static int tls_process_certificate_verify(struct tlsv1_server *conn, u8 ct,
const u8 *in_data, size_t *in_len) {
const u8 *pos, *end;
size_t left, len;
u8 type;
size_t hlen, buflen;
u8 hash[MD5_MAC_LEN + SHA1_MAC_LEN], *hpos, *buf;
enum {
SIGN_ALG_RSA, SIGN_ALG_DSA
} alg = SIGN_ALG_RSA;
u16 slen;
if (ct == TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC) {
if (conn->verify_peer) {
wpa_printf(MSG_DEBUG, "TLSv1: Client did not include "
"CertificateVerify");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_UNEXPECTED_MESSAGE);
return -1;
}
return tls_process_change_cipher_spec(conn, ct, in_data,
in_len);
}
if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
wpa_printf(MSG_DEBUG, "TLSv1: Expected Handshake; "
"received content type 0x%x", ct);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_UNEXPECTED_MESSAGE);
return -1;
}
pos = in_data;
left = *in_len;
if (left < 4) {
wpa_printf(MSG_DEBUG, "TLSv1: Too short CertificateVerify "
"message (len=%lu)", (unsigned long) left);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_DECODE_ERROR);
return -1;
}
type = *pos++;
len = WPA_GET_BE24(pos);
pos += 3;
left -= 4;
if (len > left) {
wpa_printf(MSG_DEBUG, "TLSv1: Unexpected CertificateVerify "
"message length (len=%lu != left=%lu)",
(unsigned long) len, (unsigned long) left);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_DECODE_ERROR);
return -1;
}
end = pos + len;
if (type != TLS_HANDSHAKE_TYPE_CERTIFICATE_VERIFY) {
wpa_printf(MSG_DEBUG, "TLSv1: Received unexpected handshake "
"message %d (expected CertificateVerify)", type);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_UNEXPECTED_MESSAGE);
return -1;
}
wpa_printf(MSG_DEBUG, "TLSv1: Received CertificateVerify");
/*
* struct {
* Signature signature;
* } CertificateVerify;
*/
hpos = hash;
if (alg == SIGN_ALG_RSA) {
hlen = MD5_MAC_LEN;
if (conn->verify.md5_cert == NULL ||
crypto_hash_finish(conn->verify.md5_cert, hpos, &hlen) < 0) {
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
conn->verify.md5_cert = NULL;
crypto_hash_finish(conn->verify.sha1_cert, NULL, NULL);
conn->verify.sha1_cert = NULL;
return -1;
}
hpos += MD5_MAC_LEN;
} else
crypto_hash_finish(conn->verify.md5_cert, NULL, NULL);
conn->verify.md5_cert = NULL;
hlen = SHA1_MAC_LEN;
if (conn->verify.sha1_cert == NULL ||
crypto_hash_finish(conn->verify.sha1_cert, hpos, &hlen) < 0) {
conn->verify.sha1_cert = NULL;
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
return -1;
}
conn->verify.sha1_cert = NULL;
if (alg == SIGN_ALG_RSA)
hlen += MD5_MAC_LEN;
wpa_hexdump(MSG_MSGDUMP, "TLSv1: CertificateVerify hash", hash, hlen);
if (end - pos < 2) {
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_DECODE_ERROR);
return -1;
}
slen = WPA_GET_BE16(pos);
pos += 2;
if (end - pos < slen) {
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_DECODE_ERROR);
return -1;
}
wpa_hexdump(MSG_MSGDUMP, "TLSv1: Signature", pos, end - pos);
if (conn->client_rsa_key == NULL) {
wpa_printf(MSG_DEBUG, "TLSv1: No client public key to verify "
"signature");
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_INTERNAL_ERROR);
return -1;
}
buflen = end - pos;
buf = os_malloc(end - pos);
if (crypto_public_key_decrypt_pkcs1(conn->client_rsa_key,
pos, end - pos, buf, &buflen) < 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to decrypt signature");
os_free(buf);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_DECRYPT_ERROR);
return -1;
}
wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: Decrypted Signature",
buf, buflen);
if (buflen != hlen || os_memcmp(buf, hash, buflen) != 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Invalid Signature in "
"CertificateVerify - did not match with calculated "
"hash");
os_free(buf);
tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
TLS_ALERT_DECRYPT_ERROR);
return -1;
}
os_free(buf);
*in_len = end - in_data;
conn->state = CHANGE_CIPHER_SPEC;
return 0;
}
int tls_verify_signature(u16 tls_version, struct crypto_public_key *pk,
const u8 *data, size_t data_len,
const u8 *pos, size_t len, u8 *alert)
{
u8 *buf;
const u8 *end = pos + len;
const u8 *decrypted;
u16 slen;
size_t buflen;
if (end - pos < 2) {
*alert = TLS_ALERT_DECODE_ERROR;
return -1;
}
slen = WPA_GET_BE16(pos);
pos += 2;
if (end - pos < slen) {
*alert = TLS_ALERT_DECODE_ERROR;
return -1;
}
if (end - pos > slen) {
wpa_hexdump(MSG_MSGDUMP, "Additional data after Signature",
pos + slen, end - pos - slen);
end = pos + slen;
}
wpa_hexdump(MSG_MSGDUMP, "TLSv1: Signature", pos, end - pos);
if (pk == NULL) {
wpa_printf(MSG_DEBUG, "TLSv1: No public key to verify signature");
*alert = TLS_ALERT_INTERNAL_ERROR;
return -1;
}
buflen = end - pos;
buf = os_malloc(end - pos);
if (buf == NULL) {
*alert = TLS_ALERT_INTERNAL_ERROR;
return -1;
}
if (crypto_public_key_decrypt_pkcs1(pk, pos, end - pos, buf, &buflen) <
0) {
wpa_printf(MSG_DEBUG, "TLSv1: Failed to decrypt signature");
os_free(buf);
*alert = TLS_ALERT_DECRYPT_ERROR;
return -1;
}
decrypted = buf;
wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: Decrypted Signature",
decrypted, buflen);
#ifdef CONFIG_TLSV12
if (tls_version >= TLS_VERSION_1_2) {
/*
* RFC 3447, A.2.4 RSASSA-PKCS1-v1_5
*
* DigestInfo ::= SEQUENCE {
* digestAlgorithm DigestAlgorithm,
* digest OCTET STRING
* }
*
* SHA-256 OID: sha256WithRSAEncryption ::= {pkcs-1 11}
*
* DER encoded DigestInfo for SHA256 per RFC 3447:
* 30 31 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20 ||
* H
*/
if (buflen >= 19 + 32 &&
os_memcmp(buf, "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01"
"\x65\x03\x04\x02\x01\x05\x00\x04\x20", 19) == 0)
{
wpa_printf(MSG_DEBUG, "TLSv1.2: DigestAlgorithn = SHA-256");
decrypted = buf + 19;
buflen -= 19;
} else if (buflen >= 19 + 48 &&
os_memcmp(buf, "\x30\x41\x30\x0d\x06\x09\x60\x86\x48\x01"
"\x65\x03\x04\x02\x02\x05\x00\x04\x30", 19) == 0)
{
wpa_printf(MSG_DEBUG, "TLSv1.2: DigestAlgorithn = SHA-384");
decrypted = buf + 19;
buflen -= 19;
} else if (buflen >= 19 + 64 &&
os_memcmp(buf, "\x30\x51\x30\x0d\x06\x09\x60\x86\x48\x01"
"\x65\x03\x04\x02\x03\x05\x00\x04\x40", 19) == 0)
{
wpa_printf(MSG_DEBUG, "TLSv1.2: DigestAlgorithn = SHA-512");
decrypted = buf + 19;
buflen -= 19;
} else {
wpa_printf(MSG_DEBUG, "TLSv1.2: Unrecognized DigestInfo");
os_free(buf);
*alert = TLS_ALERT_DECRYPT_ERROR;
return -1;
}
}
#endif /* CONFIG_TLSV12 */
if (buflen != data_len ||
os_memcmp_const(decrypted, data, data_len) != 0) {
wpa_printf(MSG_DEBUG, "TLSv1: Invalid Signature in CertificateVerify - did not match calculated hash");
os_free(buf);
*alert = TLS_ALERT_DECRYPT_ERROR;
return -1;
}
os_free(buf);
return 0;
}
