--- crypto/openssl/crypto/bn/bn_sqrt.c.orig +++ crypto/openssl/crypto/bn/bn_sqrt.c @@ -14,7 +14,8 @@ /* * Returns 'ret' such that ret^2 == a (mod p), using the Tonelli/Shanks * algorithm (cf. Henri Cohen, "A Course in Algebraic Computational Number - * Theory", algorithm 1.5.1). 'p' must be prime! + * Theory", algorithm 1.5.1). 'p' must be prime, otherwise an error or + * an incorrect "result" will be returned. */ { BIGNUM *ret = in; @@ -301,18 +302,23 @@ goto vrfy; } - /* find smallest i such that b^(2^i) = 1 */ - i = 1; - if (!BN_mod_sqr(t, b, p, ctx)) - goto end; - while (!BN_is_one(t)) { - i++; - if (i == e) { - BNerr(BN_F_BN_MOD_SQRT, BN_R_NOT_A_SQUARE); - goto end; + /* Find the smallest i, 0 < i < e, such that b^(2^i) = 1. */ + for (i = 1; i < e; i++) { + if (i == 1) { + if (!BN_mod_sqr(t, b, p, ctx)) + goto end; + + } else { + if (!BN_mod_mul(t, t, t, p, ctx)) + goto end; } - if (!BN_mod_mul(t, t, t, p, ctx)) - goto end; + if (BN_is_one(t)) + break; + } + /* If not found, a is not a square or p is not prime. */ + if (i >= e) { + BNerr(BN_F_BN_MOD_SQRT, BN_R_NOT_A_SQUARE); + goto end; } /* t := y^2^(e - i - 1) */ --- crypto/openssl/doc/man3/BN_add.pod.orig +++ crypto/openssl/doc/man3/BN_add.pod @@ -3,7 +3,7 @@ =head1 NAME BN_add, BN_sub, BN_mul, BN_sqr, BN_div, BN_mod, BN_nnmod, BN_mod_add, -BN_mod_sub, BN_mod_mul, BN_mod_sqr, BN_exp, BN_mod_exp, BN_gcd - +BN_mod_sub, BN_mod_mul, BN_mod_sqr, BN_mod_sqrt, BN_exp, BN_mod_exp, BN_gcd - arithmetic operations on BIGNUMs =head1 SYNOPSIS @@ -36,6 +36,8 @@ int BN_mod_sqr(BIGNUM *r, BIGNUM *a, const BIGNUM *m, BN_CTX *ctx); + BIGNUM *BN_mod_sqrt(BIGNUM *in, BIGNUM *a, const BIGNUM *p, BN_CTX *ctx); + int BN_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx); int BN_mod_exp(BIGNUM *r, BIGNUM *a, const BIGNUM *p, @@ -87,6 +89,12 @@ BN_mod_sqr() takes the square of I modulo B and places the result in I. +BN_mod_sqrt() returns the modular square root of I such that +C. The modulus I

-th power and places the result in I (C). This function is faster than repeated applications of BN_mul(). @@ -108,7 +116,10 @@ =head1 RETURN VALUES -For all functions, 1 is returned for success, 0 on error. The return +The BN_mod_sqrt() returns the result (possibly incorrect if I

is +not a prime), or NULL. + +For all remaining functions, 1 is returned for success, 0 on error. The return value should always be checked (e.g., C). The error codes can be obtained by L.