tls: work-in-progress TLS1.2 test applet
function old new delta tls_main - 733 +733 dump - 230 +230 xread_tls_block - 180 +180 get_der_len - 76 +76 enter_der_item - 70 +70 skip_der_item - 56 +56 get24be - 24 +24 tls_error_die - 19 +19 packed_usage 31010 31027 +17 applet_names 2549 2553 +4 applet_main 1472 1476 +4 applet_suid 92 93 +1 applet_install_loc 184 185 +1 ------------------------------------------------------------------------------ (add/remove: 9/0 grow/shrink: 5/0 up/down: 1415/0) Total: 1415 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
parent
a6f8651911
commit
ceff6b0ea9
643
networking/tls.c
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643
networking/tls.c
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@ -0,0 +1,643 @@
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/*
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* Licensed under GPLv2, see file LICENSE in this source tree.
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*
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* Copyright (C) 2017 Denys Vlasenko
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*/
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//config:config TLS
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//config: bool "tls (debugging)"
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//config: default n
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//applet:IF_TLS(APPLET(tls, BB_DIR_USR_BIN, BB_SUID_DROP))
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//kbuild:lib-$(CONFIG_TLS) += tls.o
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////kbuild:lib-$(CONFIG_TLS) += tls_ciphers.o
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////kbuild:lib-$(CONFIG_TLS) += tls_aes.o
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////kbuild:lib-$(CONFIG_TLS) += tls_aes_gcm.o
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//usage:#define tls_trivial_usage
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//usage: "HOST[:PORT]"
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//usage:#define tls_full_usage "\n\n"
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#include "libbb.h"
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//#include "tls_cryptoapi.h"
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//#include "tls_ciphers.h"
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#if 1
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# define dbg(...) fprintf(stderr, __VA_ARGS__)
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#else
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# define dbg(...) ((void)0)
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#endif
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#define RECORD_TYPE_CHANGE_CIPHER_SPEC 20
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#define RECORD_TYPE_ALERT 21
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#define RECORD_TYPE_HANDSHAKE 22
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#define RECORD_TYPE_APPLICATION_DATA 23
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#define HANDSHAKE_HELLO_REQUEST 0
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#define HANDSHAKE_CLIENT_HELLO 1
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#define HANDSHAKE_SERVER_HELLO 2
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#define HANDSHAKE_HELLO_VERIFY_REQUEST 3
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#define HANDSHAKE_NEW_SESSION_TICKET 4
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#define HANDSHAKE_CERTIFICATE 11
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#define HANDSHAKE_SERVER_KEY_EXCHANGE 12
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#define HANDSHAKE_CERTIFICATE_REQUEST 13
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#define HANDSHAKE_SERVER_HELLO_DONE 14
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#define HANDSHAKE_CERTIFICATE_VERIFY 15
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#define HANDSHAKE_CLIENT_KEY_EXCHANGE 16
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#define HANDSHAKE_FINISHED 20
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#define SSL_NULL_WITH_NULL_NULL 0x0000
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#define SSL_RSA_WITH_NULL_MD5 0x0001
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#define SSL_RSA_WITH_NULL_SHA 0x0002
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#define SSL_RSA_WITH_RC4_128_MD5 0x0004
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#define SSL_RSA_WITH_RC4_128_SHA 0x0005
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#define SSL_RSA_WITH_3DES_EDE_CBC_SHA 0x000A /* 10 */
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#define TLS_RSA_WITH_AES_128_CBC_SHA 0x002F /* 47 */
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#define TLS_RSA_WITH_AES_256_CBC_SHA 0x0035 /* 53 */
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#define TLS_EMPTY_RENEGOTIATION_INFO_SCSV 0x00FF
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#define TLS_RSA_WITH_IDEA_CBC_SHA 0x0007 /* 7 */
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#define SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA 0x0016 /* 22 */
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#define SSL_DH_anon_WITH_RC4_128_MD5 0x0018 /* 24 */
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#define SSL_DH_anon_WITH_3DES_EDE_CBC_SHA 0x001B /* 27 */
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#define TLS_DHE_RSA_WITH_AES_128_CBC_SHA 0x0033 /* 51 */
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#define TLS_DHE_RSA_WITH_AES_256_CBC_SHA 0x0039 /* 57 */
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#define TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 0x0067 /* 103 */
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#define TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 0x006B /* 107 */
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#define TLS_DH_anon_WITH_AES_128_CBC_SHA 0x0034 /* 52 */
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#define TLS_DH_anon_WITH_AES_256_CBC_SHA 0x003A /* 58 */
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#define TLS_RSA_WITH_AES_128_CBC_SHA256 0x003C /* 60 */
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#define TLS_RSA_WITH_AES_256_CBC_SHA256 0x003D /* 61 */
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#define TLS_RSA_WITH_SEED_CBC_SHA 0x0096 /* 150 */
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#define TLS_PSK_WITH_AES_128_CBC_SHA 0x008C /* 140 */
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#define TLS_PSK_WITH_AES_128_CBC_SHA256 0x00AE /* 174 */
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#define TLS_PSK_WITH_AES_256_CBC_SHA384 0x00AF /* 175 */
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#define TLS_PSK_WITH_AES_256_CBC_SHA 0x008D /* 141 */
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#define TLS_DHE_PSK_WITH_AES_128_CBC_SHA 0x0090 /* 144 */
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#define TLS_DHE_PSK_WITH_AES_256_CBC_SHA 0x0091 /* 145 */
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#define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA 0xC004 /* 49156 */
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#define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA 0xC005 /* 49157 */
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#define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA 0xC009 /* 49161 */
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#define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA 0xC00A /* 49162 */
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#define TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA 0xC012 /* 49170 */
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#define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA 0xC013 /* 49171 */
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#define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA 0xC014 /* 49172 */
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#define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA 0xC00E /* 49166 */
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#define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA 0xC00F /* 49167 */
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#define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 0xC023 /* 49187 */
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#define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 0xC024 /* 49188 */
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#define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 0xC025 /* 49189 */
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#define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 0xC026 /* 49190 */
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#define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 0xC027 /* 49191 */
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#define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 0xC028 /* 49192 */
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#define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 0xC029 /* 49193 */
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#define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 0xC02A /* 49194 */
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#define TLS_RSA_WITH_AES_128_GCM_SHA256 0x009C /* 156 */
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#define TLS_RSA_WITH_AES_256_GCM_SHA384 0x009D /* 157 */
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#define TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 0xC02B /* 49195 */
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#define TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 0xC02C /* 49196 */
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#define TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 0xC02D /* 49197 */
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#define TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 0xC02E /* 49198 */
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#define TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 0xC02F /* 49199 */
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#define TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 0xC030 /* 49200 */
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#define TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 0xC031 /* 49201 */
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#define TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 0xC032 /* 49202 */
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//Tested against kernel.org:
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//TLS 1.1
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//#define TLS_MAJ 3
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//#define TLS_MIN 2
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//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA // ok, recvs SERVER_KEY_EXCHANGE
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//TLS 1.2
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#define TLS_MAJ 3
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#define TLS_MIN 3
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//#define CIPHER_ID TLS_RSA_WITH_AES_256_CBC_SHA256 // ok, no SERVER_KEY_EXCHANGE
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// All GCMs:
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//#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 // SSL_ALERT_HANDSHAKE_FAILURE
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//#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
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//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 // ok, recvs SERVER_KEY_EXCHANGE
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//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
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//#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384
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//#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
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//#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384
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//#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
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//#define CIPHER_ID TLS_RSA_WITH_AES_256_GCM_SHA384 // ok, no SERVER_KEY_EXCHANGE
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#define CIPHER_ID TLS_RSA_WITH_AES_128_GCM_SHA256 // ok, no SERVER_KEY_EXCHANGE
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//#define CIPHER_ID TLS_DH_anon_WITH_AES_256_CBC_SHA // SSL_ALERT_HANDSHAKE_FAILURE
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// (tested b/c this one doesn't req server certs... no luck)
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//test TLS_RSA_WITH_AES_128_CBC_SHA, in tls 1.2 it's mandated to be always supported
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struct transport_hdr {
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uint8_t type;
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uint8_t proto_maj, proto_min;
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uint8_t len16_hi, len16_lo;
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};
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typedef struct tls_state {
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int fd;
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uint8_t *pubkey;
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int pubkey_len;
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int insize;
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int tail;
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// RFC 5246
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// |6.2.1. Fragmentation
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// | The record layer fragments information blocks into TLSPlaintext
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// | records carrying data in chunks of 2^14 bytes or less. Client
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// | message boundaries are not preserved in the record layer (i.e.,
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// | multiple client messages of the same ContentType MAY be coalesced
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// | into a single TLSPlaintext record, or a single message MAY be
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// | fragmented across several records)
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// |...
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// | length
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// | The length (in bytes) of the following TLSPlaintext.fragment.
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// | The length MUST NOT exceed 2^14.
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// |...
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// | 6.2.2. Record Compression and Decompression
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// |...
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// | Compression must be lossless and may not increase the content length
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// | by more than 1024 bytes. If the decompression function encounters a
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// | TLSCompressed.fragment that would decompress to a length in excess of
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// | 2^14 bytes, it MUST report a fatal decompression failure error.
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// |...
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// | length
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// | The length (in bytes) of the following TLSCompressed.fragment.
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// | The length MUST NOT exceed 2^14 + 1024.
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//
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// Since our buffer also contains 5-byte headers, make it a bit bigger:
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uint8_t inbuf[18*1024];
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} tls_state_t;
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static
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tls_state_t *new_tls_state(void)
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{
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tls_state_t *tls = xzalloc(sizeof(*tls));
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tls->fd = -1;
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return tls;
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}
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static unsigned get24be(const uint8_t *p)
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{
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return 0x100*(0x100*p[0] + p[1]) + p[2];
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}
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static void dump(const void *vp, int len)
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{
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char hexbuf[32 * 1024 + 4];
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const uint8_t *p = vp;
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while (len > 0) {
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unsigned xhdr_len;
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if (len < 5) {
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bin2hex(hexbuf, (void*)p, len)[0] = '\0';
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dbg("< |%s|\n", hexbuf);
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return;
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}
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xhdr_len = 0x100*p[3] + p[4];
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dbg("< hdr_type:%u ver:%u.%u len:%u", p[0], p[1], p[2], xhdr_len);
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p += 5;
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len -= 5;
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if (len >= 4 && p[-5] == RECORD_TYPE_HANDSHAKE) {
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unsigned len24 = get24be(p + 1);
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dbg(" type:%u len24:%u", p[0], len24);
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}
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if (xhdr_len > len)
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xhdr_len = len;
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bin2hex(hexbuf, (void*)p, xhdr_len)[0] = '\0';
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dbg(" |%s|\n", hexbuf);
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p += xhdr_len;
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len -= xhdr_len;
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}
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}
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static void tls_error_die(tls_state_t *tls)
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{
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dump(tls->inbuf, tls->insize + tls->tail);
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xfunc_die();
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}
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static int xread_tls_block(tls_state_t *tls)
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{
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int len;
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int total;
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int target;
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dbg("insize:%u tail:%u\n", tls->insize, tls->tail);
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memmove(tls->inbuf, tls->inbuf + tls->insize, tls->tail);
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errno = 0;
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total = tls->tail;
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target = sizeof(tls->inbuf);
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for (;;) {
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if (total >= sizeof(struct transport_hdr) && target == sizeof(tls->inbuf)) {
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struct transport_hdr *xhdr = (void*)tls->inbuf;
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target = sizeof(*xhdr) + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
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}
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/* if total >= target, we have a full packet (and possibly more)... */
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if (target - total <= 0)
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break;
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len = safe_read(tls->fd, tls->inbuf + total, sizeof(tls->inbuf) - total);
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if (len <= 0)
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bb_perror_msg_and_die("short read");
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total += len;
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}
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tls->tail = -(target - total);
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tls->insize = target;
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target -= sizeof(struct transport_hdr);
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dbg("got block len:%u\n", target);
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return target;
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}
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static void send_client_hello(tls_state_t *tls)
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{
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struct client_hello {
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struct transport_hdr xhdr;
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uint8_t type;
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uint8_t len24_hi, len24_mid, len24_lo;
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uint8_t proto_maj, proto_min;
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uint8_t rand32[32];
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uint8_t session_id_len;
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/* uint8_t session_id[]; */
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uint8_t cipherid_len16_hi, cipherid_len16_lo;
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uint8_t cipherid[2 * 1]; /* actually variable */
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uint8_t comprtypes_len;
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uint8_t comprtypes[1]; /* actually variable */
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};
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struct client_hello hello;
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memset(&hello, 0, sizeof(hello));
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hello.xhdr.type = RECORD_TYPE_HANDSHAKE;
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hello.xhdr.proto_maj = TLS_MAJ;
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hello.xhdr.proto_min = TLS_MIN;
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hello.xhdr.len16_hi = (sizeof(hello) - sizeof(hello.xhdr)) >> 8;
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hello.xhdr.len16_lo = (sizeof(hello) - sizeof(hello.xhdr));
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hello.type = HANDSHAKE_CLIENT_HELLO;
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hello.len24_mid = (sizeof(hello) - sizeof(hello.xhdr) - 4) >> 8;
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hello.len24_lo = (sizeof(hello) - sizeof(hello.xhdr) - 4);
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hello.proto_maj = TLS_MAJ;
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hello.proto_min = TLS_MIN;
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//fillrand(hello.rand32, sizeof(hello.rand32));
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open_read_close("/dev/urandom", hello.rand32, sizeof(hello.rand32));
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//hello.session_id_len = 0;
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//hello.cipherid_len16_hi = 0;
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hello.cipherid_len16_lo = 2;
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hello.cipherid[0] = CIPHER_ID >> 8;
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hello.cipherid[1] = CIPHER_ID & 0xff;
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hello.comprtypes_len = 1;
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//hello.comprtypes[0] = 0;
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xwrite(tls->fd, &hello, sizeof(hello));
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}
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static void get_server_hello_or_die(tls_state_t *tls)
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{
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struct server_hello {
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struct transport_hdr xhdr;
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uint8_t type;
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uint8_t len24_hi, len24_mid, len24_lo;
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uint8_t proto_maj, proto_min;
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uint8_t rand32[32]; /* first 4 bytes are unix time in BE format */
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uint8_t session_id_len;
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uint8_t session_id[32];
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uint8_t cipherid_hi, cipherid_lo;
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uint8_t comprtype;
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/* extensions may follow, but only those which client offered in its Hello */
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};
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struct server_hello *hp;
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int len;
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len = xread_tls_block(tls);
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hp = (void*)tls->inbuf;
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if (len != 74 /* TODO: if we accept extensions, should be < instead of != */
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|| hp->xhdr.type != RECORD_TYPE_HANDSHAKE
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|| hp->xhdr.proto_maj != TLS_MAJ
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|| hp->xhdr.proto_min != TLS_MIN
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) {
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/* example: RECORD_TYPE_ALERT if server can't support our ciphers */
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tls_error_die(tls);
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}
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dbg("got HANDSHAKE\n");
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// 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|
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// SvHl len=70 maj.min unixtime^^^ 28randbytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^ slen sid32bytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cipSel comprSel
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if (hp->type != HANDSHAKE_SERVER_HELLO
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|| hp->len24_hi != 0
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|| hp->len24_mid != 0
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|| hp->len24_lo != 70
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|| hp->proto_maj != TLS_MAJ
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|| hp->proto_min != TLS_MIN
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|| hp->session_id_len != 32
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|| hp->cipherid_hi != (CIPHER_ID >> 8)
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|| hp->cipherid_lo != (CIPHER_ID & 0xff)
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|| hp->comprtype != 0
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) {
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tls_error_die(tls);
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}
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dbg("got SERVER_HELLO\n");
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}
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static unsigned get_der_len(uint8_t **bodyp, uint8_t *der, uint8_t *end)
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{
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unsigned len;
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if (end - der < 2)
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xfunc_die();
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// if ((der[0] & 0x1f) == 0x1f) /* not single-byte item code? */
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// xfunc_die();
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len = der[1]; /* maybe it's short len */
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if (len >= 0x80) {
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/* no */
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if (len != 0x82) {
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/* 0x80 is "0 bytes of len", invalid DER: must use short len if can */
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/* 0x81 is "1 byte of len", invalid DER */
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/* >0x82 is "3+ bytes of len", should not happen realistically */
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xfunc_die();
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}
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if (end - der < 4)
|
||||
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 */
|
||||
|
||||
der += 2; /* skip [code]+[82]+[2byte_len] */
|
||||
}
|
||||
der += 2; /* skip [code]+[1byte_len] */
|
||||
|
||||
if (end - der < len)
|
||||
xfunc_die();
|
||||
*bodyp = der;
|
||||
|
||||
return len;
|
||||
}
|
||||
|
||||
static uint8_t *enter_der_item(uint8_t *der, uint8_t **endp)
|
||||
{
|
||||
uint8_t *new_der;
|
||||
unsigned len = get_der_len(&new_der, der, *endp);
|
||||
dbg("entered der @%p:0x%02x len:%u inner_byte @%p:0x%02x\n", der, der[0], len, new_der, new_der[0]);
|
||||
/* Move "end" position to cover only this item */
|
||||
*endp = new_der + len;
|
||||
return new_der;
|
||||
}
|
||||
|
||||
static uint8_t *skip_der_item(uint8_t *der, uint8_t *end)
|
||||
{
|
||||
uint8_t *new_der;
|
||||
unsigned len = get_der_len(&new_der, der, end);
|
||||
/* Skip body */
|
||||
new_der += len;
|
||||
dbg("skipped der 0x%02x, next byte 0x%02x\n", der[0], new_der[0]);
|
||||
return new_der;
|
||||
}
|
||||
|
||||
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.
|
||||
* SEQ 0x05ac/1452 bytes (Certificate): 308205ac
|
||||
* SEQ 0x0494/1172 bytes (tbsCertificate): 30820494
|
||||
* [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0] 3 bytes: a003
|
||||
* INTEGER (version): 0201 02
|
||||
* INTEGER 0x11 bytes (serialNumber): 0211 00 9f85bf664b0cddafca508679501b2be4
|
||||
* //^^^^^^note: matrixSSL also allows [ASN_CONTEXT_SPECIFIC | ASN_PRIMITIVE | 2] = 0x82 type
|
||||
* SEQ 0x0d bytes (signatureAlgo): 300d
|
||||
* OID 9 bytes: 0609 2a864886f70d01010b (OID_SHA256_RSA_SIG 42.134.72.134.247.13.1.1.11)
|
||||
* NULL: 0500
|
||||
* SEQ 0x5f bytes (issuer): 305f
|
||||
* SET 11 bytes: 310b
|
||||
* SEQ 9 bytes: 3009
|
||||
* OID 3 bytes: 0603 550406
|
||||
* Printable string "FR": 1302 4652
|
||||
* SET 14 bytes: 310e
|
||||
* SEQ 12 bytes: 300c
|
||||
* OID 3 bytes: 0603 550408
|
||||
* Printable string "Paris": 1305 5061726973
|
||||
* SET 14 bytes: 310e
|
||||
* SEQ 12 bytes: 300c
|
||||
* OID 3 bytes: 0603 550407
|
||||
* Printable string "Paris": 1305 5061726973
|
||||
* SET 14 bytes: 310e
|
||||
* SEQ 12 bytes: 300c
|
||||
* OID 3 bytes: 0603 55040a
|
||||
* Printable string "Gandi": 1305 47616e6469
|
||||
* SET 32 bytes: 3120
|
||||
* SEQ 30 bytes: 301e
|
||||
* OID 3 bytes: 0603 550403
|
||||
* Printable string "Gandi Standard SSL CA 2": 1317
|
||||
* 47616e6469205374616e646172642053534c2043412032
|
||||
* SEQ 30 bytes (validity): 301e
|
||||
* TIME "161011000000Z": 170d 3136313031313030303030305a
|
||||
* TIME "191011235959Z": 170d 3139313031313233353935395a
|
||||
* SEQ 0x5b/91 bytes (subject): 305b //I did not decode this
|
||||
* 3121301f060355040b1318446f6d61696e20436f
|
||||
* 6e74726f6c2056616c6964617465643121301f06
|
||||
* 0355040b1318506f73697469766553534c204d75
|
||||
* 6c74692d446f6d61696e31133011060355040313
|
||||
* 0a6b65726e656c2e6f7267
|
||||
* SEQ 0x01a2/418 bytes (subjectPublicKeyInfo): 308201a2
|
||||
* SEQ 13 bytes (algorithm): 300d
|
||||
* OID 9 bytes: 0609 2a864886f70d010101 (OID_RSA_KEY_ALG 42.134.72.134.247.13.1.1.1)
|
||||
* NULL: 0500
|
||||
* BITSTRING 0x018f/399 bytes (publicKey): 0382018f
|
||||
* ????: 00
|
||||
* //after the zero byte, it appears key itself uses DER encoding:
|
||||
* SEQ 0x018a/394 bytes: 3082018a
|
||||
* INTEGER 0x0181/385 bytes (modulus): 02820181
|
||||
* 00b1ab2fc727a3bef76780c9349bf3
|
||||
* ...24 more blocks of 15 bytes each...
|
||||
* 90e895291c6bc8693b65
|
||||
* INTEGER 3 bytes (exponent): 0203 010001
|
||||
* [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)
|
||||
* signatureValue (BIT STRING)
|
||||
*
|
||||
* In turn, tbsCertificate is a sequence of:
|
||||
* version
|
||||
* serialNumber
|
||||
* signatureAlgo (AlgorithmIdentifier)
|
||||
* issuer (Name, has complex structure)
|
||||
* validity (Validity, SEQ of two Times)
|
||||
* subject (Name)
|
||||
* subjectPublicKeyInfo (SEQ)
|
||||
* ...
|
||||
*
|
||||
* subjectPublicKeyInfo is a sequence of:
|
||||
* algorithm (AlgorithmIdentifier)
|
||||
* publicKey (BIT STRING)
|
||||
*
|
||||
* Essentially, we want subjectPublicKeyInfo.publicKey
|
||||
*/
|
||||
uint8_t *end = der + len;
|
||||
|
||||
/* enter "Certificate" item: [der, end) will be only Cert */
|
||||
der = enter_der_item(der, &end);
|
||||
|
||||
/* enter "tbsCertificate" item: [der, end) will be only tbsCert */
|
||||
der = enter_der_item(der, &end);
|
||||
|
||||
/* skip up to subjectPublicKeyInfo */
|
||||
der = skip_der_item(der, end); /* version */
|
||||
der = skip_der_item(der, end); /* serialNumber */
|
||||
der = skip_der_item(der, end); /* signatureAlgo */
|
||||
der = skip_der_item(der, end); /* issuer */
|
||||
der = skip_der_item(der, end); /* validity */
|
||||
der = skip_der_item(der, end); /* subject */
|
||||
|
||||
/* enter "subjectPublicKeyInfo" */
|
||||
der = enter_der_item(der, &end);
|
||||
|
||||
/* skip "subjectPublicKeyInfo.algorithm" */
|
||||
der = skip_der_item(der, end);
|
||||
/* enter "subjectPublicKeyInfo.publicKey" */
|
||||
// die_if_not_this_der_type(der, end, 0x03); /* must be BITSTRING */
|
||||
der = enter_der_item(der, &end);
|
||||
|
||||
/* return a copy */
|
||||
*key_len = end - der;
|
||||
dbg("copying key bytes:%u, first:0x%02x\n", *key_len, der[0]);
|
||||
return xmemdup(der, *key_len);
|
||||
}
|
||||
|
||||
static void get_server_cert_or_die(tls_state_t *tls)
|
||||
{
|
||||
struct transport_hdr *xhdr;
|
||||
uint8_t *certbuf;
|
||||
int len, len1;
|
||||
|
||||
len = xread_tls_block(tls);
|
||||
xhdr = (void*)tls->inbuf;
|
||||
if (len < sizeof(*xhdr) + 10
|
||||
|| xhdr->type != RECORD_TYPE_HANDSHAKE
|
||||
|| xhdr->proto_maj != TLS_MAJ
|
||||
|| xhdr->proto_min != TLS_MIN
|
||||
) {
|
||||
tls_error_die(tls);
|
||||
}
|
||||
dbg("got HANDSHAKE\n");
|
||||
certbuf = (void*)(xhdr + 1);
|
||||
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
|
||||
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;
|
||||
|
||||
if (len)
|
||||
tls->pubkey = find_key_in_der_cert(&tls->pubkey_len, certbuf + 10, len);
|
||||
}
|
||||
|
||||
static void tls_handshake(tls_state_t *tls)
|
||||
{
|
||||
// Client RFC 5246 Server
|
||||
// (*) - optional messages, not always sent
|
||||
//
|
||||
// ClientHello ------->
|
||||
// ServerHello
|
||||
// Certificate*
|
||||
// ServerKeyExchange*
|
||||
// CertificateRequest*
|
||||
// <------- ServerHelloDone
|
||||
// Certificate*
|
||||
// ClientKeyExchange
|
||||
// CertificateVerify*
|
||||
// [ChangeCipherSpec]
|
||||
// Finished ------->
|
||||
// [ChangeCipherSpec]
|
||||
// <------- Finished
|
||||
// Application Data <------> Application Data
|
||||
int len;
|
||||
|
||||
send_client_hello(tls);
|
||||
#if 0 /* dump */
|
||||
for (;;) {
|
||||
uint8_t buf[16*1024];
|
||||
sleep(2);
|
||||
len = recv(tls->fd, buf, sizeof(buf), 0); //MSG_DONTWAIT);
|
||||
if (len < 0) {
|
||||
if (errno == EAGAIN)
|
||||
continue;
|
||||
bb_perror_msg_and_die("recv");
|
||||
}
|
||||
if (len == 0)
|
||||
break;
|
||||
dump(buf, len);
|
||||
}
|
||||
#endif
|
||||
|
||||
get_server_hello_or_die(tls);
|
||||
|
||||
//RFC 5246
|
||||
// The server MUST send a Certificate message whenever the agreed-
|
||||
// upon key exchange method uses certificates for authentication
|
||||
// (this includes all key exchange methods defined in this document
|
||||
// except DH_anon). This message will always immediately follow the
|
||||
// ServerHello message.
|
||||
//
|
||||
// IOW: in practice, Certificate *always* follows.
|
||||
// (for example, kernel.org does not even accept DH_anon cipher id)
|
||||
get_server_cert_or_die(tls);
|
||||
|
||||
len = xread_tls_block(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^^^
|
||||
dbg("got SERVER_KEY_EXCHANGE\n");
|
||||
len = xread_tls_block(tls);
|
||||
break;
|
||||
case HANDSHAKE_CERTIFICATE_REQUEST:
|
||||
dbg("got CERTIFICATE_REQUEST\n");
|
||||
len = xread_tls_block(tls);
|
||||
break;
|
||||
case HANDSHAKE_SERVER_HELLO_DONE:
|
||||
// 0e 000000 (len:0)
|
||||
dbg("got SERVER_HELLO_DONE\n");
|
||||
break;
|
||||
default:
|
||||
tls_error_die(tls);
|
||||
}
|
||||
}
|
||||
|
||||
int tls_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
||||
int tls_main(int argc UNUSED_PARAM, char **argv)
|
||||
{
|
||||
tls_state_t *tls;
|
||||
len_and_sockaddr *lsa;
|
||||
int fd;
|
||||
|
||||
// INIT_G();
|
||||
// getopt32(argv, "myopts")
|
||||
|
||||
if (!argv[1])
|
||||
bb_show_usage();
|
||||
|
||||
lsa = xhost2sockaddr(argv[1], 443);
|
||||
fd = xconnect_stream(lsa);
|
||||
|
||||
tls = new_tls_state();
|
||||
tls->fd = fd;
|
||||
tls_handshake(tls);
|
||||
|
||||
return EXIT_SUCCESS;
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user