Segfault when setting key for chacha20

[mscdex]

As in #50, I'm only explicitly compiling in support for chacha20, however when I set the key via PRAGMA key = 'foobarbaz', I get a segfault. Here's the backtrace:

0x00007ffff41dccfd in sqlite3mcGetCipherParameter (cipherParams=0x7ffff41dd14c <sqlite3mcFreeCodecParameterTable>, paramName=0x7ffff41f8f5f "legacy") at ../deps/sqlite3/sqlite3mc_amalgamation.c:256475
256475	  for (; strlen(cipherParams->m_name) > 0; ++cipherParams)
(gdb) bt
#0  0x00007ffff41dccfd in sqlite3mcGetCipherParameter (cipherParams=0x7ffff41dd14c <sqlite3mcFreeCodecParameterTable>, paramName=0x7ffff41f8f5f "legacy") at ../deps/sqlite3/sqlite3mc_amalgamation.c:256475
#1  0x00007ffff41dc01f in AllocateChaCha20Cipher (db=0x4a22050) at ../deps/sqlite3/sqlite3mc_amalgamation.c:255434
#2  0x00007ffff41dd5d3 in sqlite3mcCodecSetup (codec=0x7fffe0008950, cipherType=3, userPassword=0x4a35470 "foobarbaz", passwordLength=9) at ../deps/sqlite3/sqlite3mc_amalgamation.c:256716
#3  0x00007ffff41e13ee in sqlite3mcCodecAttach (db=0x4a22050, nDb=0, zPath=0x4a22eac "/tmp/encrypted.db", zKey=0x4a35470, nKey=9) at ../deps/sqlite3/sqlite3mc_amalgamation.c:258683
#4  0x00007ffff41e1654 in sqlite3_key_v2 (db=0x4a22050, zDbName=0x0, zKey=0x4a35470, nKey=9) at ../deps/sqlite3/sqlite3mc_amalgamation.c:258758
#5  0x00007ffff41dfdba in sqlite3mcFileControlPragma (db=0x4a22050, zDbName=0x0, op=14, pArg=0x7fffe7ffddd0) at ../deps/sqlite3/sqlite3mc_amalgamation.c:257939
#6  0x00007ffff413af73 in sqlite3Pragma (pParse=0x7fffe7ffea90, pId1=0x7fffe7ffe0d8, pId2=0x7fffe7ffe0f0, pValue=0x7fffe7ffe120, minusFlag=0) at ../deps/sqlite3/sqlite3mc_amalgamation.c:129007
#7  0x00007ffff4176a94 in yy_reduce (yypParser=0x7fffe7ffe090, yyruleno=247, yyLookahead=1, yyLookaheadToken=..., pParse=0x7fffe7ffea90) at ../deps/sqlite3/sqlite3mc_amalgamation.c:162666
#8  0x00007ffff4177fd5 in sqlite3Parser (yyp=0x7fffe7ffe090, yymajor=1, yyminor=...) at ../deps/sqlite3/sqlite3mc_amalgamation.c:163298
#9  0x00007ffff4179227 in sqlite3RunParser (pParse=0x7fffe7ffea90, zSql=0x4a35588 "", pzErrMsg=0x7fffe7ffea68) at ../deps/sqlite3/sqlite3mc_amalgamation.c:164594
#10 0x00007ffff4140ff2 in sqlite3Prepare (db=0x4a22050, zSql=0x4a35718 "PRAGMA key = 'foobarbaz'", nBytes=24, prepFlags=128, pReprepare=0x0, ppStmt=0x7fffe7ffed38, pzTail=0x7fffe7ffed40) at ../deps/sqlite3/sqlite3mc_amalgamation.c:131874
#11 0x00007ffff41412dc in sqlite3LockAndPrepare (db=0x4a22050, zSql=0x4a35718 "PRAGMA key = 'foobarbaz'", nBytes=24, prepFlags=128, pOld=0x0, ppStmt=0x7fffe7ffed38, pzTail=0x7fffe7ffed40) at ../deps/sqlite3/sqlite3mc_amalgamation.c:131956
#12 0x00007ffff4141532 in sqlite3_prepare_v3 (db=0x4a22050, zSql=0x4a35718 "PRAGMA key = 'foobarbaz'", nBytes=24, prepFlags=0, ppStmt=0x7fffe7ffed38, pzTail=0x7fffe7ffed40) at ../deps/sqlite3/sqlite3mc_amalgamation.c:132062
(gdb) print *cipherParams
$1 = {m_name = 0x10ec8348e5894855 <error: Cannot access memory at address 0x10ec8348e5894855>, m_value = -125990584, m_default = -129660088, m_minValue = 272665416, m_maxValue = -389576376}

If I compile in all codecs/ciphers, then it works fine, so I suspect there is code assuming the size of globalCodecParameterTable or something similar.

[mscdex]

I was able to quickly verify that it's the same underlying problem as in #50. If I explicitly change:

#define CODEC_TYPE_CHACHA20  3

to

#define CODEC_TYPE_CHACHA20  1

and rebuild, then everything works fine.

[utelle]

Yes, the cause of the problem is indeed the same as in #50. I will provide a fix soon.

"Fixing" the problem by simply changing the numeric id of a cipher scheme is not recommended, because using the same numeric cipher id for different cipher schemes can possibly cause problems in the long run.

[mscdex]

I've verified this is fixed now. Thanks!