2 * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files (the
6 * "Software"), to deal in the Software without restriction, including
7 * without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sublicense, and/or sell copies of the Software, and to
9 * permit persons to whom the Software is furnished to do so, subject to
10 * the following conditions:
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
35 * Maximum size for a RSA modulus (in bits). Allocated stack buffers
36 * depend on that size, so this value should be kept small. Currently,
37 * 2048-bit RSA keys offer adequate security, and should still do so for
38 * the next few decades; however, a number of widespread PKI have
39 * already set their root keys to RSA-4096, so we should be able to
42 * This value MUST be a multiple of 64.
44 #define BR_MAX_RSA_SIZE 4096
47 * Maximum size for a RSA factor (in bits). This is for RSA private-key
48 * operations. Default is to support factors up to a bit more than half
49 * the maximum modulus size.
51 * This value MUST be a multiple of 32.
53 #define BR_MAX_RSA_FACTOR ((BR_MAX_RSA_SIZE + 64) >> 1)
56 * Maximum size for an EC curve (modulus or order), in bits. Size of
57 * stack buffers depends on that parameter. This size MUST be a multiple
58 * of 8 (so that decoding an integer with that many bytes does not
61 #define BR_MAX_EC_SIZE 528
64 * Some macros to recognize the current architecture. Right now, we are
65 * interested into automatically recognizing architecture with efficient
66 * 64-bit types so that we may automatically use implementations that
67 * use 64-bit registers in that case. Future versions may detect, e.g.,
68 * availability of SSE2 intrinsics.
70 * If 'unsigned long' is a 64-bit type, then we assume that 64-bit types
71 * are efficient. Otherwise, we rely on macros that depend on compiler,
72 * OS and architecture. In any case, failure to detect the architecture
73 * as 64-bit means that the 32-bit code will be used, and that code
74 * works also on 64-bit architectures (the 64-bit code may simply be
77 * The test on 'unsigned long' should already catch most cases, the one
78 * notable exception being Windows code where 'unsigned long' is kept to
79 * 32-bit for compatbility with all the legacy code that liberally uses
80 * the 'DWORD' type for 32-bit values.
82 * Macro names are taken from: http://nadeausoftware.com/articles/2012/02/c_c_tip_how_detect_processor_type_using_compiler_predefined_macros
85 #if ((ULONG_MAX >> 31) >> 31) == 3
87 #elif defined(__ia64) || defined(__itanium__) || defined(_M_IA64)
89 #elif defined(__powerpc64__) || defined(__ppc64__) || defined(__PPC64__) \
90 || defined(__64BIT__) || defined(_LP64) || defined(__LP64__)
92 #elif defined(__sparc64__)
94 #elif defined(__x86_64__) || defined(_M_X64)
99 /* ==================================================================== */
101 * Encoding/decoding functions.
103 * 32-bit and 64-bit decoding, both little-endian and big-endian, is
104 * implemented with the inline functions below. These functions are
105 * generic: they don't depend on the architecture natural endianness,
106 * and they can handle unaligned accesses. Optimized versions for some
107 * specific architectures may be implemented at a later time.
111 br_enc16le(void *dst
, unsigned x
)
116 buf
[0] = (unsigned char)x
;
117 buf
[1] = (unsigned char)(x
>> 8);
121 br_enc16be(void *dst
, unsigned x
)
126 buf
[0] = (unsigned char)(x
>> 8);
127 buf
[1] = (unsigned char)x
;
130 static inline unsigned
131 br_dec16le(const void *src
)
133 const unsigned char *buf
;
136 return (unsigned)buf
[0] | ((unsigned)buf
[1] << 8);
139 static inline unsigned
140 br_dec16be(const void *src
)
142 const unsigned char *buf
;
145 return ((unsigned)buf
[0] << 8) | (unsigned)buf
[1];
149 br_enc32le(void *dst
, uint32_t x
)
154 buf
[0] = (unsigned char)x
;
155 buf
[1] = (unsigned char)(x
>> 8);
156 buf
[2] = (unsigned char)(x
>> 16);
157 buf
[3] = (unsigned char)(x
>> 24);
161 br_enc32be(void *dst
, uint32_t x
)
166 buf
[0] = (unsigned char)(x
>> 24);
167 buf
[1] = (unsigned char)(x
>> 16);
168 buf
[2] = (unsigned char)(x
>> 8);
169 buf
[3] = (unsigned char)x
;
172 static inline uint32_t
173 br_dec32le(const void *src
)
175 const unsigned char *buf
;
178 return (uint32_t)buf
[0]
179 | ((uint32_t)buf
[1] << 8)
180 | ((uint32_t)buf
[2] << 16)
181 | ((uint32_t)buf
[3] << 24);
184 static inline uint32_t
185 br_dec32be(const void *src
)
187 const unsigned char *buf
;
190 return ((uint32_t)buf
[0] << 24)
191 | ((uint32_t)buf
[1] << 16)
192 | ((uint32_t)buf
[2] << 8)
197 br_enc64le(void *dst
, uint64_t x
)
202 br_enc32le(buf
, (uint32_t)x
);
203 br_enc32le(buf
+ 4, (uint32_t)(x
>> 32));
207 br_enc64be(void *dst
, uint64_t x
)
212 br_enc32be(buf
, (uint32_t)(x
>> 32));
213 br_enc32be(buf
+ 4, (uint32_t)x
);
216 static inline uint64_t
217 br_dec64le(const void *src
)
219 const unsigned char *buf
;
222 return (uint64_t)br_dec32le(buf
)
223 | ((uint64_t)br_dec32le(buf
+ 4) << 32);
226 static inline uint64_t
227 br_dec64be(const void *src
)
229 const unsigned char *buf
;
232 return ((uint64_t)br_dec32be(buf
) << 32)
233 | (uint64_t)br_dec32be(buf
+ 4);
237 * Range decoding and encoding (for several successive values).
239 void br_range_dec16le(uint16_t *v
, size_t num
, const void *src
);
240 void br_range_dec16be(uint16_t *v
, size_t num
, const void *src
);
241 void br_range_enc16le(void *dst
, const uint16_t *v
, size_t num
);
242 void br_range_enc16be(void *dst
, const uint16_t *v
, size_t num
);
244 void br_range_dec32le(uint32_t *v
, size_t num
, const void *src
);
245 void br_range_dec32be(uint32_t *v
, size_t num
, const void *src
);
246 void br_range_enc32le(void *dst
, const uint32_t *v
, size_t num
);
247 void br_range_enc32be(void *dst
, const uint32_t *v
, size_t num
);
249 void br_range_dec64le(uint64_t *v
, size_t num
, const void *src
);
250 void br_range_dec64be(uint64_t *v
, size_t num
, const void *src
);
251 void br_range_enc64le(void *dst
, const uint64_t *v
, size_t num
);
252 void br_range_enc64be(void *dst
, const uint64_t *v
, size_t num
);
255 * Byte-swap a 32-bit integer.
257 static inline uint32_t
258 br_swap32(uint32_t x
)
260 x
= ((x
& (uint32_t)0x00FF00FF) << 8)
261 | ((x
>> 8) & (uint32_t)0x00FF00FF);
262 return (x
<< 16) | (x
>> 16);
265 /* ==================================================================== */
267 * Support code for hash functions.
271 * IV for MD5, SHA-1, SHA-224 and SHA-256.
273 extern const uint32_t br_md5_IV
[];
274 extern const uint32_t br_sha1_IV
[];
275 extern const uint32_t br_sha224_IV
[];
276 extern const uint32_t br_sha256_IV
[];
279 * Round functions for MD5, SHA-1, SHA-224 and SHA-256 (SHA-224 and
280 * SHA-256 use the same round function).
282 void br_md5_round(const unsigned char *buf
, uint32_t *val
);
283 void br_sha1_round(const unsigned char *buf
, uint32_t *val
);
284 void br_sha2small_round(const unsigned char *buf
, uint32_t *val
);
287 * The core function for the TLS PRF. It computes
288 * P_hash(secret, label + seed), and XORs the result into the dst buffer.
290 void br_tls_phash(void *dst
, size_t len
,
291 const br_hash_class
*dig
,
292 const void *secret
, size_t secret_len
,
293 const char *label
, const void *seed
, size_t seed_len
);
296 * Copy all configured hash implementations from a multihash context
300 br_multihash_copyimpl(br_multihash_context
*dst
,
301 const br_multihash_context
*src
)
303 memcpy(dst
->impl
, src
->impl
, sizeof src
->impl
);
306 /* ==================================================================== */
308 * Constant-time primitives. These functions manipulate 32-bit values in
309 * order to provide constant-time comparisons and multiplexers.
311 * Boolean values (the "ctl" bits) MUST have value 0 or 1.
313 * Implementation notes:
314 * =====================
316 * The uintN_t types are unsigned and with width exactly N bits; the C
317 * standard guarantees that computations are performed modulo 2^N, and
318 * there can be no overflow. Negation (unary '-') works on unsigned types
321 * The intN_t types are guaranteed to have width exactly N bits, with no
322 * padding bit, and using two's complement representation. Casting
323 * intN_t to uintN_t really is conversion modulo 2^N. Beware that intN_t
324 * types, being signed, trigger implementation-defined behaviour on
325 * overflow (including raising some signal): with GCC, while modular
326 * arithmetics are usually applied, the optimizer may assume that
327 * overflows don't occur (unless the -fwrapv command-line option is
328 * added); Clang has the additional -ftrapv option to explicitly trap on
329 * integer overflow or underflow.
335 static inline uint32_t
342 * Multiplexer: returns x if ctl == 1, y if ctl == 0.
344 static inline uint32_t
345 MUX(uint32_t ctl
, uint32_t x
, uint32_t y
)
347 return y
^ (-ctl
& (x
^ y
));
351 * Equality check: returns 1 if x == y, 0 otherwise.
353 static inline uint32_t
354 EQ(uint32_t x
, uint32_t y
)
359 return NOT((q
| -q
) >> 31);
363 * Inequality check: returns 1 if x != y, 0 otherwise.
365 static inline uint32_t
366 NEQ(uint32_t x
, uint32_t y
)
371 return (q
| -q
) >> 31;
375 * Comparison: returns 1 if x > y, 0 otherwise.
377 static inline uint32_t
378 GT(uint32_t x
, uint32_t y
)
381 * If both x < 2^31 and x < 2^31, then y-x will have its high
382 * bit set if x > y, cleared otherwise.
384 * If either x >= 2^31 or y >= 2^31 (but not both), then the
385 * result is the high bit of x.
387 * If both x >= 2^31 and y >= 2^31, then we can virtually
388 * subtract 2^31 from both, and we are back to the first case.
389 * Since (y-2^31)-(x-2^31) = y-x, the subtraction is already
395 return (z
^ ((x
^ y
) & (x
^ z
))) >> 31;
399 * Other comparisons (greater-or-equal, lower-than, lower-or-equal).
401 #define GE(x, y) NOT(GT(y, x))
402 #define LT(x, y) GT(y, x)
403 #define LE(x, y) NOT(GT(x, y))
406 * General comparison: returned value is -1, 0 or 1, depending on
407 * whether x is lower than, equal to, or greater than y.
409 static inline int32_t
410 CMP(uint32_t x
, uint32_t y
)
412 return (int32_t)GT(x
, y
) | -(int32_t)GT(y
, x
);
416 * Returns 1 if x == 0, 0 otherwise. Take care that the operand is signed.
418 static inline uint32_t
424 return ~(q
| -q
) >> 31;
428 * Returns 1 if x > 0, 0 otherwise. Take care that the operand is signed.
430 static inline uint32_t
434 * High bit of -x is 0 if x == 0, but 1 if x > 0.
439 return (~q
& -q
) >> 31;
443 * Returns 1 if x >= 0, 0 otherwise. Take care that the operand is signed.
445 static inline uint32_t
448 return ~(uint32_t)x
>> 31;
452 * Returns 1 if x < 0, 0 otherwise. Take care that the operand is signed.
454 static inline uint32_t
457 return (uint32_t)x
>> 31;
461 * Returns 1 if x <= 0, 0 otherwise. Take care that the operand is signed.
463 static inline uint32_t
469 * ~-x has its high bit set if and only if -x is nonnegative (as
470 * a signed int), i.e. x is in the -(2^31-1) to 0 range. We must
471 * do an OR with x itself to account for x = -2^31.
474 return (q
| ~-q
) >> 31;
478 * Conditional copy: src[] is copied into dst[] if and only if ctl is 1.
479 * dst[] and src[] may overlap completely (but not partially).
481 void br_ccopy(uint32_t ctl
, void *dst
, const void *src
, size_t len
);
483 #define CCOPY br_ccopy
486 * Compute the bit length of a 32-bit integer. Returned value is between 0
487 * and 32 (inclusive).
489 static inline uint32_t
490 BIT_LENGTH(uint32_t x
)
495 c
= GT(x
, 0xFFFF); x
= MUX(c
, x
>> 16, x
); k
+= c
<< 4;
496 c
= GT(x
, 0x00FF); x
= MUX(c
, x
>> 8, x
); k
+= c
<< 3;
497 c
= GT(x
, 0x000F); x
= MUX(c
, x
>> 4, x
); k
+= c
<< 2;
498 c
= GT(x
, 0x0003); x
= MUX(c
, x
>> 2, x
); k
+= c
<< 1;
504 * Compute the minimum of x and y.
506 static inline uint32_t
507 MIN(uint32_t x
, uint32_t y
)
509 return MUX(GT(x
, y
), y
, x
);
513 * Compute the maximum of x and y.
515 static inline uint32_t
516 MAX(uint32_t x
, uint32_t y
)
518 return MUX(GT(x
, y
), x
, y
);
522 * Multiply two 32-bit integers, with a 64-bit result. This default
523 * implementation assumes that the basic multiplication operator
524 * yields constant-time code.
526 #define MUL(x, y) ((uint64_t)(x) * (uint64_t)(y))
531 * Alternate implementation of MUL31, that will be constant-time on some
532 * (old) platforms where the default MUL31 is not. Unfortunately, it is
533 * also substantially slower, and yields larger code, on more modern
534 * platforms, which is why it is deactivated by default.
536 #define MUL31(x, y) ((uint64_t)((x) | (uint32_t)0x80000000) \
537 * (uint64_t)((y) | (uint32_t)0x80000000) \
538 - ((uint64_t)(x) << 31) - ((uint64_t)(y) << 31) \
539 - ((uint64_t)1 << 62))
544 * Multiply two 31-bit integers, with a 62-bit result. This default
545 * implementation assumes that the basic multiplication operator
546 * yields constant-time code.
548 #define MUL31(x, y) ((uint64_t)(x) * (uint64_t)(y))
553 * Constant-time division. The dividend hi:lo is divided by the
554 * divisor d; the quotient is returned and the remainder is written
555 * in *r. If hi == d, then the quotient does not fit on 32 bits;
556 * returned value is thus truncated. If hi > d, returned values are
559 uint32_t br_divrem(uint32_t hi
, uint32_t lo
, uint32_t d
, uint32_t *r
);
562 * Wrapper for br_divrem(); the remainder is returned, and the quotient
565 static inline uint32_t
566 br_rem(uint32_t hi
, uint32_t lo
, uint32_t d
)
570 br_divrem(hi
, lo
, d
, &r
);
575 * Wrapper for br_divrem(); the quotient is returned, and the remainder
578 static inline uint32_t
579 br_div(uint32_t hi
, uint32_t lo
, uint32_t d
)
583 return br_divrem(hi
, lo
, d
, &r
);
586 /* ==================================================================== */
592 * The 'i32' functions implement computations on big integers using
593 * an internal representation as an array of 32-bit integers. For
595 * -- x[0] contains the "announced bit length" of the integer
596 * -- x[1], x[2]... contain the value in little-endian order (x[1]
597 * contains the least significant 32 bits)
599 * Multiplications rely on the elementary 32x32->64 multiplication.
601 * The announced bit length specifies the number of bits that are
602 * significant in the subsequent 32-bit words. Unused bits in the
603 * last (most significant) word are set to 0; subsequent words are
604 * uninitialized and need not exist at all.
606 * The execution time and memory access patterns of all computations
607 * depend on the announced bit length, but not on the actual word
608 * values. For modular integers, the announced bit length of any integer
609 * modulo n is equal to the actual bit length of n; thus, computations
610 * on modular integers are "constant-time" (only the modulus length may
615 * Compute the actual bit length of an integer. The argument x should
616 * point to the first (least significant) value word of the integer.
617 * The len 'xlen' contains the number of 32-bit words to access.
619 * CT: value or length of x does not leak.
621 uint32_t br_i32_bit_length(uint32_t *x
, size_t xlen
);
624 * Decode an integer from its big-endian unsigned representation. The
625 * "true" bit length of the integer is computed, but all words of x[]
626 * corresponding to the full 'len' bytes of the source are set.
628 * CT: value or length of x does not leak.
630 void br_i32_decode(uint32_t *x
, const void *src
, size_t len
);
633 * Decode an integer from its big-endian unsigned representation. The
634 * integer MUST be lower than m[]; the announced bit length written in
635 * x[] will be equal to that of m[]. All 'len' bytes from the source are
638 * Returned value is 1 if the decode value fits within the modulus, 0
639 * otherwise. In the latter case, the x[] buffer will be set to 0 (but
640 * still with the announced bit length of m[]).
642 * CT: value or length of x does not leak. Memory access pattern depends
643 * only of 'len' and the announced bit length of m. Whether x fits or
644 * not does not leak either.
646 uint32_t br_i32_decode_mod(uint32_t *x
,
647 const void *src
, size_t len
, const uint32_t *m
);
650 * Reduce an integer (a[]) modulo another (m[]). The result is written
651 * in x[] and its announced bit length is set to be equal to that of m[].
653 * x[] MUST be distinct from a[] and m[].
655 * CT: only announced bit lengths leak, not values of x, a or m.
657 void br_i32_reduce(uint32_t *x
, const uint32_t *a
, const uint32_t *m
);
660 * Decode an integer from its big-endian unsigned representation, and
661 * reduce it modulo the provided modulus m[]. The announced bit length
662 * of the result is set to be equal to that of the modulus.
664 * x[] MUST be distinct from m[].
666 void br_i32_decode_reduce(uint32_t *x
,
667 const void *src
, size_t len
, const uint32_t *m
);
670 * Encode an integer into its big-endian unsigned representation. The
671 * output length in bytes is provided (parameter 'len'); if the length
672 * is too short then the integer is appropriately truncated; if it is
673 * too long then the extra bytes are set to 0.
675 void br_i32_encode(void *dst
, size_t len
, const uint32_t *x
);
678 * Multiply x[] by 2^32 and then add integer z, modulo m[]. This
679 * function assumes that x[] and m[] have the same announced bit
680 * length, and the announced bit length of m[] matches its true
683 * x[] and m[] MUST be distinct arrays.
685 * CT: only the common announced bit length of x and m leaks, not
686 * the values of x, z or m.
688 void br_i32_muladd_small(uint32_t *x
, uint32_t z
, const uint32_t *m
);
691 * Extract one word from an integer. The offset is counted in bits.
692 * The word MUST entirely fit within the word elements corresponding
693 * to the announced bit length of a[].
695 static inline uint32_t
696 br_i32_word(const uint32_t *a
, uint32_t off
)
701 u
= (size_t)(off
>> 5) + 1;
702 j
= (unsigned)off
& 31;
706 return (a
[u
] >> j
) | (a
[u
+ 1] << (32 - j
));
711 * Test whether an integer is zero.
713 uint32_t br_i32_iszero(const uint32_t *x
);
716 * Add b[] to a[] and return the carry (0 or 1). If ctl is 0, then a[]
717 * is unmodified, but the carry is still computed and returned. The
718 * arrays a[] and b[] MUST have the same announced bit length.
720 * a[] and b[] MAY be the same array, but partial overlap is not allowed.
722 uint32_t br_i32_add(uint32_t *a
, const uint32_t *b
, uint32_t ctl
);
725 * Subtract b[] from a[] and return the carry (0 or 1). If ctl is 0,
726 * then a[] is unmodified, but the carry is still computed and returned.
727 * The arrays a[] and b[] MUST have the same announced bit length.
729 * a[] and b[] MAY be the same array, but partial overlap is not allowed.
731 uint32_t br_i32_sub(uint32_t *a
, const uint32_t *b
, uint32_t ctl
);
734 * Compute d+a*b, result in d. The initial announced bit length of d[]
735 * MUST match that of a[]. The d[] array MUST be large enough to
736 * accommodate the full result, plus (possibly) an extra word. The
737 * resulting announced bit length of d[] will be the sum of the announced
738 * bit lengths of a[] and b[] (therefore, it may be larger than the actual
739 * bit length of the numerical result).
741 * a[] and b[] may be the same array. d[] must be disjoint from both a[]
744 void br_i32_mulacc(uint32_t *d
, const uint32_t *a
, const uint32_t *b
);
747 * Zeroize an integer. The announced bit length is set to the provided
748 * value, and the corresponding words are set to 0.
751 br_i32_zero(uint32_t *x
, uint32_t bit_len
)
754 memset(x
, 0, ((bit_len
+ 31) >> 5) * sizeof *x
);
758 * Compute -(1/x) mod 2^32. If x is even, then this function returns 0.
760 uint32_t br_i32_ninv32(uint32_t x
);
763 * Convert a modular integer to Montgomery representation. The integer x[]
764 * MUST be lower than m[], but with the same announced bit length.
766 void br_i32_to_monty(uint32_t *x
, const uint32_t *m
);
769 * Convert a modular integer back from Montgomery representation. The
770 * integer x[] MUST be lower than m[], but with the same announced bit
771 * length. The "m0i" parameter is equal to -(1/m0) mod 2^32, where m0 is
772 * the least significant value word of m[] (this works only if m[] is
775 void br_i32_from_monty(uint32_t *x
, const uint32_t *m
, uint32_t m0i
);
778 * Compute a modular Montgomery multiplication. d[] is filled with the
779 * value of x*y/R modulo m[] (where R is the Montgomery factor). The
780 * array d[] MUST be distinct from x[], y[] and m[]. x[] and y[] MUST be
781 * numerically lower than m[]. x[] and y[] MAY be the same array. The
782 * "m0i" parameter is equal to -(1/m0) mod 2^32, where m0 is the least
783 * significant value word of m[] (this works only if m[] is an odd
786 void br_i32_montymul(uint32_t *d
, const uint32_t *x
, const uint32_t *y
,
787 const uint32_t *m
, uint32_t m0i
);
790 * Compute a modular exponentiation. x[] MUST be an integer modulo m[]
791 * (same announced bit length, lower value). m[] MUST be odd. The
792 * exponent is in big-endian unsigned notation, over 'elen' bytes. The
793 * "m0i" parameter is equal to -(1/m0) mod 2^32, where m0 is the least
794 * significant value word of m[] (this works only if m[] is an odd
795 * integer). The t1[] and t2[] parameters must be temporary arrays,
796 * each large enough to accommodate an integer with the same size as m[].
798 void br_i32_modpow(uint32_t *x
, const unsigned char *e
, size_t elen
,
799 const uint32_t *m
, uint32_t m0i
, uint32_t *t1
, uint32_t *t2
);
801 /* ==================================================================== */
807 * The 'i31' functions implement computations on big integers using
808 * an internal representation as an array of 32-bit integers. For
810 * -- x[0] encodes the array length and the "announced bit length"
811 * of the integer: namely, if the announced bit length is k,
812 * then x[0] = ((k / 31) << 5) + (k % 31).
813 * -- x[1], x[2]... contain the value in little-endian order, 31
814 * bits per word (x[1] contains the least significant 31 bits).
815 * The upper bit of each word is 0.
817 * Multiplications rely on the elementary 32x32->64 multiplication.
819 * The announced bit length specifies the number of bits that are
820 * significant in the subsequent 32-bit words. Unused bits in the
821 * last (most significant) word are set to 0; subsequent words are
822 * uninitialized and need not exist at all.
824 * The execution time and memory access patterns of all computations
825 * depend on the announced bit length, but not on the actual word
826 * values. For modular integers, the announced bit length of any integer
827 * modulo n is equal to the actual bit length of n; thus, computations
828 * on modular integers are "constant-time" (only the modulus length may
833 * Test whether an integer is zero.
835 uint32_t br_i31_iszero(const uint32_t *x
);
838 * Add b[] to a[] and return the carry (0 or 1). If ctl is 0, then a[]
839 * is unmodified, but the carry is still computed and returned. The
840 * arrays a[] and b[] MUST have the same announced bit length.
842 * a[] and b[] MAY be the same array, but partial overlap is not allowed.
844 uint32_t br_i31_add(uint32_t *a
, const uint32_t *b
, uint32_t ctl
);
847 * Subtract b[] from a[] and return the carry (0 or 1). If ctl is 0,
848 * then a[] is unmodified, but the carry is still computed and returned.
849 * The arrays a[] and b[] MUST have the same announced bit length.
851 * a[] and b[] MAY be the same array, but partial overlap is not allowed.
853 uint32_t br_i31_sub(uint32_t *a
, const uint32_t *b
, uint32_t ctl
);
856 * Compute the ENCODED actual bit length of an integer. The argument x
857 * should point to the first (least significant) value word of the
858 * integer. The len 'xlen' contains the number of 32-bit words to
859 * access. The upper bit of each value word MUST be 0.
860 * Returned value is ((k / 31) << 5) + (k % 31) if the bit length is k.
862 * CT: value or length of x does not leak.
864 uint32_t br_i31_bit_length(uint32_t *x
, size_t xlen
);
867 * Decode an integer from its big-endian unsigned representation. The
868 * "true" bit length of the integer is computed and set in the encoded
869 * announced bit length (x[0]), but all words of x[] corresponding to
870 * the full 'len' bytes of the source are set.
872 * CT: value or length of x does not leak.
874 void br_i31_decode(uint32_t *x
, const void *src
, size_t len
);
877 * Decode an integer from its big-endian unsigned representation. The
878 * integer MUST be lower than m[]; the (encoded) announced bit length
879 * written in x[] will be equal to that of m[]. All 'len' bytes from the
882 * Returned value is 1 if the decode value fits within the modulus, 0
883 * otherwise. In the latter case, the x[] buffer will be set to 0 (but
884 * still with the announced bit length of m[]).
886 * CT: value or length of x does not leak. Memory access pattern depends
887 * only of 'len' and the announced bit length of m. Whether x fits or
888 * not does not leak either.
890 uint32_t br_i31_decode_mod(uint32_t *x
,
891 const void *src
, size_t len
, const uint32_t *m
);
894 * Zeroize an integer. The announced bit length is set to the provided
895 * value, and the corresponding words are set to 0. The ENCODED bit length
899 br_i31_zero(uint32_t *x
, uint32_t bit_len
)
902 memset(x
, 0, ((bit_len
+ 31) >> 5) * sizeof *x
);
906 * Right-shift an integer. The shift amount must be lower than 31
909 void br_i31_rshift(uint32_t *x
, int count
);
912 * Reduce an integer (a[]) modulo another (m[]). The result is written
913 * in x[] and its announced bit length is set to be equal to that of m[].
915 * x[] MUST be distinct from a[] and m[].
917 * CT: only announced bit lengths leak, not values of x, a or m.
919 void br_i31_reduce(uint32_t *x
, const uint32_t *a
, const uint32_t *m
);
922 * Decode an integer from its big-endian unsigned representation, and
923 * reduce it modulo the provided modulus m[]. The announced bit length
924 * of the result is set to be equal to that of the modulus.
926 * x[] MUST be distinct from m[].
928 void br_i31_decode_reduce(uint32_t *x
,
929 const void *src
, size_t len
, const uint32_t *m
);
932 * Multiply x[] by 2^31 and then add integer z, modulo m[]. This
933 * function assumes that x[] and m[] have the same announced bit
934 * length, the announced bit length of m[] matches its true
937 * x[] and m[] MUST be distinct arrays. z MUST fit in 31 bits (upper
940 * CT: only the common announced bit length of x and m leaks, not
941 * the values of x, z or m.
943 void br_i31_muladd_small(uint32_t *x
, uint32_t z
, const uint32_t *m
);
946 * Encode an integer into its big-endian unsigned representation. The
947 * output length in bytes is provided (parameter 'len'); if the length
948 * is too short then the integer is appropriately truncated; if it is
949 * too long then the extra bytes are set to 0.
951 void br_i31_encode(void *dst
, size_t len
, const uint32_t *x
);
954 * Compute -(1/x) mod 2^31. If x is even, then this function returns 0.
956 uint32_t br_i31_ninv31(uint32_t x
);
959 * Compute a modular Montgomery multiplication. d[] is filled with the
960 * value of x*y/R modulo m[] (where R is the Montgomery factor). The
961 * array d[] MUST be distinct from x[], y[] and m[]. x[] and y[] MUST be
962 * numerically lower than m[]. x[] and y[] MAY be the same array. The
963 * "m0i" parameter is equal to -(1/m0) mod 2^31, where m0 is the least
964 * significant value word of m[] (this works only if m[] is an odd
967 void br_i31_montymul(uint32_t *d
, const uint32_t *x
, const uint32_t *y
,
968 const uint32_t *m
, uint32_t m0i
);
971 * Convert a modular integer to Montgomery representation. The integer x[]
972 * MUST be lower than m[], but with the same announced bit length.
974 void br_i31_to_monty(uint32_t *x
, const uint32_t *m
);
977 * Convert a modular integer back from Montgomery representation. The
978 * integer x[] MUST be lower than m[], but with the same announced bit
979 * length. The "m0i" parameter is equal to -(1/m0) mod 2^32, where m0 is
980 * the least significant value word of m[] (this works only if m[] is
983 void br_i31_from_monty(uint32_t *x
, const uint32_t *m
, uint32_t m0i
);
986 * Compute a modular exponentiation. x[] MUST be an integer modulo m[]
987 * (same announced bit length, lower value). m[] MUST be odd. The
988 * exponent is in big-endian unsigned notation, over 'elen' bytes. The
989 * "m0i" parameter is equal to -(1/m0) mod 2^31, where m0 is the least
990 * significant value word of m[] (this works only if m[] is an odd
991 * integer). The t1[] and t2[] parameters must be temporary arrays,
992 * each large enough to accommodate an integer with the same size as m[].
994 void br_i31_modpow(uint32_t *x
, const unsigned char *e
, size_t elen
,
995 const uint32_t *m
, uint32_t m0i
, uint32_t *t1
, uint32_t *t2
);
998 * Compute d+a*b, result in d. The initial announced bit length of d[]
999 * MUST match that of a[]. The d[] array MUST be large enough to
1000 * accommodate the full result, plus (possibly) an extra word. The
1001 * resulting announced bit length of d[] will be the sum of the announced
1002 * bit lengths of a[] and b[] (therefore, it may be larger than the actual
1003 * bit length of the numerical result).
1005 * a[] and b[] may be the same array. d[] must be disjoint from both a[]
1008 void br_i31_mulacc(uint32_t *d
, const uint32_t *a
, const uint32_t *b
);
1010 /* ==================================================================== */
1012 static inline size_t
1013 br_digest_size(const br_hash_class
*digest_class
)
1015 return (size_t)(digest_class
->desc
>> BR_HASHDESC_OUT_OFF
)
1016 & BR_HASHDESC_OUT_MASK
;
1020 * Get the output size (in bytes) of a hash function.
1022 size_t br_digest_size_by_ID(int digest_id
);
1025 * Get the OID (encoded OBJECT IDENTIFIER value, without tag and length)
1026 * for a hash function. If digest_id is not a supported digest identifier
1027 * (in particular if it is equal to 0, i.e. br_md5sha1_ID), then NULL is
1028 * returned and *len is set to 0.
1030 const unsigned char *br_digest_OID(int digest_id
, size_t *len
);
1032 /* ==================================================================== */
1034 * DES support functions.
1038 * Apply DES Initial Permutation.
1040 void br_des_do_IP(uint32_t *xl
, uint32_t *xr
);
1043 * Apply DES Final Permutation (inverse of IP).
1045 void br_des_do_invIP(uint32_t *xl
, uint32_t *xr
);
1048 * Key schedule unit: for a DES key (8 bytes), compute 16 subkeys. Each
1049 * subkey is two 28-bit words represented as two 32-bit words; the PC-2
1050 * bit extration is NOT applied.
1052 void br_des_keysched_unit(uint32_t *skey
, const void *key
);
1055 * Reversal of 16 DES sub-keys (for decryption).
1057 void br_des_rev_skey(uint32_t *skey
);
1060 * DES/3DES key schedule for 'des_tab' (encryption direction). Returned
1061 * value is the number of rounds.
1063 unsigned br_des_tab_keysched(uint32_t *skey
, const void *key
, size_t key_len
);
1066 * DES/3DES key schedule for 'des_ct' (encryption direction). Returned
1067 * value is the number of rounds.
1069 unsigned br_des_ct_keysched(uint32_t *skey
, const void *key
, size_t key_len
);
1072 * DES/3DES subkey decompression (from the compressed bitsliced subkeys).
1074 void br_des_ct_skey_expand(uint32_t *sk_exp
,
1075 unsigned num_rounds
, const uint32_t *skey
);
1078 * DES/3DES block encryption/decryption ('des_tab').
1080 void br_des_tab_process_block(unsigned num_rounds
,
1081 const uint32_t *skey
, void *block
);
1084 * DES/3DES block encryption/decryption ('des_ct').
1086 void br_des_ct_process_block(unsigned num_rounds
,
1087 const uint32_t *skey
, void *block
);
1089 /* ==================================================================== */
1091 * AES support functions.
1095 * The AES S-box (256-byte table).
1097 extern const unsigned char br_aes_S
[];
1100 * AES key schedule. skey[] is filled with n+1 128-bit subkeys, where n
1101 * is the number of rounds (10 to 14, depending on key size). The number
1102 * of rounds is returned. If the key size is invalid (not 16, 24 or 32),
1103 * then 0 is returned.
1105 * This implementation uses a 256-byte table and is NOT constant-time.
1107 unsigned br_aes_keysched(uint32_t *skey
, const void *key
, size_t key_len
);
1110 * AES key schedule for decryption ('aes_big' implementation).
1112 unsigned br_aes_big_keysched_inv(uint32_t *skey
,
1113 const void *key
, size_t key_len
);
1116 * AES block encryption with the 'aes_big' implementation (fast, but
1117 * not constant-time). This function encrypts a single block "in place".
1119 void br_aes_big_encrypt(unsigned num_rounds
, const uint32_t *skey
, void *data
);
1122 * AES block decryption with the 'aes_big' implementation (fast, but
1123 * not constant-time). This function decrypts a single block "in place".
1125 void br_aes_big_decrypt(unsigned num_rounds
, const uint32_t *skey
, void *data
);
1128 * AES block encryption with the 'aes_small' implementation (small, but
1129 * slow and not constant-time). This function encrypts a single block
1132 void br_aes_small_encrypt(unsigned num_rounds
,
1133 const uint32_t *skey
, void *data
);
1136 * AES block decryption with the 'aes_small' implementation (small, but
1137 * slow and not constant-time). This function decrypts a single block
1140 void br_aes_small_decrypt(unsigned num_rounds
,
1141 const uint32_t *skey
, void *data
);
1144 * The constant-time implementation is "bitsliced": the 128-bit state is
1145 * split over eight 32-bit words q* in the following way:
1147 * -- Input block consists in 16 bytes:
1148 * a00 a10 a20 a30 a01 a11 a21 a31 a02 a12 a22 a32 a03 a13 a23 a33
1149 * In the terminology of FIPS 197, this is a 4x4 matrix which is read
1152 * -- Each byte is split into eight bits which are distributed over the
1153 * eight words, at the same rank. Thus, for a byte x at rank k, bit 0
1154 * (least significant) of x will be at rank k in q0 (if that bit is b,
1155 * then it contributes "b << k" to the value of q0), bit 1 of x will be
1156 * at rank k in q1, and so on.
1158 * -- Ranks given to bits are in "row order" and are either all even, or
1159 * all odd. Two independent AES states are thus interleaved, one using
1160 * the even ranks, the other the odd ranks. Row order means:
1161 * a00 a01 a02 a03 a10 a11 a12 a13 a20 a21 a22 a23 a30 a31 a32 a33
1163 * Converting input bytes from two AES blocks to bitslice representation
1164 * is done in the following way:
1165 * -- Decode first block into the four words q0 q2 q4 q6, in that order,
1166 * using little-endian convention.
1167 * -- Decode second block into the four words q1 q3 q5 q7, in that order,
1168 * using little-endian convention.
1169 * -- Call br_aes_ct_ortho().
1171 * Converting back to bytes is done by using the reverse operations. Note
1172 * that br_aes_ct_ortho() is its own inverse.
1176 * Perform bytewise orthogonalization of eight 32-bit words. Bytes
1177 * of q0..q7 are spread over all words: for a byte x that occurs
1178 * at rank i in q[j] (byte x uses bits 8*i to 8*i+7 in q[j]), the bit
1179 * of rank k in x (0 <= k <= 7) goes to q[k] at rank 8*i+j.
1181 * This operation is an involution.
1183 void br_aes_ct_ortho(uint32_t *q
);
1186 * The AES S-box, as a bitsliced constant-time version. The input array
1187 * consists in eight 32-bit words; 32 S-box instances are computed in
1188 * parallel. Bits 0 to 7 of each S-box input (bit 0 is least significant)
1189 * are spread over the words 0 to 7, at the same rank.
1191 void br_aes_ct_bitslice_Sbox(uint32_t *q
);
1194 * Like br_aes_bitslice_Sbox(), but for the inverse S-box.
1196 void br_aes_ct_bitslice_invSbox(uint32_t *q
);
1199 * Compute AES encryption on bitsliced data. Since input is stored on
1200 * eight 32-bit words, two block encryptions are actually performed
1203 void br_aes_ct_bitslice_encrypt(unsigned num_rounds
,
1204 const uint32_t *skey
, uint32_t *q
);
1207 * Compute AES decryption on bitsliced data. Since input is stored on
1208 * eight 32-bit words, two block decryptions are actually performed
1211 void br_aes_ct_bitslice_decrypt(unsigned num_rounds
,
1212 const uint32_t *skey
, uint32_t *q
);
1215 * AES key schedule, constant-time version. skey[] is filled with n+1
1216 * 128-bit subkeys, where n is the number of rounds (10 to 14, depending
1217 * on key size). The number of rounds is returned. If the key size is
1218 * invalid (not 16, 24 or 32), then 0 is returned.
1220 unsigned br_aes_ct_keysched(uint32_t *comp_skey
,
1221 const void *key
, size_t key_len
);
1224 * Expand AES subkeys as produced by br_aes_ct_keysched(), into
1225 * a larger array suitable for br_aes_ct_bitslice_encrypt() and
1226 * br_aes_ct_bitslice_decrypt().
1228 void br_aes_ct_skey_expand(uint32_t *skey
,
1229 unsigned num_rounds
, const uint32_t *comp_skey
);
1232 * For the ct64 implementation, the same bitslicing technique is used,
1233 * but four instances are interleaved. First instance uses bits 0, 4,
1234 * 8, 12,... of each word; second instance uses bits 1, 5, 9, 13,...
1239 * Perform bytewise orthogonalization of eight 64-bit words. Bytes
1240 * of q0..q7 are spread over all words: for a byte x that occurs
1241 * at rank i in q[j] (byte x uses bits 8*i to 8*i+7 in q[j]), the bit
1242 * of rank k in x (0 <= k <= 7) goes to q[k] at rank 8*i+j.
1244 * This operation is an involution.
1246 void br_aes_ct64_ortho(uint64_t *q
);
1249 * Interleave bytes for an AES input block. If input bytes are
1250 * denoted 0123456789ABCDEF, and have been decoded with little-endian
1251 * convention (w[0] contains 0123, with '3' being most significant;
1252 * w[1] contains 4567, and so on), then output word q0 will be
1253 * set to 08192A3B (again little-endian convention) and q1 will
1254 * be set to 4C5D6E7F.
1256 void br_aes_ct64_interleave_in(uint64_t *q0
, uint64_t *q1
, const uint32_t *w
);
1259 * Perform the opposite of br_aes_ct64_interleave_in().
1261 void br_aes_ct64_interleave_out(uint32_t *w
, uint64_t q0
, uint64_t q1
);
1264 * The AES S-box, as a bitsliced constant-time version. The input array
1265 * consists in eight 64-bit words; 64 S-box instances are computed in
1266 * parallel. Bits 0 to 7 of each S-box input (bit 0 is least significant)
1267 * are spread over the words 0 to 7, at the same rank.
1269 void br_aes_ct64_bitslice_Sbox(uint64_t *q
);
1272 * Like br_aes_bitslice_Sbox(), but for the inverse S-box.
1274 void br_aes_ct64_bitslice_invSbox(uint64_t *q
);
1277 * Compute AES encryption on bitsliced data. Since input is stored on
1278 * eight 64-bit words, four block encryptions are actually performed
1281 void br_aes_ct64_bitslice_encrypt(unsigned num_rounds
,
1282 const uint64_t *skey
, uint64_t *q
);
1285 * Compute AES decryption on bitsliced data. Since input is stored on
1286 * eight 64-bit words, four block decryptions are actually performed
1289 void br_aes_ct64_bitslice_decrypt(unsigned num_rounds
,
1290 const uint64_t *skey
, uint64_t *q
);
1293 * AES key schedule, constant-time version. skey[] is filled with n+1
1294 * 128-bit subkeys, where n is the number of rounds (10 to 14, depending
1295 * on key size). The number of rounds is returned. If the key size is
1296 * invalid (not 16, 24 or 32), then 0 is returned.
1298 unsigned br_aes_ct64_keysched(uint64_t *comp_skey
,
1299 const void *key
, size_t key_len
);
1302 * Expand AES subkeys as produced by br_aes_ct64_keysched(), into
1303 * a larger array suitable for br_aes_ct64_bitslice_encrypt() and
1304 * br_aes_ct64_bitslice_decrypt().
1306 void br_aes_ct64_skey_expand(uint64_t *skey
,
1307 unsigned num_rounds
, const uint64_t *comp_skey
);
1309 /* ==================================================================== */
1315 * Type for generic EC parameters: curve order (unsigned big-endian
1316 * encoding) and encoded conventional generator.
1320 const unsigned char *order
;
1322 const unsigned char *generator
;
1323 size_t generator_len
;
1326 extern const br_ec_curve_def br_secp256r1
;
1327 extern const br_ec_curve_def br_secp384r1
;
1328 extern const br_ec_curve_def br_secp521r1
;
1331 * Type for the parameters for a "prime curve":
1332 * coordinates are in GF(p), with p prime
1333 * curve equation is Y^2 = X^3 - 3*X + b
1334 * b is in Montgomery representation
1335 * curve order is n and is prime
1336 * base point is G (encoded) and has order n
1342 } br_ec_prime_i31_curve
;
1344 extern const br_ec_prime_i31_curve br_ec_prime_i31_secp256r1
;
1345 extern const br_ec_prime_i31_curve br_ec_prime_i31_secp384r1
;
1346 extern const br_ec_prime_i31_curve br_ec_prime_i31_secp521r1
;
1348 #define BR_EC_I31_LEN ((BR_MAX_EC_SIZE + 61) / 31)
1351 * Decode some bytes as an i31 integer, with truncation (corresponding
1352 * to the 'bits2int' operation in RFC 6979). The target ENCODED bit
1353 * length is provided as last parameter. The resulting value will have
1354 * this declared bit length, and consists the big-endian unsigned decoding
1355 * of exactly that many bits in the source (capped at the source length).
1357 void br_ecdsa_i31_bits2int(uint32_t *x
,
1358 const void *src
, size_t len
, uint32_t ebitlen
);
1360 /* ==================================================================== */
1362 * SSL/TLS support functions.
1368 #define BR_SSL_CHANGE_CIPHER_SPEC 20
1369 #define BR_SSL_ALERT 21
1370 #define BR_SSL_HANDSHAKE 22
1371 #define BR_SSL_APPLICATION_DATA 23
1374 * Handshake message types.
1376 #define BR_SSL_HELLO_REQUEST 0
1377 #define BR_SSL_CLIENT_HELLO 1
1378 #define BR_SSL_SERVER_HELLO 2
1379 #define BR_SSL_CERTIFICATE 11
1380 #define BR_SSL_SERVER_KEY_EXCHANGE 12
1381 #define BR_SSL_CERTIFICATE_REQUEST 13
1382 #define BR_SSL_SERVER_HELLO_DONE 14
1383 #define BR_SSL_CERTIFICATE_VERIFY 15
1384 #define BR_SSL_CLIENT_KEY_EXCHANGE 16
1385 #define BR_SSL_FINISHED 20
1390 #define BR_LEVEL_WARNING 1
1391 #define BR_LEVEL_FATAL 2
1394 * Low-level I/O state.
1396 #define BR_IO_FAILED 0
1399 #define BR_IO_INOUT 3
1402 * Mark a SSL engine as failed. The provided error code is recorded if
1403 * the engine was not already marked as failed. If 'err' is 0, then the
1404 * engine is marked as closed (without error).
1406 void br_ssl_engine_fail(br_ssl_engine_context
*cc
, int err
);
1409 * Test whether the engine is closed (normally or as a failure).
1412 br_ssl_engine_closed(const br_ssl_engine_context
*cc
)
1414 return cc
->iomode
== BR_IO_FAILED
;
1418 * Configure a new maximum fragment length. If possible, the maximum
1419 * length for outgoing records is immediately adjusted (if there are
1420 * not already too many buffered bytes for that).
1422 void br_ssl_engine_new_max_frag_len(
1423 br_ssl_engine_context
*rc
, unsigned max_frag_len
);
1426 * Test whether the current incoming record has been fully received
1427 * or not. This functions returns 0 only if a complete record header
1428 * has been received, but some of the (possibly encrypted) payload
1429 * has not yet been obtained.
1431 int br_ssl_engine_recvrec_finished(const br_ssl_engine_context
*rc
);
1434 * Flush the current record (if not empty). This is meant to be called
1435 * from the handshake processor only.
1437 void br_ssl_engine_flush_record(br_ssl_engine_context
*cc
);
1440 * Test whether there is some accumulated payload to send.
1443 br_ssl_engine_has_pld_to_send(const br_ssl_engine_context
*rc
)
1445 return rc
->oxa
!= rc
->oxb
&& rc
->oxa
!= rc
->oxc
;
1449 * Initialize RNG in engine. Returned value is 1 on success, 0 on error.
1450 * This function will try to use the OS-provided RNG, if available. If
1451 * there is no OS-provided RNG, or if it failed, and no entropy was
1452 * injected by the caller, then a failure will be reported. On error,
1453 * the context error code is set.
1455 int br_ssl_engine_init_rand(br_ssl_engine_context
*cc
);
1458 * Reset the handshake-related parts of the engine.
1460 void br_ssl_engine_hs_reset(br_ssl_engine_context
*cc
,
1461 void (*hsinit
)(void *), void (*hsrun
)(void *));
1464 * Get the PRF to use for this context, for the provided PRF hash
1467 br_tls_prf_impl
br_ssl_engine_get_PRF(br_ssl_engine_context
*cc
, int prf_id
);
1470 * Consume the provided pre-master secret and compute the corresponding
1471 * master secret. The 'prf_id' is the ID of the hash function to use
1472 * with the TLS 1.2 PRF (ignored if the version is TLS 1.0 or 1.1).
1474 void br_ssl_engine_compute_master(br_ssl_engine_context
*cc
,
1475 int prf_id
, const void *pms
, size_t len
);
1478 * Switch to CBC decryption for incoming records.
1479 * cc the engine context
1480 * is_client non-zero for a client, zero for a server
1481 * prf_id id of hash function for PRF (ignored if not TLS 1.2+)
1482 * mac_id id of hash function for HMAC
1483 * bc_impl block cipher implementation (CBC decryption)
1484 * cipher_key_len block cipher key length (in bytes)
1486 void br_ssl_engine_switch_cbc_in(br_ssl_engine_context
*cc
,
1487 int is_client
, int prf_id
, int mac_id
,
1488 const br_block_cbcdec_class
*bc_impl
, size_t cipher_key_len
);
1491 * Switch to CBC encryption for outgoing records.
1492 * cc the engine context
1493 * is_client non-zero for a client, zero for a server
1494 * prf_id id of hash function for PRF (ignored if not TLS 1.2+)
1495 * mac_id id of hash function for HMAC
1496 * bc_impl block cipher implementation (CBC encryption)
1497 * cipher_key_len block cipher key length (in bytes)
1499 void br_ssl_engine_switch_cbc_out(br_ssl_engine_context
*cc
,
1500 int is_client
, int prf_id
, int mac_id
,
1501 const br_block_cbcenc_class
*bc_impl
, size_t cipher_key_len
);
1504 * Switch to GCM decryption for incoming records.
1505 * cc the engine context
1506 * is_client non-zero for a client, zero for a server
1507 * prf_id id of hash function for PRF
1508 * bc_impl block cipher implementation (CTR)
1509 * cipher_key_len block cipher key length (in bytes)
1511 void br_ssl_engine_switch_gcm_in(br_ssl_engine_context
*cc
,
1512 int is_client
, int prf_id
,
1513 const br_block_ctr_class
*bc_impl
, size_t cipher_key_len
);
1516 * Switch to GCM encryption for outgoing records.
1517 * cc the engine context
1518 * is_client non-zero for a client, zero for a server
1519 * prf_id id of hash function for PRF
1520 * bc_impl block cipher implementation (CTR)
1521 * cipher_key_len block cipher key length (in bytes)
1523 void br_ssl_engine_switch_gcm_out(br_ssl_engine_context
*cc
,
1524 int is_client
, int prf_id
,
1525 const br_block_ctr_class
*bc_impl
, size_t cipher_key_len
);
1528 * Calls to T0-generated code.
1530 void br_ssl_hs_client_init_main(void *ctx
);
1531 void br_ssl_hs_client_run(void *ctx
);
1532 void br_ssl_hs_server_init_main(void *ctx
);
1533 void br_ssl_hs_server_run(void *ctx
);
1536 * Get the hash function to use for signatures, given a bit mask of
1537 * supported hash functions. This implements a strict choice order
1538 * (namely SHA-256, SHA-384, SHA-512, SHA-224, SHA-1). If the mask
1539 * does not document support of any of these hash functions, then this
1540 * functions returns 0.
1542 int br_ssl_choose_hash(unsigned bf
);
1544 /* ==================================================================== */