCOPED_TRACE(in);
+    BIGNUM *bn = nullptr;
+    ASSERT_TRUE(BN_asc2bn(&bn, in));
+    bssl::UniquePtr<BIGNUM> free_bn(bn);
+
+    {
+      bssl::UniquePtr<ASN1_INTEGER> asn1(BN_to_ASN1_INTEGER(bn, nullptr));
+      ASSERT_TRUE(asn1);
+      bssl::UniquePtr<char> out(i2s_ASN1_INTEGER(nullptr, asn1.get()));
+      ASSERT_TRUE(out.get());
+      EXPECT_STREQ(in, out.get());
+    }
+
+    {
+      bssl::UniquePtr<ASN1_ENUMERATED> asn1(BN_to_ASN1_ENUMERATED(bn, nullptr));
+      ASSERT_TRUE(asn1);
+      bssl::UniquePtr<char> out(i2s_ASN1_ENUMERATED(nullptr, asn1.get()));
+      ASSERT_TRUE(out.get());
+      EXPECT_STREQ(in, out.get());
+    }
+  }
+}