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- patch w/1aba38cd7d2658146675ce1737e5090f879f306; not yet in a GA release

This commit is contained in:
Chris Weyl 2010-01-19 05:34:11 +00:00
parent 43585348ef
commit 8d25ddbae1
2 changed files with 125 additions and 1 deletions
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117
libssh2-1.2.2-padding.patch Normal file
View File

@ -0,0 +1,117 @@
commit 1aba38cd7d2658146675ce1737e5090f879f3068
Author: Peter Stuge <peter@stuge.se>
Date: Sun Dec 6 07:20:58 2009 +0100
Fix padding in ssh-dss signature blob encoding
DSA signatures consist of two 160-bit integers called r and s. In ssh-dss
signature blobs r and s are stored directly after each other in binary
representation, making up a 320-bit (40 byte) string. (See RFC4253 p14.)
The crypto wrappers in libssh2 would either pack r and s incorrectly, or
fail, when at least one integer was small enough to be stored in 19 bytes
or less.
The patch ensures that r and s are always stored as two 160 bit numbers.
diff --git a/src/libgcrypt.c b/src/libgcrypt.c
index ba00284..b06be42 100644
--- a/src/libgcrypt.c
+++ b/src/libgcrypt.c
@@ -424,6 +424,8 @@ _libssh2_dsa_sha1_sign(libssh2_dsa_ctx * dsactx,
return -1;
}
+ memset(sig, 0, 40);
+
/* Extract R. */
data = gcry_sexp_find_token(sig_sexp, "r", 0);
@@ -433,22 +435,12 @@ _libssh2_dsa_sha1_sign(libssh2_dsa_ctx * dsactx,
}
tmp = gcry_sexp_nth_data(data, 1, &size);
- if (!tmp) {
- ret = -1;
- goto out;
- }
-
- if (tmp[0] == '\0') {
- tmp++;
- size--;
- }
-
- if (size != 20) {
+ if (!tmp || size < 1 || size > 20) {
ret = -1;
goto out;
}
- memcpy(sig, tmp, 20);
+ memcpy(sig + (20 - size), tmp, size);
gcry_sexp_release(data);
@@ -461,22 +453,12 @@ _libssh2_dsa_sha1_sign(libssh2_dsa_ctx * dsactx,
}
tmp = gcry_sexp_nth_data(data, 1, &size);
- if (!tmp) {
- ret = -1;
- goto out;
- }
-
- if (tmp[0] == '\0') {
- tmp++;
- size--;
- }
-
- if (size != 20) {
+ if (!tmp || size < 1 || size > 20) {
ret = -1;
goto out;
}
- memcpy(sig + 20, tmp, 20);
+ memcpy(sig + 20 + (20 - size), tmp, size);
ret = 0;
out:
diff --git a/src/openssl.c b/src/openssl.c
index 250ea63..000c9ec 100644
--- a/src/openssl.c
+++ b/src/openssl.c
@@ -420,7 +420,7 @@ _libssh2_dsa_sha1_sign(libssh2_dsa_ctx * dsactx,
unsigned long hash_len, unsigned char *signature)
{
DSA_SIG *sig;
- int r_len, s_len, rs_pad;
+ int r_len, s_len;
(void) hash_len;
sig = DSA_do_sign(hash, SHA_DIGEST_LENGTH, dsactx);
@@ -429,15 +429,20 @@ _libssh2_dsa_sha1_sign(libssh2_dsa_ctx * dsactx,
}
r_len = BN_num_bytes(sig->r);
+ if (r_len < 1 || r_len > 20) {
+ DSA_SIG_free(sig);
+ return -1;
+ }
s_len = BN_num_bytes(sig->s);
- rs_pad = (2 * SHA_DIGEST_LENGTH) - (r_len + s_len);
- if (rs_pad < 0) {
+ if (s_len < 1 || s_len > 20) {
DSA_SIG_free(sig);
return -1;
}
- BN_bn2bin(sig->r, signature + rs_pad);
- BN_bn2bin(sig->s, signature + rs_pad + r_len);
+ memset(signature, 0, 40);
+
+ BN_bn2bin(sig->r, signature + (20 - r_len));
+ BN_bn2bin(sig->s, signature + 20 + (20 - s_len));
DSA_SIG_free(sig);

9
libssh2.spec
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@ -1,6 +1,6 @@
Name: libssh2
Version: 1.2.2
Release: 2%{?dist}
Release: 3%{?dist}
Summary: A library implementing the SSH2 protocol
Group: System Environment/Libraries
@ -9,6 +9,9 @@ URL: http://www.libssh2.org
Source0: http://libssh2.org/download/libssh2-%{version}.tar.gz
BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
# aka commit 1aba38cd7d2658146675ce1737e5090f879f306
Patch0: libssh2-1.2.2-padding.patch
BuildRequires: openssl-devel
BuildRequires: zlib-devel
@ -41,6 +44,7 @@ developing applications that use %{name}.
%prep
%setup -q
%patch0 -p1
# make sure things are UTF-8...
for i in ChangeLog NEWS ; do
@ -96,6 +100,9 @@ rm -rf %{buildroot}
%{_libdir}/pkgconfig/*
%changelog
* Mon Jan 18 2010 Chris Weyl <cweyl@alumni.drew.edu> 1.2.2-3
- patch w/1aba38cd7d2658146675ce1737e5090f879f306; not yet in a GA release
* Thu Jan 14 2010 Chris Weyl <cweyl@alumni.drew.edu> 1.2.2-2
- correct bad file entry under -devel