EXTERNAL_HEADERS/corecrypto/cc.h

   1 /*
   2  *  cc.h
   3  *  corecrypto
   4  *
   5  *  Created on 12/16/2010
   6  *
   7  *  Copyright (c) 2010,2011,2012,2014,2015 Apple Inc. All rights reserved.
   8  *
   9  */
  10
  11 #ifndef _CORECRYPTO_CC_H_
  12 #define _CORECRYPTO_CC_H_
  13
  14 #include <corecrypto/cc_config.h>
  15 #include <string.h>
  16 #include <stdint.h>
  17
  18 /* Manage asserts here because a few functions in header public files do use asserts */
  19 #define cc_assert(x) assert(x)
  20 #if CC_KERNEL
  21 #include <kern/assert.h>
  22 #elif CC_USE_S3
  23 #define assert(args)  // No assert in S3
  24 #else
  25 #include <assert.h>
  26 #endif
  27
  28 /* Declare a struct element with a guarenteed alignment of _alignment_.
  29    The resulting struct can be used to create arrays that are aligned by
  30    a certain amount.  */
  31 #define cc_aligned_struct(_alignment_)  \
  32 typedef struct { \
  33 uint8_t b[_alignment_]; \
  34 } CC_ALIGNED(_alignment_)
  35
  36 /* number of array elements used in a cc_ctx_decl */
  37 #define cc_ctx_n(_type_, _size_) ((_size_ + sizeof(_type_) - 1) / sizeof(_type_))
  38
  39 /* sizeof of a context declared with cc_ctx_decl */
  40 #define cc_ctx_sizeof(_type_, _size_) sizeof(_type_[cc_ctx_n(_type_, _size_)])
  41
  42 /*
  43   1. _alloca cannot be removed becasue this header file is compiled with both MSVC++ and with clang.
  44   2. The _MSC_VER version of cc_ctx_decl() is not compatible with the way *_decl macros as used in CommonCrypto, AppleKeyStore and SecurityFrameworks. To observe the incompatibilities and errors, use below definition. Corecrypto itself, accepts both deinitions
  45       #define cc_ctx_decl(_type_, _size_, _name_)  _type_ _name_ ## _array[cc_ctx_n(_type_, (_size_))]; _type_ *_name_ = _name_ ## _array
  46   3. Never use sizeof() operator for the variables declared with cc_ctx_decl(), because it is not be compatible with the _MSC_VER version of cc_ctx_decl().
  47  */
  48 #if defined(_MSC_VER)
  49 #define cc_ctx_decl(_type_, _size_, _name_)  _type_ * _name_ = (_type_ *) _alloca(sizeof(_type_) * cc_ctx_n(_type_, _size_) )
  50 #else
  51 #define cc_ctx_decl(_type_, _size_, _name_)  _type_ _name_ [cc_ctx_n(_type_, _size_)]
  52 #endif
  53
  54 /* bzero is deprecated. memset is the way to go */
  55 /* FWIW, L4, HEXAGON and ARMCC even with gnu compatibility mode don't have bzero */
  56 #define cc_zero(_size_,_data_) memset((_data_),0 ,(_size_))
  57
  58 /*!
  59  @brief cc_clear(len, dst) zeroizes array dst and it will not be optimized out.
  60  @discussion It is used to clear sensitive data, particularly when the are defined in the stack
  61  @param len number of bytes to be cleared in dst
  62  @param dst input array
  63  */
  64 CC_NONNULL2
  65 void cc_clear(size_t len, void *dst);
  66
  67 #define cc_copy(_size_, _dst_, _src_) memcpy(_dst_, _src_, _size_)
  68
  69 CC_INLINE CC_NONNULL2 CC_NONNULL3 CC_NONNULL4
  70 void cc_xor(size_t size, void *r, const void *s, const void *t) {
  71     uint8_t *_r=(uint8_t *)r;
  72     const uint8_t *_s=(const uint8_t *)s;
  73     const uint8_t *_t=(const uint8_t *)t;
  74     while (size--) {
  75         _r[size] = _s[size] ^ _t[size];
  76     }
  77 }
  78
  79 /*!
  80  @brief cc_cmp_safe(num, pt1, pt2) compares two array ptr1 and ptr2 of num bytes.
  81  @discussion The execution time/cycles is independent of the data and therefore guarantees no leak about the data. However, the execution time depends on num.
  82  @param num  number of bytes in each array
  83  @param ptr1 input array
  84  @param ptr2 input array
  85  @return  returns 0 if the num bytes starting at ptr1 are identical to the num bytes starting at ptr2 and 1 if they are different or if num is 0 (empty arrays).
  86  */
  87 CC_NONNULL2 CC_NONNULL3
  88 int cc_cmp_safe (size_t num, const void * ptr1, const void * ptr2);
  89
  90 /* Exchange S and T of any type.  NOTE: Both and S and T are evaluated
  91    mutliple times and MUST NOT be expressions. */
  92 #define CC_SWAP(S,T)  do { \
  93     __typeof__(S) _cc_swap_tmp = S; S = T; T = _cc_swap_tmp; \
  94 } while(0)
  95
  96 /* Return the maximum value between S and T. */
  97 #define CC_MAX(S, T) ({__typeof__(S) _cc_max_s = S; __typeof__(T) _cc_max_t = T; _cc_max_s > _cc_max_t ? _cc_max_s : _cc_max_t;})
  98
  99 /* Return the minimum value between S and T. */
 100 #define CC_MIN(S, T) ({__typeof__(S) _cc_min_s = S; __typeof__(T) _cc_min_t = T; _cc_min_s <= _cc_min_t ? _cc_min_s : _cc_min_t;})
 101
 102 #endif /* _CORECRYPTO_CC_H_ */