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 <corecrypto/cc_error.h>
  16 #include <string.h>
  17 #include <stdint.h>
  18
  19 /* Provide a general purpose macro concat method. */
  20 #define cc_concat_(a, b) a##b
  21 #define cc_concat(a, b) cc_concat_(a, b)
  22
  23 /* Manage asserts here because a few functions in header public files do use asserts */
  24 #define cc_assert(x) assert(x)
  25 #if CC_KERNEL
  26 #include <kern/assert.h>
  27 #elif CC_USE_S3
  28 #define assert(args)  // No assert in S3
  29 #else
  30 #include <assert.h>
  31 #endif
  32
  33 /* Provide a static assert that can be used to create compile-type failures. */
  34 #define cc_static_assert(e,m)                                               \
  35     ;enum { cc_concat(static_assert_, __COUNTER__) = 1/(int)(!!(e)) }
  36
  37 /* Declare a struct element with a guarenteed alignment of _alignment_.
  38    The resulting struct can be used to create arrays that are aligned by
  39    a certain amount.  */
  40 #define cc_aligned_struct(_alignment_)  \
  41 typedef struct { \
  42 uint8_t b[_alignment_]; \
  43 } CC_ALIGNED(_alignment_)
  44
  45 /* number of array elements used in a cc_ctx_decl */
  46 #define cc_ctx_n(_type_, _size_) ((_size_ + sizeof(_type_) - 1) / sizeof(_type_))
  47
  48 /* sizeof of a context declared with cc_ctx_decl */
  49 #define cc_ctx_sizeof(_type_, _size_) sizeof(_type_[cc_ctx_n(_type_, _size_)])
  50
  51 /*
  52   1. _alloca cannot be removed becasue this header file is compiled with both MSVC++ and with clang.
  53   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
  54       #define cc_ctx_decl(_type_, _size_, _name_)  _type_ _name_ ## _array[cc_ctx_n(_type_, (_size_))]; _type_ *_name_ = _name_ ## _array
  55   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().
  56  */
  57 #if defined(_MSC_VER)
  58 #define cc_ctx_decl(_type_, _size_, _name_)  _type_ * _name_ = (_type_ *) _alloca(sizeof(_type_) * cc_ctx_n(_type_, _size_) )
  59 #else
  60 #define cc_ctx_decl(_type_, _size_, _name_)  _type_ _name_ [cc_ctx_n(_type_, _size_)]
  61 #endif
  62
  63 /* bzero is deprecated. memset is the way to go */
  64 /* FWIW, L4, HEXAGON and ARMCC even with gnu compatibility mode don't have bzero */
  65 #define cc_zero(_size_,_data_) memset((_data_),0 ,(_size_))
  66
  67 /*!
  68  @brief cc_clear(len, dst) zeroizes array dst and it will not be optimized out.
  69  @discussion It is used to clear sensitive data, particularly when the are defined in the stack
  70  @param len number of bytes to be cleared in dst
  71  @param dst input array
  72  */
  73 CC_NONNULL((2))
  74 void cc_clear(size_t len, void *dst);
  75
  76 #define cc_copy(_size_, _dst_, _src_) memcpy(_dst_, _src_, _size_)
  77
  78 CC_INLINE CC_NONNULL((2, 3, 4))
  79 void cc_xor(size_t size, void *r, const void *s, const void *t) {
  80     uint8_t *_r=(uint8_t *)r;
  81     const uint8_t *_s=(const uint8_t *)s;
  82     const uint8_t *_t=(const uint8_t *)t;
  83     while (size--) {
  84         _r[size] = _s[size] ^ _t[size];
  85     }
  86 }
  87
  88 /*!
  89  @brief cc_cmp_safe(num, pt1, pt2) compares two array ptr1 and ptr2 of num bytes.
  90  @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.
  91  @param num  number of bytes in each array
  92  @param ptr1 input array
  93  @param ptr2 input array
  94  @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).
  95  */
  96 CC_NONNULL((2, 3))
  97 int cc_cmp_safe (size_t num, const void * ptr1, const void * ptr2);
  98
  99 /* Exchange S and T of any type.  NOTE: Both and S and T are evaluated
 100    mutliple times and MUST NOT be expressions. */
 101 #define CC_SWAP(S,T)  do { \
 102     __typeof__(S) _cc_swap_tmp = S; S = T; T = _cc_swap_tmp; \
 103 } while(0)
 104
 105 /* Return the maximum value between S and T. */
 106 #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;})
 107
 108 /* Return the minimum value between S and T. */
 109 #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;})
 110
 111 #endif /* _CORECRYPTO_CC_H_ */