diff options
-rw-r--r-- | CHANGES | 15 | ||||
-rw-r--r-- | apps/speed.c | 4 | ||||
-rw-r--r-- | crypto/bn/bn.h | 44 | ||||
-rw-r--r-- | crypto/bn/bn_err.c | 7 | ||||
-rw-r--r-- | crypto/bn/bn_exp.c | 244 | ||||
-rw-r--r-- | crypto/bn/bn_lcl.h | 39 | ||||
-rw-r--r-- | crypto/bn/bntest.c | 56 | ||||
-rw-r--r-- | crypto/bn/expspeed.c | 2 | ||||
-rw-r--r-- | crypto/bn/exptest.c | 18 | ||||
-rw-r--r-- | crypto/dh/dh.h | 9 | ||||
-rw-r--r-- | crypto/dh/dh_key.c | 27 | ||||
-rw-r--r-- | crypto/dh/dhtest.c | 4 | ||||
-rw-r--r-- | crypto/dsa/dsa.h | 7 | ||||
-rw-r--r-- | crypto/dsa/dsa_key.c | 15 | ||||
-rw-r--r-- | crypto/dsa/dsa_ossl.c | 4 | ||||
-rw-r--r-- | crypto/dsa/dsatest.c | 9 | ||||
-rw-r--r-- | crypto/rsa/rsa.h | 33 | ||||
-rw-r--r-- | crypto/rsa/rsa_eay.c | 127 | ||||
-rw-r--r-- | crypto/rsa/rsa_test.c | 5 |
19 files changed, 617 insertions, 52 deletions
@@ -799,6 +799,21 @@ Changes between 0.9.7g and 0.9.7h [XX xxx XXXX] + *) Make a new fixed-window mod_exp implementation the default for + RSA, DSA, and DH private-key operations to mitigate the + hyper-threading timing attacks pointed out by Colin Percival + (http://www.daemonology.net/hyperthreading-considered-harmful/), + and potential related attacks. + + BN_mod_exp_mont_consttime() is the new exponentiation implementation, + and this is automatically used by BN_mod_exp_mont() if the new flag + BN_FLG_EXP_CONSTTIME is set for the exponent. RSA, DSA, and DH + will use this BN flag for private exponents unless the flag + RSA_FLAG_NO_EXP_CONSTTIME, DSA_FLAG_NO_EXP_CONSTTIME, or + DH_FLAG_NO_EXP_CONSTTIME, respectively, is set. + + [Matthew D Wood (Intel Corp), with some changes by Bodo Moeller] + *) Change the client implementation for SSLv23_method() and SSLv23_client_method() so that is uses the SSL 3.0/TLS 1.0 Client Hello message format if the SSL_OP_NO_SSLv2 option is set. diff --git a/apps/speed.c b/apps/speed.c index bd5b217b57..2ecbb1e9c6 100644 --- a/apps/speed.c +++ b/apps/speed.c @@ -2365,7 +2365,7 @@ show_res: k,rsa_bits[k],rsa_results[k][0], rsa_results[k][1]); else - fprintf(stdout,"rsa %4u bits %8.4fs %8.4fs %8.1f %8.1f\n", + fprintf(stdout,"rsa %4u bits %8.6fs %8.6fs %8.1f %8.1f\n", rsa_bits[k],rsa_results[k][0],rsa_results[k][1], 1.0/rsa_results[k][0],1.0/rsa_results[k][1]); } @@ -2384,7 +2384,7 @@ show_res: fprintf(stdout,"+F3:%u:%u:%f:%f\n", k,dsa_bits[k],dsa_results[k][0],dsa_results[k][1]); else - fprintf(stdout,"dsa %4u bits %8.4fs %8.4fs %8.1f %8.1f\n", + fprintf(stdout,"dsa %4u bits %8.6fs %8.6fs %8.1f %8.1f\n", dsa_bits[k],dsa_results[k][0],dsa_results[k][1], 1.0/dsa_results[k][0],1.0/dsa_results[k][1]); } diff --git a/crypto/bn/bn.h b/crypto/bn/bn.h index 99faf8f07e..6d52735207 100644 --- a/crypto/bn/bn.h +++ b/crypto/bn/bn.h @@ -245,12 +245,23 @@ extern "C" { #define BN_FLG_MALLOCED 0x01 #define BN_FLG_STATIC_DATA 0x02 +#define BN_FLG_EXP_CONSTTIME 0x04 /* avoid leaking exponent information through timings + * (BN_mod_exp_mont() will call BN_mod_exp_mont_consttime) */ #ifndef OPENSSL_NO_DEPRECATED #define BN_FLG_FREE 0x8000 /* used for debuging */ #endif #define BN_set_flags(b,n) ((b)->flags|=(n)) #define BN_get_flags(b,n) ((b)->flags&(n)) +#define BN_with_flags(dest,b,n) ((dest)->d=(b)->d, \ + (dest)->top=(b)->top, \ + (dest)->dmax=(b)->dmax, \ + (dest)->neg=(b)->neg, \ + (dest)->flags=(((dest)->flags & BN_FLG_MALLOCED) \ + | ((b)->flags & ~BN_FLG_MALLOCED) \ + | BN_FLG_STATIC_DATA \ + | (n))) + /* Already declared in ossl_typ.h */ #if 0 typedef struct bignum_st BIGNUM; @@ -439,6 +450,8 @@ int BN_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m,BN_CTX *ctx); int BN_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx); +int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p, + const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont); int BN_mod_exp_mont_word(BIGNUM *r, BN_ULONG a, const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx); int BN_mod_exp2_mont(BIGNUM *r, const BIGNUM *a1, const BIGNUM *p1, @@ -728,9 +741,9 @@ void ERR_load_BN_strings(void); /* Error codes for the BN functions. */ /* Function codes. */ -#define BN_F_BNRAND 114 +#define BN_F_BNRAND 127 #define BN_F_BN_BLINDING_CONVERT_EX 100 -#define BN_F_BN_BLINDING_CREATE_PARAM 133 +#define BN_F_BN_BLINDING_CREATE_PARAM 128 #define BN_F_BN_BLINDING_INVERT_EX 101 #define BN_F_BN_BLINDING_NEW 102 #define BN_F_BN_BLINDING_UPDATE 103 @@ -738,28 +751,32 @@ void ERR_load_BN_strings(void); #define BN_F_BN_BN2HEX 105 #define BN_F_BN_CTX_GET 116 #define BN_F_BN_CTX_NEW 106 -#define BN_F_BN_CTX_START 130 +#define BN_F_BN_CTX_START 129 #define BN_F_BN_DIV 107 -#define BN_F_BN_DIV_RECP 131 +#define BN_F_BN_DIV_RECP 130 +#define BN_F_BN_EXP 123 #define BN_F_BN_EXPAND2 108 #define BN_F_BN_EXPAND_INTERNAL 120 -#define BN_F_BN_GF2M_MOD 126 -#define BN_F_BN_GF2M_MOD_DIV 123 -#define BN_F_BN_GF2M_MOD_EXP 127 -#define BN_F_BN_GF2M_MOD_MUL 124 -#define BN_F_BN_GF2M_MOD_SOLVE_QUAD 128 -#define BN_F_BN_GF2M_MOD_SOLVE_QUAD_ARR 129 -#define BN_F_BN_GF2M_MOD_SQR 125 -#define BN_F_BN_GF2M_MOD_SQRT 132 +#define BN_F_BN_GF2M_MOD 131 +#define BN_F_BN_GF2M_MOD_EXP 132 +#define BN_F_BN_GF2M_MOD_MUL 133 +#define BN_F_BN_GF2M_MOD_SOLVE_QUAD 134 +#define BN_F_BN_GF2M_MOD_SOLVE_QUAD_ARR 135 +#define BN_F_BN_GF2M_MOD_SQR 136 +#define BN_F_BN_GF2M_MOD_SQRT 137 #define BN_F_BN_MOD_EXP2_MONT 118 #define BN_F_BN_MOD_EXP_MONT 109 +#define BN_F_BN_MOD_EXP_MONT_CONSTTIME 124 #define BN_F_BN_MOD_EXP_MONT_WORD 117 +#define BN_F_BN_MOD_EXP_RECP 125 +#define BN_F_BN_MOD_EXP_SIMPLE 126 #define BN_F_BN_MOD_INVERSE 110 #define BN_F_BN_MOD_LSHIFT_QUICK 119 #define BN_F_BN_MOD_MUL_RECIPROCAL 111 #define BN_F_BN_MOD_SQRT 121 #define BN_F_BN_MPI2BN 112 #define BN_F_BN_NEW 113 +#define BN_F_BN_RAND 114 #define BN_F_BN_RAND_RANGE 122 #define BN_F_BN_USUB 115 @@ -775,10 +792,9 @@ void ERR_load_BN_strings(void); #define BN_R_INVALID_LENGTH 106 #define BN_R_INVALID_RANGE 115 #define BN_R_NOT_A_SQUARE 111 -#define BN_R_NOT_IMPLEMENTED 116 #define BN_R_NOT_INITIALIZED 107 #define BN_R_NO_INVERSE 108 -#define BN_R_NO_SOLUTION 117 +#define BN_R_NO_SOLUTION 116 #define BN_R_P_IS_NOT_PRIME 112 #define BN_R_TOO_MANY_ITERATIONS 113 #define BN_R_TOO_MANY_TEMPORARY_VARIABLES 109 diff --git a/crypto/bn/bn_err.c b/crypto/bn/bn_err.c index 58a7d0617f..a253959a5c 100644 --- a/crypto/bn/bn_err.c +++ b/crypto/bn/bn_err.c @@ -83,10 +83,10 @@ static ERR_STRING_DATA BN_str_functs[]= {ERR_FUNC(BN_F_BN_CTX_START), "BN_CTX_start"}, {ERR_FUNC(BN_F_BN_DIV), "BN_div"}, {ERR_FUNC(BN_F_BN_DIV_RECP), "BN_div_recp"}, +{ERR_FUNC(BN_F_BN_EXP), "BN_exp"}, {ERR_FUNC(BN_F_BN_EXPAND2), "bn_expand2"}, {ERR_FUNC(BN_F_BN_EXPAND_INTERNAL), "BN_EXPAND_INTERNAL"}, {ERR_FUNC(BN_F_BN_GF2M_MOD), "BN_GF2m_mod"}, -{ERR_FUNC(BN_F_BN_GF2M_MOD_DIV), "BN_GF2m_mod_div"}, {ERR_FUNC(BN_F_BN_GF2M_MOD_EXP), "BN_GF2m_mod_exp"}, {ERR_FUNC(BN_F_BN_GF2M_MOD_MUL), "BN_GF2m_mod_mul"}, {ERR_FUNC(BN_F_BN_GF2M_MOD_SOLVE_QUAD), "BN_GF2m_mod_solve_quad"}, @@ -95,13 +95,17 @@ static ERR_STRING_DATA BN_str_functs[]= {ERR_FUNC(BN_F_BN_GF2M_MOD_SQRT), "BN_GF2m_mod_sqrt"}, {ERR_FUNC(BN_F_BN_MOD_EXP2_MONT), "BN_mod_exp2_mont"}, {ERR_FUNC(BN_F_BN_MOD_EXP_MONT), "BN_mod_exp_mont"}, +{ERR_FUNC(BN_F_BN_MOD_EXP_MONT_CONSTTIME), "BN_mod_exp_mont_consttime"}, {ERR_FUNC(BN_F_BN_MOD_EXP_MONT_WORD), "BN_mod_exp_mont_word"}, +{ERR_FUNC(BN_F_BN_MOD_EXP_RECP), "BN_mod_exp_recp"}, +{ERR_FUNC(BN_F_BN_MOD_EXP_SIMPLE), "BN_mod_exp_simple"}, {ERR_FUNC(BN_F_BN_MOD_INVERSE), "BN_mod_inverse"}, {ERR_FUNC(BN_F_BN_MOD_LSHIFT_QUICK), "BN_mod_lshift_quick"}, {ERR_FUNC(BN_F_BN_MOD_MUL_RECIPROCAL), "BN_mod_mul_reciprocal"}, {ERR_FUNC(BN_F_BN_MOD_SQRT), "BN_mod_sqrt"}, {ERR_FUNC(BN_F_BN_MPI2BN), "BN_mpi2bn"}, {ERR_FUNC(BN_F_BN_NEW), "BN_new"}, +{ERR_FUNC(BN_F_BN_RAND), "BN_rand"}, {ERR_FUNC(BN_F_BN_RAND_RANGE), "BN_rand_range"}, {ERR_FUNC(BN_F_BN_USUB), "BN_usub"}, {0,NULL} @@ -120,7 +124,6 @@ static ERR_STRING_DATA BN_str_reasons[]= {ERR_REASON(BN_R_INVALID_LENGTH) ,"invalid length"}, {ERR_REASON(BN_R_INVALID_RANGE) ,"invalid range"}, {ERR_REASON(BN_R_NOT_A_SQUARE) ,"not a square"}, -{ERR_REASON(BN_R_NOT_IMPLEMENTED) ,"not implemented"}, {ERR_REASON(BN_R_NOT_INITIALIZED) ,"not initialized"}, {ERR_REASON(BN_R_NO_INVERSE) ,"no inverse"}, {ERR_REASON(BN_R_NO_SOLUTION) ,"no solution"}, diff --git a/crypto/bn/bn_exp.c b/crypto/bn/bn_exp.c index d6bb2b4397..8f8c694481 100644 --- a/crypto/bn/bn_exp.c +++ b/crypto/bn/bn_exp.c @@ -56,7 +56,7 @@ * [including the GNU Public Licence.] */ /* ==================================================================== - * Copyright (c) 1998-2000 The OpenSSL Project. All rights reserved. + * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -113,6 +113,7 @@ #include "cryptlib.h" #include "bn_lcl.h" +/* maximum precomputation table size for *variable* sliding windows */ #define TABLE_SIZE 32 /* this one works - simple but works */ @@ -121,6 +122,13 @@ int BN_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx) int i,bits,ret=0; BIGNUM *v,*rr; + if (BN_get_flags(p, BN_FLG_EXP_CONSTTIME) != 0) + { + /* BN_FLG_EXP_CONSTTIME only supported by BN_mod_exp_mont() */ + BNerr(BN_F_BN_EXP,ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); + return -1; + } + BN_CTX_start(ctx); if ((r == a) || (r == p)) rr = BN_CTX_get(ctx); @@ -205,7 +213,7 @@ int BN_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m, if (BN_is_odd(m)) { # ifdef MONT_EXP_WORD - if (a->top == 1 && !a->neg) + if (a->top == 1 && !a->neg && (BN_get_flags(p, BN_FLG_EXP_CONSTTIME) == 0)) { BN_ULONG A = a->d[0]; ret=BN_mod_exp_mont_word(r,A,p,m,ctx,NULL); @@ -237,6 +245,13 @@ int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BIGNUM *val[TABLE_SIZE]; BN_RECP_CTX recp; + if (BN_get_flags(p, BN_FLG_EXP_CONSTTIME) != 0) + { + /* BN_FLG_EXP_CONSTTIME only supported by BN_mod_exp_mont() */ + BNerr(BN_F_BN_MOD_EXP_RECP,ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); + return -1; + } + bits=BN_num_bits(p); if (bits == 0) @@ -364,6 +379,11 @@ int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p, BIGNUM *val[TABLE_SIZE]; BN_MONT_CTX *mont=NULL; + if (BN_get_flags(p, BN_FLG_EXP_CONSTTIME) != 0) + { + return BN_mod_exp_mont_consttime(rr, a, p, m, ctx, in_mont); + } + bn_check_top(a); bn_check_top(p); bn_check_top(m); @@ -495,6 +515,212 @@ err: return(ret); } + +/* BN_mod_exp_mont_consttime() stores the precomputed powers in a specific layout + * so that accessing any of these table values shows the same access pattern as far + * as cache lines are concerned. The following functions are used to transfer a BIGNUM + * from/to that table. */ + +static int MOD_EXP_CTIME_COPY_TO_PREBUF(BIGNUM *b, int top, unsigned char *buf, int idx, int width) + { + size_t i, j; + + if (bn_wexpand(b, top) == NULL) + return 0; + while (b->top < top) + { + b->d[b->top++] = 0; + } + + for (i = 0, j=idx; i < top * sizeof b->d[0]; i++, j+=width) + { + buf[j] = ((unsigned char*)b->d)[i]; + } + + bn_correct_top(b); + return 1; + } + +static int MOD_EXP_CTIME_COPY_FROM_PREBUF(BIGNUM *b, int top, unsigned char *buf, int idx, int width) + { + size_t i, j; + + if (bn_wexpand(b, top) == NULL) + return 0; + + for (i=0, j=idx; i < top * sizeof b->d[0]; i++, j+=width) + { + ((unsigned char*)b->d)[i] = buf[j]; + } + + b->top = top; + bn_correct_top(b); + return 1; + } + +/* Given a pointer value, compute the next address that is a cache line multiple. */ +#define MOD_EXP_CTIME_ALIGN(x_) \ + ((unsigned char*)(x_) + (MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH - (((BN_ULONG)(x_)) & (MOD_EXP_CTIME_MIN_CACHE_LINE_MASK)))) + +/* This variant of BN_mod_exp_mont() uses fixed windows and the special + * precomputation memory layout to limit data-dependency to a minimum + * to protect secret exponents (cf. the hyper-threading timing attacks + * pointed out by Colin Percival, + * http://www.daemonology.net/hyperthreading-considered-harmful/) + */ +int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p, + const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont) + { + int i,bits,ret=0,idx,window,wvalue; + int top; + BIGNUM *r; + const BIGNUM *aa; + BN_MONT_CTX *mont=NULL; + + int numPowers; + unsigned char *powerbufFree=NULL; + int powerbufLen = 0; + unsigned char *powerbuf=NULL; + BIGNUM *computeTemp=NULL, *am=NULL; + + bn_check_top(a); + bn_check_top(p); + bn_check_top(m); + + top = m->top; + + if (!(m->d[0] & 1)) + { + BNerr(BN_F_BN_MOD_EXP_MONT_CONSTTIME,BN_R_CALLED_WITH_EVEN_MODULUS); + return(0); + } + bits=BN_num_bits(p); + if (bits == 0) + { + ret = BN_one(rr); + return ret; + } + + /* Initialize BIGNUM context and allocate intermediate result */ + BN_CTX_start(ctx); + r = BN_CTX_get(ctx); + if (r == NULL) goto err; + + /* Allocate a montgomery context if it was not supplied by the caller. + * If this is not done, things will break in the montgomery part. + */ + if (in_mont != NULL) + mont=in_mont; + else + { + if ((mont=BN_MONT_CTX_new()) == NULL) goto err; + if (!BN_MONT_CTX_set(mont,m,ctx)) goto err; + } + + /* Get the window size to use with size of p. */ + window = BN_window_bits_for_ctime_exponent_size(bits); + + /* Allocate a buffer large enough to hold all of the pre-computed + * powers of a. + */ + numPowers = 1 << window; + powerbufLen = sizeof(m->d[0])*top*numPowers; + if ((powerbufFree=(unsigned char*)OPENSSL_malloc(powerbufLen+MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH)) == NULL) + goto err; + + powerbuf = MOD_EXP_CTIME_ALIGN(powerbufFree); + memset(powerbuf, 0, powerbufLen); + + /* Initialize the intermediate result. Do this early to save double conversion, + * once each for a^0 and intermediate result. + */ + if (!BN_to_montgomery(r,BN_value_one(),mont,ctx)) goto err; + if (!MOD_EXP_CTIME_COPY_TO_PREBUF(r, top, powerbuf, 0, numPowers)) goto err; + + /* Initialize computeTemp as a^1 with montgomery precalcs */ + computeTemp = BN_CTX_get(ctx); + am = BN_CTX_get(ctx); + if (computeTemp==NULL || am==NULL) goto err; + + if (a->neg || BN_ucmp(a,m) >= 0) + { + if (!BN_mod(am,a,m,ctx)) + goto err; + aa= am; + } + else + aa=a; + if (!BN_to_montgomery(am,aa,mont,ctx)) goto err; + if (!BN_copy(computeTemp, am)) goto err; + if (!MOD_EXP_CTIME_COPY_TO_PREBUF(am, top, powerbuf, 1, numPowers)) goto err; + + /* If the window size is greater than 1, then calculate + * val[i=2..2^winsize-1]. Powers are computed as a*a^(i-1) + * (even powers could instead be computed as (a^(i/2))^2 + * to use the slight performance advantage of sqr over mul). + */ + if (window > 1) + { + for (i=2; i<numPowers; i++) + { + /* Calculate a^i = a^(i-1) * a */ + if (!BN_mod_mul_montgomery(computeTemp,am,computeTemp,mont,ctx)) + goto err; + if (!MOD_EXP_CTIME_COPY_TO_PREBUF(computeTemp, top, powerbuf, i, numPowers)) goto err; + } + } + + /* Adjust the number of bits up to a multiple of the window size. + * If the exponent length is not a multiple of the window size, then + * this pads the most significant bits with zeros to normalize the + * scanning loop to there's no special cases. + * + * * NOTE: Making the window size a power of two less than the native + * * word size ensures that the padded bits won't go past the last + * * word in the internal BIGNUM structure. Going past the end will + * * still produce the correct result, but causes a different branch + * * to be taken in the BN_is_bit_set function. + */ + bits = ((bits+window-1)/window)*window; + idx=bits-1; /* The top bit of the window */ + + /* Scan the exponent one window at a time starting from the most + * significant bits. + */ + while (idx >= 0) + { + wvalue=0; /* The 'value' of the window */ + + /* Scan the window, squaring the result as we go */ + for (i=0; i<window; i++,idx--) + { + if (!BN_mod_mul_montgomery(r,r,r,mont,ctx)) goto err; + wvalue = (wvalue<<1)+BN_is_bit_set(p,idx); + } + + /* Fetch the appropriate pre-computed value from the pre-buf */ + if (!MOD_EXP_CTIME_COPY_FROM_PREBUF(computeTemp, top, powerbuf, wvalue, numPowers)) goto err; + + /* Multiply the result into the intermediate result */ + if (!BN_mod_mul_montgomery(r,r,computeTemp,mont,ctx)) goto err; + } + + /* Convert the final result from montgomery to standard format */ + if (!BN_from_montgomery(rr,r,mont,ctx)) goto err; + ret=1; +err: + if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont); + if (powerbuf!=NULL) + { + OPENSSL_cleanse(powerbuf,powerbufLen); + OPENSSL_free(powerbufFree); + } + if (am!=NULL) BN_clear(am); + if (computeTemp!=NULL) BN_clear(computeTemp); + BN_CTX_end(ctx); + return(ret); + } + int BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont) { @@ -519,6 +745,13 @@ int BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p, #define BN_TO_MONTGOMERY_WORD(r, w, mont) \ (BN_set_word(r, (w)) && BN_to_montgomery(r, r, (mont), ctx)) + if (BN_get_flags(p, BN_FLG_EXP_CONSTTIME) != 0) + { + /* BN_FLG_EXP_CONSTTIME only supported by BN_mod_exp_mont() */ + BNerr(BN_F_BN_MOD_EXP_MONT_WORD,ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); + return -1; + } + bn_check_top(p); bn_check_top(m); @@ -648,6 +881,13 @@ int BN_mod_exp_simple(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, /* Table of variables obtained from 'ctx' */ BIGNUM *val[TABLE_SIZE]; + if (BN_get_flags(p, BN_FLG_EXP_CONSTTIME) != 0) + { + /* BN_FLG_EXP_CONSTTIME only supported by BN_mod_exp_mont() */ + BNerr(BN_F_BN_MOD_EXP_SIMPLE,ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); + return -1; + } + bits=BN_num_bits(p); if (bits == 0) diff --git a/crypto/bn/bn_lcl.h b/crypto/bn/bn_lcl.h index 45e19221aa..1c680fc3ce 100644 --- a/crypto/bn/bn_lcl.h +++ b/crypto/bn/bn_lcl.h @@ -163,6 +163,45 @@ extern "C" { +/* BN_mod_exp_mont_conttime is based on the assumption that the + * L1 data cache line width of the target processor is at least + * the following value. + */ +#define MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH ( 64 ) +#define MOD_EXP_CTIME_MIN_CACHE_LINE_MASK (MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH - 1) + +/* Window sizes optimized for fixed window size modular exponentiation + * algorithm (BN_mod_exp_mont_consttime). + * + * To achieve the security goals of BN_mode_exp_mont_consttime, the + * maximum size of the window must not exceed + * log_2(MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH). + * + * Window size thresholds are defined for cache line sizes of 32 and 64, + * cache line sizes where log_2(32)=5 and log_2(64)=6 respectively. A + * window size of 7 should only be used on processors that have a 128 + * byte or greater cache line size. + */ +#if MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 64 + +# define BN_window_bits_for_ctime_exponent_size(b) \ + ((b) > 937 ? 6 : \ + (b) > 306 ? 5 : \ + (b) > 89 ? 4 : \ + (b) > 22 ? 3 : 1) +# define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE (6) + +#elif MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 32 + +# define BN_window_bits_for_ctime_exponent_size(b) \ + ((b) > 306 ? 5 : \ + (b) > 89 ? 4 : \ + (b) > 22 ? 3 : 1) +# define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE (5) + +#endif + + /* Pentium pro 16,16,16,32,64 */ /* Alpha 16,16,16,16.64 */ #define BN_MULL_SIZE_NORMAL (16) /* 32 */ diff --git a/crypto/bn/bntest.c b/crypto/bn/bntest.c index 9169cc8813..c885300a66 100644 --- a/crypto/bn/bntest.c +++ b/crypto/bn/bntest.c @@ -106,6 +106,7 @@ int test_mont(BIO *bp,BN_CTX *ctx); int test_mod(BIO *bp,BN_CTX *ctx); int test_mod_mul(BIO *bp,BN_CTX *ctx); int test_mod_exp(BIO *bp,BN_CTX *ctx); +int test_mod_exp_mont_consttime(BIO *bp,BN_CTX *ctx); int test_exp(BIO *bp,BN_CTX *ctx); int test_gf2m_add(BIO *bp); int test_gf2m_mod(BIO *bp); @@ -246,6 +247,10 @@ int main(int argc, char *argv[]) if (!test_mod_exp(out,ctx)) goto err; BIO_flush(out); + message(out,"BN_mod_exp_mont_consttime"); + if (!test_mod_exp_mont_consttime(out,ctx)) goto err; + BIO_flush(out); + message(out,"BN_exp"); if (!test_exp(out,ctx)) goto err; BIO_flush(out); @@ -954,6 +959,57 @@ int test_mod_exp(BIO *bp, BN_CTX *ctx) return(1); } +int test_mod_exp_mont_consttime(BIO *bp, BN_CTX *ctx) + { + BIGNUM *a,*b,*c,*d,*e; + int i; + + a=BN_new(); + b=BN_new(); + c=BN_new(); + d=BN_new(); + e=BN_new(); + + BN_bntest_rand(c,30,0,1); /* must be odd for montgomery */ + for (i=0; i<num2; i++) + { + BN_bntest_rand(a,20+i*5,0,0); /**/ + BN_bntest_rand(b,2+i,0,0); /**/ + + if (!BN_mod_exp_mont_consttime(d,a,b,c,ctx,NULL)) + return(00); + + if (bp != NULL) + { + if (!results) + { + BN_print(bp,a); + BIO_puts(bp," ^ "); + BN_print(bp,b); + BIO_puts(bp," % "); + BN_print(bp,c); + BIO_puts(bp," - "); + } + BN_print(bp,d); + BIO_puts(bp,"\n"); + } + BN_exp(e,a,b,ctx); + BN_sub(e,e,d); + BN_div(a,b,e,c,ctx); + if(!BN_is_zero(b)) + { + fprintf(stderr,"Modulo exponentiation test failed!\n"); + return 0; + } + } + BN_free(a); + BN_free(b); + BN_free(c); + BN_free(d); + BN_free(e); + return(1); + } + int test_exp(BIO *bp, BN_CTX *ctx) { BIGNUM *a,*b,*d,*e,*one; diff --git a/crypto/bn/expspeed.c b/crypto/bn/expspeed.c index 07a1bcf51c..4d5f221f33 100644 --- a/crypto/bn/expspeed.c +++ b/crypto/bn/expspeed.c @@ -321,7 +321,7 @@ void do_mul_exp(BIGNUM *r, BIGNUM *a, BIGNUM *b, BIGNUM *c, BN_CTX *ctx) #else /* TEST_SQRT */ "2*sqrt [prime == %d (mod 64)] %4d %4d mod %4d" #endif - " -> %8.3fms %5.1f (%ld)\n", + " -> %8.6fms %5.1f (%ld)\n", #ifdef TEST_SQRT P_MOD_64, #endif diff --git a/crypto/bn/exptest.c b/crypto/bn/exptest.c index 37aec55b89..f598a07cf5 100644 --- a/crypto/bn/exptest.c +++ b/crypto/bn/exptest.c @@ -77,7 +77,7 @@ int main(int argc, char *argv[]) BIO *out=NULL; int i,ret; unsigned char c; - BIGNUM *r_mont,*r_recp,*r_simple,*a,*b,*m; + BIGNUM *r_mont,*r_mont_const,*r_recp,*r_simple,*a,*b,*m; RAND_seed(rnd_seed, sizeof rnd_seed); /* or BN_rand may fail, and we don't * even check its return value @@ -88,6 +88,7 @@ int main(int argc, char *argv[]) ctx=BN_CTX_new(); if (ctx == NULL) EXIT(1); r_mont=BN_new(); + r_mont_const=BN_new(); r_recp=BN_new(); r_simple=BN_new(); a=BN_new(); @@ -143,8 +144,17 @@ int main(int argc, char *argv[]) EXIT(1); } + ret=BN_mod_exp_mont_consttime(r_mont_const,a,b,m,ctx,NULL); + if (ret <= 0) + { + printf("BN_mod_exp_mont_consttime() problems\n"); + ERR_print_errors(out); + EXIT(1); + } + if (BN_cmp(r_simple, r_mont) == 0 - && BN_cmp(r_simple,r_recp) == 0) + && BN_cmp(r_simple,r_recp) == 0 + && BN_cmp(r_simple,r_mont_const) == 0) { printf("."); fflush(stdout); @@ -153,6 +163,8 @@ int main(int argc, char *argv[]) { if (BN_cmp(r_simple,r_mont) != 0) printf("\nsimple and mont results differ\n"); + if (BN_cmp(r_simple,r_mont) != 0) + printf("\nsimple and mont const time results differ\n"); if (BN_cmp(r_simple,r_recp) != 0) printf("\nsimple and recp results differ\n"); @@ -162,11 +174,13 @@ int main(int argc, char *argv[]) printf("\nsimple ="); BN_print(out,r_simple); printf("\nrecp ="); BN_print(out,r_recp); printf("\nmont ="); BN_print(out,r_mont); + printf("\nmont_ct ="); BN_print(out,r_mont_const); printf("\n"); EXIT(1); } } BN_free(r_mont); + BN_free(r_mont_const); BN_free(r_recp); BN_free(r_simple); BN_free(a); diff --git a/crypto/dh/dh.h b/crypto/dh/dh.h index da44778b58..d1559fd4f8 100644 --- a/crypto/dh/dh.h +++ b/crypto/dh/dh.h @@ -73,7 +73,14 @@ #include <openssl/bn.h> #endif -#define DH_FLAG_CACHE_MONT_P 0x01 +#define DH_FLAG_CACHE_MONT_P 0x01 +#define DH_FLAG_NO_EXP_CONSTTIME 0x02 /* new with 0.9.7h; the built-in DH + * implementation now uses constant time + * modular exponentiation for secret exponents + * by default. This flag causes the + * faster variable sliding window method to + * be used for all exponents. + */ #ifdef __cplusplus extern "C" { diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c index 9148f179f7..e384286c73 100644 --- a/crypto/dh/dh_key.c +++ b/crypto/dh/dh_key.c @@ -141,8 +141,21 @@ static int generate_key(DH *dh) l = dh->length ? dh->length : BN_num_bits(dh->p)-1; /* secret exponent length */ if (!BN_rand(priv_key, l, 0, 0)) goto err; } - if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, priv_key,dh->p,ctx,mont)) - goto err; + + { + BIGNUM local_prk; + BIGNUM *prk; + + if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) + { + prk = &local_prk; + BN_with_flags(prk, priv_key, BN_FLG_EXP_CONSTTIME); + } + else + prk = priv_key; + + if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, prk, dh->p, ctx, mont)) goto err; + } dh->pub_key=pub_key; dh->priv_key=priv_key; @@ -179,6 +192,11 @@ static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh) { mont = BN_MONT_CTX_set_locked(&dh->method_mont_p, CRYPTO_LOCK_DH, dh->p, ctx); + if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) + { + /* XXX */ + BN_set_flags(dh->priv_key, BN_FLG_EXP_CONSTTIME); + } if (!mont) goto err; } @@ -201,7 +219,10 @@ static int dh_bn_mod_exp(const DH *dh, BIGNUM *r, const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx) { - if (a->top == 1) + /* If a is only one word long and constant time is false, use the faster + * exponenentiation function. + */ + if (a->top == 1 && ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) != 0)) { BN_ULONG A = a->d[0]; return BN_mod_exp_mont_word(r,A,p,m,ctx,m_ctx); diff --git a/crypto/dh/dhtest.c b/crypto/dh/dhtest.c index 1b193649d3..882f5c310a 100644 --- a/crypto/dh/dhtest.c +++ b/crypto/dh/dhtest.c @@ -145,6 +145,10 @@ int main(int argc, char *argv[]) b->g=BN_dup(a->g); if ((b->p == NULL) || (b->g == NULL)) goto err; + /* Set a to run with normal modexp and b to use constant time */ + a->flags &= ~DH_FLAG_NO_EXP_CONSTTIME; + b->flags |= DH_FLAG_NO_EXP_CONSTTIME; + if (!DH_generate_key(a)) goto err; BIO_puts(out,"pri 1="); BN_print(out,a->priv_key); diff --git a/crypto/dsa/dsa.h b/crypto/dsa/dsa.h index c7ba059f25..b12db98b13 100644 --- a/crypto/dsa/dsa.h +++ b/crypto/dsa/dsa.h @@ -85,6 +85,13 @@ #endif #define DSA_FLAG_CACHE_MONT_P 0x01 +#define DSA_FLAG_NO_EXP_CONSTTIME 0x02 /* new with 0.9.7h; the built-in DSA + * implementation now uses constant time + * modular exponentiation for secret exponents + * by default. This flag causes the + * faster variable sliding window method to + * be used for all exponents. + */ #ifdef __cplusplus extern "C" { diff --git a/crypto/dsa/dsa_key.c b/crypto/dsa/dsa_key.c index 8427b77970..5ba885e1e2 100644 --- a/crypto/dsa/dsa_key.c +++ b/crypto/dsa/dsa_key.c @@ -98,8 +98,21 @@ static int dsa_builtin_keygen(DSA *dsa) } else pub_key=dsa->pub_key; + + { + BIGNUM local_prk; + BIGNUM *prk; + + if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) + { + prk = &local_prk; + BN_with_flags(prk, priv_key, BN_FLG_EXP_CONSTTIME); + } + else + prk = priv_key; - if (!BN_mod_exp(pub_key,dsa->g,priv_key,dsa->p,ctx)) goto err; + if (!BN_mod_exp(pub_key,dsa->g,prk,dsa->p,ctx)) goto err; + } dsa->priv_key=priv_key; dsa->pub_key=pub_key; diff --git a/crypto/dsa/dsa_ossl.c b/crypto/dsa/dsa_ossl.c index 25cd8484aa..2e5ede7826 100644 --- a/crypto/dsa/dsa_ossl.c +++ b/crypto/dsa/dsa_ossl.c @@ -227,6 +227,10 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp) do if (!BN_rand_range(&k, dsa->q)) goto err; while (BN_is_zero(&k)); + if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) + { + BN_set_flags(&k, BN_FLG_EXP_CONSTTIME); + } if (dsa->flags & DSA_FLAG_CACHE_MONT_P) { diff --git a/crypto/dsa/dsatest.c b/crypto/dsa/dsatest.c index ccc456eab7..66ff417398 100644 --- a/crypto/dsa/dsatest.c +++ b/crypto/dsa/dsatest.c @@ -204,10 +204,19 @@ int main(int argc, char **argv) BIO_printf(bio_err,"g value is wrong\n"); goto end; } + + dsa->flags |= DSA_FLAG_NO_EXP_CONSTTIME; DSA_generate_key(dsa); DSA_sign(0, str1, 20, sig, &siglen, dsa); if (DSA_verify(0, str1, 20, sig, siglen, dsa) == 1) ret=1; + + dsa->flags &= ~DSA_FLAG_NO_EXP_CONSTTIME; + DSA_generate_key(dsa); + DSA_sign(0, str1, 20, sig, &siglen, dsa); + if (DSA_verify(0, str1, 20, sig, siglen, dsa) == 1) + ret=1; + end: if (!ret) ERR_print_errors(bio_err); diff --git a/crypto/rsa/rsa.h b/crypto/rsa/rsa.h index f8bcbc3b8d..dcefebad21 100644 --- a/crypto/rsa/rsa.h +++ b/crypto/rsa/rsa.h @@ -162,28 +162,35 @@ struct rsa_st #define RSA_3 0x3L #define RSA_F4 0x10001L -#define RSA_METHOD_FLAG_NO_CHECK 0x01 /* don't check pub/private match */ +#define RSA_METHOD_FLAG_NO_CHECK 0x0001 /* don't check pub/private match */ -#define RSA_FLAG_CACHE_PUBLIC 0x02 -#define RSA_FLAG_CACHE_PRIVATE 0x04 -#define RSA_FLAG_BLINDING 0x08 -#define RSA_FLAG_THREAD_SAFE 0x10 +#define RSA_F |