xref: /openbmc/linux/drivers/crypto/caam/key_gen.c (revision 1c2dd16a)
1 /*
2  * CAAM/SEC 4.x functions for handling key-generation jobs
3  *
4  * Copyright 2008-2011 Freescale Semiconductor, Inc.
5  *
6  */
7 #include "compat.h"
8 #include "jr.h"
9 #include "error.h"
10 #include "desc_constr.h"
11 #include "key_gen.h"
12 
13 /**
14  * split_key_len - Compute MDHA split key length for a given algorithm
15  * @hash: Hashing algorithm selection, one of OP_ALG_ALGSEL_* - MD5, SHA1,
16  *        SHA224, SHA384, SHA512.
17  *
18  * Return: MDHA split key length
19  */
20 static inline u32 split_key_len(u32 hash)
21 {
22 	/* Sizes for MDHA pads (*not* keys): MD5, SHA1, 224, 256, 384, 512 */
23 	static const u8 mdpadlen[] = { 16, 20, 32, 32, 64, 64 };
24 	u32 idx;
25 
26 	idx = (hash & OP_ALG_ALGSEL_SUBMASK) >> OP_ALG_ALGSEL_SHIFT;
27 
28 	return (u32)(mdpadlen[idx] * 2);
29 }
30 
31 /**
32  * split_key_pad_len - Compute MDHA split key pad length for a given algorithm
33  * @hash: Hashing algorithm selection, one of OP_ALG_ALGSEL_* - MD5, SHA1,
34  *        SHA224, SHA384, SHA512.
35  *
36  * Return: MDHA split key pad length
37  */
38 static inline u32 split_key_pad_len(u32 hash)
39 {
40 	return ALIGN(split_key_len(hash), 16);
41 }
42 
43 void split_key_done(struct device *dev, u32 *desc, u32 err,
44 			   void *context)
45 {
46 	struct split_key_result *res = context;
47 
48 #ifdef DEBUG
49 	dev_err(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
50 #endif
51 
52 	if (err)
53 		caam_jr_strstatus(dev, err);
54 
55 	res->err = err;
56 
57 	complete(&res->completion);
58 }
59 EXPORT_SYMBOL(split_key_done);
60 /*
61 get a split ipad/opad key
62 
63 Split key generation-----------------------------------------------
64 
65 [00] 0xb0810008    jobdesc: stidx=1 share=never len=8
66 [01] 0x04000014        key: class2->keyreg len=20
67 			@0xffe01000
68 [03] 0x84410014  operation: cls2-op sha1 hmac init dec
69 [04] 0x24940000     fifold: class2 msgdata-last2 len=0 imm
70 [05] 0xa4000001       jump: class2 local all ->1 [06]
71 [06] 0x64260028    fifostr: class2 mdsplit-jdk len=40
72 			@0xffe04000
73 */
74 int gen_split_key(struct device *jrdev, u8 *key_out,
75 		  struct alginfo * const adata, const u8 *key_in, u32 keylen,
76 		  int max_keylen)
77 {
78 	u32 *desc;
79 	struct split_key_result result;
80 	dma_addr_t dma_addr_in, dma_addr_out;
81 	int ret = -ENOMEM;
82 
83 	adata->keylen = split_key_len(adata->algtype & OP_ALG_ALGSEL_MASK);
84 	adata->keylen_pad = split_key_pad_len(adata->algtype &
85 					      OP_ALG_ALGSEL_MASK);
86 
87 #ifdef DEBUG
88 	dev_err(jrdev, "split keylen %d split keylen padded %d\n",
89 		adata->keylen, adata->keylen_pad);
90 	print_hex_dump(KERN_ERR, "ctx.key@" __stringify(__LINE__)": ",
91 		       DUMP_PREFIX_ADDRESS, 16, 4, key_in, keylen, 1);
92 #endif
93 
94 	if (adata->keylen_pad > max_keylen)
95 		return -EINVAL;
96 
97 	desc = kmalloc(CAAM_CMD_SZ * 6 + CAAM_PTR_SZ * 2, GFP_KERNEL | GFP_DMA);
98 	if (!desc) {
99 		dev_err(jrdev, "unable to allocate key input memory\n");
100 		return ret;
101 	}
102 
103 	dma_addr_in = dma_map_single(jrdev, (void *)key_in, keylen,
104 				     DMA_TO_DEVICE);
105 	if (dma_mapping_error(jrdev, dma_addr_in)) {
106 		dev_err(jrdev, "unable to map key input memory\n");
107 		goto out_free;
108 	}
109 
110 	dma_addr_out = dma_map_single(jrdev, key_out, adata->keylen_pad,
111 				      DMA_FROM_DEVICE);
112 	if (dma_mapping_error(jrdev, dma_addr_out)) {
113 		dev_err(jrdev, "unable to map key output memory\n");
114 		goto out_unmap_in;
115 	}
116 
117 	init_job_desc(desc, 0);
118 	append_key(desc, dma_addr_in, keylen, CLASS_2 | KEY_DEST_CLASS_REG);
119 
120 	/* Sets MDHA up into an HMAC-INIT */
121 	append_operation(desc, (adata->algtype & OP_ALG_ALGSEL_MASK) |
122 			 OP_ALG_AAI_HMAC | OP_TYPE_CLASS2_ALG | OP_ALG_DECRYPT |
123 			 OP_ALG_AS_INIT);
124 
125 	/*
126 	 * do a FIFO_LOAD of zero, this will trigger the internal key expansion
127 	 * into both pads inside MDHA
128 	 */
129 	append_fifo_load_as_imm(desc, NULL, 0, LDST_CLASS_2_CCB |
130 				FIFOLD_TYPE_MSG | FIFOLD_TYPE_LAST2);
131 
132 	/*
133 	 * FIFO_STORE with the explicit split-key content store
134 	 * (0x26 output type)
135 	 */
136 	append_fifo_store(desc, dma_addr_out, adata->keylen,
137 			  LDST_CLASS_2_CCB | FIFOST_TYPE_SPLIT_KEK);
138 
139 #ifdef DEBUG
140 	print_hex_dump(KERN_ERR, "ctx.key@"__stringify(__LINE__)": ",
141 		       DUMP_PREFIX_ADDRESS, 16, 4, key_in, keylen, 1);
142 	print_hex_dump(KERN_ERR, "jobdesc@"__stringify(__LINE__)": ",
143 		       DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
144 #endif
145 
146 	result.err = 0;
147 	init_completion(&result.completion);
148 
149 	ret = caam_jr_enqueue(jrdev, desc, split_key_done, &result);
150 	if (!ret) {
151 		/* in progress */
152 		wait_for_completion_interruptible(&result.completion);
153 		ret = result.err;
154 #ifdef DEBUG
155 		print_hex_dump(KERN_ERR, "ctx.key@"__stringify(__LINE__)": ",
156 			       DUMP_PREFIX_ADDRESS, 16, 4, key_out,
157 			       adata->keylen_pad, 1);
158 #endif
159 	}
160 
161 	dma_unmap_single(jrdev, dma_addr_out, adata->keylen_pad,
162 			 DMA_FROM_DEVICE);
163 out_unmap_in:
164 	dma_unmap_single(jrdev, dma_addr_in, keylen, DMA_TO_DEVICE);
165 out_free:
166 	kfree(desc);
167 	return ret;
168 }
169 EXPORT_SYMBOL(gen_split_key);
170