xref: /openbmc/linux/include/crypto/poly1305.h (revision 63705da3)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Common values for the Poly1305 algorithm
4  */
5 
6 #ifndef _CRYPTO_POLY1305_H
7 #define _CRYPTO_POLY1305_H
8 
9 #include <linux/types.h>
10 #include <linux/crypto.h>
11 
12 #define POLY1305_BLOCK_SIZE	16
13 #define POLY1305_KEY_SIZE	32
14 #define POLY1305_DIGEST_SIZE	16
15 
16 /* The poly1305_key and poly1305_state types are mostly opaque and
17  * implementation-defined. Limbs might be in base 2^64 or base 2^26, or
18  * different yet. The union type provided keeps these 64-bit aligned for the
19  * case in which this is implemented using 64x64 multiplies.
20  */
21 
22 struct poly1305_key {
23 	union {
24 		u32 r[5];
25 		u64 r64[3];
26 	};
27 };
28 
29 struct poly1305_core_key {
30 	struct poly1305_key key;
31 	struct poly1305_key precomputed_s;
32 };
33 
34 struct poly1305_state {
35 	union {
36 		u32 h[5];
37 		u64 h64[3];
38 	};
39 };
40 
41 struct poly1305_desc_ctx {
42 	/* partial buffer */
43 	u8 buf[POLY1305_BLOCK_SIZE];
44 	/* bytes used in partial buffer */
45 	unsigned int buflen;
46 	/* how many keys have been set in r[] */
47 	unsigned short rset;
48 	/* whether s[] has been set */
49 	bool sset;
50 	/* finalize key */
51 	u32 s[4];
52 	/* accumulator */
53 	struct poly1305_state h;
54 	/* key */
55 	union {
56 		struct poly1305_key opaque_r[CONFIG_CRYPTO_LIB_POLY1305_RSIZE];
57 		struct poly1305_core_key core_r;
58 	};
59 };
60 
61 void poly1305_init_arch(struct poly1305_desc_ctx *desc,
62 			const u8 key[POLY1305_KEY_SIZE]);
63 void poly1305_init_generic(struct poly1305_desc_ctx *desc,
64 			   const u8 key[POLY1305_KEY_SIZE]);
65 
66 static inline void poly1305_init(struct poly1305_desc_ctx *desc, const u8 *key)
67 {
68 	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
69 		poly1305_init_arch(desc, key);
70 	else
71 		poly1305_init_generic(desc, key);
72 }
73 
74 void poly1305_update_arch(struct poly1305_desc_ctx *desc, const u8 *src,
75 			  unsigned int nbytes);
76 void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
77 			     unsigned int nbytes);
78 
79 static inline void poly1305_update(struct poly1305_desc_ctx *desc,
80 				   const u8 *src, unsigned int nbytes)
81 {
82 	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
83 		poly1305_update_arch(desc, src, nbytes);
84 	else
85 		poly1305_update_generic(desc, src, nbytes);
86 }
87 
88 void poly1305_final_arch(struct poly1305_desc_ctx *desc, u8 *digest);
89 void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *digest);
90 
91 static inline void poly1305_final(struct poly1305_desc_ctx *desc, u8 *digest)
92 {
93 	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
94 		poly1305_final_arch(desc, digest);
95 	else
96 		poly1305_final_generic(desc, digest);
97 }
98 
99 #endif
100