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-rw-r--r--src/lib/protocols/tls.c1384
1 files changed, 1384 insertions, 0 deletions
diff --git a/src/lib/protocols/tls.c b/src/lib/protocols/tls.c
new file mode 100644
index 000000000..188d0bc9a
--- /dev/null
+++ b/src/lib/protocols/tls.c
@@ -0,0 +1,1384 @@
+/*
+ * tls.c - SSL/TLS/DTLS dissector
+ *
+ * Copyright (C) 2016-19 - ntop.org
+ *
+ * This file is part of nDPI, an open source deep packet inspection
+ * library based on the OpenDPI and PACE technology by ipoque GmbH
+ *
+ * nDPI is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * nDPI is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with nDPI. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "ndpi_protocol_ids.h"
+
+#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_TLS
+
+#include "ndpi_api.h"
+
+/* #define CERTIFICATE_DEBUG 1 */
+
+#define NDPI_MAX_TLS_REQUEST_SIZE 10000
+
+/* Skype.c */
+extern u_int8_t is_skype_flow(struct ndpi_detection_module_struct *ndpi_struct,
+ struct ndpi_flow_struct *flow);
+
+/* **************************************** */
+
+typedef struct MD5Context {
+ uint32_t buf[4];
+ uint32_t bits[2];
+ unsigned char in[64];
+} MD5_CTX;
+
+/* **************************************** */
+
+static int is_big_endian(void) {
+ static const int n = 1;
+ return ((char *) &n)[0] == 0;
+}
+
+static void byteReverse(unsigned char *buf, unsigned longs) {
+ // Forrest: MD5 expect LITTLE_ENDIAN, swap if BIG_ENDIAN
+ if (is_big_endian()) {
+ do {
+ uint32_t t;
+
+ t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
+ ((unsigned) buf[1] << 8 | buf[0]);
+ * (uint32_t *) buf = t;
+ buf += 4;
+ } while (--longs);
+ }
+}
+
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+#define MD5STEP(f, w, x, y, z, data, s) \
+ ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
+
+// Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
+// initialization constants.
+static void MD5Init(MD5_CTX *ctx) {
+ ctx->buf[0] = 0x67452301;
+ ctx->buf[1] = 0xefcdab89;
+ ctx->buf[2] = 0x98badcfe;
+ ctx->buf[3] = 0x10325476;
+
+ ctx->bits[0] = 0;
+ ctx->bits[1] = 0;
+}
+
+static void MD5Transform(uint32_t buf[4], uint32_t const in[16]) {
+ uint32_t a, b, c, d;
+
+ a = buf[0];
+ b = buf[1];
+ c = buf[2];
+ d = buf[3];
+
+ MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
+ MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
+ MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
+ MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
+ MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
+ MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
+ MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
+ MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
+ MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
+ MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
+ MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
+ MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
+ MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
+ MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
+ MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
+ MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
+
+ MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
+ MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
+ MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
+ MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
+ MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
+ MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
+ MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
+ MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
+ MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
+ MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
+ MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
+ MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
+ MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
+ MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
+ MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
+ MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
+
+ MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
+ MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
+ MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
+ MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
+ MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
+ MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
+ MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
+ MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
+ MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
+ MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
+ MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
+ MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
+ MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
+ MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
+ MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
+ MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
+
+ MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
+ MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
+ MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
+ MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
+ MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
+ MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
+ MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
+ MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
+ MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
+ MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
+ MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
+ MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
+ MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
+ MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
+ MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
+ MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
+
+ buf[0] += a;
+ buf[1] += b;
+ buf[2] += c;
+ buf[3] += d;
+}
+
+static void MD5Update(MD5_CTX *ctx, unsigned char const *buf, unsigned len) {
+ uint32_t t;
+
+ t = ctx->bits[0];
+ if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
+ ctx->bits[1]++;
+ ctx->bits[1] += len >> 29;
+
+ t = (t >> 3) & 0x3f;
+
+ if (t) {
+ unsigned char *p = (unsigned char *) ctx->in + t;
+
+ t = 64 - t;
+ if (len < t) {
+ memcpy(p, buf, len);
+ return;
+ }
+ memcpy(p, buf, t);
+ byteReverse(ctx->in, 16);
+ MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+ buf += t;
+ len -= t;
+ }
+
+ while (len >= 64) {
+ memcpy(ctx->in, buf, 64);
+ byteReverse(ctx->in, 16);
+ MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+ buf += 64;
+ len -= 64;
+ }
+
+ memcpy(ctx->in, buf, len);
+}
+
+static void MD5Final(unsigned char digest[16], MD5_CTX *ctx) {
+ unsigned count;
+ unsigned char *p;
+ uint32_t *c = (uint32_t*)ctx->in;
+
+ count = (ctx->bits[0] >> 3) & 0x3F;
+
+ p = ctx->in + count;
+ *p++ = 0x80;
+ count = 64 - 1 - count;
+ if (count < 8) {
+ memset(p, 0, count);
+ byteReverse(ctx->in, 16);
+ MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+ memset(ctx->in, 0, 56);
+ } else {
+ memset(p, 0, count - 8);
+ }
+ byteReverse(ctx->in, 14);
+
+ c[14] = ctx->bits[0];
+ c[15] = ctx->bits[1];
+
+ MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+ byteReverse((unsigned char *) ctx->buf, 4);
+ memcpy(digest, ctx->buf, 16);
+ memset((char *) ctx, 0, sizeof(*ctx));
+}
+
+/* **************************************** */
+
+static u_int32_t ndpi_tls_refine_master_protocol(struct ndpi_detection_module_struct *ndpi_struct,
+ struct ndpi_flow_struct *flow, u_int32_t protocol) {
+ struct ndpi_packet_struct *packet = &flow->packet;
+
+ if(((flow->l4.tcp.tls_seen_client_cert == 1) && (flow->protos.stun_tls.tls.ja3_client[0] != '\0'))
+ || ((flow->l4.tcp.tls_seen_server_cert == 1) && (flow->protos.stun_tls.tls.ja3_server[0] != '\0'))
+ // || (flow->host_server_name[0] != '\0')
+ )
+ protocol = NDPI_PROTOCOL_TLS;
+ else
+ protocol = NDPI_PROTOCOL_TLS_NO_CERT;
+
+ if(packet->tcp != NULL) {
+ switch(protocol) {
+
+ case NDPI_PROTOCOL_TLS:
+ case NDPI_PROTOCOL_TLS_NO_CERT:
+ {
+ /*
+ In case of SSL there are probably sub-protocols
+ such as IMAPS that can be otherwise detected
+ */
+ u_int16_t sport = ntohs(packet->tcp->source);
+ u_int16_t dport = ntohs(packet->tcp->dest);
+
+ if((sport == 465) || (dport == 465) || (sport == 587) || (dport == 587))
+ protocol = NDPI_PROTOCOL_MAIL_SMTPS;
+ else if((sport == 993) || (dport == 993)
+ || (flow->l4.tcp.mail_imap_starttls)
+ ) protocol = NDPI_PROTOCOL_MAIL_IMAPS;
+ else if((sport == 995) || (dport == 995)) protocol = NDPI_PROTOCOL_MAIL_POPS;
+ }
+ break;
+ }
+ }
+
+ return protocol;
+}
+
+/* **************************************** */
+
+static void ndpi_int_tls_add_connection(struct ndpi_detection_module_struct *ndpi_struct,
+ struct ndpi_flow_struct *flow, u_int32_t protocol) {
+ if((protocol != NDPI_PROTOCOL_TLS)
+ && (protocol != NDPI_PROTOCOL_TLS_NO_CERT)) {
+ ndpi_set_detected_protocol(ndpi_struct, flow, protocol, NDPI_PROTOCOL_UNKNOWN);
+ } else {
+ protocol = ndpi_tls_refine_master_protocol(ndpi_struct, flow, protocol);
+ ndpi_set_detected_protocol(ndpi_struct, flow, protocol, NDPI_PROTOCOL_UNKNOWN);
+ }
+}
+
+/* **************************************** */
+
+/* Can't call libc functions from kernel space, define some stub instead */
+
+#define ndpi_isalpha(ch) (((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z'))
+#define ndpi_isdigit(ch) ((ch) >= '0' && (ch) <= '9')
+#define ndpi_isspace(ch) (((ch) >= '\t' && (ch) <= '\r') || ((ch) == ' '))
+#define ndpi_isprint(ch) ((ch) >= 0x20 && (ch) <= 0x7e)
+#define ndpi_ispunct(ch) (((ch) >= '!' && (ch) <= '/') || \
+ ((ch) >= ':' && (ch) <= '@') || \
+ ((ch) >= '[' && (ch) <= '`') || \
+ ((ch) >= '{' && (ch) <= '~'))
+
+/* **************************************** */
+
+static void stripCertificateTrailer(char *buffer, int buffer_len) {
+ int i, is_puny;
+
+ // printf("->%s<-\n", buffer);
+
+ for(i = 0; i < buffer_len; i++) {
+ // printf("%c [%d]\n", buffer[i], buffer[i]);
+
+ if((buffer[i] != '.')
+ && (buffer[i] != '-')
+ && (buffer[i] != '_')
+ && (buffer[i] != '*')
+ && (!ndpi_isalpha(buffer[i]))
+ && (!ndpi_isdigit(buffer[i]))) {
+ buffer[i] = '\0';
+ buffer_len = i;
+ break;
+ }
+ }
+
+ /* check for punycode encoding */
+ is_puny = ndpi_check_punycode_string(buffer, buffer_len);
+
+ // not a punycode string - need more checks
+ if(is_puny == 0) {
+
+ if(i > 0) i--;
+
+ while(i > 0) {
+ if(!ndpi_isalpha(buffer[i])) {
+ buffer[i] = '\0';
+ buffer_len = i;
+ i--;
+ } else
+ break;
+ }
+
+ for(i = buffer_len; i > 0; i--) {
+ if(buffer[i] == '.') break;
+ else if(ndpi_isdigit(buffer[i]))
+ buffer[i] = '\0', buffer_len = i;
+ }
+ }
+
+ /* Now all lowecase */
+ for(i=0; i<buffer_len; i++)
+ buffer[i] = tolower(buffer[i]);
+}
+
+/* **************************************** */
+
+/* https://engineering.salesforce.com/tls-fingerprinting-with-ja3-and-ja3s-247362855967 */
+
+#define JA3_STR_LEN 1024
+#define MAX_NUM_JA3 128
+
+struct ja3_info {
+ u_int16_t tls_version;
+ u_int16_t num_cipher, cipher[MAX_NUM_JA3];
+ u_int16_t num_tls_extension, tls_extension[MAX_NUM_JA3];
+ u_int16_t num_elliptic_curve, elliptic_curve[MAX_NUM_JA3];
+ u_int8_t num_elliptic_curve_point_format, elliptic_curve_point_format[MAX_NUM_JA3];
+};
+
+/* **************************************** */
+
+int getTLScertificate(struct ndpi_detection_module_struct *ndpi_struct,
+ struct ndpi_flow_struct *flow,
+ char *buffer, int buffer_len) {
+ struct ndpi_packet_struct *packet = &flow->packet;
+ struct ja3_info ja3;
+ int i;
+ u_int8_t invalid_ja3 = 0;
+ u_int16_t pkt_tls_version = (packet->payload[1] << 8) + packet->payload[2], ja3_str_len;
+ char ja3_str[JA3_STR_LEN];
+ MD5_CTX ctx;
+ u_char md5_hash[16];
+
+ if(packet->udp) {
+ /* Check if this is DTLS or return */
+ if((packet->payload[1] != 0xfe)
+ || ((packet->payload[2] != 0xff) && (packet->payload[2] != 0xfd))) {
+ NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+ return(0);
+ }
+ }
+
+ flow->protos.stun_tls.tls.tls_version = pkt_tls_version;
+
+ memset(&ja3, 0, sizeof(ja3));
+
+#ifdef CERTIFICATE_DEBUG
+ {
+ u_int16_t tls_len = (packet->payload[3] << 8) + packet->payload[4];
+
+ printf("SSL Record [version: 0x%04X][len: %u]\n", pkt_tls_version, tls_len);
+ }
+#endif
+
+ /*
+ Nothing matched so far: let's decode the certificate with some heuristics
+ Patches courtesy of Denys Fedoryshchenko <nuclearcat@nuclearcat.com>
+ */
+ if(packet->payload[0] == 0x16 /* Handshake */) {
+ u_int16_t total_len;
+ u_int8_t handshake_protocol, header_len;
+
+ if(packet->tcp) {
+ header_len = 5; /* SSL Header */
+ handshake_protocol = packet->payload[5]; /* handshake protocol a bit misleading, it is message type according TLS specs */
+ total_len = (packet->payload[3] << 8) + packet->payload[4];
+ } else {
+ header_len = 13; /* DTLS header */
+ handshake_protocol = packet->payload[13];
+ total_len = ntohs(*((u_int16_t*)&packet->payload[11]));
+ }
+
+ total_len += header_len;
+
+ memset(buffer, 0, buffer_len);
+
+ /* Truncate total len, search at least in incomplete packet */
+ if(total_len > packet->payload_packet_len)
+ total_len = packet->payload_packet_len;
+
+ /* At least "magic" 3 bytes, null for string end, otherwise no need to waste cpu cycles */
+ if(total_len > 4) {
+ u_int16_t base_offset = packet->tcp ? 43 : 59;
+
+#ifdef CERTIFICATE_DEBUG
+ printf("SSL [len: %u][handshake_protocol: %02X]\n", packet->payload_packet_len, handshake_protocol);
+#endif
+
+ if((handshake_protocol == 0x02)
+ || (handshake_protocol == 0x0b) /* Server Hello and Certificate message types are interesting for us */) {
+ u_int num_found = 0;
+ u_int16_t tls_version;
+ int i;
+
+ if(packet->tcp)
+ tls_version = ntohs(*((u_int16_t*)&packet->payload[header_len+4]));
+ else
+ tls_version = ntohs(*((u_int16_t*)&packet->payload[header_len+12]));
+
+ ja3.tls_version = tls_version;
+
+ if(handshake_protocol == 0x02) {
+ u_int16_t offset = base_offset, extension_len, j;
+ u_int8_t session_id_len = packet->payload[offset];
+
+#ifdef CERTIFICATE_DEBUG
+ printf("SSL Server Hello [version: 0x%04X]\n", tls_version);
+#endif
+
+ /*
+ The server hello decides about the SSL version of this flow
+ https://networkengineering.stackexchange.com/questions/55752/why-does-wireshark-show-version-tls-1-2-here-instead-of-tls-1-3
+ */
+ flow->protos.stun_tls.tls.tls_version = tls_version;
+
+ if(packet->udp)
+ offset += 1;
+ else {
+ if(tls_version < 0x7F15 /* TLS 1.3 lacks of session id */)
+ offset += session_id_len+1;
+ }
+
+ ja3.num_cipher = 1, ja3.cipher[0] = ntohs(*((u_int16_t*)&packet->payload[offset]));
+ flow->protos.stun_tls.tls.server_unsafe_cipher = ndpi_is_safe_tls_cipher(ja3.cipher[0]);
+ flow->protos.stun_tls.tls.server_cipher = ja3.cipher[0];
+
+#ifdef CERTIFICATE_DEBUG
+ printf("SSL [server][session_id_len: %u][cipher: %04X]\n", session_id_len, ja3.cipher[0]);
+#endif
+
+ offset += 2 + 1;
+ extension_len = ntohs(*((u_int16_t*)&packet->payload[offset]));
+
+#ifdef CERTIFICATE_DEBUG
+ printf("SSL [server][extension_len: %u]\n", extension_len);
+#endif
+ offset += 2;
+
+ for(i=0; i<extension_len; ) {
+ u_int16_t id, len;
+
+ if(offset >= (packet->payload_packet_len+4)) break;
+
+ id = ntohs(*((u_int16_t*)&packet->payload[offset]));
+ len = ntohs(*((u_int16_t*)&packet->payload[offset+2]));
+
+ if(ja3.num_tls_extension < MAX_NUM_JA3)
+ ja3.tls_extension[ja3.num_tls_extension++] = id;
+
+#ifdef CERTIFICATE_DEBUG
+ printf("SSL [server][extension_id: %u/0x%04X]\n", id, id);
+#endif
+
+ i += 4 + len, offset += 4 + len;
+ }
+
+ ja3_str_len = snprintf(ja3_str, sizeof(ja3_str), "%u,", ja3.tls_version);
+
+ for(i=0; i<ja3.num_cipher; i++)
+ ja3_str_len += snprintf(&ja3_str[ja3_str_len], sizeof(ja3_str)-ja3_str_len, "%s%u", (i > 0) ? "-" : "", ja3.cipher[i]);
+
+ ja3_str_len += snprintf(&ja3_str[ja3_str_len], sizeof(ja3_str)-ja3_str_len, ",");
+
+ /* ********** */
+
+ for(i=0; i<ja3.num_tls_extension; i++)
+ ja3_str_len += snprintf(&ja3_str[ja3_str_len], sizeof(ja3_str)-ja3_str_len, "%s%u", (i > 0) ? "-" : "", ja3.tls_extension[i]);
+
+#ifdef CERTIFICATE_DEBUG
+ printf("SSL [server] %s\n", ja3_str);
+#endif
+
+#ifdef CERTIFICATE_DEBUG
+ printf("[JA3] Server: %s \n", ja3_str);
+#endif
+
+ MD5Init(&ctx);
+ MD5Update(&ctx, (const unsigned char *)ja3_str, strlen(ja3_str));
+ MD5Final(md5_hash, &ctx);
+
+ for(i=0, j=0; i<16; i++)
+ j += snprintf(&flow->protos.stun_tls.tls.ja3_server[j],
+ sizeof(flow->protos.stun_tls.tls.ja3_server)-j, "%02x", md5_hash[i]);
+
+#ifdef CERTIFICATE_DEBUG
+ printf("[JA3] Server: %s \n", flow->protos.stun_tls.tls.ja3_server);
+#endif
+
+ flow->l4.tcp.tls_seen_server_cert = 1;
+ } else
+ flow->l4.tcp.tls_seen_certificate = 1;
+
+ /* Check after handshake protocol header (5 bytes) and message header (4 bytes) */
+ for(i = 9; i < packet->payload_packet_len-3; i++) {
+ if(((packet->payload[i] == 0x04) && (packet->payload[i+1] == 0x03) && (packet->payload[i+2] == 0x0c))
+ || ((packet->payload[i] == 0x04) && (packet->payload[i+1] == 0x03) && (packet->payload[i+2] == 0x13))
+ || ((packet->payload[i] == 0x55) && (packet->payload[i+1] == 0x04) && (packet->payload[i+2] == 0x03))) {
+ u_int8_t server_len = packet->payload[i+3];
+
+ if(packet->payload[i] == 0x55) {
+ num_found++;
+
+ if(num_found != 2) continue;
+ }
+
+ if((server_len+i+3) < packet->payload_packet_len) {
+ char *server_name = (char*)&packet->payload[i+4];
+ u_int8_t begin = 0, len, j, num_dots;
+
+ while(begin < server_len) {
+ if(!ndpi_isprint(server_name[begin]))
+ begin++;
+ else
+ break;
+ }
+
+ // len = ndpi_min(server_len-begin, buffer_len-1);
+ len = buffer_len-1;
+ strncpy(buffer, &server_name[begin], len);
+ buffer[len] = '\0';
+
+ /* We now have to check if this looks like an IP address or host name */
+ for(j=0, num_dots = 0; j<len; j++) {
+ if(!ndpi_isprint((buffer[j]))) {
+ num_dots = 0; /* This is not what we look for */
+ break;
+ } else if(buffer[j] == '.') {
+ num_dots++;
+ if(num_dots >=1) break;
+ }
+ }
+
+ if(num_dots >= 1) {
+ if(!ndpi_struct->disable_metadata_export) {
+ stripCertificateTrailer(buffer, buffer_len);
+ snprintf(flow->protos.stun_tls.tls.server_certificate,
+ sizeof(flow->protos.stun_tls.tls.server_certificate), "%s", buffer);
+ }
+
+ return(1 /* Server Certificate */);
+ }
+ }
+ }
+ }
+ } else if(handshake_protocol == 0x01 /* Client Hello */) {
+ u_int offset;
+
+#ifdef CERTIFICATE_DEBUG
+ printf("[base_offset: %u][payload_packet_len: %u]\n", base_offset, packet->payload_packet_len);
+#endif
+
+ if(base_offset + 2 <= packet->payload_packet_len) {
+ u_int16_t session_id_len;
+ u_int16_t tls_version;
+
+ if(packet->tcp)
+ tls_version = ntohs(*((u_int16_t*)&packet->payload[header_len+4]));
+ else
+ tls_version = ntohs(*((u_int16_t*)&packet->payload[header_len+12]));
+
+ session_id_len = packet->payload[base_offset];
+
+ ja3.tls_version = tls_version;
+
+ if((session_id_len+base_offset+2) <= total_len) {
+ u_int16_t cipher_len, cipher_offset;
+
+ if(packet->tcp) {
+ cipher_len = packet->payload[session_id_len+base_offset+2] + (packet->payload[session_id_len+base_offset+1] << 8);
+ cipher_offset = base_offset + session_id_len + 3;
+ } else {
+ cipher_len = ntohs(*((u_int16_t*)&packet->payload[base_offset+2]));
+ cipher_offset = base_offset+4;
+ }
+
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL [client cipher_len: %u][tls_version: 0x%04X]\n", cipher_len, tls_version);
+#endif
+
+ if((cipher_offset+cipher_len) <= total_len) {
+ for(i=0; i<cipher_len;) {
+ u_int16_t *id = (u_int16_t*)&packet->payload[cipher_offset+i];
+
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL [cipher suite: %u/0x%04X] [%u/%u]\n", ntohs(*id), ntohs(*id), i, cipher_len);
+#endif
+ if((*id == 0) || (packet->payload[cipher_offset+i] != packet->payload[cipher_offset+i+1])) {
+ /*
+ Skip GREASE [https://tools.ietf.org/id/draft-ietf-tls-grease-01.html]
+ https://engineering.salesforce.com/tls-fingerprinting-with-ja3-and-ja3s-247362855967
+ */
+
+ if(ja3.num_cipher < MAX_NUM_JA3)
+ ja3.cipher[ja3.num_cipher++] = ntohs(*id);
+ else {
+ invalid_ja3 = 1;
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL Invalid cipher %u\n", ja3.num_cipher);
+#endif
+ }
+ }
+
+ i += 2;
+ }
+ } else {
+ invalid_ja3 = 1;
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL Invalid len %u vs %u\n", (cipher_offset+cipher_len), total_len);
+#endif
+ }
+
+ offset = base_offset + session_id_len + cipher_len + 2;
+
+ flow->l4.tcp.tls_seen_client_cert = 1;
+
+ if(offset < total_len) {
+ u_int16_t compression_len;
+ u_int16_t extensions_len;
+
+ offset += packet->tcp ? 1 : 2;
+ compression_len = packet->payload[offset];
+ offset++;
+
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL [compression_len: %u]\n", compression_len);
+#endif
+
+ // offset += compression_len + 3;
+ offset += compression_len;
+
+ if(offset < total_len) {
+ extensions_len = ntohs(*((u_int16_t*)&packet->payload[offset]));
+ offset += 2;
+
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL [extensions_len: %u]\n", extensions_len);
+#endif
+
+ if((extensions_len+offset) <= total_len) {
+ /* Move to the first extension
+ Type is u_int to avoid possible overflow on extension_len addition */
+ u_int extension_offset = 0;
+ u_int32_t j;
+
+ while(extension_offset < extensions_len) {
+ u_int16_t extension_id, extension_len, extn_off = offset+extension_offset;
+
+ extension_id = ntohs(*((u_int16_t*)&packet->payload[offset+extension_offset]));
+ extension_offset += 2;
+
+ extension_len = ntohs(*((u_int16_t*)&packet->payload[offset+extension_offset]));
+ extension_offset += 2;
+
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL [extension_id: %u][extension_len: %u]\n", extension_id, extension_len);
+#endif
+
+ if((extension_id == 0) || (packet->payload[extn_off] != packet->payload[extn_off+1])) {
+ /* Skip GREASE */
+
+ if(ja3.num_tls_extension < MAX_NUM_JA3)
+ ja3.tls_extension[ja3.num_tls_extension++] = extension_id;
+ else {
+ invalid_ja3 = 1;
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL Invalid extensions %u\n", ja3.num_tls_extension);
+#endif
+ }
+ }
+
+ if(extension_id == 0 /* server name */) {
+ u_int16_t len;
+
+ len = (packet->payload[offset+extension_offset+3] << 8) + packet->payload[offset+extension_offset+4];
+ len = (u_int)ndpi_min(len, buffer_len-1);
+ strncpy(buffer, (char*)&packet->payload[offset+extension_offset+5], len);
+ buffer[len] = '\0';
+
+ stripCertificateTrailer(buffer, buffer_len);
+
+ if(!ndpi_struct->disable_metadata_export) {
+ snprintf(flow->protos.stun_tls.tls.client_certificate,
+ sizeof(flow->protos.stun_tls.tls.client_certificate), "%s", buffer);
+ }
+ } else if(extension_id == 10 /* supported groups */) {
+ u_int16_t s_offset = offset+extension_offset + 2;
+
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL [EllipticCurveGroups: len=%u]\n", extension_len);
+#endif
+
+ if((s_offset+extension_len-2) <= total_len) {
+ for(i=0; i<extension_len-2;) {
+ u_int16_t s_group = ntohs(*((u_int16_t*)&packet->payload[s_offset+i]));
+
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL [EllipticCurve: %u/0x%04X]\n", s_group, s_group);
+#endif
+ if((s_group == 0) || (packet->payload[s_offset+i] != packet->payload[s_offset+i+1])) {
+ /* Skip GREASE */
+ if(ja3.num_elliptic_curve < MAX_NUM_JA3)
+ ja3.elliptic_curve[ja3.num_elliptic_curve++] = s_group;
+ else {
+ invalid_ja3 = 1;
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL Invalid num elliptic %u\n", ja3.num_elliptic_curve);
+#endif
+ }
+ }
+
+ i += 2;
+ }
+ } else {
+ invalid_ja3 = 1;
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL Invalid len %u vs %u\n", (s_offset+extension_len-1), total_len);
+#endif
+ }
+ } else if(extension_id == 11 /* ec_point_formats groups */) {
+ u_int16_t s_offset = offset+extension_offset + 1;
+
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL [EllipticCurveFormat: len=%u]\n", extension_len);
+#endif
+ if((s_offset+extension_len) < total_len) {
+ for(i=0; i<extension_len-1;i++) {
+ u_int8_t s_group = packet->payload[s_offset+i];
+
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL [EllipticCurveFormat: %u]\n", s_group);
+#endif
+
+ if(ja3.num_elliptic_curve_point_format < MAX_NUM_JA3)
+ ja3.elliptic_curve_point_format[ja3.num_elliptic_curve_point_format++] = s_group;
+ else {
+ invalid_ja3 = 1;
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL Invalid num elliptic %u\n", ja3.num_elliptic_curve_point_format);
+#endif
+ }
+ }
+ } else {
+ invalid_ja3 = 1;
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL Invalid len %u vs %u\n", s_offset+extension_len, total_len);
+#endif
+ }
+ }
+
+ extension_offset += extension_len;
+
+#ifdef CERTIFICATE_DEBUG
+ printf("Client SSL [extension_offset/len: %u/%u]\n", extension_offset, extension_len);
+#endif
+ } /* while */
+
+ if(!invalid_ja3) {
+ ja3_str_len = snprintf(ja3_str, sizeof(ja3_str), "%u,", ja3.tls_version);
+
+ for(i=0; i<ja3.num_cipher; i++) {
+ ja3_str_len += snprintf(&ja3_str[ja3_str_len], sizeof(ja3_str)-ja3_str_len, "%s%u",
+ (i > 0) ? "-" : "", ja3.cipher[i]);
+ }
+
+ ja3_str_len += snprintf(&ja3_str[ja3_str_len], sizeof(ja3_str)-ja3_str_len, ",");
+
+ /* ********** */
+
+ for(i=0; i<ja3.num_tls_extension; i++)
+ ja3_str_len += snprintf(&ja3_str[ja3_str_len], sizeof(ja3_str)-ja3_str_len, "%s%u",
+ (i > 0) ? "-" : "", ja3.tls_extension[i]);
+
+ ja3_str_len += snprintf(&ja3_str[ja3_str_len], sizeof(ja3_str)-ja3_str_len, ",");
+
+ /* ********** */
+
+ for(i=0; i<ja3.num_elliptic_curve; i++)
+ ja3_str_len += snprintf(&ja3_str[ja3_str_len], sizeof(ja3_str)-ja3_str_len, "%s%u",
+ (i > 0) ? "-" : "", ja3.elliptic_curve[i]);
+
+ ja3_str_len += snprintf(&ja3_str[ja3_str_len], sizeof(ja3_str)-ja3_str_len, ",");
+
+ for(i=0; i<ja3.num_elliptic_curve_point_format; i++)
+ ja3_str_len += snprintf(&ja3_str[ja3_str_len], sizeof(ja3_str)-ja3_str_len, "%s%u",
+ (i > 0) ? "-" : "", ja3.elliptic_curve_point_format[i]);
+
+#ifdef CERTIFICATE_DEBUG
+ printf("[JA3] Client: %s \n", ja3_str);
+#endif
+
+ MD5Init(&ctx);
+ MD5Update(&ctx, (const unsigned char *)ja3_str, strlen(ja3_str));
+ MD5Final(md5_hash, &ctx);
+
+ for(i=0, j=0; i<16; i++)
+ j += snprintf(&flow->protos.stun_tls.tls.ja3_client[j],
+ sizeof(flow->protos.stun_tls.tls.ja3_client)-j, "%02x", md5_hash[i]);
+
+#ifdef CERTIFICATE_DEBUG
+ printf("[JA3] Client: %s \n", flow->protos.stun_tls.tls.ja3_client);
+#endif
+ }
+
+ return(2 /* Client Certificate */);
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+
+ return(0); /* Not found */
+}
+
+/* **************************************** */
+
+void getSSLorganization(struct ndpi_detection_module_struct *ndpi_struct,
+ struct ndpi_flow_struct *flow,
+ char *buffer, int buffer_len) {
+ struct ndpi_packet_struct *packet = &flow->packet;
+
+ if(packet->payload[0] != 0x16 /* Handshake */)
+ return;
+
+ u_int16_t total_len = (packet->payload[3] << 8) + packet->payload[4] + 5 /* SSL Header */;
+ u_int8_t handshake_protocol = packet->payload[5]; /* handshake protocol a bit misleading, it is message type according TLS specs */
+
+ if(handshake_protocol != 0x02 && handshake_protocol != 0xb /* Server Hello and Certificate message types are interesting for us */)
+ return;
+
+ /* Truncate total len, search at least in incomplete packet */
+ if(total_len > packet->payload_packet_len)
+ total_len = packet->payload_packet_len;
+
+ memset(buffer, 0, buffer_len);
+
+ /* Check after handshake protocol header (5 bytes) and message header (4 bytes) */
+ u_int num_found = 0;
+ u_int i, j;
+ for(i = 9; i < packet->payload_packet_len-4; i++) {
+ /* Organization OID: 2.5.4.10 */
+ if((packet->payload[i] == 0x55) && (packet->payload[i+1] == 0x04) && (packet->payload[i+2] == 0x0a)) {
+ u_int8_t server_len = packet->payload[i+4];
+
+ num_found++;
+ /* what we want is subject certificate, so we bypass the issuer certificate */
+ if(num_found != 2) continue;
+
+ // packet is truncated... further inspection is not needed
+ if(i+4+server_len >= packet->payload_packet_len) {
+ break;
+ }
+
+ char *server_org = (char*)&packet->payload[i+5];
+
+ u_int len = (u_int)ndpi_min(server_len, buffer_len-1);
+ strncpy(buffer, server_org, len);
+ buffer[len] = '\0';
+
+ // check if organization string are all printable
+ u_int8_t is_printable = 1;
+ for (j = 0; j < len; j++) {
+ if(!ndpi_isprint(buffer[j])) {
+ is_printable = 0;
+ break;
+ }
+ }
+
+ if(is_printable == 1) {
+ snprintf(flow->protos.stun_tls.tls.server_organization,
+ sizeof(flow->protos.stun_tls.tls.server_organization), "%s", buffer);
+#ifdef CERTIFICATE_DEBUG
+ printf("Certificate organization: %s\n", flow->protos.stun_tls.tls.server_organization);
+#endif
+ }
+ }
+ }
+}
+
+/* **************************************** */
+
+int sslTryAndRetrieveServerCertificate(struct ndpi_detection_module_struct *ndpi_struct,
+ struct ndpi_flow_struct *flow) {
+ struct ndpi_packet_struct *packet = &flow->packet;
+
+ /* consider only specific SSL packets (handshake) */
+ if((packet->payload_packet_len > 9) && (packet->payload[0] == 0x16)) {
+ char certificate[64];
+ int rc;
+
+ certificate[0] = '\0';
+ rc = getTLScertificate(ndpi_struct, flow, certificate, sizeof(certificate));
+ packet->tls_certificate_num_checks++;
+
+ if(rc > 0) {
+ char organization[64];
+
+ // try fetch server organization once server certificate is found
+ organization[0] = '\0';
+ getSSLorganization(ndpi_struct, flow, organization, sizeof(organization));
+
+ packet->tls_certificate_detected++;
+ if((flow->l4.tcp.tls_seen_server_cert == 1) && (flow->protos.stun_tls.tls.server_certificate[0] != '\0'))
+ /* 0 means we're done processing extra packets (since we found what we wanted) */
+ return 0;
+ }
+
+ /* Client hello, Server Hello, and certificate packets probably all checked in this case */
+ if((packet->tls_certificate_num_checks >= 3)
+ && (flow->l4.tcp.seen_syn)
+ && (flow->l4.tcp.seen_syn_ack)
+ && (flow->l4.tcp.seen_ack) /* We have seen the 3-way handshake */)
+ {
+ /* We're done processing extra packets since we've probably checked all possible cert packets */
+ return 0;
+ }
+ }
+
+ /* 1 means keep looking for more packets */
+ return 1;
+}
+
+/* **************************************** */
+
+void sslInitExtraPacketProcessing(int caseNum, struct ndpi_flow_struct *flow) {
+ flow->check_extra_packets = 1;
+ /* 0 is the case for waiting for the server certificate */
+ if(caseNum == 0) {
+ /* At most 7 packets should almost always be enough to find the server certificate if it's there */
+ flow->max_extra_packets_to_check = 7;
+ flow->extra_packets_func = sslTryAndRetrieveServerCertificate;
+ }
+}
+
+/* **************************************** */
+
+int tlsDetectProtocolFromCertificate(struct ndpi_detection_module_struct *ndpi_struct,
+ struct ndpi_flow_struct *flow) {
+ struct ndpi_packet_struct *packet = &flow->packet;
+
+ if((packet->payload_packet_len > 9)
+ && (packet->payload[0] == 0x16 /* consider only specific SSL packets (handshake) */)) {
+ if((packet->detected_protocol_stack[0] == NDPI_PROTOCOL_UNKNOWN)
+ || (packet->detected_protocol_stack[0] == NDPI_PROTOCOL_TLS)) {
+ char certificate[64];
+ int rc;
+
+ certificate[0] = '\0';
+ rc = getTLScertificate(ndpi_struct, flow, certificate, sizeof(certificate));
+ packet->tls_certificate_num_checks++;
+
+ if(rc > 0) {
+ packet->tls_certificate_detected++;
+#ifdef CERTIFICATE_DEBUG
+ NDPI_LOG_DBG2(ndpi_struct, "***** [SSL] %s\n", certificate);
+#endif
+ ndpi_protocol_match_result ret_match;
+ u_int32_t subproto = ndpi_match_host_subprotocol(ndpi_struct, flow, certificate,
+ strlen(certificate),
+ &ret_match,
+ NDPI_PROTOCOL_TLS);
+
+ if(subproto != NDPI_PROTOCOL_UNKNOWN) {
+ /* If we've detected the subprotocol from client certificate but haven't had a chance
+ * to see the server certificate yet, set up extra packet processing to wait
+ * a few more packets. */
+ if(((flow->l4.tcp.tls_seen_client_cert == 1) && (flow->protos.stun_tls.tls.client_certificate[0] != '\0'))
+ && ((flow->l4.tcp.tls_seen_server_cert != 1) && (flow->protos.stun_tls.tls.server_certificate[0] == '\0'))) {
+ sslInitExtraPacketProcessing(0, flow);
+ }
+
+ ndpi_set_detected_protocol(ndpi_struct, flow, subproto,
+ ndpi_tls_refine_master_protocol(ndpi_struct, flow, NDPI_PROTOCOL_TLS));
+ return(rc); /* Fix courtesy of Gianluca Costa <g.costa@xplico.org> */
+ }
+
+ if(ndpi_is_tls_tor(ndpi_struct, flow, certificate) != 0)
+ return(rc);
+ }
+
+ if(((packet->tls_certificate_num_checks >= 3)
+ && flow->l4.tcp.seen_syn
+ && flow->l4.tcp.seen_syn_ack
+ && flow->l4.tcp.seen_ack /* We have seen the 3-way handshake */)
+ || ((flow->l4.tcp.tls_seen_certificate == 1)
+ && (flow->l4.tcp.tls_seen_server_cert == 1)
+ && (flow->protos.stun_tls.tls.server_certificate[0] != '\0'))
+ /* || ((flow->l4.tcp.tls_seen_client_cert == 1) && (flow->protos.stun_tls.tls.client_certificate[0] != '\0')) */
+ ) {
+ ndpi_int_tls_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_TLS);
+ }
+ }
+ }
+ return(0);
+}
+
+/* **************************************** */
+
+static void tls_mark_and_payload_search_for_other_protocols(struct ndpi_detection_module_struct
+ *ndpi_struct, struct ndpi_flow_struct *flow) {
+ struct ndpi_packet_struct *packet = &flow->packet;
+ u_int32_t a;
+ u_int32_t end;
+
+ if(NDPI_COMPARE_PROTOCOL_TO_BITMASK(ndpi_struct->detection_bitmask, NDPI_PROTOCOL_UNENCRYPTED_JABBER) != 0)
+ goto check_for_tls_payload;
+
+ if(NDPI_COMPARE_PROTOCOL_TO_BITMASK(ndpi_struct->detection_bitmask, NDPI_PROTOCOL_OSCAR) != 0)
+ goto check_for_tls_payload;
+ else
+ goto no_check_for_tls_payload;
+
+ check_for_tls_payload:
+ end = packet->payload_packet_len - 20;
+ for (a = 5; a < end; a++) {
+
+ if(packet->payload[a] == 't') {
+ if(memcmp(&packet->payload[a], "talk.google.com", 15) == 0) {
+ if(NDPI_COMPARE_PROTOCOL_TO_BITMASK
+ (ndpi_struct->detection_bitmask, NDPI_PROTOCOL_UNENCRYPTED_JABBER) != 0) {
+ NDPI_LOG_INFO(ndpi_struct, "found ssl jabber unencrypted\n");
+ ndpi_int_tls_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_UNENCRYPTED_JABBER);
+ return;
+ }
+ }
+ }
+
+ if(packet->payload[a] == 'A' || packet->payload[a] == 'k' || packet->payload[a] == 'c'
+ || packet->payload[a] == 'h') {
+ if(((a + 19) < packet->payload_packet_len && memcmp(&packet->payload[a], "America Online Inc.", 19) == 0)
+ // || (end - c > 3 memcmp (&packet->payload[c],"AOL", 3) == 0 )
+ // || (end - c > 7 && memcmp (&packet->payload[c], "AOL LLC", 7) == 0)
+ || ((a + 15) < packet->payload_packet_len && memcmp(&packet->payload[a], "kdc.uas.aol.com", 15) == 0)
+ || ((a + 14) < packet->payload_packet_len && memcmp(&packet->payload[a], "corehc@aol.net", 14) == 0)
+ || ((a + 41) < packet->payload_packet_len
+ && memcmp(&packet->payload[a], "http://crl.aol.com/AOLMSPKI/aolServerCert", 41) == 0)
+ || ((a + 28) < packet->payload_packet_len
+ && memcmp(&packet->payload[a], "http://ocsp.web.aol.com/ocsp", 28) == 0)
+ || ((a + 32) < packet->payload_packet_len
+ && memcmp(&packet->payload[a], "http://pki-info.aol.com/AOLMSPKI", 32) == 0)) {
+ NDPI_LOG_INFO(ndpi_struct, "found OSCAR SERVER SSL DETECTED\n");
+
+ if(flow->dst != NULL && packet->payload_packet_len > 75) {
+ memcpy(flow->dst->oscar_tls_session_id, &packet->payload[44], 32);
+ flow->dst->oscar_tls_session_id[32] = '\0';
+ flow->dst->oscar_last_safe_access_time = packet->tick_timestamp;
+ }
+
+ ndpi_int_tls_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_OSCAR);
+ return;
+ }
+ }
+
+ if(packet->payload[a] == 'm' || packet->payload[a] == 's') {
+ if((a + 21) < packet->payload_packet_len &&
+ (memcmp(&packet->payload[a], "my.screenname.aol.com", 21) == 0
+ || memcmp(&packet->payload[a], "sns-static.aolcdn.com", 21) == 0)) {
+ NDPI_LOG_DBG(ndpi_struct, "found OSCAR SERVER SSL DETECTED\n");
+ ndpi_int_tls_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_OSCAR);
+ return;
+ }
+ }
+ }
+
+ no_check_for_tls_payload:
+ if(packet->detected_protocol_stack[0] == NDPI_PROTOCOL_UNKNOWN) {
+ NDPI_LOG_DBG(ndpi_struct, "found ssl connection\n");
+ tlsDetectProtocolFromCertificate(ndpi_struct, flow);
+
+ if(!packet->tls_certificate_detected
+ && (!(flow->l4.tcp.tls_seen_client_cert && flow->l4.tcp.tls_seen_server_cert))) {
+ /* SSL without certificate (Skype, Ultrasurf?) */
+ NDPI_LOG_INFO(ndpi_struct, "found ssl NO_CERT\n");
+ ndpi_int_tls_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_TLS_NO_CERT);
+ } else if(packet->tls_certificate_num_checks >= 3) {
+ NDPI_LOG_INFO(ndpi_struct, "found ssl\n");
+ ndpi_int_tls_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_TLS);
+ }
+ }
+}
+
+/* **************************************** */
+
+static u_int8_t ndpi_search_tlsv3_direction1(struct ndpi_detection_module_struct *ndpi_struct,
+ struct ndpi_flow_struct *flow) {
+ struct ndpi_packet_struct *packet = &flow->packet;
+
+ if((packet->payload_packet_len >= 5)
+ && ((packet->payload[0] == 0x16) || packet->payload[0] == 0x17)
+ && (packet->payload[1] == 0x03)
+ && ((packet->payload[2] == 0x00) || (packet->payload[2] == 0x01) ||
+ (packet->payload[2] == 0x02) || (packet->payload[2] == 0x03))) {
+ u_int32_t temp;
+ NDPI_LOG_DBG2(ndpi_struct, "search sslv3\n");
+ // SSLv3 Record
+ if(packet->payload_packet_len >= 1300) {
+ return 1;
+ }
+ temp = ntohs(get_u_int16_t(packet->payload, 3)) + 5;
+ NDPI_LOG_DBG2(ndpi_struct, "temp = %u\n", temp);
+ if(packet->payload_packet_len == temp
+ || (temp < packet->payload_packet_len && packet->payload_packet_len > 500)) {
+ return 1;
+ }
+
+ if(packet->payload_packet_len < temp && temp < 5000 && packet->payload_packet_len > 9) {
+ /* the server hello may be split into small packets */
+ u_int32_t cert_start;
+
+ NDPI_LOG_DBG2(ndpi_struct,
+ "maybe SSLv3 server hello split into smaller packets\n");
+
+ /* lets hope at least the server hello and the start of the certificate block are in the first packet */
+ cert_start = ntohs(get_u_int16_t(packet->payload, 7)) + 5 + 4;
+ NDPI_LOG_DBG2(ndpi_struct, "suspected start of certificate: %u\n",
+ cert_start);
+
+ if(cert_start < packet->payload_packet_len && packet->payload[cert_start] == 0x0b) {
+ NDPI_LOG_DBG2(ndpi_struct,
+ "found 0x0b at suspected start of certificate block\n");
+ return 2;
+ }
+ }
+
+ if((packet->payload_packet_len > temp) && (packet->payload_packet_len > 100)) {
+ /* the server hello may be split into small packets and the certificate has its own SSL Record
+ * so temp contains only the length for the first ServerHello block */
+ u_int32_t cert_start;
+
+ NDPI_LOG_DBG2(ndpi_struct,
+ "maybe SSLv3 server hello split into smaller packets but with seperate record for the certificate\n");
+
+ /* lets hope at least the server hello record and the start of the certificate record are in the first packet */
+ cert_start = ntohs(get_u_int16_t(packet->payload, 7)) + 5 + 5 + 4;
+ NDPI_LOG_DBG2(ndpi_struct, "suspected start of certificate: %u\n",
+ cert_start);
+
+ if(cert_start < packet->payload_packet_len && packet->payload[cert_start] == 0x0b) {
+ NDPI_LOG_DBG2(ndpi_struct,
+ "found 0x0b at suspected start of certificate block\n");
+ return 2;
+ }
+ }
+
+
+ if(packet->payload_packet_len >= temp + 5 && (packet->payload[temp] == 0x14 || packet->payload[temp] == 0x16)
+ && packet->payload[temp + 1] == 0x03) {
+ u_int32_t temp2 = ntohs(get_u_int16_t(packet->payload, temp + 3)) + 5;
+ if(temp + temp2 > NDPI_MAX_TLS_REQUEST_SIZE) {
+ return 1;
+ }
+ temp += temp2;
+ NDPI_LOG_DBG2(ndpi_struct, "temp = %u\n", temp);
+ if(packet->payload_packet_len == temp) {
+ return 1;
+ }
+ if(packet->payload_packet_len >= temp + 5 &&
+ packet->payload[temp] == 0x16 && packet->payload[temp + 1] == 0x03) {
+ temp2 = ntohs(get_u_int16_t(packet->payload, temp + 3)) + 5;
+ if(temp + temp2 > NDPI_MAX_TLS_REQUEST_SIZE) {
+ return 1;
+ }
+ temp += temp2;
+ NDPI_LOG_DBG2(ndpi_struct, "temp = %u\n", temp);
+ if(packet->payload_packet_len == temp) {
+ return 1;
+ }
+ if(packet->payload_packet_len >= temp + 5 &&
+ packet->payload[temp] == 0x16 && packet->payload[temp + 1] == 0x03) {
+ temp2 = ntohs(get_u_int16_t(packet->payload, temp + 3)) + 5;
+ if(temp + temp2 > NDPI_MAX_TLS_REQUEST_SIZE) {
+ return 1;
+ }
+ temp += temp2;
+ NDPI_LOG_DBG2(ndpi_struct, "temp = %u\n", temp);
+ if(temp == packet->payload_packet_len) {
+ return 1;
+ }
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+/* **************************************** */
+
+void ndpi_search_tls_tcp_udp(struct ndpi_detection_module_struct *ndpi_struct,
+ struct ndpi_flow_struct *flow) {
+ struct ndpi_packet_struct *packet = &flow->packet;
+ u_int8_t ret;
+
+ if(packet->udp != NULL) {
+ /* DTLS dissector */
+ int rc = sslTryAndRetrieveServerCertificate(ndpi_struct, flow);
+
+ if(rc) flow->guessed_protocol_id = NDPI_PROTOCOL_TLS;
+
+ if(flow->l4.tcp.tls_seen_server_cert)
+ ndpi_int_tls_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_TLS);
+ return;
+ }
+
+ if(packet->detected_protocol_stack[0] == NDPI_PROTOCOL_TLS) {
+ if(flow->l4.tcp.tls_stage == 3 && packet->payload_packet_len > 20 && flow->packet_counter < 5) {
+ /* this should only happen, when we detected SSL with a packet that had parts of the certificate in subsequent packets
+ * so go on checking for certificate patterns for a couple more packets
+ */
+ NDPI_LOG_DBG2(ndpi_struct,
+ "ssl flow but check another packet for patterns\n");
+ tls_mark_and_payload_search_for_other_protocols(ndpi_struct, flow);
+
+ if(packet->detected_protocol_stack[0] == NDPI_PROTOCOL_TLS) {
+ /* still ssl so check another packet */
+ return;
+ } else {
+ /* protocol has changed so we are done */
+ return;
+ }
+ }
+
+ return;
+ }
+
+ NDPI_LOG_DBG(ndpi_struct, "search ssl\n");
+
+ /* Check if this is whatsapp first (this proto runs over port 443) */
+ if((packet->payload_packet_len > 5)
+ && ((packet->payload[0] == 'W')
+ && (packet->payload[1] == 'A')
+ && (packet->payload[4] == 0)
+ && (packet->payload[2] <= 9)
+ && (packet->payload[3] <= 9))) {
+ ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_WHATSAPP, NDPI_PROTOCOL_UNKNOWN);
+ return;
+ } else if((packet->payload_packet_len == 4)
+ && (packet->payload[0] == 'W')
+ && (packet->payload[1] == 'A')) {
+ ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_WHATSAPP, NDPI_PROTOCOL_UNKNOWN);
+ return;
+ } else {
+ /* No whatsapp, let's try SSL */
+ if(tlsDetectProtocolFromCertificate(ndpi_struct, flow) > 0)
+ return;
+ }
+
+ if(packet->payload_packet_len > 40 && flow->l4.tcp.tls_stage == 0) {
+ NDPI_LOG_DBG2(ndpi_struct, "first ssl packet\n");
+ // SSLv2 Record
+ if(packet->payload[2] == 0x01 && packet->payload[3] == 0x03
+ && (packet->payload[4] == 0x00 || packet->payload[4] == 0x01 || packet->payload[4] == 0x02)
+ && (packet->payload_packet_len - packet->payload[1] == 2)) {
+ NDPI_LOG_DBG2(ndpi_struct, "sslv2 len match\n");
+ flow->l4.tcp.tls_stage = 1 + packet->packet_direction;
+ return;
+ }
+
+ if(packet->payload[0] == 0x16 && packet->payload[1] == 0x03
+ && (packet->payload[2] == 0x00 || packet->payload[2] == 0x01 || packet->payload[2] == 0x02)
+ && (packet->payload_packet_len - ntohs(get_u_int16_t(packet->payload, 3)) == 5)) {
+ // SSLv3 Record
+ NDPI_LOG_DBG2(ndpi_struct, "sslv3 len match\n");
+ flow->l4.tcp.tls_stage = 1 + packet->packet_direction;
+ return;
+ }
+
+ // Application Data pkt
+ if(packet->payload[0] == 0x17 && packet->payload[1] == 0x03
+ && (packet->payload[2] == 0x00 || packet->payload[2] == 0x01 ||
+ packet->payload[2] == 0x02 || packet->payload[2] == 0x03)) {
+ if(packet->payload_packet_len - ntohs(get_u_int16_t(packet->payload, 3)) == 5) {
+ NDPI_LOG_DBG2(ndpi_struct, "TLS len match\n");
+ flow->l4.tcp.tls_stage = 1 + packet->packet_direction;
+ return;
+ }
+ }
+ }
+
+ if(packet->payload_packet_len > 40 &&
+ flow->l4.tcp.tls_stage == 1 + packet->packet_direction
+ && flow->packet_direction_counter[packet->packet_direction] < 5) {
+ return;
+ }
+
+ if(packet->payload_packet_len > 40 && flow->l4.tcp.tls_stage == 2 - packet->packet_direction) {
+ NDPI_LOG_DBG2(ndpi_struct, "second ssl packet\n");
+ // SSLv2 Record
+ if(packet->payload[2] == 0x01 && packet->payload[3] == 0x03
+ && (packet->payload[4] == 0x00 || packet->payload[4] == 0x01 || packet->payload[4] == 0x02)
+ && (packet->payload_packet_len - 2) >= packet->payload[1]) {
+ NDPI_LOG_DBG2(ndpi_struct, "sslv2 server len match\n");
+ tls_mark_and_payload_search_for_other_protocols(ndpi_struct, flow);
+ return;
+ }
+
+ ret = ndpi_search_tlsv3_direction1(ndpi_struct, flow);
+ if(ret == 1) {
+ NDPI_LOG_DBG2(ndpi_struct, "sslv3 server len match\n");
+ tls_mark_and_payload_search_for_other_protocols(ndpi_struct, flow);
+ return;
+ } else if(ret == 2) {
+ NDPI_LOG_DBG2(ndpi_struct,
+ "sslv3 server len match with split packet -> check some more packets for SSL patterns\n");
+ tls_mark_and_payload_search_for_other_protocols(ndpi_struct, flow);
+ if(packet->detected_protocol_stack[0] == NDPI_PROTOCOL_TLS) {
+ flow->l4.tcp.tls_stage = 3;
+ }
+ return;
+ }
+
+ if(packet->payload_packet_len > 40 && flow->packet_direction_counter[packet->packet_direction] < 5) {
+ NDPI_LOG_DBG2(ndpi_struct, "need next packet\n");
+ return;
+ }
+ }
+
+ NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+
+ return;
+}
+
+/* **************************************** */
+
+void init_tls_dissector(struct ndpi_detection_module_struct *ndpi_struct,
+ u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask) {
+ ndpi_set_bitmask_protocol_detection("TLS", ndpi_struct, detection_bitmask, *id,
+ NDPI_PROTOCOL_TLS,
+ ndpi_search_tls_tcp_udp,
+ NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_OR_UDP_WITH_PAYLOAD,
+ SAVE_DETECTION_BITMASK_AS_UNKNOWN,
+ ADD_TO_DETECTION_BITMASK);
+
+ *id += 1;
+}
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