Patrick Williams | d8c66bc | 2016-06-20 12:57:21 -0500 | [diff] [blame] | 1 | Upstream-Status: Backport |
| 2 | https://git.lysator.liu.se/nettle/nettle/commit/c71d2c9d20eeebb985e3872e4550137209e3ce4d |
| 3 | |
| 4 | CVE: CVE-2015-8803 |
| 5 | CVE: CVE-2015-8805 |
| 6 | |
| 7 | Same fix for both. |
| 8 | |
| 9 | Signed-off-by: Armin Kuster <akuster@mvista.com> |
| 10 | |
| 11 | Index: nettle-2.7.1/ecc-256.c |
| 12 | =================================================================== |
| 13 | --- nettle-2.7.1.orig/ecc-256.c |
| 14 | +++ nettle-2.7.1/ecc-256.c |
| 15 | @@ -96,9 +96,19 @@ ecc_256_modp (const struct ecc_curve *ec |
| 16 | q2 += t + (q1 < t); |
| 17 | |
| 18 | assert (q2 < 2); |
| 19 | + /* |
| 20 | + n-1 n-2 n-3 n-4 |
| 21 | + +---+---+---+---+ |
| 22 | + | u1| u0| u low | |
| 23 | + +---+---+---+---+ |
| 24 | + - | q1(2^96-1)| |
| 25 | + +-------+---+ |
| 26 | + |q2(2^.)| |
| 27 | + +-------+ |
| 28 | |
| 29 | - /* We multiply by two low limbs of p, 2^96 - 1, so we could use |
| 30 | - shifts rather than mul. */ |
| 31 | + We multiply by two low limbs of p, 2^96 - 1, so we could use |
| 32 | + shifts rather than mul. |
| 33 | + */ |
| 34 | t = mpn_submul_1 (rp + n - 4, ecc->p, 2, q1); |
| 35 | t += cnd_sub_n (q2, rp + n - 3, ecc->p, 1); |
| 36 | t += (-q2) & 0xffffffff; |
| 37 | @@ -108,7 +118,10 @@ ecc_256_modp (const struct ecc_curve *ec |
| 38 | u0 -= t; |
| 39 | t = (u1 < cy); |
| 40 | u1 -= cy; |
| 41 | - u1 += cnd_add_n (t, rp + n - 4, ecc->p, 3); |
| 42 | + |
| 43 | + cy = cnd_add_n (t, rp + n - 4, ecc->p, 2); |
| 44 | + u0 += cy; |
| 45 | + u1 += (u0 < cy); |
| 46 | u1 -= (-t) & 0xffffffff; |
| 47 | } |
| 48 | rp[2] = u0; |
| 49 | @@ -195,7 +208,7 @@ ecc_256_modq (const struct ecc_curve *ec |
| 50 | |
| 51 | /* Conditional add of p */ |
| 52 | u1 += t; |
| 53 | - u2 += (t<<32) + (u0 < t); |
| 54 | + u2 += (t<<32) + (u1 < t); |
| 55 | |
| 56 | t = cnd_add_n (t, rp + n - 4, ecc->q, 2); |
| 57 | u1 += t; |
| 58 | Index: nettle-2.7.1/ChangeLog |
| 59 | =================================================================== |
| 60 | --- nettle-2.7.1.orig/ChangeLog |
| 61 | +++ nettle-2.7.1/ChangeLog |
| 62 | @@ -1,3 +1,9 @@ |
| 63 | +2015-12-10 Niels Möller <nisse@lysator.liu.se> |
| 64 | + |
| 65 | + * ecc-256.c (ecc_256_modp): Fixed carry propagation bug. Problem |
| 66 | + reported by Hanno Böck. |
| 67 | + (ecc_256_modq): Fixed another carry propagation bug. |
| 68 | + |
| 69 | 2013-05-28 Niels Möller <nisse@lysator.liu.se> |
| 70 | |
| 71 | * Released nettle-2.7.1. |