Report decryption error instead of zlib/tar error if stream is corrupted

Signed-off-by: Lauris Kaplinski <lauris@raulwalter.com>

Author: Lauris Kaplinski

cdoc/CDoc2Reader.cpp

@@ -87,6 +87,20 @@ struct CDoc2Reader::Private {
     std::unique_ptr<libcdoc::DecryptionSource> dec;
     std::unique_ptr<libcdoc::ZSource> zsrc;
     std::unique_ptr<libcdoc::TarSource> tar;
+
+    result_t decryptAllAndClose() {
+        std::array<uint8_t, 1024> buf;
+        result_t rv = dec->read(buf.data(), buf.size());
+        while (rv == buf.size()) {
+            rv = dec->read(buf.data(), buf.size());
+        }
+        if (rv < 0) return rv;
+        zsrc.reset();
+        tar.reset();
+        rv = dec->close();
+        dec.reset();
+        return rv;
+    }
 };
 
 CDoc2Reader::~CDoc2Reader()
@@ -418,8 +432,13 @@ CDoc2Reader::nextFile(std::string& name, int64_t& size)
         LOG_ERROR("{}", last_error);
             return libcdoc::WORKFLOW_ERROR;
         }
-        result_t result = priv->tar->next(name, size);
-    if (result != OK) {
+    result_t result = priv->tar->next(name, size);
+    if (result < 0) {
+        result_t sr = priv->decryptAllAndClose();
+        if (sr != OK) {
+            setLastError("Crypto payload integrity check failed");
+            return sr;
+        }
         setLastError(priv->tar->getLastErrorStr(result));
     }
     return result;
@@ -434,7 +453,12 @@ CDoc2Reader::readData(uint8_t *dst, size_t size)
         return libcdoc::WORKFLOW_ERROR;
     }
     result_t result = priv->tar->read(dst, size);
-    if (result != OK) {
+    if (result < 0) {
+        result_t sr = priv->decryptAllAndClose();
+        if (sr != OK) {
+            setLastError("Crypto payload integrity check failed");
+            return sr;
+        }
         setLastError(priv->tar->getLastErrorStr(result));
     }
     return result;
@@ -443,11 +467,15 @@ CDoc2Reader::readData(uint8_t *dst, size_t size)
 libcdoc::result_t
 CDoc2Reader::finishDecryption()
 {
+    if (!priv->tar) {
+        setLastError("finishDecryption() called before beginDecryption()");
+        LOG_ERROR("{}", last_error);
+        return libcdoc::WORKFLOW_ERROR;
+    }
     if (!priv->zsrc->isEof()) {
         setLastError(t_("CDoc contains additional payload data that is not part of content"));
         LOG_WARN("{}", last_error);
     }
-
     setLastError({});
     priv->zsrc.reset();
     priv->tar.reset();

test/libcdoc_boost.cpp

@@ -499,16 +499,16 @@ BOOST_FIXTURE_TEST_CASE_WITH_DECOR(CDoc2DecryptErrors, DecryptFixture,
     BOOST_TEST(rdr->getFMK(fmk, 0) == libcdoc::OK);
     BOOST_TEST(rdr->beginDecryption(fmk) == libcdoc::OK);
     libcdoc::result_t rv = rdr->nextFile(fi);
-    BOOST_TEST(((rv == libcdoc::OK) || (rv == libcdoc::ZLIB_ERROR)));
+    BOOST_TEST(((rv == libcdoc::OK) || (rv == libcdoc::CRYPTO_ERROR)));
     for (int i = 0; i < 4; i++) {
         rv = rdr->readData(buf, 256);
-        BOOST_TEST(((rv == 256) || (rv == libcdoc::ZLIB_ERROR)));
+        BOOST_TEST(((rv == 256) || (rv == libcdoc::CRYPTO_ERROR)));
     }
     rv = rdr->nextFile(fi);
-    BOOST_TEST(((rv == libcdoc::OK) || (rv == libcdoc::ZLIB_ERROR)));
+    BOOST_TEST(((rv == libcdoc::OK) || (rv == libcdoc::CRYPTO_ERROR)));
     rv = rdr->readData(buf, 256);
-    BOOST_TEST(((rv == 255) || (rv == libcdoc::ZLIB_ERROR)));
-    BOOST_TEST(rdr->finishDecryption() == libcdoc::CRYPTO_ERROR);
+    BOOST_TEST(((rv == 255) || (rv == libcdoc::CRYPTO_ERROR)));
+    BOOST_TEST(rdr->finishDecryption() == libcdoc::WORKFLOW_ERROR);
     delete rdr;
 }
 BOOST_AUTO_TEST_SUITE_END()