xref: /openbmc/linux/drivers/crypto/caam/key_gen.c (revision 4a075bd4)
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 void split_key_done(struct device *dev, u32 *desc, u32 err,
15 			   void *context)
16 {
17 	struct split_key_result *res = context;
18 
19 #ifdef DEBUG
20 	dev_err(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
21 #endif
22 
23 	if (err)
24 		caam_jr_strstatus(dev, err);
25 
26 	res->err = err;
27 
28 	complete(&res->completion);
29 }
30 EXPORT_SYMBOL(split_key_done);
31 /*
32 get a split ipad/opad key
33 
34 Split key generation-----------------------------------------------
35 
36 [00] 0xb0810008    jobdesc: stidx=1 share=never len=8
37 [01] 0x04000014        key: class2->keyreg len=20
38 			@0xffe01000
39 [03] 0x84410014  operation: cls2-op sha1 hmac init dec
40 [04] 0x24940000     fifold: class2 msgdata-last2 len=0 imm
41 [05] 0xa4000001       jump: class2 local all ->1 [06]
42 [06] 0x64260028    fifostr: class2 mdsplit-jdk len=40
43 			@0xffe04000
44 */
45 int gen_split_key(struct device *jrdev, u8 *key_out,
46 		  struct alginfo * const adata, const u8 *key_in, u32 keylen,
47 		  int max_keylen)
48 {
49 	u32 *desc;
50 	struct split_key_result result;
51 	dma_addr_t dma_addr;
52 	int ret = -ENOMEM;
53 
54 	adata->keylen = split_key_len(adata->algtype & OP_ALG_ALGSEL_MASK);
55 	adata->keylen_pad = split_key_pad_len(adata->algtype &
56 					      OP_ALG_ALGSEL_MASK);
57 
58 #ifdef DEBUG
59 	dev_err(jrdev, "split keylen %d split keylen padded %d\n",
60 		adata->keylen, adata->keylen_pad);
61 	print_hex_dump(KERN_ERR, "ctx.key@" __stringify(__LINE__)": ",
62 		       DUMP_PREFIX_ADDRESS, 16, 4, key_in, keylen, 1);
63 #endif
64 
65 	if (adata->keylen_pad > max_keylen)
66 		return -EINVAL;
67 
68 	desc = kmalloc(CAAM_CMD_SZ * 6 + CAAM_PTR_SZ * 2, GFP_KERNEL | GFP_DMA);
69 	if (!desc) {
70 		dev_err(jrdev, "unable to allocate key input memory\n");
71 		return ret;
72 	}
73 
74 	memcpy(key_out, key_in, keylen);
75 
76 	dma_addr = dma_map_single(jrdev, key_out, adata->keylen_pad,
77 				  DMA_BIDIRECTIONAL);
78 	if (dma_mapping_error(jrdev, dma_addr)) {
79 		dev_err(jrdev, "unable to map key memory\n");
80 		goto out_free;
81 	}
82 
83 	init_job_desc(desc, 0);
84 	append_key(desc, dma_addr, keylen, CLASS_2 | KEY_DEST_CLASS_REG);
85 
86 	/* Sets MDHA up into an HMAC-INIT */
87 	append_operation(desc, (adata->algtype & OP_ALG_ALGSEL_MASK) |
88 			 OP_ALG_AAI_HMAC | OP_TYPE_CLASS2_ALG | OP_ALG_DECRYPT |
89 			 OP_ALG_AS_INIT);
90 
91 	/*
92 	 * do a FIFO_LOAD of zero, this will trigger the internal key expansion
93 	 * into both pads inside MDHA
94 	 */
95 	append_fifo_load_as_imm(desc, NULL, 0, LDST_CLASS_2_CCB |
96 				FIFOLD_TYPE_MSG | FIFOLD_TYPE_LAST2);
97 
98 	/*
99 	 * FIFO_STORE with the explicit split-key content store
100 	 * (0x26 output type)
101 	 */
102 	append_fifo_store(desc, dma_addr, adata->keylen,
103 			  LDST_CLASS_2_CCB | FIFOST_TYPE_SPLIT_KEK);
104 
105 #ifdef DEBUG
106 	print_hex_dump(KERN_ERR, "jobdesc@"__stringify(__LINE__)": ",
107 		       DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
108 #endif
109 
110 	result.err = 0;
111 	init_completion(&result.completion);
112 
113 	ret = caam_jr_enqueue(jrdev, desc, split_key_done, &result);
114 	if (!ret) {
115 		/* in progress */
116 		wait_for_completion(&result.completion);
117 		ret = result.err;
118 #ifdef DEBUG
119 		print_hex_dump(KERN_ERR, "ctx.key@"__stringify(__LINE__)": ",
120 			       DUMP_PREFIX_ADDRESS, 16, 4, key_out,
121 			       adata->keylen_pad, 1);
122 #endif
123 	}
124 
125 	dma_unmap_single(jrdev, dma_addr, adata->keylen_pad, DMA_BIDIRECTIONAL);
126 out_free:
127 	kfree(desc);
128 	return ret;
129 }
130 EXPORT_SYMBOL(gen_split_key);
131