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#--
# =============================================================================
# Copyright (c) 2004,2005 Jamis Buck (jamis@37signals.com)
# All rights reserved.
#
# This source file is distributed as part of the Net::SSH Secure Shell Client
# library for Ruby. This file (and the library as a whole) may be used only as
# allowed by either the BSD license, or the Ruby license (or, by association
# with the Ruby license, the GPL). See the "doc" subdirectory of the Net::SSH
# distribution for the texts of these licenses.
# -----------------------------------------------------------------------------
# net-ssh website : http://net-ssh.rubyforge.org
# project website: http://rubyforge.org/projects/net-ssh
# =============================================================================
#++
require 'base64'
require 'openssl'
require 'net/ssh/util/buffer'
module OpenSSL
# This class is originally defined in the OpenSSL module. As needed, methods
# have been added to it by the Net::SSH module for convenience in dealing with
# SSH functionality.
class BN
# Converts a BN object to a string. The format used is that which is
# required by the SSH2 protocol.
def to_ssh
if zero?
return [ 0 ].pack( "N" )
else
buf = to_s( 2 )
if buf[0][7] == 1
return [ buf.length+1, 0, buf ].pack( "NCA*" )
else
return [ buf.length, buf ].pack( "NA*" )
end
end
end
end
module PKey
# This class is originally defined in the OpenSSL module. As needed, methods
# have been added to it by the Net::SSH module for convenience in dealing
# with SSH functionality.
class DH
# Determines whether the pub_key for this key is valid. (This algorithm
# lifted more-or-less directly from OpenSSH, dh.c, dh_pub_is_valid.)
def valid?
return false if pub_key < 0
bits_set = 0
pub_key.num_bits.times { |i| bits_set += 1 if pub_key.bit_set? i }
return ( bits_set > 1 && pub_key < p )
end
end
# This class is originally defined in the OpenSSL module. As needed, methods
# have been added to it by the Net::SSH module for convenience in dealing
# with SSH functionality.
class RSA
# Returns "ssh-rsa", which is the description of this key type used by the
# SSH2 protocol.
def ssh_type
"ssh-rsa"
end
# Converts the key to a blob, according to the SSH2 protocol.
def to_blob
buffer = Net::SSH::Util::WriterBuffer.new
buffer.write_bignum( e )
buffer.write_bignum( n )
return buffer.to_s
end
# Verifies the given signature matches the given data.
def ssh_do_verify( sig, data )
verify( OpenSSL::Digest::SHA1.new, sig, data )
end
# Returns the signature for the given data.
def ssh_do_sign( data )
sign( OpenSSL::Digest::SHA1.new, data )
end
end
# This class is originally defined in the OpenSSL module. As needed, methods
# have been added to it by the Net::SSH module for convenience in dealing
# with SSH functionality.
class DSA
# Returns "ssh-dss", which is the description of this key type used by the
# SSH2 protocol.
def ssh_type
"ssh-dss"
end
# Converts the key to a blob, according to the SSH2 protocol.
def to_blob
buffer = Net::SSH::Util::WriterBuffer.new
buffer.write_bignum( p )
buffer.write_bignum( q )
buffer.write_bignum( g )
buffer.write_bignum( pub_key )
return buffer.to_s
end
# Verifies the given signature matches the given data.
def ssh_do_verify( sig, data )
sig_r = sig[0,20].unpack("H*")[0].to_i(16)
sig_s = sig[20,20].unpack("H*")[0].to_i(16)
a1sig = OpenSSL::ASN1::Sequence([
OpenSSL::ASN1::Integer(sig_r),
OpenSSL::ASN1::Integer(sig_s)
])
return verify(OpenSSL::Digest::DSS1.new, a1sig.to_der, data)
end
# Signs the given data.
def ssh_do_sign( data )
sig = sign( OpenSSL::Digest::DSS1.new, data)
a1sig = OpenSSL::ASN1.decode( sig )
sig_r = a1sig.value[0].value.to_s(2)
sig_s = a1sig.value[1].value.to_s(2)
if sig_r.length > 20 || sig_s.length > 20
raise OpenSSL::PKey::DSAError, "bad sig size"
end
sig_r = "\0" * ( 20 - sig_r.length ) + sig_r if sig_r.length < 20
sig_s = "\0" * ( 20 - sig_s.length ) + sig_s if sig_s.length < 20
return sig_r + sig_s
end
end
end
end
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