xref: /freebsd/contrib/bearssl/src/config.h (revision cc9e6590773dba57440750c124173ed531349a06)
10957b409SSimon J. Gerraty /*
20957b409SSimon J. Gerraty  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
30957b409SSimon J. Gerraty  *
40957b409SSimon J. Gerraty  * Permission is hereby granted, free of charge, to any person obtaining
50957b409SSimon J. Gerraty  * a copy of this software and associated documentation files (the
60957b409SSimon J. Gerraty  * "Software"), to deal in the Software without restriction, including
70957b409SSimon J. Gerraty  * without limitation the rights to use, copy, modify, merge, publish,
80957b409SSimon J. Gerraty  * distribute, sublicense, and/or sell copies of the Software, and to
90957b409SSimon J. Gerraty  * permit persons to whom the Software is furnished to do so, subject to
100957b409SSimon J. Gerraty  * the following conditions:
110957b409SSimon J. Gerraty  *
120957b409SSimon J. Gerraty  * The above copyright notice and this permission notice shall be
130957b409SSimon J. Gerraty  * included in all copies or substantial portions of the Software.
140957b409SSimon J. Gerraty  *
150957b409SSimon J. Gerraty  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
160957b409SSimon J. Gerraty  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
170957b409SSimon J. Gerraty  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
180957b409SSimon J. Gerraty  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
190957b409SSimon J. Gerraty  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
200957b409SSimon J. Gerraty  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
210957b409SSimon J. Gerraty  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
220957b409SSimon J. Gerraty  * SOFTWARE.
230957b409SSimon J. Gerraty  */
240957b409SSimon J. Gerraty 
250957b409SSimon J. Gerraty #ifndef CONFIG_H__
260957b409SSimon J. Gerraty #define CONFIG_H__
270957b409SSimon J. Gerraty 
280957b409SSimon J. Gerraty /*
290957b409SSimon J. Gerraty  * This file contains compile-time flags that can override the
300957b409SSimon J. Gerraty  * autodetection performed in relevant files. Each flag is a macro; it
310957b409SSimon J. Gerraty  * deactivates the feature if defined to 0, activates it if defined to a
320957b409SSimon J. Gerraty  * non-zero integer (normally 1). If the macro is not defined, then
330957b409SSimon J. Gerraty  * autodetection applies.
340957b409SSimon J. Gerraty  */
350957b409SSimon J. Gerraty 
360957b409SSimon J. Gerraty /*
370957b409SSimon J. Gerraty  * When BR_64 is enabled, 64-bit integer types are assumed to be
380957b409SSimon J. Gerraty  * efficient (i.e. the architecture has 64-bit registers and can
390957b409SSimon J. Gerraty  * do 64-bit operations as fast as 32-bit operations).
400957b409SSimon J. Gerraty  *
410957b409SSimon J. Gerraty #define BR_64   1
420957b409SSimon J. Gerraty  */
430957b409SSimon J. Gerraty 
440957b409SSimon J. Gerraty /*
450957b409SSimon J. Gerraty  * When BR_LOMUL is enabled, then multiplications of 32-bit values whose
460957b409SSimon J. Gerraty  * result are truncated to the low 32 bits are assumed to be
470957b409SSimon J. Gerraty  * substantially more efficient than 32-bit multiplications that yield
480957b409SSimon J. Gerraty  * 64-bit results. This is typically the case on low-end ARM Cortex M
490957b409SSimon J. Gerraty  * systems (M0, M0+, M1, and arguably M3 and M4 as well).
500957b409SSimon J. Gerraty  *
510957b409SSimon J. Gerraty #define BR_LOMUL   1
520957b409SSimon J. Gerraty  */
530957b409SSimon J. Gerraty 
540957b409SSimon J. Gerraty /*
550957b409SSimon J. Gerraty  * When BR_SLOW_MUL is enabled, multiplications are assumed to be
560957b409SSimon J. Gerraty  * substantially slow with regards to other integer operations, thus
570957b409SSimon J. Gerraty  * making it worth to make more operations for a given task if it allows
580957b409SSimon J. Gerraty  * using less multiplications.
590957b409SSimon J. Gerraty  *
600957b409SSimon J. Gerraty #define BR_SLOW_MUL   1
610957b409SSimon J. Gerraty  */
620957b409SSimon J. Gerraty 
630957b409SSimon J. Gerraty /*
640957b409SSimon J. Gerraty  * When BR_SLOW_MUL15 is enabled, short multplications (on 15-bit words)
650957b409SSimon J. Gerraty  * are assumed to be substantially slow with regards to other integer
660957b409SSimon J. Gerraty  * operations, thus making it worth to make more integer operations if
670957b409SSimon J. Gerraty  * it allows using less multiplications.
680957b409SSimon J. Gerraty  *
690957b409SSimon J. Gerraty #define BR_SLOW_MUL15   1
700957b409SSimon J. Gerraty  */
710957b409SSimon J. Gerraty 
720957b409SSimon J. Gerraty /*
730957b409SSimon J. Gerraty  * When BR_CT_MUL31 is enabled, multiplications of 31-bit values (used
740957b409SSimon J. Gerraty  * in the "i31" big integer implementation) use an alternate implementation
750957b409SSimon J. Gerraty  * which is slower and larger than the normal multiplication, but should
760957b409SSimon J. Gerraty  * ensure constant-time multiplications even on architectures where the
770957b409SSimon J. Gerraty  * multiplication opcode takes a variable number of cycles to complete.
780957b409SSimon J. Gerraty  *
790957b409SSimon J. Gerraty #define BR_CT_MUL31   1
800957b409SSimon J. Gerraty  */
810957b409SSimon J. Gerraty 
820957b409SSimon J. Gerraty /*
830957b409SSimon J. Gerraty  * When BR_CT_MUL15 is enabled, multiplications of 15-bit values (held
840957b409SSimon J. Gerraty  * in 32-bit words) use an alternate implementation which is slower and
850957b409SSimon J. Gerraty  * larger than the normal multiplication, but should ensure
860957b409SSimon J. Gerraty  * constant-time multiplications on most/all architectures where the
870957b409SSimon J. Gerraty  * basic multiplication is not constant-time.
880957b409SSimon J. Gerraty #define BR_CT_MUL15   1
890957b409SSimon J. Gerraty  */
900957b409SSimon J. Gerraty 
910957b409SSimon J. Gerraty /*
920957b409SSimon J. Gerraty  * When BR_NO_ARITH_SHIFT is enabled, arithmetic right shifts (with sign
930957b409SSimon J. Gerraty  * extension) are performed with a sequence of operations which is bigger
940957b409SSimon J. Gerraty  * and slower than a simple right shift on a signed value. This avoids
950957b409SSimon J. Gerraty  * relying on an implementation-defined behaviour. However, most if not
960957b409SSimon J. Gerraty  * all C compilers use sign extension for right shifts on signed values,
970957b409SSimon J. Gerraty  * so this alternate macro is disabled by default.
980957b409SSimon J. Gerraty #define BR_NO_ARITH_SHIFT   1
990957b409SSimon J. Gerraty  */
1000957b409SSimon J. Gerraty 
1010957b409SSimon J. Gerraty /*
1020957b409SSimon J. Gerraty  * When BR_RDRAND is enabled, the SSL engine will use the RDRAND opcode
1030957b409SSimon J. Gerraty  * to automatically obtain quality randomness for seeding its internal
1040957b409SSimon J. Gerraty  * PRNG. Since that opcode is present only in recent x86 CPU, its
1050957b409SSimon J. Gerraty  * support is dynamically tested; if the current CPU does not support
1060957b409SSimon J. Gerraty  * it, then another random source will be used, such as /dev/urandom or
1070957b409SSimon J. Gerraty  * CryptGenRandom().
1080957b409SSimon J. Gerraty  *
1090957b409SSimon J. Gerraty #define BR_RDRAND   1
1100957b409SSimon J. Gerraty  */
1110957b409SSimon J. Gerraty 
1120957b409SSimon J. Gerraty /*
113*cc9e6590SSimon J. Gerraty  * When BR_USE_GETENTROPY is enabled, the SSL engine will use the
114*cc9e6590SSimon J. Gerraty  * getentropy() function to obtain quality randomness for seeding its
115*cc9e6590SSimon J. Gerraty  * internal PRNG. On Linux and FreeBSD, getentropy() is implemented by
116*cc9e6590SSimon J. Gerraty  * the standard library with the system call getrandom(); on OpenBSD,
117*cc9e6590SSimon J. Gerraty  * getentropy() is the system call, and there is no getrandom() wrapper,
118*cc9e6590SSimon J. Gerraty  * hence the use of the getentropy() function for maximum portability.
119*cc9e6590SSimon J. Gerraty  *
120*cc9e6590SSimon J. Gerraty  * If the getentropy() call fails, and BR_USE_URANDOM is not explicitly
121*cc9e6590SSimon J. Gerraty  * disabled, then /dev/urandom will be used as a fallback mechanism. On
122*cc9e6590SSimon J. Gerraty  * FreeBSD and OpenBSD, this does not change much, since /dev/urandom
123*cc9e6590SSimon J. Gerraty  * will block if not enough entropy has been obtained since last boot.
124*cc9e6590SSimon J. Gerraty  * On Linux, /dev/urandom might not block, which can be troublesome in
125*cc9e6590SSimon J. Gerraty  * early boot stages, which is why getentropy() is preferred.
126*cc9e6590SSimon J. Gerraty  *
127*cc9e6590SSimon J. Gerraty #define BR_USE_GETENTROPY   1
128*cc9e6590SSimon J. Gerraty  */
129*cc9e6590SSimon J. Gerraty 
130*cc9e6590SSimon J. Gerraty /*
1310957b409SSimon J. Gerraty  * When BR_USE_URANDOM is enabled, the SSL engine will use /dev/urandom
132*cc9e6590SSimon J. Gerraty  * to automatically obtain quality randomness for seeding its internal
1330957b409SSimon J. Gerraty  * PRNG.
1340957b409SSimon J. Gerraty  *
1350957b409SSimon J. Gerraty #define BR_USE_URANDOM   1
1360957b409SSimon J. Gerraty  */
1370957b409SSimon J. Gerraty 
1380957b409SSimon J. Gerraty /*
1390957b409SSimon J. Gerraty  * When BR_USE_WIN32_RAND is enabled, the SSL engine will use the Win32
1400957b409SSimon J. Gerraty  * (CryptoAPI) functions (CryptAcquireContext(), CryptGenRandom()...) to
141*cc9e6590SSimon J. Gerraty  * automatically obtain quality randomness for seeding its internal PRNG.
1420957b409SSimon J. Gerraty  *
1430957b409SSimon J. Gerraty  * Note: if both BR_USE_URANDOM and BR_USE_WIN32_RAND are defined, the
1440957b409SSimon J. Gerraty  * former takes precedence.
1450957b409SSimon J. Gerraty  *
1460957b409SSimon J. Gerraty #define BR_USE_WIN32_RAND   1
1470957b409SSimon J. Gerraty  */
1480957b409SSimon J. Gerraty 
1490957b409SSimon J. Gerraty /*
1500957b409SSimon J. Gerraty  * When BR_USE_UNIX_TIME is enabled, the X.509 validation engine obtains
1510957b409SSimon J. Gerraty  * the current time from the OS by calling time(), and assuming that the
1520957b409SSimon J. Gerraty  * returned value (a 'time_t') is an integer that counts time in seconds
1530957b409SSimon J. Gerraty  * since the Unix Epoch (Jan 1st, 1970, 00:00 UTC).
1540957b409SSimon J. Gerraty  *
1550957b409SSimon J. Gerraty #define BR_USE_UNIX_TIME   1
1560957b409SSimon J. Gerraty  */
1570957b409SSimon J. Gerraty 
1580957b409SSimon J. Gerraty /*
1590957b409SSimon J. Gerraty  * When BR_USE_WIN32_TIME is enabled, the X.509 validation engine obtains
1600957b409SSimon J. Gerraty  * the current time from the OS by calling the Win32 function
1610957b409SSimon J. Gerraty  * GetSystemTimeAsFileTime().
1620957b409SSimon J. Gerraty  *
1630957b409SSimon J. Gerraty  * Note: if both BR_USE_UNIX_TIME and BR_USE_WIN32_TIME are defined, the
1640957b409SSimon J. Gerraty  * former takes precedence.
1650957b409SSimon J. Gerraty  *
1660957b409SSimon J. Gerraty #define BR_USE_WIN32_TIME   1
1670957b409SSimon J. Gerraty  */
1680957b409SSimon J. Gerraty 
1690957b409SSimon J. Gerraty /*
1700957b409SSimon J. Gerraty  * When BR_ARMEL_CORTEXM_GCC is enabled, some operations are replaced with
1710957b409SSimon J. Gerraty  * inline assembly which is shorter and/or faster. This should be used
1720957b409SSimon J. Gerraty  * only when all of the following are true:
1730957b409SSimon J. Gerraty  *   - target architecture is ARM in Thumb mode
1740957b409SSimon J. Gerraty  *   - target endianness is little-endian
1750957b409SSimon J. Gerraty  *   - compiler is GCC (or GCC-compatible for inline assembly syntax)
1760957b409SSimon J. Gerraty  *
1770957b409SSimon J. Gerraty  * This is meant for the low-end cores (Cortex M0, M0+, M1, M3).
1780957b409SSimon J. Gerraty  * Note: if BR_LOMUL is not explicitly enabled or disabled, then
1790957b409SSimon J. Gerraty  * enabling BR_ARMEL_CORTEXM_GCC also enables BR_LOMUL.
1800957b409SSimon J. Gerraty  *
1810957b409SSimon J. Gerraty #define BR_ARMEL_CORTEXM_GCC   1
1820957b409SSimon J. Gerraty  */
1830957b409SSimon J. Gerraty 
1840957b409SSimon J. Gerraty /*
1850957b409SSimon J. Gerraty  * When BR_AES_X86NI is enabled, the AES implementation using the x86 "NI"
1860957b409SSimon J. Gerraty  * instructions (dedicated AES opcodes) will be compiled. If this is not
1870957b409SSimon J. Gerraty  * enabled explicitly, then that AES implementation will be compiled only
1880957b409SSimon J. Gerraty  * if a compatible compiler is detected. If set explicitly to 0, the
1890957b409SSimon J. Gerraty  * implementation will not be compiled at all.
1900957b409SSimon J. Gerraty  *
1910957b409SSimon J. Gerraty #define BR_AES_X86NI   1
1920957b409SSimon J. Gerraty  */
1930957b409SSimon J. Gerraty 
1940957b409SSimon J. Gerraty /*
1950957b409SSimon J. Gerraty  * When BR_SSE2 is enabled, SSE2 intrinsics will be used for some
1960957b409SSimon J. Gerraty  * algorithm implementations that use them (e.g. chacha20_sse2). If this
1970957b409SSimon J. Gerraty  * is not enabled explicitly, then support for SSE2 intrinsics will be
1980957b409SSimon J. Gerraty  * automatically detected. If set explicitly to 0, then SSE2 code will
1990957b409SSimon J. Gerraty  * not be compiled at all.
2000957b409SSimon J. Gerraty  *
2010957b409SSimon J. Gerraty #define BR_SSE2   1
2020957b409SSimon J. Gerraty  */
2030957b409SSimon J. Gerraty 
2040957b409SSimon J. Gerraty /*
2050957b409SSimon J. Gerraty  * When BR_POWER8 is enabled, the AES implementation using the POWER ISA
2060957b409SSimon J. Gerraty  * 2.07 opcodes (available on POWER8 processors and later) is compiled.
2070957b409SSimon J. Gerraty  * If this is not enabled explicitly, then that implementation will be
2080957b409SSimon J. Gerraty  * compiled only if a compatible compiler is detected, _and_ the target
2090957b409SSimon J. Gerraty  * architecture is POWER8 or later.
2100957b409SSimon J. Gerraty  *
2110957b409SSimon J. Gerraty #define BR_POWER8   1
2120957b409SSimon J. Gerraty  */
2130957b409SSimon J. Gerraty 
2140957b409SSimon J. Gerraty /*
2150957b409SSimon J. Gerraty  * When BR_INT128 is enabled, then code using the 'unsigned __int64'
2160957b409SSimon J. Gerraty  * and 'unsigned __int128' types will be used to leverage 64x64->128
2170957b409SSimon J. Gerraty  * unsigned multiplications. This should work with GCC and compatible
2180957b409SSimon J. Gerraty  * compilers on 64-bit architectures.
2190957b409SSimon J. Gerraty  *
2200957b409SSimon J. Gerraty #define BR_INT128   1
2210957b409SSimon J. Gerraty  */
2220957b409SSimon J. Gerraty 
2230957b409SSimon J. Gerraty /*
2240957b409SSimon J. Gerraty  * When BR_UMUL128 is enabled, then code using the '_umul128()' and
2250957b409SSimon J. Gerraty  * '_addcarry_u64()' intrinsics will be used to implement 64x64->128
2260957b409SSimon J. Gerraty  * unsigned multiplications. This should work on Visual C on x64 systems.
2270957b409SSimon J. Gerraty  *
2280957b409SSimon J. Gerraty #define BR_UMUL128   1
2290957b409SSimon J. Gerraty  */
2300957b409SSimon J. Gerraty 
2310957b409SSimon J. Gerraty /*
2320957b409SSimon J. Gerraty  * When BR_LE_UNALIGNED is enabled, then the current architecture is
2330957b409SSimon J. Gerraty  * assumed to use little-endian encoding for integers, and to tolerate
2340957b409SSimon J. Gerraty  * unaligned accesses with no or minimal time penalty.
2350957b409SSimon J. Gerraty  *
2360957b409SSimon J. Gerraty #define BR_LE_UNALIGNED   1
2370957b409SSimon J. Gerraty  */
2380957b409SSimon J. Gerraty 
2390957b409SSimon J. Gerraty /*
2400957b409SSimon J. Gerraty  * When BR_BE_UNALIGNED is enabled, then the current architecture is
2410957b409SSimon J. Gerraty  * assumed to use big-endian encoding for integers, and to tolerate
2420957b409SSimon J. Gerraty  * unaligned accesses with no or minimal time penalty.
2430957b409SSimon J. Gerraty  *
2440957b409SSimon J. Gerraty #define BR_BE_UNALIGNED   1
2450957b409SSimon J. Gerraty  */
2460957b409SSimon J. Gerraty 
2470957b409SSimon J. Gerraty #endif
248