xref: /openbmc/linux/drivers/crypto/caam/key_gen.c (revision 68198dca)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * CAAM/SEC 4.x functions for handling key-generation jobs
4  *
5  * Copyright 2008-2011 Freescale Semiconductor, Inc.
6  *
7  */
8 #include "compat.h"
9 #include "jr.h"
10 #include "error.h"
11 #include "desc_constr.h"
12 #include "key_gen.h"
13 
14 /**
15  * split_key_len - Compute MDHA split key length for a given algorithm
16  * @hash: Hashing algorithm selection, one of OP_ALG_ALGSEL_* - MD5, SHA1,
17  *        SHA224, SHA384, SHA512.
18  *
19  * Return: MDHA split key length
20  */
21 static inline u32 split_key_len(u32 hash)
22 {
23 	/* Sizes for MDHA pads (*not* keys): MD5, SHA1, 224, 256, 384, 512 */
24 	static const u8 mdpadlen[] = { 16, 20, 32, 32, 64, 64 };
25 	u32 idx;
26 
27 	idx = (hash & OP_ALG_ALGSEL_SUBMASK) >> OP_ALG_ALGSEL_SHIFT;
28 
29 	return (u32)(mdpadlen[idx] * 2);
30 }
31 
32 /**
33  * split_key_pad_len - Compute MDHA split key pad length for a given algorithm
34  * @hash: Hashing algorithm selection, one of OP_ALG_ALGSEL_* - MD5, SHA1,
35  *        SHA224, SHA384, SHA512.
36  *
37  * Return: MDHA split key pad length
38  */
39 static inline u32 split_key_pad_len(u32 hash)
40 {
41 	return ALIGN(split_key_len(hash), 16);
42 }
43 
44 void split_key_done(struct device *dev, u32 *desc, u32 err,
45 			   void *context)
46 {
47 	struct split_key_result *res = context;
48 
49 #ifdef DEBUG
50 	dev_err(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
51 #endif
52 
53 	if (err)
54 		caam_jr_strstatus(dev, err);
55 
56 	res->err = err;
57 
58 	complete(&res->completion);
59 }
60 EXPORT_SYMBOL(split_key_done);
61 /*
62 get a split ipad/opad key
63 
64 Split key generation-----------------------------------------------
65 
66 [00] 0xb0810008    jobdesc: stidx=1 share=never len=8
67 [01] 0x04000014        key: class2->keyreg len=20
68 			@0xffe01000
69 [03] 0x84410014  operation: cls2-op sha1 hmac init dec
70 [04] 0x24940000     fifold: class2 msgdata-last2 len=0 imm
71 [05] 0xa4000001       jump: class2 local all ->1 [06]
72 [06] 0x64260028    fifostr: class2 mdsplit-jdk len=40
73 			@0xffe04000
74 */
75 int gen_split_key(struct device *jrdev, u8 *key_out,
76 		  struct alginfo * const adata, const u8 *key_in, u32 keylen,
77 		  int max_keylen)
78 {
79 	u32 *desc;
80 	struct split_key_result result;
81 	dma_addr_t dma_addr_in, dma_addr_out;
82 	int ret = -ENOMEM;
83 
84 	adata->keylen = split_key_len(adata->algtype & OP_ALG_ALGSEL_MASK);
85 	adata->keylen_pad = split_key_pad_len(adata->algtype &
86 					      OP_ALG_ALGSEL_MASK);
87 
88 #ifdef DEBUG
89 	dev_err(jrdev, "split keylen %d split keylen padded %d\n",
90 		adata->keylen, adata->keylen_pad);
91 	print_hex_dump(KERN_ERR, "ctx.key@" __stringify(__LINE__)": ",
92 		       DUMP_PREFIX_ADDRESS, 16, 4, key_in, keylen, 1);
93 #endif
94 
95 	if (adata->keylen_pad > max_keylen)
96 		return -EINVAL;
97 
98 	desc = kmalloc(CAAM_CMD_SZ * 6 + CAAM_PTR_SZ * 2, GFP_KERNEL | GFP_DMA);
99 	if (!desc) {
100 		dev_err(jrdev, "unable to allocate key input memory\n");
101 		return ret;
102 	}
103 
104 	dma_addr_in = dma_map_single(jrdev, (void *)key_in, keylen,
105 				     DMA_TO_DEVICE);
106 	if (dma_mapping_error(jrdev, dma_addr_in)) {
107 		dev_err(jrdev, "unable to map key input memory\n");
108 		goto out_free;
109 	}
110 
111 	dma_addr_out = dma_map_single(jrdev, key_out, adata->keylen_pad,
112 				      DMA_FROM_DEVICE);
113 	if (dma_mapping_error(jrdev, dma_addr_out)) {
114 		dev_err(jrdev, "unable to map key output memory\n");
115 		goto out_unmap_in;
116 	}
117 
118 	init_job_desc(desc, 0);
119 	append_key(desc, dma_addr_in, keylen, CLASS_2 | KEY_DEST_CLASS_REG);
120 
121 	/* Sets MDHA up into an HMAC-INIT */
122 	append_operation(desc, (adata->algtype & OP_ALG_ALGSEL_MASK) |
123 			 OP_ALG_AAI_HMAC | OP_TYPE_CLASS2_ALG | OP_ALG_DECRYPT |
124 			 OP_ALG_AS_INIT);
125 
126 	/*
127 	 * do a FIFO_LOAD of zero, this will trigger the internal key expansion
128 	 * into both pads inside MDHA
129 	 */
130 	append_fifo_load_as_imm(desc, NULL, 0, LDST_CLASS_2_CCB |
131 				FIFOLD_TYPE_MSG | FIFOLD_TYPE_LAST2);
132 
133 	/*
134 	 * FIFO_STORE with the explicit split-key content store
135 	 * (0x26 output type)
136 	 */
137 	append_fifo_store(desc, dma_addr_out, adata->keylen,
138 			  LDST_CLASS_2_CCB | FIFOST_TYPE_SPLIT_KEK);
139 
140 #ifdef DEBUG
141 	print_hex_dump(KERN_ERR, "ctx.key@"__stringify(__LINE__)": ",
142 		       DUMP_PREFIX_ADDRESS, 16, 4, key_in, keylen, 1);
143 	print_hex_dump(KERN_ERR, "jobdesc@"__stringify(__LINE__)": ",
144 		       DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
145 #endif
146 
147 	result.err = 0;
148 	init_completion(&result.completion);
149 
150 	ret = caam_jr_enqueue(jrdev, desc, split_key_done, &result);
151 	if (!ret) {
152 		/* in progress */
153 		wait_for_completion(&result.completion);
154 		ret = result.err;
155 #ifdef DEBUG
156 		print_hex_dump(KERN_ERR, "ctx.key@"__stringify(__LINE__)": ",
157 			       DUMP_PREFIX_ADDRESS, 16, 4, key_out,
158 			       adata->keylen_pad, 1);
159 #endif
160 	}
161 
162 	dma_unmap_single(jrdev, dma_addr_out, adata->keylen_pad,
163 			 DMA_FROM_DEVICE);
164 out_unmap_in:
165 	dma_unmap_single(jrdev, dma_addr_in, keylen, DMA_TO_DEVICE);
166 out_free:
167 	kfree(desc);
168 	return ret;
169 }
170 EXPORT_SYMBOL(gen_split_key);
171