2 * mppe.h - Definitions for MPPE
4 * Copyright (c) 2008 Paul Mackerras. All rights reserved.
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7 * modification, are permitted provided that the following conditions
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24 * "This product includes software developed by Paul Mackerras
25 * <paulus@samba.org>".
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36 #define MPPE_PAD 4 /* MPPE growth per frame */
37 #define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */
39 /* option bits for ccp_options.mppe */
40 #define MPPE_OPT_40 0x01 /* 40 bit */
41 #define MPPE_OPT_128 0x02 /* 128 bit */
42 #define MPPE_OPT_STATEFUL 0x04 /* stateful mode */
43 /* unsupported opts */
44 #define MPPE_OPT_56 0x08 /* 56 bit */
45 #define MPPE_OPT_MPPC 0x10 /* MPPC compression */
46 #define MPPE_OPT_D 0x20 /* Unknown */
47 #define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D)
48 #define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */
51 * This is not nice ... the alternative is a bitfield struct though.
52 * And unfortunately, we cannot share the same bits for the option
53 * names above since C and H are the same bit. We could do a u_int32
54 * but then we have to do a htonl() all the time and/or we still need
55 * to know which octet is which.
57 #define MPPE_C_BIT 0x01 /* MPPC */
58 #define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */
59 #define MPPE_L_BIT 0x20 /* 40-bit */
60 #define MPPE_S_BIT 0x40 /* 128-bit */
61 #define MPPE_M_BIT 0x80 /* 56-bit, not supported */
62 #define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */
64 /* Does not include H bit; used for least significant octet only. */
65 #define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT)
67 /* Build a CI from mppe opts (see RFC 3078) */
68 #define MPPE_OPTS_TO_CI(opts, ci) \
70 u_char *ptr = ci; /* u_char[4] */ \
73 if (opts & MPPE_OPT_STATEFUL) \
76 *ptr++ = MPPE_H_BIT; \
82 if (opts & MPPE_OPT_128) \
84 if (opts & MPPE_OPT_40) \
86 /* M,D,C bits not supported */ \
87 } while (/* CONSTCOND */ 0)
89 /* The reverse of the above */
90 #define MPPE_CI_TO_OPTS(ci, opts) \
92 u_char *ptr = ci; /* u_char[4] */ \
97 if (!(ptr[0] & MPPE_H_BIT)) \
98 opts |= MPPE_OPT_STATEFUL; \
101 if (ptr[3] & MPPE_S_BIT) \
102 opts |= MPPE_OPT_128; \
103 if (ptr[3] & MPPE_L_BIT) \
104 opts |= MPPE_OPT_40; \
107 if (ptr[3] & MPPE_M_BIT) \
108 opts |= MPPE_OPT_56; \
109 if (ptr[3] & MPPE_D_BIT) \
110 opts |= MPPE_OPT_D; \
111 if (ptr[3] & MPPE_C_BIT) \
112 opts |= MPPE_OPT_MPPC; \
115 if (ptr[0] & ~MPPE_H_BIT) \
116 opts |= MPPE_OPT_UNKNOWN; \
117 if (ptr[1] || ptr[2]) \
118 opts |= MPPE_OPT_UNKNOWN; \
119 if (ptr[3] & ~MPPE_ALL_BITS) \
120 opts |= MPPE_OPT_UNKNOWN; \
121 } while (/* CONSTCOND */ 0)