Rename SHA2 implementation (non-bisectable)

1 files changed, 158 insertions, 0 deletions

diff --git a/libqpdf/SHA2_native.cc b/libqpdf/SHA2_native.cc
new file mode 100644
index 00000000..17eff7e3
--- /dev/null
+++ b/libqpdf/SHA2_native.cc
@@ -0,0 +1,158 @@
+#include <qpdf/Pl_SHA2.hh>
+#include <stdexcept>
+#include <cstdio>
+#include <qpdf/PointerHolder.hh>
+#include <qpdf/QUtil.hh>
+
+Pl_SHA2::Pl_SHA2(int bits, Pipeline* next) :
+    Pipeline("sha2", next),
+    in_progress(false),
+    bits(0)
+{
+    if (bits)
+    {
+        resetBits(bits);
+    }
+}
+
+Pl_SHA2::~Pl_SHA2()
+{
+}
+
+void
+Pl_SHA2::badBits()
+{
+    throw std::logic_error("Pl_SHA2 has unexpected value for bits");
+}
+
+void
+Pl_SHA2::write(unsigned char* buf, size_t len)
+{
+    if (! this->in_progress)
+    {
+        switch (bits)
+        {
+          case 256:
+            sph_sha256_init(&this->ctx256);
+            break;
+          case 384:
+            sph_sha384_init(&this->ctx384);
+            break;
+          case 512:
+            sph_sha512_init(&this->ctx512);
+            break;
+          default:
+            badBits();
+            break;
+        }
+	this->in_progress = true;
+    }
+
+    // Write in chunks in case len is too big to fit in an int.
+    // Assume int is at least 32 bits.
+    static size_t const max_bytes = 1 << 30;
+    size_t bytes_left = len;
+    unsigned char* data = buf;
+    while (bytes_left > 0)
+    {
+	size_t bytes = (bytes_left >= max_bytes ? max_bytes : bytes_left);
+        switch (bits)
+        {
+          case 256:
+            sph_sha256(&this->ctx256, data, bytes);
+            break;
+          case 384:
+            sph_sha384(&this->ctx384, data, bytes);
+            break;
+          case 512:
+            sph_sha512(&this->ctx512, data, bytes);
+            break;
+          default:
+            badBits();
+            break;
+        }
+	bytes_left -= bytes;
+        data += bytes;
+    }
+
+    if (this->getNext(true))
+    {
+        this->getNext()->write(buf, len);
+    }
+}
+
+void
+Pl_SHA2::finish()
+{
+    if (this->getNext(true))
+    {
+        this->getNext()->finish();
+    }
+    switch (bits)
+    {
+      case 256:
+        sph_sha256_close(&this->ctx256, sha256sum);
+        break;
+      case 384:
+        sph_sha384_close(&this->ctx384, sha384sum);
+        break;
+      case 512:
+        sph_sha512_close(&this->ctx512, sha512sum);
+        break;
+      default:
+        badBits();
+        break;
+    }
+    this->in_progress = false;
+}
+
+void
+Pl_SHA2::resetBits(int bits)
+{
+    if (this->in_progress)
+    {
+	throw std::logic_error(
+	    "bit reset requested for in-progress SHA2 Pipeline");
+    }
+    if (! ((bits == 256) || (bits == 384) || (bits == 512)))
+    {
+	throw std::logic_error("Pl_SHA2 called with bits != 256, 384, or 512");
+    }
+    this->bits = bits;
+}
+
+std::string
+Pl_SHA2::getRawDigest()
+{
+    std::string result;
+    switch (bits)
+    {
+      case 256:
+        result = std::string(reinterpret_cast<char*>(this->sha256sum),
+                             sizeof(this->sha256sum));
+        break;
+      case 384:
+        result = std::string(reinterpret_cast<char*>(this->sha384sum),
+                             sizeof(this->sha384sum));
+        break;
+      case 512:
+        result = std::string(reinterpret_cast<char*>(this->sha512sum),
+                             sizeof(this->sha512sum));
+        break;
+      default:
+        badBits();
+        break;
+    }
+    return result;
+}
+
+std::string
+Pl_SHA2::getHexDigest()
+{
+    if (this->in_progress)
+    {
+	throw std::logic_error(
+	    "digest requested for in-progress SHA2 Pipeline");
+    }
+    return QUtil::hex_encode(getRawDigest());
+}