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_) \
41typedef struct { \
42uint8_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 */
73CC_NONNULL((2))
74void cc_clear(size_t len, void *dst);
75
76#define cc_copy(_size_, _dst_, _src_) memcpy(_dst_, _src_, _size_)
77
78CC_INLINE CC_NONNULL((2, 3, 4))
79void 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 */
96CC_NONNULL((2, 3))
97int 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_ */
112