Mercurial > dropbear
view libtomcrypt/notes/tech0005.txt @ 1705:5b701bf529aa
Fix ChaCha20 on 32-bit platforms (#99)
* Fix ChaCha20 on 32-bit platforms
On 32-bit platforms with old compiler STORE64H() parameter is
not auto-expanded to 64-bit value, causing wrong IV data.
Spotted on BCM4706 MIPS32r2 with GCC 4.2.4:
Exit before auth: Integrity error (bad packet size 2065808956)
* Fix Chacha20-Poly1305 and AES-GCM debug messages
Functions were renamed earlier and trace messages - not.
| author | Vladislav Grishenko <themiron@users.noreply.github.com> |
|---|---|
| date | Fri, 29 May 2020 18:26:22 +0500 |
| parents | f849a5ca2efc |
| children |
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Tech Note 0005 Minimizing Code Space Tom St Denis Introduction ------------ Tweaking... You can disable whole classes of algorithms on the command line with the LTC_NO_* defines. From there you can manually turn on what you want to enable. The following build with GCC 3.4.4 on an AMD64 box gets you AES, CTR mode, SHA-256, HMAC, Yarrow, full RSA PKCS #1, PKCS #5 and ASN.1 DER in roughly 40KB of code (49KB on the ARMv4) (both excluding the math library). CFLAGS="-DLTC_NO_CIPHERS -DLTC_NO_HASHES -DLTC_NO_PRNGS -DLTC_NO_MACS -DLTC_NO_MODES -DLTC_NO_PK -DLTC_RIJNDAEL -DLTC_CTR_MODE -DSHA256 \ -DLTC_HMAC -DYARROW -DMRSA -DMPI -DTFM_DESC -DARGTYPE=3 -Os -DLTC_SMALL_CODE -fomit-frame-pointer" make IGNORE_SPEED=1 Obviously this won't get you performance but if you need to pack a crypto lib in a device with limited means it's more than enough... Neato eh?