Mercurial > dropbear
view libtommath/tommath_private.h @ 1715:3974f087d9c0
Disallow leading lines before the ident for server (#102)
Per RFC4253 4.2 clients must be able to process other lines of data
before the version string, server behavior is not defined neither
with MUST/SHOULD nor with MAY.
If server process up to 50 lines too - it may cause too long hanging
session with invalid/evil client that consume host resources and
potentially may lead to DDoS on poor embedded boxes.
Let's require first line from client to be version string and fail
early if it's not - matches both RFC and real OpenSSH behavior.
| author | Vladislav Grishenko <themiron@users.noreply.github.com> |
|---|---|
| date | Mon, 15 Jun 2020 18:22:18 +0500 |
| parents | 1051e4eea25a |
| children |
line wrap: on
line source
/* LibTomMath, multiple-precision integer library -- Tom St Denis */ /* SPDX-License-Identifier: Unlicense */ #ifndef TOMMATH_PRIV_H_ #define TOMMATH_PRIV_H_ #include "tommath.h" #include "tommath_class.h" /* * Private symbols * --------------- * * On Unix symbols can be marked as hidden if libtommath is compiled * as a shared object. By default, symbols are visible. * As of now, this feature is opt-in via the MP_PRIVATE_SYMBOLS define. * * On Win32 a .def file must be used to specify the exported symbols. */ #if defined (MP_PRIVATE_SYMBOLS) && defined(__GNUC__) && __GNUC__ >= 4 # define MP_PRIVATE __attribute__ ((visibility ("hidden"))) #else # define MP_PRIVATE #endif /* Hardening libtommath * -------------------- * * By default memory is zeroed before calling * MP_FREE to avoid leaking data. This is good * practice in cryptographical applications. * * Note however that memory allocators used * in cryptographical applications can often * be configured by itself to clear memory, * rendering the clearing in tommath unnecessary. * See for example https://github.com/GrapheneOS/hardened_malloc * and the option CONFIG_ZERO_ON_FREE. * * Furthermore there are applications which * value performance more and want this * feature to be disabled. For such applications * define MP_NO_ZERO_ON_FREE during compilation. */ #ifdef MP_NO_ZERO_ON_FREE # define MP_FREE_BUFFER(mem, size) MP_FREE((mem), (size)) # define MP_FREE_DIGITS(mem, digits) MP_FREE((mem), sizeof (mp_digit) * (size_t)(digits)) #else # define MP_FREE_BUFFER(mem, size) \ do { \ size_t fs_ = (size); \ void* fm_ = (mem); \ if (fm_ != NULL) { \ MP_ZERO_BUFFER(fm_, fs_); \ MP_FREE(fm_, fs_); \ } \ } while (0) # define MP_FREE_DIGITS(mem, digits) \ do { \ int fd_ = (digits); \ void* fm_ = (mem); \ if (fm_ != NULL) { \ size_t fs_ = sizeof (mp_digit) * (size_t)fd_; \ MP_ZERO_BUFFER(fm_, fs_); \ MP_FREE(fm_, fs_); \ } \ } while (0) #endif #ifdef MP_USE_MEMSET # include <string.h> # define MP_ZERO_BUFFER(mem, size) memset((mem), 0, (size)) # define MP_ZERO_DIGITS(mem, digits) \ do { \ int zd_ = (digits); \ if (zd_ > 0) { \ memset((mem), 0, sizeof(mp_digit) * (size_t)zd_); \ } \ } while (0) #else # define MP_ZERO_BUFFER(mem, size) \ do { \ size_t zs_ = (size); \ char* zm_ = (char*)(mem); \ while (zs_-- > 0u) { \ *zm_++ = '\0'; \ } \ } while (0) # define MP_ZERO_DIGITS(mem, digits) \ do { \ int zd_ = (digits); \ mp_digit* zm_ = (mem); \ while (zd_-- > 0) { \ *zm_++ = 0; \ } \ } while (0) #endif /* Tunable cutoffs * --------------- * * - In the default settings, a cutoff X can be modified at runtime * by adjusting the corresponding X_CUTOFF variable. * * - Tunability of the library can be disabled at compile time * by defining the MP_FIXED_CUTOFFS macro. * * - There is an additional file tommath_cutoffs.h, which defines * the default cutoffs. These can be adjusted manually or by the * autotuner. * */ #ifdef MP_FIXED_CUTOFFS # include "tommath_cutoffs.h" # define MP_KARATSUBA_MUL_CUTOFF MP_DEFAULT_KARATSUBA_MUL_CUTOFF # define MP_KARATSUBA_SQR_CUTOFF MP_DEFAULT_KARATSUBA_SQR_CUTOFF # define MP_TOOM_MUL_CUTOFF MP_DEFAULT_TOOM_MUL_CUTOFF # define MP_TOOM_SQR_CUTOFF MP_DEFAULT_TOOM_SQR_CUTOFF #else # define MP_KARATSUBA_MUL_CUTOFF KARATSUBA_MUL_CUTOFF # define MP_KARATSUBA_SQR_CUTOFF KARATSUBA_SQR_CUTOFF # define MP_TOOM_MUL_CUTOFF TOOM_MUL_CUTOFF # define MP_TOOM_SQR_CUTOFF TOOM_SQR_CUTOFF #endif /* define heap macros */ #ifndef MP_MALLOC /* default to libc stuff */ # include <stdlib.h> # define MP_MALLOC(size) malloc(size) # define MP_REALLOC(mem, oldsize, newsize) realloc((mem), (newsize)) # define MP_CALLOC(nmemb, size) calloc((nmemb), (size)) # define MP_FREE(mem, size) free(mem) #else /* prototypes for our heap functions */ extern void *MP_MALLOC(size_t size); extern void *MP_REALLOC(void *mem, size_t oldsize, size_t newsize); extern void *MP_CALLOC(size_t nmemb, size_t size); extern void MP_FREE(void *mem, size_t size); #endif /* feature detection macro */ #ifdef _MSC_VER /* Prevent false positive: not enough arguments for function-like macro invocation */ #pragma warning(disable: 4003) #endif #define MP_STRINGIZE(x) MP__STRINGIZE(x) #define MP__STRINGIZE(x) ""#x"" #define MP_HAS(x) (sizeof(MP_STRINGIZE(BN_##x##_C)) == 1u) /* TODO: Remove private_mp_word as soon as deprecated mp_word is removed from tommath. */ #undef mp_word typedef private_mp_word mp_word; #define MP_MIN(x, y) (((x) < (y)) ? (x) : (y)) #define MP_MAX(x, y) (((x) > (y)) ? (x) : (y)) /* Static assertion */ #define MP_STATIC_ASSERT(msg, cond) typedef char mp_static_assert_##msg[(cond) ? 1 : -1]; /* ---> Basic Manipulations <--- */ #define MP_IS_ZERO(a) ((a)->used == 0) #define MP_IS_EVEN(a) (((a)->used == 0) || (((a)->dp[0] & 1u) == 0u)) #define MP_IS_ODD(a) (((a)->used > 0) && (((a)->dp[0] & 1u) == 1u)) #define MP_SIZEOF_BITS(type) ((size_t)CHAR_BIT * sizeof(type)) #define MP_MAXFAST (int)(1uL << (MP_SIZEOF_BITS(mp_word) - (2u * (size_t)MP_DIGIT_BIT))) /* TODO: Remove PRIVATE_MP_WARRAY as soon as deprecated MP_WARRAY is removed from tommath.h */ #undef MP_WARRAY #define MP_WARRAY PRIVATE_MP_WARRAY /* TODO: Remove PRIVATE_MP_PREC as soon as deprecated MP_PREC is removed from tommath.h */ #ifdef PRIVATE_MP_PREC # undef MP_PREC # define MP_PREC PRIVATE_MP_PREC #endif /* Minimum number of available digits in mp_int, MP_PREC >= MP_MIN_PREC */ #define MP_MIN_PREC ((((int)MP_SIZEOF_BITS(long long) + MP_DIGIT_BIT) - 1) / MP_DIGIT_BIT) MP_STATIC_ASSERT(prec_geq_min_prec, MP_PREC >= MP_MIN_PREC) /* random number source */ extern MP_PRIVATE mp_err(*s_mp_rand_source)(void *out, size_t size); /* lowlevel functions, do not call! */ MP_PRIVATE mp_bool s_mp_get_bit(const mp_int *a, unsigned int b); MP_PRIVATE mp_err s_mp_add(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; MP_PRIVATE mp_err s_mp_sub(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; MP_PRIVATE mp_err s_mp_mul_digs_fast(const mp_int *a, const mp_int *b, mp_int *c, int digs) MP_WUR; MP_PRIVATE mp_err s_mp_mul_digs(const mp_int *a, const mp_int *b, mp_int *c, int digs) MP_WUR; MP_PRIVATE mp_err s_mp_mul_high_digs_fast(const mp_int *a, const mp_int *b, mp_int *c, int digs) MP_WUR; MP_PRIVATE mp_err s_mp_mul_high_digs(const mp_int *a, const mp_int *b, mp_int *c, int digs) MP_WUR; MP_PRIVATE mp_err s_mp_sqr_fast(const mp_int *a, mp_int *b) MP_WUR; MP_PRIVATE mp_err s_mp_sqr(const mp_int *a, mp_int *b) MP_WUR; MP_PRIVATE mp_err s_mp_balance_mul(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; MP_PRIVATE mp_err s_mp_karatsuba_mul(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; MP_PRIVATE mp_err s_mp_toom_mul(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; MP_PRIVATE mp_err s_mp_karatsuba_sqr(const mp_int *a, mp_int *b) MP_WUR; MP_PRIVATE mp_err s_mp_toom_sqr(const mp_int *a, mp_int *b) MP_WUR; MP_PRIVATE mp_err s_mp_invmod_fast(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; MP_PRIVATE mp_err s_mp_invmod_slow(const mp_int *a, const mp_int *b, mp_int *c) MP_WUR; MP_PRIVATE mp_err s_mp_montgomery_reduce_fast(mp_int *x, const mp_int *n, mp_digit rho) MP_WUR; MP_PRIVATE mp_err s_mp_exptmod_fast(const mp_int *G, const mp_int *X, const mp_int *P, mp_int *Y, int redmode) MP_WUR; MP_PRIVATE mp_err s_mp_exptmod(const mp_int *G, const mp_int *X, const mp_int *P, mp_int *Y, int redmode) MP_WUR; MP_PRIVATE mp_err s_mp_rand_platform(void *p, size_t n) MP_WUR; MP_PRIVATE mp_err s_mp_prime_random_ex(mp_int *a, int t, int size, int flags, private_mp_prime_callback cb, void *dat); MP_PRIVATE void s_mp_reverse(unsigned char *s, size_t len); MP_PRIVATE mp_err s_mp_prime_is_divisible(const mp_int *a, mp_bool *result); /* TODO: jenkins prng is not thread safe as of now */ MP_PRIVATE mp_err s_mp_rand_jenkins(void *p, size_t n) MP_WUR; MP_PRIVATE void s_mp_rand_jenkins_init(uint64_t seed); extern MP_PRIVATE const char *const mp_s_rmap; extern MP_PRIVATE const uint8_t mp_s_rmap_reverse[]; extern MP_PRIVATE const size_t mp_s_rmap_reverse_sz; extern MP_PRIVATE const mp_digit *s_mp_prime_tab; /* deprecated functions */ MP_DEPRECATED(s_mp_invmod_fast) mp_err fast_mp_invmod(const mp_int *a, const mp_int *b, mp_int *c); MP_DEPRECATED(s_mp_montgomery_reduce_fast) mp_err fast_mp_montgomery_reduce(mp_int *x, const mp_int *n, mp_digit rho); MP_DEPRECATED(s_mp_mul_digs_fast) mp_err fast_s_mp_mul_digs(const mp_int *a, const mp_int *b, mp_int *c, int digs); MP_DEPRECATED(s_mp_mul_high_digs_fast) mp_err fast_s_mp_mul_high_digs(const mp_int *a, const mp_int *b, mp_int *c, int digs); MP_DEPRECATED(s_mp_sqr_fast) mp_err fast_s_mp_sqr(const mp_int *a, mp_int *b); MP_DEPRECATED(s_mp_balance_mul) mp_err mp_balance_mul(const mp_int *a, const mp_int *b, mp_int *c); MP_DEPRECATED(s_mp_exptmod_fast) mp_err mp_exptmod_fast(const mp_int *G, const mp_int *X, const mp_int *P, mp_int *Y, int redmode); MP_DEPRECATED(s_mp_invmod_slow) mp_err mp_invmod_slow(const mp_int *a, const mp_int *b, mp_int *c); MP_DEPRECATED(s_mp_karatsuba_mul) mp_err mp_karatsuba_mul(const mp_int *a, const mp_int *b, mp_int *c); MP_DEPRECATED(s_mp_karatsuba_sqr) mp_err mp_karatsuba_sqr(const mp_int *a, mp_int *b); MP_DEPRECATED(s_mp_toom_mul) mp_err mp_toom_mul(const mp_int *a, const mp_int *b, mp_int *c); MP_DEPRECATED(s_mp_toom_sqr) mp_err mp_toom_sqr(const mp_int *a, mp_int *b); MP_DEPRECATED(s_mp_reverse) void bn_reverse(unsigned char *s, int len); #define MP_GET_ENDIANNESS(x) \ do{\ int16_t n = 0x1; \ char *p = (char *)&n; \ x = (p[0] == '\x01') ? MP_LITTLE_ENDIAN : MP_BIG_ENDIAN; \ } while (0) /* code-generating macros */ #define MP_SET_UNSIGNED(name, type) \ void name(mp_int * a, type b) \ { \ int i = 0; \ while (b != 0u) { \ a->dp[i++] = ((mp_digit)b & MP_MASK); \ if (MP_SIZEOF_BITS(type) <= MP_DIGIT_BIT) { break; } \ b >>= ((MP_SIZEOF_BITS(type) <= MP_DIGIT_BIT) ? 0 : MP_DIGIT_BIT); \ } \ a->used = i; \ a->sign = MP_ZPOS; \ MP_ZERO_DIGITS(a->dp + a->used, a->alloc - a->used); \ } #define MP_SET_SIGNED(name, uname, type, utype) \ void name(mp_int * a, type b) \ { \ uname(a, (b < 0) ? -(utype)b : (utype)b); \ if (b < 0) { a->sign = MP_NEG; } \ } #define MP_INIT_INT(name , set, type) \ mp_err name(mp_int * a, type b) \ { \ mp_err err; \ if ((err = mp_init(a)) != MP_OKAY) { \ return err; \ } \ set(a, b); \ return MP_OKAY; \ } #define MP_GET_MAG(name, type) \ type name(const mp_int* a) \ { \ unsigned i = MP_MIN((unsigned)a->used, (unsigned)((MP_SIZEOF_BITS(type) + MP_DIGIT_BIT - 1) / MP_DIGIT_BIT)); \ type res = 0u; \ while (i --> 0u) { \ res <<= ((MP_SIZEOF_BITS(type) <= MP_DIGIT_BIT) ? 0 : MP_DIGIT_BIT); \ res |= (type)a->dp[i]; \ if (MP_SIZEOF_BITS(type) <= MP_DIGIT_BIT) { break; } \ } \ return res; \ } #define MP_GET_SIGNED(name, mag, type, utype) \ type name(const mp_int* a) \ { \ utype res = mag(a); \ return (a->sign == MP_NEG) ? (type)-res : (type)res; \ } #endif