Merge #17511: Add bounds checks before base58 decoding

5909bcd3bf3c3502355e89fd0b76bb8e93d8a95b Add bounds checks in key_io before DecodeBase58Check (Pieter Wuille)
2bcf1fc444d5c4b8efa879e54e7b6134b7e6b986 Pass a maximum output length to DecodeBase58 and DecodeBase58Check (Pieter Wuille)

Pull request description:

  Fixes #17501.

ACKs for top commit:
  laanwj:
    code review ACK 5909bcd3bf3c3502355e89fd0b76bb8e93d8a95b
  practicalswift:
    ACK 5909bcd3bf3c3502355e89fd0b76bb8e93d8a95b -- code looks correct

Tree-SHA512: 4807f4a9508dee9c0f1ad63f56f70f4ec4e6b7e35eb91322a525e3da3828521a41de9b8338a6bf67250803660b480d95fd02ce6b2fe79c4c88bc19b54f9d8889

1 files changed, 21 insertions, 4 deletions

diff --git a/src/test/base58_tests.cpp b/src/test/base58_tests.cpp
index 52301f799a..96fdf8c86d 100644
--- a/src/test/base58_tests.cpp
+++ b/src/test/base58_tests.cpp
@@ -7,6 +7,7 @@
 #include <base58.h>
 #include <test/util/setup_common.h>
 #include <util/strencodings.h>
+#include <util/vector.h>
 
 #include <univalue.h>
 
@@ -53,17 +54,33 @@ BOOST_AUTO_TEST_CASE(base58_DecodeBase58)
         }
         std::vector<unsigned char> expected = ParseHex(test[0].get_str());
         std::string base58string = test[1].get_str();
-        BOOST_CHECK_MESSAGE(DecodeBase58(base58string, result), strTest);
+        BOOST_CHECK_MESSAGE(DecodeBase58(base58string, result, 256), strTest);
         BOOST_CHECK_MESSAGE(result.size() == expected.size() && std::equal(result.begin(), result.end(), expected.begin()), strTest);
     }
 
-    BOOST_CHECK(!DecodeBase58("invalid", result));
+    BOOST_CHECK(!DecodeBase58("invalid", result, 100));
 
     // check that DecodeBase58 skips whitespace, but still fails with unexpected non-whitespace at the end.
-    BOOST_CHECK(!DecodeBase58(" \t\n\v\f\r skip \r\f\v\n\t a", result));
-    BOOST_CHECK( DecodeBase58(" \t\n\v\f\r skip \r\f\v\n\t ", result));
+    BOOST_CHECK(!DecodeBase58(" \t\n\v\f\r skip \r\f\v\n\t a", result, 3));
+    BOOST_CHECK( DecodeBase58(" \t\n\v\f\r skip \r\f\v\n\t ", result, 3));
     std::vector<unsigned char> expected = ParseHex("971a55");
     BOOST_CHECK_EQUAL_COLLECTIONS(result.begin(), result.end(), expected.begin(), expected.end());
 }
 
+BOOST_AUTO_TEST_CASE(base58_random_encode_decode)
+{
+    for (int n = 0; n < 1000; ++n) {
+        unsigned int len = 1 + InsecureRandBits(8);
+        unsigned int zeroes = InsecureRandBool() ? InsecureRandRange(len + 1) : 0;
+        auto data = Cat(std::vector<unsigned char>(zeroes, '\000'), g_insecure_rand_ctx.randbytes(len - zeroes));
+        auto encoded = EncodeBase58Check(data);
+        std::vector<unsigned char> decoded;
+        auto ok_too_small = DecodeBase58Check(encoded, decoded, InsecureRandRange(len));
+        BOOST_CHECK(!ok_too_small);
+        auto ok = DecodeBase58Check(encoded, decoded, len + InsecureRandRange(257 - len));
+        BOOST_CHECK(ok);
+        BOOST_CHECK(data == decoded);
+    }
+}
+
 BOOST_AUTO_TEST_SUITE_END()