Mercurial > dropbear
annotate libtommath/bn_mp_montgomery_calc_normalization.c @ 1930:299f4f19ba19
Add /usr/sbin and /sbin to default root PATH
When dropbear is used in a very restricted environment (such as in a
initrd), the default user shell is often also very restricted
and doesn't take care of setting the PATH so the user ends up
with the PATH set by dropbear. Unfortunately, dropbear always
sets "/usr/bin:/bin" as default PATH even for the root user
which should have /usr/sbin and /sbin too.
For a concrete instance of this problem, see the "Remote Unlocking"
section in this tutorial: https://paxswill.com/blog/2013/11/04/encrypted-raspberry-pi/
It speaks of a bug in the initramfs script because it's written "blkid"
instead of "/sbin/blkid"... this is just because the scripts from the
initramfs do not expect to have a PATH without the sbin directories and
because dropbear is not setting the PATH appropriately for the root user.
I'm thus suggesting to use the attached patch to fix this misbehaviour (I
did not test it, but it's easy enough). It might seem anecdotic but
multiple Kali users have been bitten by this.
From https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903403
author | Raphael Hertzog <hertzog@debian.org> |
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date | Mon, 09 Jul 2018 16:27:53 +0200 |
parents | 1051e4eea25a |
children |
rev | line source |
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update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
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1 #include "tommath_private.h" |
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2 #ifdef BN_MP_MONTGOMERY_CALC_NORMALIZATION_C |
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3 /* LibTomMath, multiple-precision integer library -- Tom St Denis */ |
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4 /* SPDX-License-Identifier: Unlicense */ |
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5 |
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6 /* |
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7 * shifts with subtractions when the result is greater than b. |
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8 * |
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9 * The method is slightly modified to shift B unconditionally upto just under |
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10 * the leading bit of b. This saves alot of multiple precision shifting. |
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11 */ |
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12 mp_err mp_montgomery_calc_normalization(mp_int *a, const mp_int *b) |
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13 { |
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14 int x, bits; |
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15 mp_err err; |
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16 |
1655
f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
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17 /* how many bits of last digit does b use */ |
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18 bits = mp_count_bits(b) % MP_DIGIT_BIT; |
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19 |
1655
f52919ffd3b1
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20 if (b->used > 1) { |
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21 if ((err = mp_2expt(a, ((b->used - 1) * MP_DIGIT_BIT) + bits - 1)) != MP_OKAY) { |
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22 return err; |
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f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
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23 } |
f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
1470
diff
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24 } else { |
f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
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25 mp_set(a, 1uL); |
f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
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26 bits = 1; |
f52919ffd3b1
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Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
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27 } |
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28 |
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29 |
1655
f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
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30 /* now compute C = A * B mod b */ |
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31 for (x = bits - 1; x < (int)MP_DIGIT_BIT; x++) { |
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32 if ((err = mp_mul_2(a, a)) != MP_OKAY) { |
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33 return err; |
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34 } |
1655
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update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
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parents:
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35 if (mp_cmp_mag(a, b) != MP_LT) { |
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36 if ((err = s_mp_sub(a, b, a)) != MP_OKAY) { |
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37 return err; |
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f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
1470
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38 } |
f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
1470
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39 } |
f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
Steffen Jaeckel <s_jaeckel@gmx.de>
parents:
1470
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40 } |
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41 |
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42 return MP_OKAY; |
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43 } |
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44 #endif |