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-rw-r--r--networking/tls.c72
1 files changed, 39 insertions, 33 deletions
diff --git a/networking/tls.c b/networking/tls.c
index 983ed50..3b6347e 100644
--- a/networking/tls.c
+++ b/networking/tls.c
@@ -128,7 +128,7 @@
// (tested b/c this one doesn't req server certs... no luck)
//test TLS_RSA_WITH_AES_128_CBC_SHA, in tls 1.2 it's mandated to be always supported
-struct transport_hdr {
+struct record_hdr {
uint8_t type;
uint8_t proto_maj, proto_min;
uint8_t len16_hi, len16_lo;
@@ -140,8 +140,6 @@ typedef struct tls_state {
uint8_t *pubkey;
int pubkey_len;
- int insize;
- int tail;
// RFC 5246
// |6.2.1. Fragmentation
// | The record layer fragments information blocks into TLSPlaintext
@@ -167,6 +165,8 @@ typedef struct tls_state {
// | The length MUST NOT exceed 2^14 + 1024.
//
// Since our buffer also contains 5-byte headers, make it a bit bigger:
+ int insize;
+ int tail;
uint8_t inbuf[18*1024];
} tls_state_t;
@@ -220,6 +220,7 @@ static void tls_error_die(tls_state_t *tls)
static int xread_tls_block(tls_state_t *tls)
{
+ struct record_hdr *xhdr;
int len;
int total;
int target;
@@ -230,21 +231,28 @@ static int xread_tls_block(tls_state_t *tls)
total = tls->tail;
target = sizeof(tls->inbuf);
for (;;) {
- if (total >= sizeof(struct transport_hdr) && target == sizeof(tls->inbuf)) {
- struct transport_hdr *xhdr = (void*)tls->inbuf;
+ if (total >= sizeof(*xhdr) && target == sizeof(tls->inbuf)) {
+ xhdr = (void*)tls->inbuf;
target = sizeof(*xhdr) + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
+ if (target >= sizeof(tls->inbuf)) {
+ /* malformed input (too long): yell and die */
+ tls->tail = 0;
+ tls->insize = total;
+ tls_error_die(tls);
+ }
+ // can also check type/proto_maj/proto_min here
}
/* if total >= target, we have a full packet (and possibly more)... */
- if (target - total <= 0)
+ if (total - target >= 0)
break;
len = safe_read(tls->fd, tls->inbuf + total, sizeof(tls->inbuf) - total);
if (len <= 0)
bb_perror_msg_and_die("short read");
total += len;
}
- tls->tail = -(target - total);
+ tls->tail = total - target;
tls->insize = target;
- target -= sizeof(struct transport_hdr);
+ target -= sizeof(*xhdr);
dbg("got block len:%u\n", target);
return target;
}
@@ -252,7 +260,7 @@ static int xread_tls_block(tls_state_t *tls)
static void send_client_hello(tls_state_t *tls)
{
struct client_hello {
- struct transport_hdr xhdr;
+ struct record_hdr xhdr;
uint8_t type;
uint8_t len24_hi, len24_mid, len24_lo;
uint8_t proto_maj, proto_min;
@@ -270,18 +278,18 @@ static void send_client_hello(tls_state_t *tls)
hello.xhdr.type = RECORD_TYPE_HANDSHAKE;
hello.xhdr.proto_maj = TLS_MAJ;
hello.xhdr.proto_min = TLS_MIN;
- hello.xhdr.len16_hi = (sizeof(hello) - sizeof(hello.xhdr)) >> 8;
+ //zero: hello.xhdr.len16_hi = (sizeof(hello) - sizeof(hello.xhdr)) >> 8;
hello.xhdr.len16_lo = (sizeof(hello) - sizeof(hello.xhdr));
hello.type = HANDSHAKE_CLIENT_HELLO;
- hello.len24_mid = (sizeof(hello) - sizeof(hello.xhdr) - 4) >> 8;
+ //hello.len24_hi = 0;
+ //zero: hello.len24_mid = (sizeof(hello) - sizeof(hello.xhdr) - 4) >> 8;
hello.len24_lo = (sizeof(hello) - sizeof(hello.xhdr) - 4);
hello.proto_maj = TLS_MAJ;
hello.proto_min = TLS_MIN;
- //fillrand(hello.rand32, sizeof(hello.rand32));
open_read_close("/dev/urandom", hello.rand32, sizeof(hello.rand32));
//hello.session_id_len = 0;
//hello.cipherid_len16_hi = 0;
- hello.cipherid_len16_lo = 2;
+ hello.cipherid_len16_lo = 2 * 1;
hello.cipherid[0] = CIPHER_ID >> 8;
hello.cipherid[1] = CIPHER_ID & 0xff;
hello.comprtypes_len = 1;
@@ -293,7 +301,7 @@ static void send_client_hello(tls_state_t *tls)
static void get_server_hello_or_die(tls_state_t *tls)
{
struct server_hello {
- struct transport_hdr xhdr;
+ struct record_hdr xhdr;
uint8_t type;
uint8_t len24_hi, len24_mid, len24_lo;
uint8_t proto_maj, proto_min;
@@ -319,8 +327,9 @@ static void get_server_hello_or_die(tls_state_t *tls)
tls_error_die(tls);
}
dbg("got HANDSHAKE\n");
- // 02 000046 03|03 58|78|cf|c1 50|a5|49|ee|7e|29|48|71|fe|97|fa|e8|2d|19|87|72|90|84|9d|37|a3|f0|cb|6f|5f|e3|3c|2f |20 |d8|1a|78|96|52|d6|91|01|24|b3|d6|5b|b7|d0|6c|b3|e1|78|4e|3c|95|de|74|a0|ba|eb|a7|3a|ff|bd|a2|bf |00|9c |00|
- // SvHl len=70 maj.min unixtime^^^ 28randbytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^ slen sid32bytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cipSel comprSel
+ // 74 bytes:
+ // 02 000046 03|03 58|78|cf|c1 50|a5|49|ee|7e|29|48|71|fe|97|fa|e8|2d|19|87|72|90|84|9d|37|a3|f0|cb|6f|5f|e3|3c|2f |20 |d8|1a|78|96|52|d6|91|01|24|b3|d6|5b|b7|d0|6c|b3|e1|78|4e|3c|95|de|74|a0|ba|eb|a7|3a|ff|bd|a2|bf |00|9c |00|
+ //SvHl len=70 maj.min unixtime^^^ 28randbytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^ slen sid32bytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cipSel comprSel
if (hp->type != HANDSHAKE_SERVER_HELLO
|| hp->len24_hi != 0
|| hp->len24_mid != 0
@@ -359,8 +368,8 @@ static unsigned get_der_len(uint8_t **bodyp, uint8_t *der, uint8_t *end)
xfunc_die();
/* it's "ii 82 xx yy" */
len = 0x100*der[2] + der[3];
- if (len < 0x80)
- xfunc_die(); /* invalid DER: must use short len if can */
+// if (len < 0x80)
+// xfunc_die(); /* invalid DER: must use short len if can */
der += 2; /* skip [code]+[82]+[2byte_len] */
}
@@ -395,7 +404,9 @@ static uint8_t *skip_der_item(uint8_t *der, uint8_t *end)
static void *find_key_in_der_cert(int *key_len, uint8_t *der, int len)
{
-/* Example: partial decode of kernel.org certificate in DER format.
+/* Certificate is a DER-encoded data structure. Each DER element has a length,
+ * which makes it easy to skip over large compound elements of any complexity
+ * without parsing them. Example: partial decode of kernel.org certificate:
* SEQ 0x05ac/1452 bytes (Certificate): 308205ac
* SEQ 0x0494/1172 bytes (tbsCertificate): 30820494
* [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0] 3 bytes: a003
@@ -425,8 +436,7 @@ static void *find_key_in_der_cert(int *key_len, uint8_t *der, int len)
* SET 32 bytes: 3120
* SEQ 30 bytes: 301e
* OID 3 bytes: 0603 550403
- * Printable string "Gandi Standard SSL CA 2": 1317
- * 47616e6469205374616e646172642053534c2043412032
+ * Printable string "Gandi Standard SSL CA 2": 1317 47616e6469205374616e646172642053534c2043412032
* SEQ 30 bytes (validity): 301e
* TIME "161011000000Z": 170d 3136313031313030303030305a
* TIME "191011235959Z": 170d 3139313031313233353935395a
@@ -452,10 +462,6 @@ static void *find_key_in_der_cert(int *key_len, uint8_t *der, int len)
* [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0x3] 0x01e5 bytes (X509v3 extensions): a38201e5
* SEQ 0x01e1 bytes: 308201e1
* ...
- * Certificate is a DER-encoded data structure. Each DER element has a length,
- * which makes it easy to skip over large compound elements of any complexity
- * without parsing them.
- *
* Certificate is a sequence of three elements:
* tbsCertificate (SEQ)
* signatureAlgorithm (AlgorithmIdentifier)
@@ -475,7 +481,7 @@ static void *find_key_in_der_cert(int *key_len, uint8_t *der, int len)
* algorithm (AlgorithmIdentifier)
* publicKey (BIT STRING)
*
- * Essentially, we want subjectPublicKeyInfo.publicKey
+ * We need Certificate.tbsCertificate.subjectPublicKeyInfo.publicKey
*/
uint8_t *end = der + len;
@@ -510,7 +516,7 @@ static void *find_key_in_der_cert(int *key_len, uint8_t *der, int len)
static void get_server_cert_or_die(tls_state_t *tls)
{
- struct transport_hdr *xhdr;
+ struct record_hdr *xhdr;
uint8_t *certbuf;
int len, len1;
@@ -528,16 +534,15 @@ static void get_server_cert_or_die(tls_state_t *tls)
if (certbuf[0] != HANDSHAKE_CERTIFICATE)
tls_error_die(tls);
dbg("got CERTIFICATE\n");
- // 0b 00|11|24 00|11|21 00|05|b0 30|82|05|ac|30|82|04|94|a0|03|02|01|02|02|11|00|9f|85|bf|66|4b|0c|dd|af|ca|50|86|79|50|1b|2b|e4|30|0d... (4392 bytes)
- // Cert len=4388 ChainLen CertLen^ DER encoded X509 starts here. openssl x509 -in FILE -inform DER -noout -text
+ // 4392 bytes:
+ // 0b 00|11|24 00|11|21 00|05|b0 30|82|05|ac|30|82|04|94|a0|03|02|01|02|02|11|00|9f|85|bf|66|4b|0c|dd|af|ca|50|86|79|50|1b|2b|e4|30|0d...
+ //Cert len=4388 ChainLen CertLen^ DER encoded X509 starts here. openssl x509 -in FILE -inform DER -noout -text
len1 = get24be(certbuf + 1);
if (len1 > len - 4) tls_error_die(tls);
len = len1;
-
len1 = get24be(certbuf + 4);
if (len1 > len - 3) tls_error_die(tls);
len = len1;
-
len1 = get24be(certbuf + 7);
if (len1 > len - 3) tls_error_die(tls);
len = len1;
@@ -601,8 +606,9 @@ static void tls_handshake(tls_state_t *tls)
/* Next handshake type is not predetermined */
switch (tls->inbuf[5]) {
case HANDSHAKE_SERVER_KEY_EXCHANGE:
- //0c 0001c7 03|00|17|41|04|87|94|2e|2f|68|d0|c9|f4|97|a8|2d|ef|ed|67|ea|c6|f3|b3|56|47|5d|27|b6|bd|ee|70|25|30|5e|b0|8e|f6|21|5a... 459 bytes
- //SvKey len^^^
+ // 459 bytes:
+ // 0c 00|01|c7 03|00|17|41|04|87|94|2e|2f|68|d0|c9|f4|97|a8|2d|ef|ed|67|ea|c6|f3|b3|56|47|5d|27|b6|bd|ee|70|25|30|5e|b0|8e|f6|21|5a...
+ //SvKey len=455^
dbg("got SERVER_KEY_EXCHANGE\n");
len = xread_tls_block(tls);
break;
generated by cgit v1.1 at 2024-12-29 05:32:43 +0000