1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Glue code for MD5 implementation for PPC assembler
  4 *
  5 * Based on generic implementation.
  6 *
  7 * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
  8 */
  9
 10#include <crypto/internal/hash.h>
 11#include <linux/init.h>
 12#include <linux/module.h>
 13#include <linux/mm.h>
 14#include <linux/types.h>
 15#include <crypto/md5.h>
 16#include <asm/byteorder.h>
 17
 18extern void ppc_md5_transform(u32 *state, const u8 *src, u32 blocks);
 19
 20static inline void ppc_md5_clear_context(struct md5_state *sctx)
 21{
 22	int count = sizeof(struct md5_state) >> 2;
 23	u32 *ptr = (u32 *)sctx;
 24
 25	/* make sure we can clear the fast way */
 26	BUILD_BUG_ON(sizeof(struct md5_state) % 4);
 27	do { *ptr++ = 0; } while (--count);
 28}
 29
 30static int ppc_md5_init(struct shash_desc *desc)
 31{
 32	struct md5_state *sctx = shash_desc_ctx(desc);
 33
 34	sctx->hash[0] = MD5_H0;
 35	sctx->hash[1] = MD5_H1;
 36	sctx->hash[2] = MD5_H2;
 37	sctx->hash[3] =	MD5_H3;
 38	sctx->byte_count = 0;
 39
 40	return 0;
 41}
 42
 43static int ppc_md5_update(struct shash_desc *desc, const u8 *data,
 44			unsigned int len)
 45{
 46	struct md5_state *sctx = shash_desc_ctx(desc);
 47	const unsigned int offset = sctx->byte_count & 0x3f;
 48	unsigned int avail = 64 - offset;
 49	const u8 *src = data;
 50
 51	sctx->byte_count += len;
 52
 53	if (avail > len) {
 54		memcpy((char *)sctx->block + offset, src, len);
 55		return 0;
 56	}
 57
 58	if (offset) {
 59		memcpy((char *)sctx->block + offset, src, avail);
 60		ppc_md5_transform(sctx->hash, (const u8 *)sctx->block, 1);
 61		len -= avail;
 62		src += avail;
 63	}
 64
 65	if (len > 63) {
 66		ppc_md5_transform(sctx->hash, src, len >> 6);
 67		src += len & ~0x3f;
 68		len &= 0x3f;
 69	}
 70
 71	memcpy((char *)sctx->block, src, len);
 72	return 0;
 73}
 74
 75static int ppc_md5_final(struct shash_desc *desc, u8 *out)
 76{
 77	struct md5_state *sctx = shash_desc_ctx(desc);
 78	const unsigned int offset = sctx->byte_count & 0x3f;
 79	const u8 *src = (const u8 *)sctx->block;
 80	u8 *p = (u8 *)src + offset;
 81	int padlen = 55 - offset;
 82	__le64 *pbits = (__le64 *)((char *)sctx->block + 56);
 83	__le32 *dst = (__le32 *)out;
 84
 85	*p++ = 0x80;
 86
 87	if (padlen < 0) {
 88		memset(p, 0x00, padlen + sizeof (u64));
 89		ppc_md5_transform(sctx->hash, src, 1);
 90		p = (char *)sctx->block;
 91		padlen = 56;
 92	}
 93
 94	memset(p, 0, padlen);
 95	*pbits = cpu_to_le64(sctx->byte_count << 3);
 96	ppc_md5_transform(sctx->hash, src, 1);
 97
 98	dst[0] = cpu_to_le32(sctx->hash[0]);
 99	dst[1] = cpu_to_le32(sctx->hash[1]);
100	dst[2] = cpu_to_le32(sctx->hash[2]);
101	dst[3] = cpu_to_le32(sctx->hash[3]);
102
103	ppc_md5_clear_context(sctx);
104	return 0;
105}
106
107static int ppc_md5_export(struct shash_desc *desc, void *out)
108{
109	struct md5_state *sctx = shash_desc_ctx(desc);
110
111	memcpy(out, sctx, sizeof(*sctx));
112	return 0;
113}
114
115static int ppc_md5_import(struct shash_desc *desc, const void *in)
116{
117	struct md5_state *sctx = shash_desc_ctx(desc);
118
119	memcpy(sctx, in, sizeof(*sctx));
120	return 0;
121}
122
123static struct shash_alg alg = {
124	.digestsize	=	MD5_DIGEST_SIZE,
125	.init		=	ppc_md5_init,
126	.update		=	ppc_md5_update,
127	.final		=	ppc_md5_final,
128	.export		=	ppc_md5_export,
129	.import		=	ppc_md5_import,
130	.descsize	=	sizeof(struct md5_state),
131	.statesize	=	sizeof(struct md5_state),
132	.base		=	{
133		.cra_name	=	"md5",
134		.cra_driver_name=	"md5-ppc",
135		.cra_priority	=	200,
136		.cra_blocksize	=	MD5_HMAC_BLOCK_SIZE,
137		.cra_module	=	THIS_MODULE,
138	}
139};
140
141static int __init ppc_md5_mod_init(void)
142{
143	return crypto_register_shash(&alg);
144}
145
146static void __exit ppc_md5_mod_fini(void)
147{
148	crypto_unregister_shash(&alg);
149}
150
151module_init(ppc_md5_mod_init);
152module_exit(ppc_md5_mod_fini);
153
154MODULE_LICENSE("GPL");
155MODULE_DESCRIPTION("MD5 Secure Hash Algorithm, PPC assembler");
156
157MODULE_ALIAS_CRYPTO("md5");
158MODULE_ALIAS_CRYPTO("md5-ppc");