Description: Patch fixes CVE-2011-0766 (cryptographic weakness) vulnerability in Erlang SSH application. It is taken from upstream git repository https://github.com/erlang/otp/commit/f228601de45c5 Author: Upstream Bug-Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=628456 Last-Updated: Tue, 03 Jan 2012 14:05:07 +0400 --- erlang-14.a-dfsg.orig/lib/crypto/c_src/crypto.c +++ erlang-14.a-dfsg/lib/crypto/c_src/crypto.c @@ -127,7 +127,9 @@ static ERL_NIF_TERM des_ede3_cbc_crypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]); static ERL_NIF_TERM aes_cfb_128_crypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]); static ERL_NIF_TERM rand_bytes_1(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM strong_rand_bytes_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]); static ERL_NIF_TERM rand_bytes_3(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM strong_rand_mpint_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]); static ERL_NIF_TERM rand_uniform_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]); static ERL_NIF_TERM mod_exp_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]); static ERL_NIF_TERM dss_verify(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]); @@ -195,7 +197,9 @@ {"des_ede3_cbc_crypt", 6, des_ede3_cbc_crypt}, {"aes_cfb_128_crypt", 4, aes_cfb_128_crypt}, {"rand_bytes", 1, rand_bytes_1}, + {"strong_rand_bytes_nif", 1, strong_rand_bytes_nif}, {"rand_bytes", 3, rand_bytes_3}, + {"strong_rand_mpint_nif", 3, strong_rand_mpint_nif}, {"rand_uniform_nif", 2, rand_uniform_nif}, {"mod_exp_nif", 3, mod_exp_nif}, {"dss_verify", 4, dss_verify}, @@ -667,6 +671,22 @@ ERL_VALGRIND_MAKE_MEM_DEFINED(data, bytes); return ret; } +static ERL_NIF_TERM strong_rand_bytes_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{/* (Bytes) */ + unsigned bytes; + unsigned char* data; + ERL_NIF_TERM ret; + if (!enif_get_uint(env, argv[0], &bytes)) { + return enif_make_badarg(env); + } + data = enif_make_new_binary(env, bytes, &ret); + if ( RAND_bytes(data, bytes) != 1) { + return atom_false; + } + ERL_VALGRIND_MAKE_MEM_DEFINED(data, bytes); + return ret; +} + static ERL_NIF_TERM rand_bytes_3(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) {/* (Bytes, TopMask, BottomMask) */ unsigned bytes; @@ -687,6 +707,47 @@ } return ret; } +static ERL_NIF_TERM strong_rand_mpint_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{/* (Bytes, TopMask, BottomMask) */ + unsigned bits; + BIGNUM *bn_rand; + int top, bottom; + unsigned char* data; + unsigned dlen; + ERL_NIF_TERM ret; + if (!enif_get_uint(env, argv[0], &bits) + || !enif_get_int(env, argv[1], &top) + || !enif_get_int(env, argv[2], &bottom)) { + return enif_make_badarg(env); + } + if (! (top == -1 || top == 0 || top == 1) ) { + return enif_make_badarg(env); + } + if (! (bottom == 0 || bottom == 1) ) { + return enif_make_badarg(env); + } + + bn_rand = BN_new(); + if (! bn_rand ) { + return enif_make_badarg(env); + } + + /* Get a (bits) bit random number */ + if (!BN_rand(bn_rand, bits, top, bottom)) { + ret = atom_false; + } + else { + /* Copy the bignum into an erlang mpint binary. */ + dlen = BN_num_bytes(bn_rand); + data = enif_make_new_binary(env, dlen+4, &ret); + put_int32(data, dlen); + BN_bn2bin(bn_rand, data+4); + ERL_VALGRIND_MAKE_MEM_DEFINED(data+4, dlen); + } + BN_free(bn_rand); + + return ret; +} static int get_bn_from_mpint(ErlNifEnv* env, ERL_NIF_TERM term, BIGNUM** bnp) { --- erlang-14.a-dfsg.orig/lib/crypto/doc/src/crypto.xml +++ erlang-14.a-dfsg/lib/crypto/doc/src/crypto.xml @@ -587,6 +587,21 @@ + strong_rand_bytes(N) -> binary() + Generate a binary of random bytes + + N = integer() + + +

Generates N bytes randomly uniform 0..255, and returns the + result in a binary. Uses a cryptographically secure prng seeded and + periodically mixed with operating system provided entropy. By default + this is the RAND_bytes method from OpenSSL.

+

May throw exception low_entropy in case the random generator + failed due to lack of secure "randomness".

+ + + rand_uniform(Lo, Hi) -> N Generate a random number @@ -601,6 +616,31 @@ + strong_rand_mpint(N, Top, Bottom) -> Mpint + Generate an N bit random number + + N = non_neg_integer() + Top = -1 | 0 | 1 + Bottom = 0 | 1 + Mpint = binary() + + +

Generate an N bit random number using OpenSSL's + cryptographically strong pseudo random number generator + BN_rand.

+

The parameter Top places constraints on the most + significant bits of the generated number. If Top is 1, then the + two most significant bits will be set to 1, if Top is 0, the + most significant bit will be 1, and if Top is -1 then no + constraints are applied and thus the generated number may be less than + N bits long.

+

If Bottom is 1, then the generated number is + constrained to be odd.

+

May throw exception low_entropy in case the random generator + failed due to lack of secure "randomness".

+ + + mod_exp(N, P, M) -> Result Perform N ^ P mod M --- erlang-14.a-dfsg.orig/lib/crypto/src/crypto.erl +++ erlang-14.a-dfsg/lib/crypto/src/crypto.erl @@ -46,6 +46,7 @@ -export([rsa_private_encrypt/3, rsa_public_decrypt/3]). -export([dh_generate_key/1, dh_generate_key/2, dh_compute_key/3]). -export([rand_bytes/1, rand_bytes/3, rand_uniform/2]). +-export([strong_rand_bytes/1, strong_rand_mpint/3]). -export([mod_exp/3, mpint/1, erlint/1]). %% -export([idea_cbc_encrypt/3, idea_cbc_decrypt/3]). -export([aes_cbc_128_encrypt/3, aes_cbc_128_decrypt/3]). @@ -67,6 +68,8 @@ des_ede3_cbc_encrypt, des_ede3_cbc_decrypt, aes_cfb_128_encrypt, aes_cfb_128_decrypt, rand_bytes, + strong_rand_bytes, + strong_rand_mpint, rand_uniform, mod_exp, dss_verify,dss_sign, @@ -340,12 +343,32 @@ %% RAND - pseudo random numbers using RN_ functions in crypto lib %% -spec rand_bytes(non_neg_integer()) -> binary(). +-spec strong_rand_bytes(non_neg_integer()) -> binary(). -spec rand_uniform(crypto_integer(), crypto_integer()) -> crypto_integer(). +-spec strong_rand_mpint(Bits::non_neg_integer(), + Top::-1..1, + Bottom::0..1) -> binary(). rand_bytes(_Bytes) -> ?nif_stub. + +strong_rand_bytes(Bytes) -> + case strong_rand_bytes_nif(Bytes) of + false -> erlang:error(low_entropy); + Bin -> Bin + end. +strong_rand_bytes_nif(_Bytes) -> ?nif_stub. + rand_bytes(_Bytes, _Topmask, _Bottommask) -> ?nif_stub. +strong_rand_mpint(Bits, Top, Bottom) -> + case strong_rand_mpint_nif(Bits,Top,Bottom) of + false -> erlang:error(low_entropy); + Bin -> Bin + end. +strong_rand_mpint_nif(_Bits, _Top, _Bottom) -> ?nif_stub. + + rand_uniform(From,To) when is_binary(From), is_binary(To) -> case rand_uniform_nif(From,To) of <> when MSB > 127 -> --- erlang-14.a-dfsg.orig/lib/ssh/src/ssh.appup.src +++ erlang-14.a-dfsg/lib/ssh/src/ssh.appup.src @@ -19,8 +19,40 @@ {"%VSN%", [ + {"2.0.3", [{load_module, ssh_bits, soft_purge, soft_purge, []}, + {load_module, ssh_connection_handler, soft_purge, soft_purge, []}, + {load_module, ssh_file, soft_purge, soft_purge, []}, + {load_module, ssh, soft_purge, soft_purge, []}, + {load_module, ssh_rsa, soft_purge, soft_purge, []}, + {load_module, ssh_acceptor, soft_purge, soft_purge, []}, + {load_module, ssh_transport, soft_purge, soft_purge, []}, + {load_module, ssh_connection_manager, soft_purge, soft_purge, []}]}, + {"2.0.2", [{load_module, ssh_bits, soft_purge, soft_purge, []}, + {load_module, ssh_connection_handler, soft_purge, soft_purge, []}, + {load_module, ssh_file, soft_purge, soft_purge, []}, + {load_module, ssh, soft_purge, soft_purge, []}, + {load_module, ssh_rsa, soft_purge, soft_purge, []}, + {load_module, ssh_acceptor, soft_purge, soft_purge, []}, + {load_module, ssh_transport, soft_purge, soft_purge, []}, + {load_module, ssh_connection_manager, soft_purge, soft_purge, []}]} ], [ + {"2.0.3", [{load_module, ssh_bits, soft_purge, soft_purge, []}, + {load_module, ssh_connection_handler, soft_purge, soft_purge, []}, + {load_module, ssh_file, soft_purge, soft_purge, []}, + {load_module, ssh, soft_purge, soft_purge, []}, + {load_module, ssh_rsa, soft_purge, soft_purge, []}, + {load_module, ssh_acceptor, soft_purge, soft_purge, []}, + {load_module, ssh_transport, soft_purge, soft_purge, []}, + {load_module, ssh_connection_manager, soft_purge, soft_purge, []}]}, + {"2.0.2", [{load_module, ssh_bits, soft_purge, soft_purge, []}, + {load_module, ssh_connection_handler, soft_purge, soft_purge, []}, + {load_module, ssh_file, soft_purge, soft_purge, []}, + {load_module, ssh, soft_purge, soft_purge, []}, + {load_module, ssh_rsa, soft_purge, soft_purge, []}, + {load_module, ssh_acceptor, soft_purge, soft_purge, []}, + {load_module, ssh_transport, soft_purge, soft_purge, []}, + {load_module, ssh_connection_manager, soft_purge, soft_purge, []}]} ] }. --- erlang-14.a-dfsg.orig/lib/ssh/src/ssh_bits.erl +++ erlang-14.a-dfsg/lib/ssh/src/ssh_bits.erl @@ -34,7 +34,7 @@ %% integer utils -export([isize/1]). -export([irandom/1, irandom/3]). --export([random/1, random/3]). +-export([random/1]). -export([xor_bits/2, fill_bits/2]). -export([i2bin/2, bin2i/1]). @@ -401,9 +401,6 @@ irandom(Bits) -> irandom(Bits, 1, 0). -%% irandom_odd(Bits) -> -%% irandom(Bits, 1, 1). - %% %% irandom(N, Top, Bottom) %% @@ -414,57 +411,16 @@ %% Bot = 0 - do not set the least signifcant bit %% Bot = 1 - set the least signifcant bit (i.e always odd) %% -irandom(0, _Top, _Bottom) -> - 0; -irandom(Bits, Top, Bottom) -> - Bytes = (Bits+7) div 8, - Skip = (8-(Bits rem 8)) rem 8, - TMask = case Top of - 0 -> 0; - 1 -> 16#80; - 2 -> 16#c0 - end, - BMask = case Bottom of - 0 -> 0; - 1 -> (1 bsl Skip) - end, - <> = random(Bytes, TMask, BMask), - X. +irandom(Bits, Top, Bottom) when is_integer(Top), + 0 =< Top, Top =< 2 -> + crypto:erlint(crypto:strong_rand_mpint(Bits, Top - 1, Bottom)). %% %% random/1 %% Generate N random bytes %% random(N) -> - random(N, 0, 0). - -random(N, TMask, BMask) -> - list_to_binary(rnd(N, TMask, BMask)). - -%% random/3 -%% random(Bytes, TopMask, BotMask) -%% where -%% Bytes is the number of bytes to generate -%% TopMask is bitwised or'ed to the first byte -%% BotMask is bitwised or'ed to the last byte -%% -rnd(0, _TMask, _BMask) -> - []; -rnd(1, TMask, BMask) -> - [(rand8() bor TMask) bor BMask]; -rnd(N, TMask, BMask) -> - [(rand8() bor TMask) | rnd_n(N-1, BMask)]. - -rnd_n(1, BMask) -> - [rand8() bor BMask]; -rnd_n(I, BMask) -> - [rand8() | rnd_n(I-1, BMask)]. - -rand8() -> - (rand32() bsr 8) band 16#ff. - -rand32() -> - random:uniform(16#100000000) -1. + crypto:strong_rand_bytes(N). %% %% Base 64 encode/decode --- erlang-14.a-dfsg.orig/lib/ssh/src/ssh_connection_handler.erl +++ erlang-14.a-dfsg/lib/ssh/src/ssh_connection_handler.erl @@ -106,8 +106,6 @@ %% initialize. %%-------------------------------------------------------------------- init([Role, Manager, Socket, SshOpts]) -> - {A,B,C} = erlang:now(), - random:seed(A, B, C), {NumVsn, StrVsn} = ssh_transport:versions(Role, SshOpts), ssh_bits:install_messages(ssh_transport:transport_messages(NumVsn)), {Protocol, Callback, CloseTag} =