1 /*
2 * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (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 <sys/libkern.h>
11 #include <sys/malloc.h>
12
13 #include <opencrypto/cryptodev.h>
14 #include <opencrypto/xform_auth.h>
15
16 #include <crypto/openssl/ossl.h>
17 #include <crypto/openssl/ossl_poly1305.h>
18
19 #define POLY1305_ASM
20
21 /* From crypto/poly1305/poly1305.c */
22
23 /* pick 32-bit unsigned integer in little endian order */
U8TOU32(const unsigned char * p)24 static unsigned int U8TOU32(const unsigned char *p)
25 {
26 return (((unsigned int)(p[0] & 0xff)) |
27 ((unsigned int)(p[1] & 0xff) << 8) |
28 ((unsigned int)(p[2] & 0xff) << 16) |
29 ((unsigned int)(p[3] & 0xff) << 24));
30 }
31
32 /*
33 * Implementations can be classified by amount of significant bits in
34 * words making up the multi-precision value, or in other words radix
35 * or base of numerical representation, e.g. base 2^64, base 2^32,
36 * base 2^26. Complementary characteristic is how wide is the result of
37 * multiplication of pair of digits, e.g. it would take 128 bits to
38 * accommodate multiplication result in base 2^64 case. These are used
39 * interchangeably. To describe implementation that is. But interface
40 * is designed to isolate this so that low-level primitives implemented
41 * in assembly can be self-contained/self-coherent.
42 */
43 int poly1305_init(void *ctx, const unsigned char key[16], void *func);
44 void poly1305_blocks(void *ctx, const unsigned char *inp, size_t len,
45 unsigned int padbit);
46 void poly1305_emit(void *ctx, unsigned char mac[16],
47 const unsigned int nonce[4]);
48
Poly1305_Init(POLY1305 * ctx,const unsigned char key[32])49 void Poly1305_Init(POLY1305 *ctx, const unsigned char key[32])
50 {
51 ctx->nonce[0] = U8TOU32(&key[16]);
52 ctx->nonce[1] = U8TOU32(&key[20]);
53 ctx->nonce[2] = U8TOU32(&key[24]);
54 ctx->nonce[3] = U8TOU32(&key[28]);
55
56 /*
57 * Unlike reference poly1305_init assembly counterpart is expected
58 * to return a value: non-zero if it initializes ctx->func, and zero
59 * otherwise. Latter is to simplify assembly in cases when there no
60 * multiple code paths to switch between.
61 */
62 if (!poly1305_init(ctx->opaque, key, &ctx->func)) {
63 ctx->func.blocks = poly1305_blocks;
64 ctx->func.emit = poly1305_emit;
65 }
66
67 ctx->num = 0;
68
69 }
70
71 #ifdef POLY1305_ASM
72 /*
73 * This "eclipses" poly1305_blocks and poly1305_emit, but it's
74 * conscious choice imposed by -Wshadow compiler warnings.
75 */
76 # define poly1305_blocks (*poly1305_blocks_p)
77 # define poly1305_emit (*poly1305_emit_p)
78 #endif
79
Poly1305_Update(POLY1305 * ctx,const unsigned char * inp,size_t len)80 void Poly1305_Update(POLY1305 *ctx, const unsigned char *inp, size_t len)
81 {
82 #ifdef POLY1305_ASM
83 /*
84 * As documented, poly1305_blocks is never called with input
85 * longer than single block and padbit argument set to 0. This
86 * property is fluently used in assembly modules to optimize
87 * padbit handling on loop boundary.
88 */
89 poly1305_blocks_f poly1305_blocks_p = ctx->func.blocks;
90 #endif
91 size_t rem, num;
92
93 if ((num = ctx->num)) {
94 rem = POLY1305_BLOCK_SIZE - num;
95 if (len >= rem) {
96 memcpy(ctx->data + num, inp, rem);
97 poly1305_blocks(ctx->opaque, ctx->data, POLY1305_BLOCK_SIZE, 1);
98 inp += rem;
99 len -= rem;
100 } else {
101 /* Still not enough data to process a block. */
102 memcpy(ctx->data + num, inp, len);
103 ctx->num = num + len;
104 return;
105 }
106 }
107
108 rem = len % POLY1305_BLOCK_SIZE;
109 len -= rem;
110
111 if (len >= POLY1305_BLOCK_SIZE) {
112 poly1305_blocks(ctx->opaque, inp, len, 1);
113 inp += len;
114 }
115
116 if (rem)
117 memcpy(ctx->data, inp, rem);
118
119 ctx->num = rem;
120 }
121
Poly1305_Final(POLY1305 * ctx,unsigned char mac[16])122 void Poly1305_Final(POLY1305 *ctx, unsigned char mac[16])
123 {
124 #ifdef POLY1305_ASM
125 poly1305_blocks_f poly1305_blocks_p = ctx->func.blocks;
126 poly1305_emit_f poly1305_emit_p = ctx->func.emit;
127 #endif
128 size_t num;
129
130 if ((num = ctx->num)) {
131 ctx->data[num++] = 1; /* pad bit */
132 while (num < POLY1305_BLOCK_SIZE)
133 ctx->data[num++] = 0;
134 poly1305_blocks(ctx->opaque, ctx->data, POLY1305_BLOCK_SIZE, 0);
135 }
136
137 poly1305_emit(ctx->opaque, mac, ctx->nonce);
138
139 /* zero out the state */
140 OPENSSL_cleanse(ctx, sizeof(*ctx));
141 }
142
143 static void
ossl_poly1305_init(void * vctx)144 ossl_poly1305_init(void *vctx)
145 {
146 }
147
148 static void
ossl_poly1305_setkey(void * vctx,const uint8_t * key,u_int klen)149 ossl_poly1305_setkey(void *vctx, const uint8_t *key, u_int klen)
150 {
151 MPASS(klen == 32);
152 Poly1305_Init(vctx, key);
153 }
154
155 int
ossl_poly1305_update(void * vctx,const void * buf,u_int len)156 ossl_poly1305_update(void *vctx, const void *buf, u_int len)
157 {
158 Poly1305_Update(vctx, buf, len);
159 return (0);
160 }
161
162 static void
ossl_poly1305_final(uint8_t * digest,void * vctx)163 ossl_poly1305_final(uint8_t *digest, void *vctx)
164 {
165 Poly1305_Final(vctx, digest);
166 }
167
168 struct auth_hash ossl_hash_poly1305 = {
169 .type = CRYPTO_POLY1305,
170 .name = "OpenSSL-Poly1305",
171 .hashsize = POLY1305_HASH_LEN,
172 .ctxsize = sizeof(struct poly1305_context),
173 .blocksize = POLY1305_BLOCK_SIZE,
174 .Init = ossl_poly1305_init,
175 .Setkey = ossl_poly1305_setkey,
176 .Update = ossl_poly1305_update,
177 .Final = ossl_poly1305_final,
178 };
179
180 _Static_assert(sizeof(struct poly1305_context) <=
181 sizeof(struct ossl_hash_context), "ossl_hash_context too small");
182