1 files changed, 49 insertions, 0 deletions
diff --git a/security/nss/lib/softoken/padbuf.c b/security/nss/lib/softoken/padbuf.c
new file mode 100644
index 0000000000..6e897f2131
--- /dev/null
+++ b/security/nss/lib/softoken/padbuf.c
@@ -0,0 +1,49 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "blapit.h"
+#include "secport.h"
+#include "secerr.h"
+
+/*
+ * Prepare a buffer for any padded CBC encryption algorithm, growing to the
+ * appropriate boundary and filling with the appropriate padding.
+ * blockSize must be a power of 2.
+ *
+ * NOTE: If arena is non-NULL, we re-allocate from there, otherwise
+ * we assume (and use) XP memory (re)allocation.
+ */
+unsigned char *
+CBC_PadBuffer(PLArenaPool *arena, unsigned char *inbuf, unsigned int inlen,
+              unsigned int *outlen, int blockSize)
+{
+    unsigned char *outbuf;
+    unsigned int des_len;
+    unsigned int i;
+    unsigned char des_pad_len;
+
+    /*
+     * We need from 1 to blockSize bytes -- we *always* grow.
+     * The extra bytes contain the value of the length of the padding:
+     * if we have 2 bytes of padding, then the padding is "0x02, 0x02".
+     */
+    des_len = (inlen + blockSize) & ~(blockSize - 1);
+
+    if (arena != NULL) {
+        outbuf = (unsigned char *)PORT_ArenaGrow(arena, inbuf, inlen, des_len);
+    } else {
+        outbuf = (unsigned char *)PORT_Realloc(inbuf, des_len);
+    }
+
+    if (outbuf == NULL) {
+        PORT_SetError(SEC_ERROR_NO_MEMORY);
+        return NULL;
+    }
+
+    des_pad_len = des_len - inlen;
+    for (i = inlen; i < des_len; i++)
+        outbuf[i] = des_pad_len;
+
+    *outlen = des_len;
+    return outbuf;
+}