Commit 051b9604 authored by Matt Caswell's avatar Matt Caswell
Browse files

Fix error return value in SRP functions 



The functions SRP_Calc_client_key() and SRP_Calc_server_key() were
incorrectly returning a valid pointer in the event of error.

Issue reported by Yuan Jochen Kang

Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
(cherry picked from commit 308ff286)
parent eea595ff

crypto/srp/srp_lib.c

+13 −7
Original line number Diff line number Diff line
@@ -159,8 +159,7 @@ BIGNUM *SRP_Calc_server_key(BIGNUM *A, BIGNUM *v, BIGNUM *u, BIGNUM *b, 
    if (u == NULL || A == NULL || v == NULL || b == NULL || N == NULL)

        return NULL;



    if ((bn_ctx = BN_CTX_new()) == NULL ||

        (tmp = BN_new()) == NULL || (S = BN_new()) == NULL)

    if ((bn_ctx = BN_CTX_new()) == NULL || (tmp = BN_new()) == NULL)

        goto err;



    /* S = (A*v**u) ** b */
@@ -169,8 +168,12 @@ BIGNUM *SRP_Calc_server_key(BIGNUM *A, BIGNUM *v, BIGNUM *u, BIGNUM *b, 
        goto err;

    if (!BN_mod_mul(tmp, A, tmp, N, bn_ctx))

        goto err;

    if (!BN_mod_exp(S, tmp, b, N, bn_ctx))

        goto err;



    S = BN_new();

    if (S != NULL && !BN_mod_exp(S, tmp, b, N, bn_ctx)) {

        BN_free(S);

        S = NULL;

    }

 err:

    BN_CTX_free(bn_ctx);

    BN_clear_free(tmp);
@@ -267,7 +270,7 @@ BIGNUM *SRP_Calc_client_key(BIGNUM *N, BIGNUM *B, BIGNUM *g, BIGNUM *x, 


    if ((tmp = BN_new()) == NULL ||

        (tmp2 = BN_new()) == NULL ||

        (tmp3 = BN_new()) == NULL || (K = BN_new()) == NULL)

        (tmp3 = BN_new()) == NULL)

        goto err;



    if (!BN_mod_exp(tmp, g, x, N, bn_ctx))
@@ -283,8 +286,11 @@ BIGNUM *SRP_Calc_client_key(BIGNUM *N, BIGNUM *B, BIGNUM *g, BIGNUM *x, 
        goto err;

    if (!BN_mod_add(tmp2, a, tmp3, N, bn_ctx))

        goto err;

    if (!BN_mod_exp(K, tmp, tmp2, N, bn_ctx))

        goto err;

    K = BN_new();

    if (K != NULL && !BN_mod_exp(K, tmp, tmp2, N, bn_ctx)) {

        BN_free(K);

        K = NULL;

    }



 err:

    BN_CTX_free(bn_ctx);