MD5: switch to pluggable crypto

1 files changed, 163 insertions, 0 deletions

diff --git a/libqpdf/MD5.cc b/libqpdf/MD5.cc
new file mode 100644
index 00000000..95edd3a4
--- /dev/null
+++ b/libqpdf/MD5.cc
@@ -0,0 +1,163 @@
+#include <qpdf/MD5.hh>
+#include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
+#include <qpdf/QPDFCryptoProvider.hh>
+
+#include <stdio.h>
+#include <memory.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+MD5::MD5()
+{
+    init();
+}
+
+void
+MD5::init()
+{
+    this->crypto = QPDFCryptoProvider::getImpl();
+    this->crypto->MD5_init();
+}
+
+void
+MD5::finalize()
+{
+    this->crypto->MD5_finalize();
+}
+
+void MD5::reset()
+{
+    init();
+}
+
+void MD5::encodeString(char const* str)
+{
+    size_t len = strlen(str);
+    crypto->MD5_init();
+    encodeDataIncrementally(str, len);
+    crypto->MD5_finalize();
+}
+
+void MD5::appendString(char const* input_string)
+{
+    encodeDataIncrementally(input_string, strlen(input_string));
+}
+
+void MD5::encodeDataIncrementally(char const* data, size_t len)
+{
+    this->crypto->MD5_update(QUtil::unsigned_char_pointer(data), len);
+}
+
+void MD5::encodeFile(char const *filename, qpdf_offset_t up_to_offset)
+{
+    char buffer[1024];
+
+    FILE *file = QUtil::safe_fopen(filename, "rb");
+    size_t len;
+    size_t so_far = 0;
+    size_t to_try = 1024;
+    size_t up_to_size = 0;
+    if (up_to_offset >= 0)
+    {
+        up_to_size = QIntC::to_size(up_to_offset);
+    }
+    do
+    {
+	if ((up_to_offset >= 0) && ((so_far + to_try) > up_to_size))
+	{
+	    to_try = up_to_size - so_far;
+	}
+	len = fread(buffer, 1, to_try, file);
+	if (len > 0)
+	{
+	    encodeDataIncrementally(buffer, len);
+	    so_far += len;
+	    if ((up_to_offset >= 0) && (so_far >= up_to_size))
+	    {
+		break;
+	    }
+	}
+    } while (len > 0);
+    if (ferror(file))
+    {
+	// Assume, perhaps incorrectly, that errno was set by the
+	// underlying call to read....
+	(void) fclose(file);
+	QUtil::throw_system_error(
+	    std::string("MD5: read error on ") + filename);
+    }
+    (void) fclose(file);
+
+    this->crypto->MD5_finalize();
+}
+
+void MD5::digest(Digest result)
+{
+    this->crypto->MD5_finalize();
+    this->crypto->MD5_digest(result);
+}
+
+void MD5::print()
+{
+    Digest digest_val;
+    digest(digest_val);
+
+    unsigned int i;
+    for (i = 0; i < 16; ++i)
+    {
+	printf("%02x", digest_val[i]);
+    }
+    printf("\n");
+}
+
+std::string MD5::unparse()
+{
+    this->crypto->MD5_finalize();
+    Digest digest_val;
+    digest(digest_val);
+    return QUtil::hex_encode(
+        std::string(reinterpret_cast<char*>(digest_val), 16));
+}
+
+std::string
+MD5::getDataChecksum(char const* buf, size_t len)
+{
+    MD5 m;
+    m.encodeDataIncrementally(buf, len);
+    return m.unparse();
+}
+
+std::string
+MD5::getFileChecksum(char const* filename, qpdf_offset_t up_to_offset)
+{
+    MD5 m;
+    m.encodeFile(filename, up_to_offset);
+    return m.unparse();
+}
+
+bool
+MD5::checkDataChecksum(char const* const checksum,
+		       char const* buf, size_t len)
+{
+    std::string actual_checksum = getDataChecksum(buf, len);
+    return (checksum == actual_checksum);
+}
+
+bool
+MD5::checkFileChecksum(char const* const checksum,
+		       char const* filename, qpdf_offset_t up_to_offset)
+{
+    bool result = false;
+    try
+    {
+	std::string actual_checksum = getFileChecksum(filename, up_to_offset);
+	result = (checksum == actual_checksum);
+    }
+    catch (std::runtime_error const&)
+    {
+	// Ignore -- return false
+    }
+    return result;
+}