xnu-2782.1.97.tar.gz

[apple/xnu.git] / osfmk / corecrypto / ccdigest / src / ccdigest_update.c

diff --git a/osfmk/corecrypto/ccdigest/src/ccdigest_update.c b/osfmk/corecrypto/ccdigest/src/ccdigest_update.c
new file mode 100644 (file)
index 0000000..1f8b9e5
--- /dev/null
+++ b/osfmk/corecrypto/ccdigest/src/ccdigest_update.c
@@ -0,0 +1,40 @@
+/*
+ *  ccdigest_update.c
+ *  corecrypto
+ *
+ *  Created by Michael Brouwer on 11/30/10.
+ *  Copyright 2010,2011 Apple Inc. All rights reserved.
+ *
+ */
+
+#include <corecrypto/ccdigest.h>
+#include <corecrypto/cc_priv.h>
+
+void ccdigest_update(const struct ccdigest_info *di, ccdigest_ctx_t ctx,
+                     unsigned long len, const void *data) {
+    char * data_ptr = (char *) data;
+    while (len > 0) {
+        if (ccdigest_num(di, ctx) == 0 && len > di->block_size) {
+            unsigned long nblocks = len / di->block_size;
+            di->compress(ccdigest_state(di, ctx), nblocks, data_ptr);
+            unsigned long nbytes = nblocks * di->block_size;
+            len -= nbytes;
+            data_ptr += nbytes;
+            ccdigest_nbits(di, ctx) += nbytes * 8;
+        } else {
+            unsigned long n = di->block_size - ccdigest_num(di, ctx);
+            if (len < n)
+                n = len;
+            CC_MEMCPY(ccdigest_data(di, ctx) + ccdigest_num(di, ctx), data_ptr, n);
+            /* typecast: less than block size, will always fit into an int */
+            ccdigest_num(di, ctx) += (unsigned int)n;
+            len -= n;
+            data_ptr += n;
+            if (ccdigest_num(di, ctx) == di->block_size) {
+                di->compress(ccdigest_state(di, ctx), 1, ccdigest_data(di, ctx));
+                ccdigest_nbits(di, ctx) += ccdigest_num(di, ctx) * 8;
+                ccdigest_num(di, ctx) = 0;
+            }
+        }
+    }
+}