Merge #17721: util: Don't allow Base58 decoding of non-Base58 strings. Add Base58 tests.

d945c6f5e6f61b6e289ac7da6834c18f1b677b0f util: Don't allow base58-decoding of std::string:s containing non-base58 characters (practicalswift)
ff7a9992263f5a19f73097c86068b6150d213c23 tests: Add tests for base58-decoding of std::string:s containing non-base58 characters (practicalswift)

Pull request description:

  Don't allow Base58 decoding of non-Base58 strings. Add Base58 tests.

  Fixes #17718.

  Added tests before the Base58 decoding patch:

  ```
  $ make check
  …
  test/base58_tests.cpp(62): error: in "base58_tests/base58_DecodeBase58":
      check !DecodeBase58(std::string("\0invalid", 8), result) has failed
  test/base58_tests.cpp(67): error: in "base58_tests/base58_DecodeBase58":
      check !DecodeBase58(std::string("good\0bad0IOl", 12), result) has failed
  test/base58_tests.cpp(76): error: in "base58_tests/base58_DecodeBase58":
      check !DecodeBase58Check(std::string("3vQB7B6MrGQZaxCuFg4oh\00IOl", 26), result) has failed
  *** 3 failures are detected in the test module "Bitcoin Core Test Suite"
  …
  $ echo $?
  1
  ```

  Added tests before the Base58 decoding patch:

  ```
  $ make check
  …
  OK
  …
  $ echo $?
  0
  ```

ACKs for top commit:
  MarcoFalke:
    ACK d945c6f5e6f61b6e289ac7da6834c18f1b677b0f 🚓
  laanwj:
    ACK d945c6f5e6f61b6e289ac7da6834c18f1b677b0f

Tree-SHA512: 78fee3a18718c9cfbf2e4b26daaf8f24b4deca00475b7b254fec7f8be740f8898c696d9cd0eaa7c50bca55909b9dff3b516b6fe4db92dc132dcc0a1c5e3d61af

1 files changed, 12 insertions, 0 deletions

diff --git a/src/test/base58_tests.cpp b/src/test/base58_tests.cpp
index 96fdf8c86..57559fa68 100644
--- a/src/test/base58_tests.cpp
+++ b/src/test/base58_tests.cpp
@@ -59,12 +59,24 @@ BOOST_AUTO_TEST_CASE(base58_DecodeBase58)
     }
 
     BOOST_CHECK(!DecodeBase58("invalid", result, 100));
+    BOOST_CHECK(!DecodeBase58(std::string("invalid"), result, 100));
+    BOOST_CHECK(!DecodeBase58(std::string("\0invalid", 8), result, 100));
+
+    BOOST_CHECK(DecodeBase58(std::string("good", 4), result, 100));
+    BOOST_CHECK(!DecodeBase58(std::string("bad0IOl", 7), result, 100));
+    BOOST_CHECK(!DecodeBase58(std::string("goodbad0IOl", 11), result, 100));
+    BOOST_CHECK(!DecodeBase58(std::string("good\0bad0IOl", 12), 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, 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_CHECK(DecodeBase58Check(std::string("3vQB7B6MrGQZaxCuFg4oh", 21), result, 100));
+    BOOST_CHECK(!DecodeBase58Check(std::string("3vQB7B6MrGQZaxCuFg4oi", 21), result, 100));
+    BOOST_CHECK(!DecodeBase58Check(std::string("3vQB7B6MrGQZaxCuFg4oh0IOl", 25), result, 100));
+    BOOST_CHECK(!DecodeBase58Check(std::string("3vQB7B6MrGQZaxCuFg4oh\00IOl", 26), result, 100));
 }
 
 BOOST_AUTO_TEST_CASE(base58_random_encode_decode)