diff options
Diffstat (limited to 'words.h')
-rw-r--r-- | words.h | 103 |
1 files changed, 103 insertions, 0 deletions
@@ -0,0 +1,103 @@ +#ifndef CRYPTOPP_WORDS_H +#define CRYPTOPP_WORDS_H + +#include "misc.h" + +NAMESPACE_BEGIN(CryptoPP) + +inline unsigned int CountWords(const word *X, unsigned int N) +{ + while (N && X[N-1]==0) + N--; + return N; +} + +inline void SetWords(word *r, word a, unsigned int n) +{ + for (unsigned int i=0; i<n; i++) + r[i] = a; +} + +inline void CopyWords(word *r, const word *a, unsigned int n) +{ + for (unsigned int i=0; i<n; i++) + r[i] = a[i]; +} + +inline void XorWords(word *r, const word *a, const word *b, unsigned int n) +{ + for (unsigned int i=0; i<n; i++) + r[i] = a[i] ^ b[i]; +} + +inline void XorWords(word *r, const word *a, unsigned int n) +{ + for (unsigned int i=0; i<n; i++) + r[i] ^= a[i]; +} + +inline void AndWords(word *r, const word *a, const word *b, unsigned int n) +{ + for (unsigned int i=0; i<n; i++) + r[i] = a[i] & b[i]; +} + +inline void AndWords(word *r, const word *a, unsigned int n) +{ + for (unsigned int i=0; i<n; i++) + r[i] &= a[i]; +} + +inline word ShiftWordsLeftByBits(word *r, unsigned int n, unsigned int shiftBits) +{ + assert (shiftBits<WORD_BITS); + word u, carry=0; + if (shiftBits) + for (unsigned int i=0; i<n; i++) + { + u = r[i]; + r[i] = (u << shiftBits) | carry; + carry = u >> (WORD_BITS-shiftBits); + } + return carry; +} + +inline word ShiftWordsRightByBits(word *r, unsigned int n, unsigned int shiftBits) +{ + assert (shiftBits<WORD_BITS); + word u, carry=0; + if (shiftBits) + for (int i=n-1; i>=0; i--) + { + u = r[i]; + r[i] = (u >> shiftBits) | carry; + carry = u << (WORD_BITS-shiftBits); + } + return carry; +} + +inline void ShiftWordsLeftByWords(word *r, unsigned int n, unsigned int shiftWords) +{ + shiftWords = STDMIN(shiftWords, n); + if (shiftWords) + { + for (unsigned int i=n-1; i>=shiftWords; i--) + r[i] = r[i-shiftWords]; + SetWords(r, 0, shiftWords); + } +} + +inline void ShiftWordsRightByWords(word *r, unsigned int n, unsigned int shiftWords) +{ + shiftWords = STDMIN(shiftWords, n); + if (shiftWords) + { + for (unsigned int i=0; i+shiftWords<n; i++) + r[i] = r[i+shiftWords]; + SetWords(r+n-shiftWords, 0, shiftWords); + } +} + +NAMESPACE_END + +#endif |