Example #1
0
PUBLIC_KEY *publickey_make_rsa(SSH_SESSION *session, BUFFER *buffer, char *type){
    STRING *e,*n;
    PUBLIC_KEY *key=malloc(sizeof(PUBLIC_KEY));
    if(!strcmp(type,"ssh-rsa"))
        key->type=TYPE_RSA;
    else
        key->type=TYPE_RSA1;
    key->type_c=type;
    e=buffer_get_ssh_string(buffer);
    n=buffer_get_ssh_string(buffer);
    buffer_free(buffer); /* we don't need it anymore */
    if(!e || !n){
        ssh_set_error(session,SSH_FATAL,"Invalid RSA public key");
        if(e)
            free(e);
        if(n)
            free(n);
        free(key);
        return NULL;
    }
#ifdef HAVE_LIBGCRYPT
    gcry_sexp_build(&key->rsa_pub,NULL,"(public-key(rsa(n %b)(e %b)))",string_len(n),n->string,string_len(e),e->string);
#elif HAVE_LIBCRYPTO
    key->rsa_pub=RSA_new();
    key->rsa_pub->e=make_string_bn(e);
    key->rsa_pub->n=make_string_bn(n);
#endif
#ifdef DEBUG_CRYPTO
    ssh_print_hexa("e",e->string,string_len(e));
    ssh_print_hexa("n",n->string,string_len(n));
#endif
    free(e);
    free(n);
    return key;
}
Example #2
0
int pki_pubkey_build_rsa(ssh_key key,
                         ssh_string e,
                         ssh_string n) {
    key->rsa = RSA_new();
    if (key->rsa == NULL) {
        return SSH_ERROR;
    }

    key->rsa->e = make_string_bn(e);
    key->rsa->n = make_string_bn(n);
    if (key->rsa->e == NULL ||
        key->rsa->n == NULL) {
        RSA_free(key->rsa);
        return SSH_ERROR;
    }

    return SSH_OK;
}
Example #3
0
File: dh.c Project: mwgoldsmith/ssh
/* used by the server implementation */
int dh_import_e(ssh_session session, ssh_string e_string) {
  session->next_crypto->e = make_string_bn(e_string);
  if (session->next_crypto->e == NULL) {
    return -1;
  }

#ifdef DEBUG_CRYPTO
    ssh_print_bignum("e",session->next_crypto->e);
#endif

  return 0;
}
Example #4
0
File: dh.c Project: mwgoldsmith/ssh
int dh_import_f(ssh_session session, ssh_string f_string) {
  session->next_crypto->f = make_string_bn(f_string);
  if (session->next_crypto->f == NULL) {
    return -1;
  }

#ifdef DEBUG_CRYPTO
  ssh_print_bignum("f",session->next_crypto->f);
#endif

  return 0;
}
Example #5
0
PUBLIC_KEY *publickey_make_dss(SSH_SESSION *session, BUFFER *buffer){
    STRING *p,*q,*g,*pubkey;
    PUBLIC_KEY *key=malloc(sizeof(PUBLIC_KEY));
    key->type=TYPE_DSS;
    key->type_c="ssh-dss";
    p=buffer_get_ssh_string(buffer);
    q=buffer_get_ssh_string(buffer);
    g=buffer_get_ssh_string(buffer);
    pubkey=buffer_get_ssh_string(buffer);
    buffer_free(buffer); /* we don't need it anymore */
    if(!p || !q || !g || !pubkey){
        ssh_set_error(session,SSH_FATAL,"Invalid DSA public key");
        if(p)
            free(p);
        if(q)
            free(q);
        if(g)
            free(g);
        if(pubkey)
            free(pubkey);
        free(key);
        return NULL;
    }
#ifdef HAVE_LIBGCRYPT
    gcry_sexp_build(&key->dsa_pub,NULL,"(public-key(dsa(p %b)(q %b)(g %b)(y %b)))",string_len(p),p->string,string_len(q),q->string,string_len(g),g->string,string_len(pubkey),pubkey->string);
#elif defined HAVE_LIBCRYPTO
    key->dsa_pub=DSA_new();
    key->dsa_pub->p=make_string_bn(p);
    key->dsa_pub->q=make_string_bn(q);
    key->dsa_pub->g=make_string_bn(g);
    key->dsa_pub->pub_key=make_string_bn(pubkey);
#endif
    free(p);
    free(q);
    free(g);
    free(pubkey);
    return key;
}
Example #6
0
int pki_pubkey_build_dss(ssh_key key,
                         ssh_string p,
                         ssh_string q,
                         ssh_string g,
                         ssh_string pubkey) {
    key->dsa = DSA_new();
    if (key->dsa == NULL) {
        return SSH_ERROR;
    }

    key->dsa->p = make_string_bn(p);
    key->dsa->q = make_string_bn(q);
    key->dsa->g = make_string_bn(g);
    key->dsa->pub_key = make_string_bn(pubkey);
    if (key->dsa->p == NULL ||
        key->dsa->q == NULL ||
        key->dsa->g == NULL ||
        key->dsa->pub_key == NULL) {
        DSA_free(key->dsa);
        return SSH_ERROR;
    }

    return SSH_OK;
}
Example #7
0
File: keys.c Project: rofl0r/libssh
/* TODO : split this function in two so it becomes smaller */
SIGNATURE *signature_from_string(ssh_session session, ssh_string signature,
                                 ssh_public_key pubkey, int needed_type) {
    SIGNATURE *sign = NULL;
    ssh_buffer tmpbuf = NULL;
    ssh_string rs = NULL;
    ssh_string type_s = NULL;
    ssh_string e = NULL;
    char *type_c = NULL;
    int type;
    int len;
    int rsalen;
#ifdef HAVE_LIBGCRYPT
    gcry_sexp_t sig;
#elif defined HAVE_LIBCRYPTO
    DSA_SIG *sig = NULL;
    ssh_string r = NULL;
    ssh_string s = NULL;
#endif

    sign = malloc(sizeof(SIGNATURE));
    if (sign == NULL) {
        ssh_set_error(session, SSH_FATAL, "Not enough space");
        return NULL;
    }
    ZERO_STRUCTP(sign);

    tmpbuf = ssh_buffer_new();
    if (tmpbuf == NULL) {
        ssh_set_error(session, SSH_FATAL, "Not enough space");
        signature_free(sign);
        return NULL;
    }

    if (buffer_add_data(tmpbuf, ssh_string_data(signature), ssh_string_len(signature)) < 0) {
        signature_free(sign);
        ssh_buffer_free(tmpbuf);
        return NULL;
    }

    type_s = buffer_get_ssh_string(tmpbuf);
    if (type_s == NULL) {
        ssh_set_error(session, SSH_FATAL, "Invalid signature packet");
        signature_free(sign);
        ssh_buffer_free(tmpbuf);
        return NULL;
    }

    type_c = ssh_string_to_char(type_s);
    ssh_string_free(type_s);
    if (type_c == NULL) {
        signature_free(sign);
        ssh_buffer_free(tmpbuf);
        return NULL;
    }
    type = ssh_type_from_name(type_c);
    SAFE_FREE(type_c);

    if (needed_type != type) {
        ssh_set_error(session, SSH_FATAL, "Invalid signature type: %s",
                      ssh_type_to_char(type));
        signature_free(sign);
        ssh_buffer_free(tmpbuf);
        return NULL;
    }

    switch(needed_type) {
    case SSH_KEYTYPE_DSS:
        rs = buffer_get_ssh_string(tmpbuf);
        ssh_buffer_free(tmpbuf);

        /* 40 is the dual signature blob len. */
        if (rs == NULL || ssh_string_len(rs) != 40) {
            ssh_string_free(rs);
            signature_free(sign);
            return NULL;
        }

        /* we make use of strings (because we have all-made functions to convert
         * them to bignums (ou pas ;) */
#ifdef HAVE_LIBGCRYPT
        if (gcry_sexp_build(&sig, NULL, "(sig-val(dsa(r %b)(s %b)))",
                            20 ,ssh_string_data(rs), 20,(unsigned char *)ssh_string_data(rs) + 20)) {
            ssh_string_free(rs);
            signature_free(sign);
            return NULL;
        }
#elif defined HAVE_LIBCRYPTO
        r = ssh_string_new(20);
        s = ssh_string_new(20);
        if (r == NULL || s == NULL) {
            ssh_string_free(r);
            ssh_string_free(s);
            ssh_string_free(rs);
            signature_free(sign);
            return NULL;
        }

        ssh_string_fill(r, ssh_string_data(rs), 20);
        ssh_string_fill(s, (char *)ssh_string_data(rs) + 20, 20);

        sig = DSA_SIG_new();
        if (sig == NULL) {
            ssh_string_free(r);
            ssh_string_free(s);
            ssh_string_free(rs);
            signature_free(sign);
            return NULL;
        }
        sig->r = make_string_bn(r); /* is that really portable ? Openssh's hack isn't better */
        sig->s = make_string_bn(s);
        ssh_string_free(r);
        ssh_string_free(s);

        if (sig->r == NULL || sig->s == NULL) {
            ssh_string_free(rs);
            DSA_SIG_free(sig);
            signature_free(sign);
            return NULL;
        }
#endif

#ifdef DEBUG_CRYPTO
        ssh_print_hexa("r", ssh_string_data(rs), 20);
        ssh_print_hexa("s", (const unsigned char *)ssh_string_data(rs) + 20, 20);
#endif
        ssh_string_free(rs);

        sign->type = SSH_KEYTYPE_DSS;
        sign->dsa_sign = sig;

        return sign;
    case SSH_KEYTYPE_RSA:
        e = buffer_get_ssh_string(tmpbuf);
        ssh_buffer_free(tmpbuf);
        if (e == NULL) {
            signature_free(sign);
            return NULL;
        }
        len = ssh_string_len(e);
#ifdef HAVE_LIBGCRYPT
        rsalen = (gcry_pk_get_nbits(pubkey->rsa_pub) + 7) / 8;
#elif defined HAVE_LIBCRYPTO
        rsalen = RSA_size(pubkey->rsa_pub);
#endif
        if (len > rsalen) {
            ssh_string_free(e);
            signature_free(sign);
            ssh_set_error(session, SSH_FATAL, "Signature too big! %d instead of %d",
                          len, rsalen);
            return NULL;
        }

        if (len < rsalen) {
            ssh_log(session, SSH_LOG_RARE, "RSA signature len %d < %d",
                    len, rsalen);
        }
        sign->type = SSH_KEYTYPE_RSA;
#ifdef HAVE_LIBGCRYPT
        if (gcry_sexp_build(&sig, NULL, "(sig-val(rsa(s %b)))",
                            ssh_string_len(e), ssh_string_data(e))) {
            signature_free(sign);
            ssh_string_free(e);
            return NULL;
        }

        sign->rsa_sign = sig;
#elif defined HAVE_LIBCRYPTO
        sign->rsa_sign = e;
#endif

#ifdef DEBUG_CRYPTO
        ssh_log(session, SSH_LOG_FUNCTIONS, "len e: %d", len);
        ssh_print_hexa("RSA signature", ssh_string_data(e), len);
#endif

#ifdef HAVE_LIBGCRYPT
        ssh_string_free(e);
#endif

        return sign;
    default:
        return NULL;
    }

    return NULL;
}
Example #8
0
File: keys.c Project: rofl0r/libssh
ssh_public_key publickey_make_dss(ssh_session session, ssh_buffer buffer) {
    ssh_string p = NULL;
    ssh_string q = NULL;
    ssh_string g = NULL;
    ssh_string pubkey = NULL;
    ssh_public_key key = NULL;

    key = malloc(sizeof(struct ssh_public_key_struct));
    if (key == NULL) {
        ssh_buffer_free(buffer);
        return NULL;
    }

    ZERO_STRUCTP(key);

    key->type = SSH_KEYTYPE_DSS;
    key->type_c = ssh_type_to_char(key->type);

    p = buffer_get_ssh_string(buffer);
    q = buffer_get_ssh_string(buffer);
    g = buffer_get_ssh_string(buffer);
    pubkey = buffer_get_ssh_string(buffer);

    ssh_buffer_free(buffer); /* we don't need it anymore */

    if (p == NULL || q == NULL || g == NULL || pubkey == NULL) {
        ssh_set_error(session, SSH_FATAL, "Invalid DSA public key");
        goto error;
    }

#ifdef HAVE_LIBGCRYPT
    gcry_sexp_build(&key->dsa_pub, NULL,
                    "(public-key(dsa(p %b)(q %b)(g %b)(y %b)))",
                    ssh_string_len(p), ssh_string_data(p),
                    ssh_string_len(q), ssh_string_data(q),
                    ssh_string_len(g), ssh_string_data(g),
                    ssh_string_len(pubkey), ssh_string_data(pubkey));
    if (key->dsa_pub == NULL) {
        goto error;
    }
#elif defined HAVE_LIBCRYPTO

    key->dsa_pub = DSA_new();
    if (key->dsa_pub == NULL) {
        goto error;
    }
    key->dsa_pub->p = make_string_bn(p);
    key->dsa_pub->q = make_string_bn(q);
    key->dsa_pub->g = make_string_bn(g);
    key->dsa_pub->pub_key = make_string_bn(pubkey);
    if (key->dsa_pub->p == NULL ||
            key->dsa_pub->q == NULL ||
            key->dsa_pub->g == NULL ||
            key->dsa_pub->pub_key == NULL) {
        goto error;
    }
#endif /* HAVE_LIBCRYPTO */

#ifdef DEBUG_CRYPTO
    ssh_print_hexa("p", ssh_string_data(p), ssh_string_len(p));
    ssh_print_hexa("q", ssh_string_data(q), ssh_string_len(q));
    ssh_print_hexa("g", ssh_string_data(g), ssh_string_len(g));
#endif

    ssh_string_burn(p);
    ssh_string_free(p);
    ssh_string_burn(q);
    ssh_string_free(q);
    ssh_string_burn(g);
    ssh_string_free(g);
    ssh_string_burn(pubkey);
    ssh_string_free(pubkey);

    return key;
error:
    ssh_string_burn(p);
    ssh_string_free(p);
    ssh_string_burn(q);
    ssh_string_free(q);
    ssh_string_burn(g);
    ssh_string_free(g);
    ssh_string_burn(pubkey);
    ssh_string_free(pubkey);
    publickey_free(key);

    return NULL;
}
Example #9
0
File: keys.c Project: rofl0r/libssh
ssh_public_key publickey_make_rsa(ssh_session session, ssh_buffer buffer,
                                  int type) {
    ssh_string e = NULL;
    ssh_string n = NULL;
    ssh_public_key key = NULL;

    key = malloc(sizeof(struct ssh_public_key_struct));
    if (key == NULL) {
        ssh_buffer_free(buffer);
        return NULL;
    }
    ZERO_STRUCTP(key);

    key->type = type;
    key->type_c = ssh_type_to_char(key->type);

    e = buffer_get_ssh_string(buffer);
    n = buffer_get_ssh_string(buffer);

    ssh_buffer_free(buffer); /* we don't need it anymore */

    if(e == NULL || n == NULL) {
        ssh_set_error(session, SSH_FATAL, "Invalid RSA public key");
        goto error;
    }
#ifdef HAVE_LIBGCRYPT
    gcry_sexp_build(&key->rsa_pub, NULL,
                    "(public-key(rsa(n %b)(e %b)))",
                    ssh_string_len(n), ssh_string_data(n),
                    ssh_string_len(e),ssh_string_data(e));
    if (key->rsa_pub == NULL) {
        goto error;
    }
#elif HAVE_LIBCRYPTO
    key->rsa_pub = RSA_new();
    if (key->rsa_pub == NULL) {
        goto error;
    }

    key->rsa_pub->e = make_string_bn(e);
    key->rsa_pub->n = make_string_bn(n);
    if (key->rsa_pub->e == NULL ||
            key->rsa_pub->n == NULL) {
        goto error;
    }
#endif

#ifdef DEBUG_CRYPTO
    ssh_print_hexa("e", ssh_string_data(e), ssh_string_len(e));
    ssh_print_hexa("n", ssh_string_data(n), ssh_string_len(n));
#endif

    ssh_string_burn(e);
    ssh_string_free(e);
    ssh_string_burn(n);
    ssh_string_free(n);

    return key;
error:
    ssh_string_burn(e);
    ssh_string_free(e);
    ssh_string_burn(n);
    ssh_string_free(n);
    publickey_free(key);

    return NULL;
}
Example #10
0
/* TODO : split this function in two so it becomes smaller */
SIGNATURE *signature_from_string(SSH_SESSION *session, STRING *signature,PUBLIC_KEY *pubkey,int needed_type){
#ifdef HAVE_LIBGCRYPT
    gcry_sexp_t sig;
#elif defined HAVE_LIBCRYPTO
    DSA_SIG *sig;
    STRING *r,*s;
#endif
    SIGNATURE *sign=malloc(sizeof(SIGNATURE));
    BUFFER *tmpbuf=buffer_new();
    STRING *rs;
    STRING *type_s,*e;
    int len,rsalen;
    char *type;
    buffer_add_data(tmpbuf,signature->string,string_len(signature));
    type_s=buffer_get_ssh_string(tmpbuf);
    if(!type_s){
        ssh_set_error(session,SSH_FATAL,"Invalid signature packet");
        buffer_free(tmpbuf);
        return NULL;
    }
    type=string_to_char(type_s);
    free(type_s);
    switch(needed_type){
        case TYPE_DSS:
            if(strcmp(type,"ssh-dss")){
                ssh_set_error(session,SSH_FATAL,"Invalid signature type : %s",type);
                buffer_free(tmpbuf);
                free(type);
                return NULL;
            }
            break;
        case TYPE_RSA:
            if(strcmp(type,"ssh-rsa")){
                ssh_set_error(session,SSH_FATAL,"Invalid signature type : %s",type);
                buffer_free(tmpbuf);
                free(type);
                return NULL;
            }
            break;
        default:
            ssh_set_error(session,SSH_FATAL,"Invalid signature type : %s",type);
            free(type);
            buffer_free(tmpbuf);
            return NULL;
    }
    free(type);
    switch(needed_type){
        case TYPE_DSS:
            rs=buffer_get_ssh_string(tmpbuf);
            buffer_free(tmpbuf);
            if(!rs || string_len(rs)!=40){ /* 40 is the dual signature blob len. */
                if(rs)
                    free(rs);
                return NULL;
            }
            /* we make use of strings (because we have all-made functions to convert them to bignums (ou pas ;)*/
#ifdef HAVE_LIBGCRYPT
            gcry_sexp_build(&sig,NULL,"(sig-val(dsa(r %b)(s %b)))",20,rs->string,20,rs->string+20);
#elif defined HAVE_LIBCRYPTO
            r=string_new(20);
            s=string_new(20);
            string_fill(r,rs->string,20);
            string_fill(s,rs->string+20,20);
            sig=DSA_SIG_new();
            sig->r=make_string_bn(r); /* is that really portable ? Openssh's hack isn't better */
            sig->s=make_string_bn(s);
            free(r);
            free(s);
#endif
#ifdef DEBUG_CRYPTO
            ssh_print_hexa("r",rs->string,20);
            ssh_print_hexa("s",rs->string+20,20);
#endif
            free(rs);
            sign->type=TYPE_DSS;
            sign->dsa_sign=sig;
            return sign;
        case TYPE_RSA:
            e=buffer_get_ssh_string(tmpbuf);
            buffer_free(tmpbuf);
            if(!e){
                return NULL;
            }
            len=string_len(e);
#ifdef HAVE_LIBGCRYPT
            rsalen=(gcry_pk_get_nbits(pubkey->rsa_pub)+7)/8;
#elif defined HAVE_LIBCRYPTO
            rsalen=RSA_size(pubkey->rsa_pub);
#endif
            if(len>rsalen){
                free(e);
                free(sign);
                ssh_set_error(session,SSH_FATAL,"signature too big ! %d instead of %d",len,rsalen);
                return NULL;
            }
            if(len<rsalen)
                ssh_log(session,SSH_LOG_RARE,"RSA signature len %d < %d",len,rsalen);
            sign->type=TYPE_RSA;
#ifdef HAVE_LIBGCRYPT
            gcry_sexp_build(&sig,NULL,"(sig-val(rsa(s %b)))",string_len(e),e->string);
            sign->rsa_sign=sig;
#elif defined HAVE_LIBCRYPTO
            sign->rsa_sign=e;
#endif
#ifdef DEBUG_CRYPTO
            ssh_say(0,"Len : %d\n",len);
            ssh_print_hexa("rsa signature",e->string,len);
#endif
#ifdef HAVE_LIBGCRYPT
            free(e);
#endif
            return sign;
        default:
            return NULL;
    }
}
Example #11
0
PUBLIC_KEY *publickey_make_dss(SSH_SESSION *session, BUFFER *buffer) {
  STRING *p = NULL;
  STRING *q = NULL;
  STRING *g = NULL;
  STRING *pubkey = NULL;
  PUBLIC_KEY *key = NULL;

  key = malloc(sizeof(PUBLIC_KEY));
  if (key == NULL) {
    buffer_free(buffer);
    return NULL;
  }

  key->type = TYPE_DSS;
  key->type_c = ssh_type_to_char(key->type);

  p = buffer_get_ssh_string(buffer);
  q = buffer_get_ssh_string(buffer);
  g = buffer_get_ssh_string(buffer);
  pubkey = buffer_get_ssh_string(buffer);

  buffer_free(buffer); /* we don't need it anymore */

  if (p == NULL || q == NULL || g == NULL || pubkey == NULL) {
    ssh_set_error(session, SSH_FATAL, "Invalid DSA public key");
    goto error;
  }

#ifdef HAVE_LIBGCRYPT
  gcry_sexp_build(&key->dsa_pub, NULL,
      "(public-key(dsa(p %b)(q %b)(g %b)(y %b)))",
      string_len(p), p->string,
      string_len(q), q->string,
      string_len(g), g->string,
      string_len(pubkey), pubkey->string);
  if (key->dsa_pub == NULL) {
    goto error;
  }
#elif defined HAVE_LIBCRYPTO

  key->dsa_pub = DSA_new();
  if (key->dsa_pub == NULL) {
    goto error;
  }
  key->dsa_pub->p = make_string_bn(p);
  key->dsa_pub->q = make_string_bn(q);
  key->dsa_pub->g = make_string_bn(g);
  key->dsa_pub->pub_key = make_string_bn(pubkey);
  if (key->dsa_pub->p == NULL ||
      key->dsa_pub->q == NULL ||
      key->dsa_pub->g == NULL ||
      key->dsa_pub->pub_key == NULL) {
    goto error;
  }
#endif /* HAVE_LIBCRYPTO */

#ifdef DEBUG_CRYPTO
  ssh_print_hexa("p", p->string, string_len(p));
  ssh_print_hexa("q", q->string, string_len(q));
  ssh_print_hexa("g", g->string, string_len(g));
#endif

  string_burn(p);
  string_free(p);
  string_burn(q);
  string_free(q);
  string_burn(g);
  string_free(g);
  string_burn(pubkey);
  string_free(pubkey);

  return key;
error:
  string_burn(p);
  string_free(p);
  string_burn(q);
  string_free(q);
  string_burn(g);
  string_free(g);
  string_burn(pubkey);
  string_free(pubkey);
  publickey_free(key);

  return NULL;
}
Example #12
0
PUBLIC_KEY *publickey_make_rsa(SSH_SESSION *session, BUFFER *buffer,
    int type) {
  STRING *e = NULL;
  STRING *n = NULL;
  PUBLIC_KEY *key = NULL;

  key = malloc(sizeof(PUBLIC_KEY));
  if (key == NULL) {
    buffer_free(buffer);
    return NULL;
  }

  key->type = type;
  key->type_c = ssh_type_to_char(key->type);

  e = buffer_get_ssh_string(buffer);
  n = buffer_get_ssh_string(buffer);

  buffer_free(buffer); /* we don't need it anymore */

  if(e == NULL || n == NULL) {
    ssh_set_error(session, SSH_FATAL, "Invalid RSA public key");
    goto error;
  }
#ifdef HAVE_LIBGCRYPT
  gcry_sexp_build(&key->rsa_pub, NULL,
      "(public-key(rsa(n %b)(e %b)))",
      string_len(n), n->string,
      string_len(e),e->string);
  if (key->rsa_pub == NULL) {
    goto error;
  }
#elif HAVE_LIBCRYPTO
  key->rsa_pub = RSA_new();
  if (key->rsa_pub == NULL) {
    goto error;
  }

  key->rsa_pub->e = make_string_bn(e);
  key->rsa_pub->n = make_string_bn(n);
  if (key->rsa_pub->e == NULL ||
      key->rsa_pub->n == NULL) {
    goto error;
  }
#endif

#ifdef DEBUG_CRYPTO
  ssh_print_hexa("e", e->string, string_len(e));
  ssh_print_hexa("n", n->string, string_len(n));
#endif

  string_burn(e);
  string_free(e);
  string_burn(n);
  string_free(n);

  return key;
error:
  string_burn(e);
  string_free(e);
  string_burn(n);
  string_free(n);
  publickey_free(key);

  return NULL;
}