Security-57031.1.35.tar.gz

[apple/security.git] / Security / libsecurity_cryptkit / lib / giantPort_Generic.h

diff --git a/Security/libsecurity_cryptkit/lib/giantPort_Generic.h b/Security/libsecurity_cryptkit/lib/giantPort_Generic.h
new file mode 100644 (file)
index 0000000..7062b40
--- /dev/null
+++ b/Security/libsecurity_cryptkit/lib/giantPort_Generic.h
@@ -0,0 +1,165 @@
+/* Copyright (c) 1998,2011,2014 Apple Inc.  All Rights Reserved.
+ *
+ * NOTICE: USE OF THE MATERIALS ACCOMPANYING THIS NOTICE IS SUBJECT
+ * TO THE TERMS OF THE SIGNED "FAST ELLIPTIC ENCRYPTION (FEE) REFERENCE
+ * SOURCE CODE EVALUATION AGREEMENT" BETWEEN APPLE, INC. AND THE
+ * ORIGINAL LICENSEE THAT OBTAINED THESE MATERIALS FROM APPLE,
+ * INC.  ANY USE OF THESE MATERIALS NOT PERMITTED BY SUCH AGREEMENT WILL
+ * EXPOSE YOU TO LIABILITY.
+ ***************************************************************************
+ *
+ * giantPort_Generic.h - Generic giant definitions routines, used when
+ *                      no platform-specific version is available.
+ *
+ * Revision History
+ * ----------------
+ * 06 Apr 1998 at Apple
+ *     Created.
+ */
+
+#ifndef        _CK_NSGIANT_PORT_GENERIC_H_
+#define _CK_NSGIANT_PORT_GENERIC_H_
+
+#include "feeDebug.h"
+#include "platform.h"
+#include "giantIntegers.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * We'll be using the compiler's 64-bit long long for these routines.
+ *
+ * Mask for upper word.
+ */
+#define GIANT_UPPER_DIGIT_MASK (~(unsigned long long(GIANT_DIGIT_MASK)))
+
+/*
+ * Multiple-precision arithmetic routines/macros.
+ */
+
+/*
+ * Add two digits, return sum. Carry bit returned as an out parameter.
+ * This should work any size giantDigits up to unsigned int.
+ */
+static inline giantDigit giantAddDigits(
+       giantDigit dig1,
+       giantDigit dig2,
+       giantDigit *carry)                      /* RETURNED, 0 or 1 */
+{
+       giantDigit sum = dig1 + dig2;
+
+       if((sum < dig1) || (sum < dig2)) {
+               *carry = 1;
+       }
+       else {
+               *carry = 0;
+       }
+       return sum & GIANT_DIGIT_MASK;
+}
+
+/*
+ * Add a single digit value to a double digit accumulator in place.
+ * Carry out of the MSD of the accumulator is not handled.
+ * This should work any size giantDigits up to unsigned int.
+ */
+static inline void giantAddDouble(
+       giantDigit *accLow,                     /* IN/OUT */
+       giantDigit *accHigh,                    /* IN/OUT */
+       giantDigit val)
+{
+       giantDigit sumLo = *accLow + val;
+
+       if((sumLo < *accLow) || (sumLo < val)) {
+           (*accHigh)++;
+           #if FEE_DEBUG
+           if(*accHigh == 0) {
+               CKRaise("giantAddDouble overflow");
+           }
+           #endif      /* FEE_DEBUG */
+       }
+       *accLow = sumLo;
+}
+
+/*
+ * Subtract a - b, return difference. Borrow bit returned as an out parameter.
+ * This should work any size giantDigits up to unsigned int.
+ */
+static inline giantDigit giantSubDigits(
+       giantDigit a,
+       giantDigit b,
+       giantDigit *borrow)                     /* RETURNED, 0 or 1 */
+{
+       giantDigit diff = a - b;
+
+       if(a < b) {
+               *borrow = 1;
+       }
+       else {
+               *borrow = 0;
+       }
+       return diff;
+}
+
+/*
+ * Multiply two digits, return two digits.
+ * This should work for 16 or 32 bit giantDigits, though it's kind of
+ * inefficient for 16 bits.
+ */
+static inline void giantMulDigits(
+       giantDigit      dig1,
+       giantDigit      dig2,
+       giantDigit      *lowProduct,            /* RETURNED, low digit */
+       giantDigit      *hiProduct)             /* RETURNED, high digit */
+{
+       unsigned long long dprod;
+
+       dprod = (unsigned long long)dig1 * (unsigned long long)dig2;
+       *hiProduct = (giantDigit)(dprod >> GIANT_BITS_PER_DIGIT);
+       *lowProduct = (giantDigit)dprod;
+}
+
+/*
+ * Multiply a vector of giantDigits, candVector, by a single giantDigit,
+ * plierDigit, adding results into prodVector. Returns m.s. digit from
+ * final multiply; only candLength digits of *prodVector will be written.
+ */
+static inline giantDigit VectorMultiply(
+       giantDigit plierDigit,
+       giantDigit *candVector,
+       unsigned candLength,
+       giantDigit *prodVector)
+{
+       unsigned candDex;               // index into multiplicandVector
+       giantDigit lastCarry = 0;
+       giantDigit prodLo;
+       giantDigit prodHi;
+
+       for(candDex=0; candDex<candLength; ++candDex) {
+           /*
+            * prod = *(candVector++) * plierDigit + *prodVector + lastCarry
+            */
+           giantMulDigits(*(candVector++),
+               plierDigit,
+               &prodLo,
+               &prodHi);
+           giantAddDouble(&prodLo, &prodHi, *prodVector);
+           giantAddDouble(&prodLo, &prodHi, lastCarry);
+
+           /*
+            * *(destptr++) = prodHi;
+            * lastCarry = prodLo;
+            */
+           *(prodVector++) = prodLo;
+           lastCarry = prodHi;
+       }
+
+       return lastCarry;
+}
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#endif /*_CK_NSGIANT_PORT_GENERIC_H_*/