3 * OpenPGP MPI helper functions.
5 * Copyright (c) 2005 Marko Kreen
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 pgp_mpi_alloc(int bits
, PGP_MPI
** mpi
)
41 int len
= (bits
+ 7) / 8;
43 if (bits
< 0 || bits
> 0xFFFF)
45 px_debug("pgp_mpi_alloc: unreasonable request: bits=%d", bits
);
46 return PXE_PGP_CORRUPT_DATA
;
48 n
= px_alloc(sizeof(*n
) + len
);
51 n
->data
= (uint8
*) (n
) + sizeof(*n
);
57 pgp_mpi_create(uint8
*data
, int bits
, PGP_MPI
** mpi
)
62 res
= pgp_mpi_alloc(bits
, &n
);
65 memcpy(n
->data
, data
, n
->bytes
);
71 pgp_mpi_free(PGP_MPI
* mpi
)
75 memset(mpi
, 0, sizeof(*mpi
) + mpi
->bytes
);
81 pgp_mpi_read(PullFilter
* src
, PGP_MPI
** mpi
)
88 res
= pullf_read_fixed(src
, 2, hdr
);
91 bits
= ((unsigned) hdr
[0] << 8) + hdr
[1];
93 res
= pgp_mpi_alloc(bits
, &n
);
97 res
= pullf_read_fixed(src
, n
->bytes
, n
->data
);
106 pgp_mpi_write(PushFilter
* dst
, PGP_MPI
* n
)
111 buf
[0] = n
->bits
>> 8;
112 buf
[1] = n
->bits
& 0xFF;
113 res
= pushf_write(dst
, buf
, 2);
115 res
= pushf_write(dst
, n
->data
, n
->bytes
);
120 pgp_mpi_hash(PX_MD
* md
, PGP_MPI
* n
)
124 buf
[0] = n
->bits
>> 8;
125 buf
[1] = n
->bits
& 0xFF;
126 px_md_update(md
, buf
, 2);
127 px_md_update(md
, n
->data
, n
->bytes
);
133 pgp_mpi_cksum(unsigned cksum
, PGP_MPI
* n
)
137 cksum
+= n
->bits
>> 8;
138 cksum
+= n
->bits
& 0xFF;
139 for (i
= 0; i
< n
->bytes
; i
++)
142 return cksum
& 0xFFFF;