1 | /* |
2 | * Copyright 2005-2017 The OpenSSL Project Authors. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
5 | * this file except in compliance with the License. You can obtain a copy |
6 | * in the file LICENSE in the source distribution or at |
7 | * https://www.openssl.org/source/license.html |
8 | */ |
9 | |
10 | #include <stdio.h> |
11 | #include "internal/cryptlib.h" |
12 | #include <openssl/bn.h> |
13 | #include <openssl/rsa.h> |
14 | #include <openssl/objects.h> |
15 | |
16 | int RSA_padding_add_X931(unsigned char *to, int tlen, |
17 | const unsigned char *from, int flen) |
18 | { |
19 | int j; |
20 | unsigned char *p; |
21 | |
22 | /* |
23 | * Absolute minimum amount of padding is 1 header nibble, 1 padding |
24 | * nibble and 2 trailer bytes: but 1 hash if is already in 'from'. |
25 | */ |
26 | |
27 | j = tlen - flen - 2; |
28 | |
29 | if (j < 0) { |
30 | RSAerr(RSA_F_RSA_PADDING_ADD_X931, RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); |
31 | return -1; |
32 | } |
33 | |
34 | p = (unsigned char *)to; |
35 | |
36 | /* If no padding start and end nibbles are in one byte */ |
37 | if (j == 0) { |
38 | *p++ = 0x6A; |
39 | } else { |
40 | *p++ = 0x6B; |
41 | if (j > 1) { |
42 | memset(p, 0xBB, j - 1); |
43 | p += j - 1; |
44 | } |
45 | *p++ = 0xBA; |
46 | } |
47 | memcpy(p, from, (unsigned int)flen); |
48 | p += flen; |
49 | *p = 0xCC; |
50 | return 1; |
51 | } |
52 | |
53 | int RSA_padding_check_X931(unsigned char *to, int tlen, |
54 | const unsigned char *from, int flen, int num) |
55 | { |
56 | int i = 0, j; |
57 | const unsigned char *p; |
58 | |
59 | p = from; |
60 | if ((num != flen) || ((*p != 0x6A) && (*p != 0x6B))) { |
61 | RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_HEADER); |
62 | return -1; |
63 | } |
64 | |
65 | if (*p++ == 0x6B) { |
66 | j = flen - 3; |
67 | for (i = 0; i < j; i++) { |
68 | unsigned char c = *p++; |
69 | if (c == 0xBA) |
70 | break; |
71 | if (c != 0xBB) { |
72 | RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_PADDING); |
73 | return -1; |
74 | } |
75 | } |
76 | |
77 | j -= i; |
78 | |
79 | if (i == 0) { |
80 | RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_PADDING); |
81 | return -1; |
82 | } |
83 | |
84 | } else { |
85 | j = flen - 2; |
86 | } |
87 | |
88 | if (p[j] != 0xCC) { |
89 | RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_TRAILER); |
90 | return -1; |
91 | } |
92 | |
93 | memcpy(to, p, (unsigned int)j); |
94 | |
95 | return j; |
96 | } |
97 | |
98 | /* Translate between X931 hash ids and NIDs */ |
99 | |
100 | int RSA_X931_hash_id(int nid) |
101 | { |
102 | switch (nid) { |
103 | case NID_sha1: |
104 | return 0x33; |
105 | |
106 | case NID_sha256: |
107 | return 0x34; |
108 | |
109 | case NID_sha384: |
110 | return 0x36; |
111 | |
112 | case NID_sha512: |
113 | return 0x35; |
114 | |
115 | } |
116 | return -1; |
117 | } |
118 | |