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     } __attribute__((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 #define cc_ctx_decl(_type_, _size_, _name_)  \
  43     _type_ _name_[cc_ctx_n(_type_, _size_)]
  44
  45 #if CC_HAS_BZERO
  46 #define cc_zero(_size_,_data_) bzero((_data_), (_size_))
  47 #else
  48 /* Alternate version if you don't have bzero. */
  49 #define cc_zero(_size_,_data_) memset((_data_),0 ,(_size_))
  50 #endif
  51
  52 /* cc_clear:
  53  Set "len" bytes of memory to zero at address "dst".
  54  cc_clear has been developed so that it won't be optimized out.
  55  To be used to clear key buffers or sensitive data.
  56 */
  57 CC_NONNULL2
  58 void cc_clear(size_t len, void *dst);
  59
  60 #define cc_copy(_size_, _dst_, _src_) memcpy(_dst_, _src_, _size_)
  61
  62 CC_INLINE CC_NONNULL2 CC_NONNULL3 CC_NONNULL4
  63 void cc_xor(size_t size, void *r, const void *s, const void *t) {
  64     uint8_t *_r=(uint8_t *)r;
  65     const uint8_t *_s=(const uint8_t *)s;
  66     const uint8_t *_t=(const uint8_t *)t;
  67     while (size--) {
  68         _r[size] = _s[size] ^ _t[size];
  69     }
  70 }
  71
  72 /* cc_cmp_safe:
  73  Compare "num" pointed by ptr1 and ptr2, array of identical size.
  74  Functional behavior: Returns 0 if the "num" bytes starting at ptr1 are identical to the "num"
  75     bytes starting at ptr2.
  76     Return !=0 if they are different or if "num" is 0 (empty arrays)
  77  Security: The execution time/cycles is *independent* of the data and therefore guarantees
  78     no leak about the data.
  79     However, the execution time depends on "num".
  80 */
  81 CC_NONNULL2 CC_NONNULL3
  82 int cc_cmp_safe (size_t num, const void * ptr1, const void * ptr2);
  83
  84
  85 /* Exchange S and T of any type.  NOTE: Both and S and T are evaluated
  86    mutliple times and MUST NOT be expressions. */
  87 #define CC_SWAP(S,T)  do { \
  88     __typeof__(S) _cc_swap_tmp = S; S = T; T = _cc_swap_tmp; \
  89 } while(0)
  90
  91 /* Return the maximum value between S and T. */
  92 #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;})
  93
  94 /* Return the minimum value between S and T. */
  95 #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;})
  96
  97 #endif /* _CORECRYPTO_CC_H_ */