diff options
author | Matt Domsch <Matt_Domsch@dell.com> | 2005-11-08 17:40:47 (GMT) |
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committer | David S. Miller <davem@davemloft.net> | 2005-11-08 17:40:47 (GMT) |
commit | b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c (patch) | |
tree | 7ca8e019573362620638e14e32bb519770ee6945 /drivers/net/ppp_mppe.h | |
parent | 6722e78c90054101e6797d5944cdc81af9897a0a (diff) | |
download | linux-b3f9b92a6ec1a9a5e4b4b36e484f2f62cc73277c.tar.xz |
[PPP]: add PPP MPPE encryption module
From: Matt Domsch <Matt_Domsch@dell.com>
The patch below implements the Microsoft Point-to-Point Encryption method
as a PPP compressor/decompressor. This is necessary for Linux clients and
servers to interoperate with Microsoft Point-to-Point Tunneling Protocol
(PPTP) servers (either Microsoft PPTP servers or the poptop project) which
use MPPE to encrypt data when creating a VPN.
This patch differs from the kernel_ppp_mppe DKMS pacakge at
pptpclient.sourceforge.net by utilizing the kernel crypto routines rather
than providing its own SHA1 and arcfour implementations.
Minor changes to ppp_generic.c try to prevent a link from disabling
compression (in our case, the encryption) after it has started using
compression (encryption).
Feedback to <pptpclient-devel@lists.sourceforge.net> please.
Signed-off-by: Matt Domsch <Matt_Domsch@dell.com>
Cc: James Cameron <james.cameron@hp.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Brice Goglin <Brice.Goglin@ens-lyon.org>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ppp_mppe.h')
-rw-r--r-- | drivers/net/ppp_mppe.h | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/net/ppp_mppe.h b/drivers/net/ppp_mppe.h new file mode 100644 index 0000000..7a14e05 --- /dev/null +++ b/drivers/net/ppp_mppe.h @@ -0,0 +1,86 @@ +#define MPPE_PAD 4 /* MPPE growth per frame */ +#define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */ + +/* option bits for ccp_options.mppe */ +#define MPPE_OPT_40 0x01 /* 40 bit */ +#define MPPE_OPT_128 0x02 /* 128 bit */ +#define MPPE_OPT_STATEFUL 0x04 /* stateful mode */ +/* unsupported opts */ +#define MPPE_OPT_56 0x08 /* 56 bit */ +#define MPPE_OPT_MPPC 0x10 /* MPPC compression */ +#define MPPE_OPT_D 0x20 /* Unknown */ +#define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D) +#define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */ + +/* + * This is not nice ... the alternative is a bitfield struct though. + * And unfortunately, we cannot share the same bits for the option + * names above since C and H are the same bit. We could do a u_int32 + * but then we have to do a htonl() all the time and/or we still need + * to know which octet is which. + */ +#define MPPE_C_BIT 0x01 /* MPPC */ +#define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */ +#define MPPE_L_BIT 0x20 /* 40-bit */ +#define MPPE_S_BIT 0x40 /* 128-bit */ +#define MPPE_M_BIT 0x80 /* 56-bit, not supported */ +#define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */ + +/* Does not include H bit; used for least significant octet only. */ +#define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT) + +/* Build a CI from mppe opts (see RFC 3078) */ +#define MPPE_OPTS_TO_CI(opts, ci) \ + do { \ + u_char *ptr = ci; /* u_char[4] */ \ + \ + /* H bit */ \ + if (opts & MPPE_OPT_STATEFUL) \ + *ptr++ = 0x0; \ + else \ + *ptr++ = MPPE_H_BIT; \ + *ptr++ = 0; \ + *ptr++ = 0; \ + \ + /* S,L bits */ \ + *ptr = 0; \ + if (opts & MPPE_OPT_128) \ + *ptr |= MPPE_S_BIT; \ + if (opts & MPPE_OPT_40) \ + *ptr |= MPPE_L_BIT; \ + /* M,D,C bits not supported */ \ + } while (/* CONSTCOND */ 0) + +/* The reverse of the above */ +#define MPPE_CI_TO_OPTS(ci, opts) \ + do { \ + u_char *ptr = ci; /* u_char[4] */ \ + \ + opts = 0; \ + \ + /* H bit */ \ + if (!(ptr[0] & MPPE_H_BIT)) \ + opts |= MPPE_OPT_STATEFUL; \ + \ + /* S,L bits */ \ + if (ptr[3] & MPPE_S_BIT) \ + opts |= MPPE_OPT_128; \ + if (ptr[3] & MPPE_L_BIT) \ + opts |= MPPE_OPT_40; \ + \ + /* M,D,C bits */ \ + if (ptr[3] & MPPE_M_BIT) \ + opts |= MPPE_OPT_56; \ + if (ptr[3] & MPPE_D_BIT) \ + opts |= MPPE_OPT_D; \ + if (ptr[3] & MPPE_C_BIT) \ + opts |= MPPE_OPT_MPPC; \ + \ + /* Other bits */ \ + if (ptr[0] & ~MPPE_H_BIT) \ + opts |= MPPE_OPT_UNKNOWN; \ + if (ptr[1] || ptr[2]) \ + opts |= MPPE_OPT_UNKNOWN; \ + if (ptr[3] & ~MPPE_ALL_BITS) \ + opts |= MPPE_OPT_UNKNOWN; \ + } while (/* CONSTCOND */ 0) |