Commit 0e83981d authored by Diego Santa Cruz's avatar Diego Santa Cruz Committed by Andy Polyakov
Browse files

Fix srp app missing NULL termination with password callback 



The password_callback() function does not necessarily NULL terminate
the password buffer, the caller must use the returned length but the
srp app uses this function as if it was doing NULL termination.

This made the -passin and -passout options of "openssl srp"
fail inexpicably and randomly or even crash.

Fixed by enlarging the buffer by one, so that the maximum password length
remains unchanged, and adding NULL termination upon return.

[Rearrange code for coding style compliance in process.]

Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
Reviewed-by: default avatarAndy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3475)
parent 48b53522

apps/srp.c

+24 −18
Original line number Diff line number Diff line
@@ -119,32 +119,35 @@ static char *srp_verify_user(const char *user, const char *srp_verifier, 
                             char *srp_usersalt, const char *g, const char *N,

                             const char *passin, int verbose)

{

    char password[1024];

    char password[1025];

    PW_CB_DATA cb_tmp;

    char *verifier = NULL;

    char *gNid = NULL;

    int len;



    cb_tmp.prompt_info = user;

    cb_tmp.password = passin;



    if (password_callback(password, sizeof(password), 0, &cb_tmp) > 0) {

    len = password_callback(password, sizeof(password)-1, 0, &cb_tmp);

    if (len > 0) {

        password[len] = 0;

        if (verbose)

            BIO_printf(bio_err,

                       "Validating\n   user=\"%s\"\n srp_verifier=\"%s\"\n srp_usersalt=\"%s\"\n g=\"%s\"\n N=\"%s\"\n",

                       user, srp_verifier, srp_usersalt, g, N);

        if (verbose > 1)

            BIO_printf(bio_err, "Pass %s\n", password);



        OPENSSL_assert(srp_usersalt != NULL);

        if (!

            (gNid =

             SRP_create_verifier(user, password, &srp_usersalt, &verifier, N,

                                 g))) {

        if (!(gNid = SRP_create_verifier(user, password, &srp_usersalt,

                                         &verifier, N, g)) ) {

            BIO_printf(bio_err, "Internal error validating SRP verifier\n");

        } else {

            if (strcmp(verifier, srp_verifier))

                gNid = NULL;

            OPENSSL_free(verifier);

        }

        OPENSSL_cleanse(password, len);

    }

    return gNid;

}
@@ -153,27 +156,30 @@ static char *srp_create_user(char *user, char **srp_verifier, 
                             char **srp_usersalt, char *g, char *N,

                             char *passout, int verbose)

{

    char password[1024];

    char password[1025];

    PW_CB_DATA cb_tmp;

    char *gNid = NULL;

    char *salt = NULL;

    int len;

    cb_tmp.prompt_info = user;

    cb_tmp.password = passout;



    if (password_callback(password, sizeof(password), 1, &cb_tmp) > 0) {

    len = password_callback(password, sizeof(password)-1, 1, &cb_tmp);

    if (len > 0) {

        password[len] = 0;

        if (verbose)

            BIO_printf(bio_err, "Creating\n user=\"%s\"\n g=\"%s\"\n N=\"%s\"\n",

                       user, g, N);

        if (!

            (gNid =

             SRP_create_verifier(user, password, &salt, srp_verifier, N,

                                 g))) {

        if (!(gNid = SRP_create_verifier(user, password, &salt,

                                         srp_verifier, N, g)) ) {

            BIO_printf(bio_err, "Internal error creating SRP verifier\n");

        } else

        } else {

            *srp_usersalt = salt;

        }

        OPENSSL_cleanse(password, len);

        if (verbose > 1)

            BIO_printf(bio_err, "gNid=%s salt =\"%s\"\n verifier =\"%s\"\n", gNid,

                       salt, *srp_verifier);

            BIO_printf(bio_err, "gNid=%s salt =\"%s\"\n verifier =\"%s\"\n",

                       gNid, salt, *srp_verifier);



    }

    return gNid;
@@ -251,7 +257,7 @@ int srp_main(int argc, char **argv) 
        case OPT_LIST:

            if (mode != OPT_ERR) {

                BIO_printf(bio_err,

                           "%s: Only one of -add/delete-modify/-list\n",

                           "%s: Only one of -add/-delete/-modify/-list\n",

                           prog);

                goto opthelp;

            }
@@ -293,7 +299,7 @@ int srp_main(int argc, char **argv) 
                   "Need at least one user for options -add, -delete, -modify. \n");

        goto opthelp;

    }

    if ((passin || passout) && argc != 1) {

    if ((passinarg || passoutarg) && argc != 1) {

        BIO_printf(bio_err,

                   "-passin, -passout arguments only valid with one user.\n");

        goto opthelp;