Mercurial > dropbear
annotate libtommath/bn_mp_sub.c @ 1732:2f5d797d9811
Don't choke on disabled authorized_keys(5) options
As of 2020.79 X11 forwarding is disabled at build time, which could lock
out users with authorized_keys(5) files containing ‘no-X11-forwarding’
options.
author | Guilhem Moulin <guilhem@debian.org> |
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date | Fri, 26 Jun 2020 20:56:03 +0800 |
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_SUB_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 /* high level subtraction (handles signs) */ |
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7 mp_err mp_sub(const mp_int *a, const mp_int *b, mp_int *c) |
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8 { |
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9 mp_sign sa = a->sign, sb = b->sign; |
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10 mp_err err; |
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11 |
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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12 if (sa != sb) { |
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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changeset
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13 /* subtract a negative from a positive, OR */ |
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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14 /* subtract a positive from a negative. */ |
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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15 /* In either case, ADD their magnitudes, */ |
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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16 /* and use the sign of the first number. */ |
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17 c->sign = sa; |
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18 err = s_mp_add(a, b, c); |
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parents:
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19 } else { |
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
changeset
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20 /* subtract a positive from a positive, OR */ |
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
changeset
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21 /* subtract a negative from a negative. */ |
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
changeset
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22 /* First, take the difference between their */ |
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
changeset
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23 /* magnitudes, then... */ |
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 if (mp_cmp_mag(a, b) != MP_LT) { |
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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changeset
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25 /* Copy the sign from the first */ |
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 c->sign = sa; |
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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27 /* The first has a larger or equal magnitude */ |
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28 err = s_mp_sub(a, b, c); |
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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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29 } 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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diff
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30 /* The result has the *opposite* sign from */ |
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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31 /* the first number. */ |
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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32 c->sign = (sa == MP_ZPOS) ? MP_NEG : MP_ZPOS; |
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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diff
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33 /* The second has a larger magnitude */ |
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Update LibTomMath to 1.2.0 (#84)
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parents:
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34 err = s_mp_sub(b, a, c); |
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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35 } |
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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36 } |
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parents:
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37 return err; |
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38 } |
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39 |
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40 #endif |