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Diffstat (limited to 'libtomcrypt/notes/tech0005.txt')
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diff --git a/libtomcrypt/notes/tech0005.txt b/libtomcrypt/notes/tech0005.txt new file mode 100644 index 0000000..ef10a43 --- /dev/null +++ b/libtomcrypt/notes/tech0005.txt @@ -0,0 +1,20 @@ +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 -DRIJNDAEL -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? |