notes.txt (3458B)
1 # This Source Code Form is subject to the terms of the Mozilla Public 2 # License, v. 2.0. If a copy of the MPL was not distributed with this 3 # file, You can obtain one at http://mozilla.org/MPL/2.0/. 4 5 SSL's Buffers: enumerated and explained. 6 7 --------------------------------------------------------------------------- 8 incoming: 9 10 gs = ss->gather 11 hs = ss->ssl3->hs 12 13 gs->inbuf incoming (encrypted) ssl records are placed here, 14 and then decrypted (or copied) to gs->buf. 15 16 gs->buf ssl3_HandleHandshake puts decrypted ssl records here. 17 18 hs.msg_body When an incoming handshake message spans more 19 than one ssl record, the first part(s) of it are accumulated 20 here until it all arrives. 21 22 hs.msgState an alternative set of pointers/lengths for gs->buf. 23 Used only when a handleHandshake function returns SECWouldBlock. 24 ssl3_HandleHandshake remembers how far it previously got by 25 using these pointers instead of gs->buf when it is called 26 after a previous SECWouldBlock return. 27 28 --------------------------------------------------------------------------- 29 outgoing: 30 31 sec = ss->sec 32 ci = ss->sec->ci /* connect info */ 33 34 ci->sendBuf Outgoing handshake messages are appended to this buffer. 35 This buffer will then be sent as a single SSL record. 36 37 sec->writeBuf outgoing ssl records are constructed here and encrypted in 38 place before being written or copied to pendingBuf. 39 40 ss->pendingBuf contains outgoing ciphertext that was saved after a write 41 attempt to the socket failed, e.g. EWouldBlock. 42 Generally empty with blocking sockets (should be no incomplete 43 writes). 44 45 ss->saveBuf Used only by socks code. Intended to be used to buffer 46 outgoing data until a socks handshake completes. However, 47 this buffer is always empty. There is no code to put 48 anything into it. 49 50 --------------------------------------------------------------------------- 51 52 SECWouldBlock means that the function cannot make progress because it is 53 waiting for some event OTHER THAN socket I/O completion (e.g. waiting for 54 user dialog to finish). It is not the same as EWOULDBLOCK. 55 56 --------------------------------------------------------------------------- 57 58 Rank (order) of locks 59 60 recvLock ->\ firstHandshake -> recvbuf -> ssl3Handshake -> xmitbuf -> "spec" 61 sendLock ->/ 62 63 crypto and hash Data that must be protected while turning plaintext into 64 ciphertext: 65 66 SSl3: (in ssl3_SendPlainText) 67 ss->ssl3 (the pointer) 68 ss->ssl3->current_write* (the pointer and the data in the spec 69 and any data referenced by the spec. 70 71 ss->sec->isServer 72 ss->sec->writebuf* (ptr & content) locked by xmitBufLock 73 "buf" locked by xmitBufLock 74 75 crypto and hash data that must be protected while turning ciphertext into 76 plaintext: 77 78 SSL3: (in ssl3_HandleRecord ) 79 ssl3->current_read* (the pointer and all data refernced) 80 ss->sec->isServer 81 82 83 Data that must be protected while being used by a "writer": 84 85 ss->pendingBuf.* 86 ss->saveBuf.* (which is dead) 87 88 in ssl3_sendPlainText 89 90 ss->ssl3->current_write-> (spec) 91 ss->sec->writeBuf.* 92 ss->sec->isServer 93 94 in SendBlock 95 96 ss->sec->writeBuf.* 97 ss->pendingBuf 98 99 -------------------------------------------------------------------------- 100 101 Data variables (not const) protected by the "sslGlobalDataLock". 102 Note, this really should be a reader/writer lock. 103 104 cipherSuites[] ssl3con.c