/**
* gnutls_priority_init:
* @priority_cache: is a #gnutls_prioritity_t structure.
* @priorities: is a string describing priorities
* @err_pos: In case of an error this will have the position in the string the error occured
*
* Sets priorities for the ciphers, key exchange methods, macs and
* compression methods.
*
* The #priorities option allows you to specify a colon
* separated list of the cipher priorities to enable.
* Some keywords are defined to provide quick access
* to common preferences.
*
* Unless there is a special need, using "NORMAL" or "NORMAL:%COMPAT" for compatibility
* is recommended.
*
* "PERFORMANCE" means all the "secure" ciphersuites are enabled,
* limited to 128 bit ciphers and sorted by terms of speed
* performance.
*
* "NORMAL" means all "secure" ciphersuites. The 256-bit ciphers are
* included as a fallback only. The ciphers are sorted by security
* margin.
*
* "PFS" means all "secure" ciphersuites that support perfect forward secrecy.
* The 256-bit ciphers are included as a fallback only.
* The ciphers are sorted by security margin.
*
* "SECURE128" means all "secure" ciphersuites of security level 128-bit
* or more.
*
* "SECURE192" means all "secure" ciphersuites of security level 192-bit
* or more.
*
* "SUITEB128" means all the NSA SuiteB ciphersuites with security level
* of 128.
*
* "SUITEB192" means all the NSA SuiteB ciphersuites with security level
* of 192.
*
* "EXPORT" means all ciphersuites are enabled, including the
* low-security 40 bit ciphers.
*
* "NONE" means nothing is enabled. This disables even protocols and
* compression methods.
*
* Special keywords are "!", "-" and "+".
* "!" or "-" appended with an algorithm will remove this algorithm.
* "+" appended with an algorithm will add this algorithm.
*
* Check the GnuTLS manual section "Priority strings" for detailed
* information.
*
* Examples:
*
* "NONE:+VERS-TLS-ALL:+MAC-ALL:+RSA:+AES-128-CBC:+SIGN-ALL:+COMP-NULL"
*
* "NORMAL:-ARCFOUR-128" means normal ciphers except for ARCFOUR-128.
*
* "SECURE128:-VERS-SSL3.0:+COMP-DEFLATE" means that only secure ciphers are
* enabled, SSL3.0 is disabled, and libz compression enabled.
*
* "NONE:+VERS-TLS-ALL:+AES-128-CBC:+RSA:+SHA1:+COMP-NULL:+SIGN-RSA-SHA1",
*
* "NONE:+VERS-TLS-ALL:+AES-128-CBC:+ECDHE-RSA:+SHA1:+COMP-NULL:+SIGN-RSA-SHA1:+CURVE-SECP256R1",
*
* "SECURE256:+SECURE128",
*
* Note that "NORMAL:%COMPAT" is the most compatible mode.
*
* Returns: On syntax error %GNUTLS_E_INVALID_REQUEST is returned,
* %GNUTLS_E_SUCCESS on success, or an error code.
**/
int
gnutls_priority_init(gnutls_priority_t * priority_cache,
const char *priorities, const char **err_pos)
{
char *broken_list[MAX_ELEMENTS];
int broken_list_size = 0, i = 0, j;
char *darg = NULL;
unsigned ikeyword_set = 0;
int algo;
rmadd_func *fn;
bulk_rmadd_func *bulk_fn;
*priority_cache =
gnutls_calloc(1, sizeof(struct gnutls_priority_st));
if (*priority_cache == NULL) {
gnutls_assert();
return GNUTLS_E_MEMORY_ERROR;
}
if (err_pos)
*err_pos = priorities;
/* for now unsafe renegotiation is default on everyone. To be removed
* when we make it the default.
*/
(*priority_cache)->sr = SR_PARTIAL;
(*priority_cache)->ssl3_record_version = 1;
(*priority_cache)->max_empty_records = DEFAULT_MAX_EMPTY_RECORDS;
if (priorities == NULL)
priorities = LEVEL_NORMAL;
darg = gnutls_strdup(priorities);
if (darg == NULL) {
gnutls_assert();
goto error;
}
break_comma_list(darg, broken_list, &broken_list_size,
MAX_ELEMENTS, ':');
/* This is our default set of protocol version, certificate types and
* compression methods.
*/
if (strcasecmp(broken_list[0], LEVEL_NONE) != 0) {
_set_priority(&(*priority_cache)->protocol,
protocol_priority);
_set_priority(&(*priority_cache)->compression,
comp_priority);
_set_priority(&(*priority_cache)->cert_type,
cert_type_priority_default);
_set_priority(&(*priority_cache)->sign_algo,
sign_priority_default);
_set_priority(&(*priority_cache)->supported_ecc,
supported_ecc_normal);
i = 0;
} else {
ikeyword_set = 1;
i = 1;
}
for (; i < broken_list_size; i++) {
if (check_level(broken_list[i], *priority_cache, ikeyword_set) != 0) {
ikeyword_set = 1;
continue;
} else if (broken_list[i][0] == '!'
|| broken_list[i][0] == '+'
|| broken_list[i][0] == '-') {
if (broken_list[i][0] == '+') {
fn = prio_add;
bulk_fn = _add_priority;
} else {
fn = prio_remove;
bulk_fn = _clear_priorities;
}
if (broken_list[i][0] == '+'
&& check_level(&broken_list[i][1],
*priority_cache, 1) != 0) {
continue;
} else if ((algo =
gnutls_mac_get_id(&broken_list[i][1]))
!= GNUTLS_MAC_UNKNOWN)
fn(&(*priority_cache)->mac, algo);
else if ((algo =
gnutls_cipher_get_id(&broken_list[i][1]))
!= GNUTLS_CIPHER_UNKNOWN)
fn(&(*priority_cache)->cipher, algo);
else if ((algo =
gnutls_kx_get_id(&broken_list[i][1])) !=
GNUTLS_KX_UNKNOWN)
fn(&(*priority_cache)->kx, algo);
else if (strncasecmp
(&broken_list[i][1], "VERS-", 5) == 0) {
if (strncasecmp
(&broken_list[i][1], "VERS-TLS-ALL",
12) == 0) {
bulk_fn(&(*priority_cache)->
protocol,
protocol_priority);
} else
if (strncasecmp
(&broken_list[i][1],
"VERS-DTLS-ALL", 13) == 0) {
bulk_fn(&(*priority_cache)->
protocol,
dtls_protocol_priority);
} else {
if ((algo =
gnutls_protocol_get_id
(&broken_list[i][6])) !=
GNUTLS_VERSION_UNKNOWN)
fn(&(*priority_cache)->
protocol, algo);
else
goto error;
}
} /* now check if the element is something like -ALGO */
else if (strncasecmp
(&broken_list[i][1], "COMP-", 5) == 0) {
if (strncasecmp
(&broken_list[i][1], "COMP-ALL",
8) == 0) {
bulk_fn(&(*priority_cache)->
compression,
comp_priority);
} else {
if ((algo =
gnutls_compression_get_id
(&broken_list[i][6])) !=
GNUTLS_COMP_UNKNOWN)
fn(&(*priority_cache)->
compression, algo);
else
goto error;
}
} /* now check if the element is something like -ALGO */
else if (strncasecmp
(&broken_list[i][1], "CURVE-", 6) == 0) {
if (strncasecmp
(&broken_list[i][1], "CURVE-ALL",
9) == 0) {
bulk_fn(&(*priority_cache)->
supported_ecc,
supported_ecc_normal);
} else {
if ((algo =
_gnutls_ecc_curve_get_id
(&broken_list[i][7])) !=
GNUTLS_ECC_CURVE_INVALID)
fn(&(*priority_cache)->
supported_ecc, algo);
else
goto error;
}
} /* now check if the element is something like -ALGO */
else if (strncasecmp
(&broken_list[i][1], "CTYPE-", 6) == 0) {
if (strncasecmp
(&broken_list[i][1], "CTYPE-ALL",
9) == 0) {
bulk_fn(&(*priority_cache)->
cert_type,
cert_type_priority_all);
} else {
if ((algo =
gnutls_certificate_type_get_id
(&broken_list[i][7])) !=
GNUTLS_CRT_UNKNOWN)
fn(&(*priority_cache)->
cert_type, algo);
else
goto error;
}
} /* now check if the element is something like -ALGO */
else if (strncasecmp
(&broken_list[i][1], "SIGN-", 5) == 0) {
if (strncasecmp
(&broken_list[i][1], "SIGN-ALL",
8) == 0) {
bulk_fn(&(*priority_cache)->
sign_algo,
sign_priority_default);
} else {
if ((algo =
gnutls_sign_get_id
(&broken_list[i][6])) !=
GNUTLS_SIGN_UNKNOWN)
fn(&(*priority_cache)->
sign_algo, algo);
else
goto error;
}
} else
if (strncasecmp
(&broken_list[i][1], "MAC-ALL", 7) == 0) {
bulk_fn(&(*priority_cache)->mac,
mac_priority_normal);
} else
if (strncasecmp
(&broken_list[i][1], "CIPHER-ALL",
10) == 0) {
bulk_fn(&(*priority_cache)->cipher,
cipher_priority_normal);
} else
if (strncasecmp
(&broken_list[i][1], "KX-ALL", 6) == 0) {
bulk_fn(&(*priority_cache)->kx,
kx_priority_secure);
} else
goto error;
} else if (broken_list[i][0] == '%') {
if (strcasecmp(&broken_list[i][1], "COMPAT") == 0) {
ENABLE_COMPAT((*priority_cache));
} else
if (strcasecmp(&broken_list[i][1], "DUMBFW") == 0) {
(*priority_cache)->dumbfw = 1;
} else
if (strcasecmp
(&broken_list[i][1],
"NO_EXTENSIONS") == 0) {
(*priority_cache)->no_extensions = 1;
} else
if (strcasecmp
(&broken_list[i][1],
"STATELESS_COMPRESSION") == 0) {
(*priority_cache)->stateless_compression =
1;
} else
if (strcasecmp
(&broken_list[i][1],
"VERIFY_ALLOW_SIGN_RSA_MD5") == 0) {
prio_add(&(*priority_cache)->sign_algo,
GNUTLS_SIGN_RSA_MD5);
(*priority_cache)->
additional_verify_flags |=
GNUTLS_VERIFY_ALLOW_SIGN_RSA_MD5;
} else
if (strcasecmp
(&broken_list[i][1],
"VERIFY_DISABLE_CRL_CHECKS") == 0) {
(*priority_cache)->
additional_verify_flags |=
GNUTLS_VERIFY_DISABLE_CRL_CHECKS;
} else
if (strcasecmp
(&broken_list[i][1],
"SSL3_RECORD_VERSION") == 0)
(*priority_cache)->ssl3_record_version = 1;
else if (strcasecmp(&broken_list[i][1],
"LATEST_RECORD_VERSION") == 0)
(*priority_cache)->ssl3_record_version = 0;
else if (strcasecmp(&broken_list[i][1],
"VERIFY_ALLOW_X509_V1_CA_CRT")
== 0)
(*priority_cache)->
additional_verify_flags |=
GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT;
else if (strcasecmp
(&broken_list[i][1],
"UNSAFE_RENEGOTIATION") == 0) {
(*priority_cache)->sr = SR_UNSAFE;
} else
if (strcasecmp
(&broken_list[i][1],
"SAFE_RENEGOTIATION") == 0) {
(*priority_cache)->sr = SR_SAFE;
} else if (strcasecmp(&broken_list[i][1],
"PARTIAL_RENEGOTIATION") ==
0) {
(*priority_cache)->sr = SR_PARTIAL;
} else if (strcasecmp(&broken_list[i][1],
"DISABLE_SAFE_RENEGOTIATION")
== 0) {
(*priority_cache)->sr = SR_DISABLED;
} else if (strcasecmp(&broken_list[i][1],
"SERVER_PRECEDENCE") == 0) {
(*priority_cache)->server_precedence = 1;
} else if (strcasecmp(&broken_list[i][1],
"NEW_PADDING") == 0) {
(*priority_cache)->new_record_padding = 1;
} else
goto error;
} else
goto error;
}
gnutls_free(darg);
return 0;
error:
if (err_pos != NULL && i < broken_list_size) {
*err_pos = priorities;
for (j = 0; j < i; j++) {
(*err_pos) += strlen(broken_list[j]) + 1;
}
}
gnutls_free(darg);
gnutls_free(*priority_cache);
*priority_cache = NULL;
return GNUTLS_E_INVALID_REQUEST;
}
static void enable_compat(gnutls_priority_t c)
{
ENABLE_COMPAT(c);
}
