mirror of git://git.savannah.gnu.org/guix.git
78 lines
2.2 KiB
Diff
78 lines
2.2 KiB
Diff
Fix CVE-2016-0739 (Weak Diffie-Hellman secret generation in
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dh_generate_x() and dh_generate_y()).
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"Due to a byte/bit confusion, the DH secret was too short. This file was
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completely reworked and will be commited in a future version."
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Source:
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https://git.libssh.org/projects/libssh.git/commit/?id=f8d0026c65fc8a55748ae481758e2cf376c26c86
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This patch was created by upstream for libssh-0.7.3, but applied without
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modification to libssh-0.6.3 by Debian. In Guix, we apply it without
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modification to libssh-0.6.5.
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References:
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https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-0739
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https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-0739
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https://security-tracker.debian.org/tracker/CVE-2016-0739
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---
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src/dh.c | 22 +++++++++++++++++-----
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1 file changed, 17 insertions(+), 5 deletions(-)
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diff --git a/src/dh.c b/src/dh.c
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index e489a1d..d27b66e 100644
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--- a/src/dh.c
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+++ b/src/dh.c
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@@ -227,15 +227,21 @@ void ssh_crypto_finalize(void) {
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}
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int dh_generate_x(ssh_session session) {
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+ int keysize;
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+ if (session->next_crypto->kex_type == SSH_KEX_DH_GROUP1_SHA1) {
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+ keysize = 1023;
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+ } else {
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+ keysize = 2047;
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+ }
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session->next_crypto->x = bignum_new();
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if (session->next_crypto->x == NULL) {
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return -1;
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}
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#ifdef HAVE_LIBGCRYPT
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- bignum_rand(session->next_crypto->x, 128);
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+ bignum_rand(session->next_crypto->x, keysize);
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#elif defined HAVE_LIBCRYPTO
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- bignum_rand(session->next_crypto->x, 128, 0, -1);
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+ bignum_rand(session->next_crypto->x, keysize, -1, 0);
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#endif
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/* not harder than this */
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@@ -248,15 +254,21 @@ int dh_generate_x(ssh_session session) {
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/* used by server */
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int dh_generate_y(ssh_session session) {
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- session->next_crypto->y = bignum_new();
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+ int keysize;
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+ if (session->next_crypto->kex_type == SSH_KEX_DH_GROUP1_SHA1) {
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+ keysize = 1023;
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+ } else {
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+ keysize = 2047;
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+ }
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+ session->next_crypto->y = bignum_new();
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if (session->next_crypto->y == NULL) {
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return -1;
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}
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#ifdef HAVE_LIBGCRYPT
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- bignum_rand(session->next_crypto->y, 128);
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+ bignum_rand(session->next_crypto->y, keysize);
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#elif defined HAVE_LIBCRYPTO
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- bignum_rand(session->next_crypto->y, 128, 0, -1);
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+ bignum_rand(session->next_crypto->y, keysize, -1, 0);
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#endif
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/* not harder than this */
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--
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cgit v0.12
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