diff options
Diffstat (limited to 'crypto')
-rw-r--r-- | crypto/bn/bntest.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/crypto/bn/bntest.c b/crypto/bn/bntest.c index 06f5954acc..7771e92023 100644 --- a/crypto/bn/bntest.c +++ b/crypto/bn/bntest.c @@ -107,6 +107,7 @@ 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_mod_exp_mont5(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); @@ -249,6 +250,7 @@ int main(int argc, char *argv[]) message(out,"BN_mod_exp_mont_consttime"); if (!test_mod_exp_mont_consttime(out,ctx)) goto err; + if (!test_mod_exp_mont5(out,ctx)) goto err; (void)BIO_flush(out); message(out,"BN_exp"); @@ -1012,6 +1014,80 @@ int test_mod_exp_mont_consttime(BIO *bp, BN_CTX *ctx) return(1); } +/* Test constant-time modular exponentiation with 1024-bit inputs, + * which on x86_64 cause a different code branch to be taken. + */ +int test_mod_exp_mont5(BIO *bp, BN_CTX *ctx) + { + BIGNUM *a,*p,*m,*d,*e; + + BN_MONT_CTX *mont; + + a=BN_new(); + p=BN_new(); + m=BN_new(); + d=BN_new(); + e=BN_new(); + + mont = BN_MONT_CTX_new(); + + BN_bntest_rand(m,1024,0,1); /* must be odd for montgomery */ + /* Zero exponent */ + BN_bntest_rand(a,1024,0,0); + BN_zero(p); + if(!BN_mod_exp_mont_consttime(d,a,p,m,ctx,NULL)) + return 0; + if(!BN_is_one(d)) + { + fprintf(stderr, "Modular exponentiation test failed!\n"); + return 0; + } + /* Zero input */ + BN_bntest_rand(p,1024,0,0); + BN_zero(a); + if(!BN_mod_exp_mont_consttime(d,a,p,m,ctx,NULL)) + return 0; + if(!BN_is_zero(d)) + { + fprintf(stderr, "Modular exponentiation test failed!\n"); + return 0; + } + /* Craft an input whose Montgomery representation is 1, + * i.e., shorter than the modulus m, in order to test + * the const time precomputation scattering/gathering. + */ + BN_one(a); + BN_MONT_CTX_set(mont,m,ctx); + if(!BN_from_montgomery(e,a,mont,ctx)) + return 0; + if(!BN_mod_exp_mont_consttime(d,e,p,m,ctx,NULL)) + return 0; + if(!BN_mod_exp_simple(a,e,p,m,ctx)) + return 0; + if(BN_cmp(a,d) != 0) + { + fprintf(stderr,"Modular exponentiation test failed!\n"); + return 0; + } + /* Finally, some regular test vectors. */ + BN_bntest_rand(e,1024,0,0); + if(!BN_mod_exp_mont_consttime(d,e,p,m,ctx,NULL)) + return 0; + if(!BN_mod_exp_simple(a,e,p,m,ctx)) + return 0; + if(BN_cmp(a,d) != 0) + { + fprintf(stderr,"Modular exponentiation test failed!\n"); + return 0; + } + BN_free(a); + BN_free(p); + BN_free(m); + BN_free(d); + BN_free(e); + return(1); + } + int test_exp(BIO *bp, BN_CTX *ctx) { BIGNUM *a,*b,*d,*e,*one; |