xref: /openbmc/linux/drivers/crypto/caam/key_gen.c (revision 6c33a6f4)
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 	int ecode = 0;
19 
20 	dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
21 
22 	if (err)
23 		ecode = caam_jr_strstatus(dev, err);
24 
25 	res->err = ecode;
26 
27 	complete(&res->completion);
28 }
29 EXPORT_SYMBOL(split_key_done);
30 /*
31 get a split ipad/opad key
32 
33 Split key generation-----------------------------------------------
34 
35 [00] 0xb0810008    jobdesc: stidx=1 share=never len=8
36 [01] 0x04000014        key: class2->keyreg len=20
37 			@0xffe01000
38 [03] 0x84410014  operation: cls2-op sha1 hmac init dec
39 [04] 0x24940000     fifold: class2 msgdata-last2 len=0 imm
40 [05] 0xa4000001       jump: class2 local all ->1 [06]
41 [06] 0x64260028    fifostr: class2 mdsplit-jdk len=40
42 			@0xffe04000
43 */
44 int gen_split_key(struct device *jrdev, u8 *key_out,
45 		  struct alginfo * const adata, const u8 *key_in, u32 keylen,
46 		  int max_keylen)
47 {
48 	u32 *desc;
49 	struct split_key_result result;
50 	dma_addr_t dma_addr;
51 	unsigned int local_max;
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 	local_max = max(keylen, adata->keylen_pad);
58 
59 	dev_dbg(jrdev, "split keylen %d split keylen padded %d\n",
60 		adata->keylen, adata->keylen_pad);
61 	print_hex_dump_debug("ctx.key@" __stringify(__LINE__)": ",
62 			     DUMP_PREFIX_ADDRESS, 16, 4, key_in, keylen, 1);
63 
64 	if (local_max > max_keylen)
65 		return -EINVAL;
66 
67 	desc = kmalloc(CAAM_CMD_SZ * 6 + CAAM_PTR_SZ * 2, GFP_KERNEL | GFP_DMA);
68 	if (!desc) {
69 		dev_err(jrdev, "unable to allocate key input memory\n");
70 		return ret;
71 	}
72 
73 	memcpy(key_out, key_in, keylen);
74 
75 	dma_addr = dma_map_single(jrdev, key_out, local_max, DMA_BIDIRECTIONAL);
76 	if (dma_mapping_error(jrdev, dma_addr)) {
77 		dev_err(jrdev, "unable to map key memory\n");
78 		goto out_free;
79 	}
80 
81 	init_job_desc(desc, 0);
82 	append_key(desc, dma_addr, keylen, CLASS_2 | KEY_DEST_CLASS_REG);
83 
84 	/* Sets MDHA up into an HMAC-INIT */
85 	append_operation(desc, (adata->algtype & OP_ALG_ALGSEL_MASK) |
86 			 OP_ALG_AAI_HMAC | OP_TYPE_CLASS2_ALG | OP_ALG_DECRYPT |
87 			 OP_ALG_AS_INIT);
88 
89 	/*
90 	 * do a FIFO_LOAD of zero, this will trigger the internal key expansion
91 	 * into both pads inside MDHA
92 	 */
93 	append_fifo_load_as_imm(desc, NULL, 0, LDST_CLASS_2_CCB |
94 				FIFOLD_TYPE_MSG | FIFOLD_TYPE_LAST2);
95 
96 	/*
97 	 * FIFO_STORE with the explicit split-key content store
98 	 * (0x26 output type)
99 	 */
100 	append_fifo_store(desc, dma_addr, adata->keylen,
101 			  LDST_CLASS_2_CCB | FIFOST_TYPE_SPLIT_KEK);
102 
103 	print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
104 			     DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc),
105 			     1);
106 
107 	result.err = 0;
108 	init_completion(&result.completion);
109 
110 	ret = caam_jr_enqueue(jrdev, desc, split_key_done, &result);
111 	if (!ret) {
112 		/* in progress */
113 		wait_for_completion(&result.completion);
114 		ret = result.err;
115 
116 		print_hex_dump_debug("ctx.key@"__stringify(__LINE__)": ",
117 				     DUMP_PREFIX_ADDRESS, 16, 4, key_out,
118 				     adata->keylen_pad, 1);
119 	}
120 
121 	dma_unmap_single(jrdev, dma_addr, local_max, DMA_BIDIRECTIONAL);
122 out_free:
123 	kfree(desc);
124 	return ret;
125 }
126 EXPORT_SYMBOL(gen_split_key);
127