aboutsummaryrefslogtreecommitdiffstats
path: root/lib/mpi/mpicoder.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/mpi/mpicoder.c')
-rw-r--r--lib/mpi/mpicoder.c91
1 files changed, 2 insertions, 89 deletions
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index 716802b774ea..f26b41fcb48c 100644
--- a/lib/mpi/mpicoder.c
+++ b/lib/mpi/mpicoder.c
@@ -20,78 +20,15 @@
20 20
21#include "mpi-internal.h" 21#include "mpi-internal.h"
22 22
23#define DIM(v) (sizeof(v)/sizeof((v)[0]))
24#define MAX_EXTERN_MPI_BITS 16384 23#define MAX_EXTERN_MPI_BITS 16384
25 24
26static uint8_t asn[15] = /* Object ID is 1.3.14.3.2.26 */
27{ 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03,
28 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14
29};
30
31MPI do_encode_md(const void *sha_buffer, unsigned nbits)
32{
33 int nframe = (nbits + 7) / 8;
34 uint8_t *frame, *fr_pt;
35 int i = 0, n;
36 size_t asnlen = DIM(asn);
37 MPI a = MPI_NULL;
38
39 if (SHA1_DIGEST_LENGTH + asnlen + 4 > nframe)
40 pr_info("MPI: can't encode a %d bit MD into a %d bits frame\n",
41 (int)(SHA1_DIGEST_LENGTH * 8), (int)nbits);
42
43 /* We encode the MD in this way:
44 *
45 * 0 A PAD(n bytes) 0 ASN(asnlen bytes) MD(len bytes)
46 *
47 * PAD consists of FF bytes.
48 */
49 frame = kmalloc(nframe, GFP_KERNEL);
50 if (!frame)
51 return MPI_NULL;
52 n = 0;
53 frame[n++] = 0;
54 frame[n++] = 1; /* block type */
55 i = nframe - SHA1_DIGEST_LENGTH - asnlen - 3;
56
57 if (i <= 1) {
58 pr_info("MPI: message digest encoding failed\n");
59 kfree(frame);
60 return a;
61 }
62
63 memset(frame + n, 0xff, i);
64 n += i;
65 frame[n++] = 0;
66 memcpy(frame + n, &asn, asnlen);
67 n += asnlen;
68 memcpy(frame + n, sha_buffer, SHA1_DIGEST_LENGTH);
69 n += SHA1_DIGEST_LENGTH;
70
71 i = nframe;
72 fr_pt = frame;
73
74 if (n != nframe) {
75 printk
76 ("MPI: message digest encoding failed, frame length is wrong\n");
77 kfree(frame);
78 return a;
79 }
80
81 a = mpi_alloc((nframe + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB);
82 mpi_set_buffer(a, frame, nframe, 0);
83 kfree(frame);
84
85 return a;
86}
87
88MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) 25MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread)
89{ 26{
90 const uint8_t *buffer = xbuffer; 27 const uint8_t *buffer = xbuffer;
91 int i, j; 28 int i, j;
92 unsigned nbits, nbytes, nlimbs, nread = 0; 29 unsigned nbits, nbytes, nlimbs, nread = 0;
93 mpi_limb_t a; 30 mpi_limb_t a;
94 MPI val = MPI_NULL; 31 MPI val = NULL;
95 32
96 if (*ret_nread < 2) 33 if (*ret_nread < 2)
97 goto leave; 34 goto leave;
@@ -108,7 +45,7 @@ MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread)
108 nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB; 45 nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
109 val = mpi_alloc(nlimbs); 46 val = mpi_alloc(nlimbs);
110 if (!val) 47 if (!val)
111 return MPI_NULL; 48 return NULL;
112 i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; 49 i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
113 i %= BYTES_PER_MPI_LIMB; 50 i %= BYTES_PER_MPI_LIMB;
114 val->nbits = nbits; 51 val->nbits = nbits;
@@ -212,30 +149,6 @@ int mpi_fromstr(MPI val, const char *str)
212EXPORT_SYMBOL_GPL(mpi_fromstr); 149EXPORT_SYMBOL_GPL(mpi_fromstr);
213 150
214/**************** 151/****************
215 * Special function to get the low 8 bytes from an mpi.
216 * This can be used as a keyid; KEYID is an 2 element array.
217 * Return the low 4 bytes.
218 */
219u32 mpi_get_keyid(const MPI a, u32 *keyid)
220{
221#if BYTES_PER_MPI_LIMB == 4
222 if (keyid) {
223 keyid[0] = a->nlimbs >= 2 ? a->d[1] : 0;
224 keyid[1] = a->nlimbs >= 1 ? a->d[0] : 0;
225 }
226 return a->nlimbs >= 1 ? a->d[0] : 0;
227#elif BYTES_PER_MPI_LIMB == 8
228 if (keyid) {
229 keyid[0] = a->nlimbs ? (u32) (a->d[0] >> 32) : 0;
230 keyid[1] = a->nlimbs ? (u32) (a->d[0] & 0xffffffff) : 0;
231 }
232 return a->nlimbs ? (u32) (a->d[0] & 0xffffffff) : 0;
233#else
234#error Make this function work with other LIMB sizes
235#endif
236}
237
238/****************
239 * Return an allocated buffer with the MPI (msb first). 152 * Return an allocated buffer with the MPI (msb first).
240 * NBYTES receives the length of this buffer. Caller must free the 153 * NBYTES receives the length of this buffer. Caller must free the
241 * return string (This function does return a 0 byte buffer with NBYTES 154 * return string (This function does return a 0 byte buffer with NBYTES