diff options
author | Steven Barth <steven@midlink.org> | 2009-02-22 23:19:25 +0000 |
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committer | Steven Barth <steven@midlink.org> | 2009-02-22 23:19:25 +0000 |
commit | d730c1263328c5990ce46cdf6394ce6e36cc3609 (patch) | |
tree | 8dc37350e69dcbd0ca82570cfa62a4c710defc93 /libs/nixio/axTLS/ssl/BigIntConfig.in | |
parent | d2b11117f26285186b711271d24733d35e0444a1 (diff) |
Add axTLS sourcecode
Diffstat (limited to 'libs/nixio/axTLS/ssl/BigIntConfig.in')
-rw-r--r-- | libs/nixio/axTLS/ssl/BigIntConfig.in | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/libs/nixio/axTLS/ssl/BigIntConfig.in b/libs/nixio/axTLS/ssl/BigIntConfig.in new file mode 100644 index 0000000000..04c7438c07 --- /dev/null +++ b/libs/nixio/axTLS/ssl/BigIntConfig.in @@ -0,0 +1,132 @@ +# +# For a description of the syntax of this configuration file, +# see scripts/config/Kconfig-language.txt +# + +menu "BigInt Options" + depends on !CONFIG_SSL_SKELETON_MODE + +choice + prompt "Reduction Algorithm" + default CONFIG_BIGINT_BARRETT + +config CONFIG_BIGINT_CLASSICAL + bool "Classical" + help + Classical uses standard division. It has no limitations and is + theoretically the slowest due to the divisions used. For this particular + implementation it is surprisingly quite fast. + +config CONFIG_BIGINT_MONTGOMERY + bool "Montgomery" + help + Montgomery uses simple addition and multiplication to achieve its + performance. In this implementation it is slower than classical, + and it has the limitation that 0 <= x, y < m, and so is not used + when CRT is active. + + This option will not be normally selected. + +config CONFIG_BIGINT_BARRETT + bool "Barrett" + help + Barrett performs expensive precomputation before reduction and partial + multiplies for computational speed. It can't be used with some of the + calculations when CRT is used, and so defaults to classical when this + occurs. + + It is about 40% faster than Classical/Montgomery with the expense of + about 2kB, and so this option is normally selected. + +endchoice + +config CONFIG_BIGINT_CRT + bool "Chinese Remainder Theorem (CRT)" + default y + help + Allow the Chinese Remainder Theorem (CRT) to be used. + + Uses a number of extra coefficients from the private key to improve the + performance of a decryption. This feature is one of the most + significant performance improvements (it reduces a decryption time by + over 3 times). + + This option should be selected. + +config CONFIG_BIGINT_KARATSUBA + bool "Karatsuba Multiplication" + default n + help + Allow Karasuba multiplication to be used. + + Uses 3 multiplications (plus a number of additions/subtractions) + instead of 4. Multiplications are O(N^2) but addition/subtraction + is O(N) hence for large numbers is beneficial. For this project, the + effect was only useful for 4096 bit keys. As these aren't likely to + be used, the feature is disabled by default. + + It costs about 2kB to enable it. + +config MUL_KARATSUBA_THRESH + int "Karatsuba Multiplication Theshold" + default 20 + depends on CONFIG_BIGINT_KARATSUBA + help + The minimum number of components needed before Karasuba muliplication + is used. + + This is very dependent on the speed/implementation of bi_add()/ + bi_subtract(). There is a bit of trial and error here and will be + at a different point for different architectures. + +config SQU_KARATSUBA_THRESH + int "Karatsuba Square Threshold" + default 40 + depends on CONFIG_BIGINT_KARATSUBA && CONFIG_BIGINT_SQUARE + help + The minimum number of components needed before Karatsuba squaring + is used. + + This is very dependent on the speed/implementation of bi_add()/ + bi_subtract(). There is a bit of trial and error here and will be + at a different point for different architectures. + +config CONFIG_BIGINT_SLIDING_WINDOW + bool "Sliding Window Exponentiation" + default y + help + Allow Sliding-Window Exponentiation to be used. + + Potentially processes more than 1 bit at a time when doing + exponentiation. The sliding-window technique reduces the number of + precomputations compared to other precomputed techniques. + + It results in a considerable performance improvement with it enabled + (it halves the decryption time) and so should be selected. + +config CONFIG_BIGINT_SQUARE + bool "Square Algorithm" + default y + help + Allow squaring to be used instead of a multiplication. + + Squaring is theoretically 50% faster than a standard multiply + (but is actually about 25% faster). + + It gives a 20% speed improvement and so should be selected. + +config CONFIG_BIGINT_CHECK_ON + bool "BigInt Integrity Checking" + default n if !CONFIG_DEBUG + default y if CONFIG_DEBUG + help + This is used when developing bigint algorithms. It performs a sanity + check on all operations at the expense of speed. + + This option is only selected when developing and should normally be + turned off. + +endmenu + + + |