xref: /openbmc/linux/drivers/crypto/caam/key_gen.c (revision b830f94f)
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 	dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
20 
21 	if (err)
22 		caam_jr_strstatus(dev, err);
23 
24 	res->err = err;
25 
26 	complete(&res->completion);
27 }
28 EXPORT_SYMBOL(split_key_done);
29 /*
30 get a split ipad/opad key
31 
32 Split key generation-----------------------------------------------
33 
34 [00] 0xb0810008    jobdesc: stidx=1 share=never len=8
35 [01] 0x04000014        key: class2->keyreg len=20
36 			@0xffe01000
37 [03] 0x84410014  operation: cls2-op sha1 hmac init dec
38 [04] 0x24940000     fifold: class2 msgdata-last2 len=0 imm
39 [05] 0xa4000001       jump: class2 local all ->1 [06]
40 [06] 0x64260028    fifostr: class2 mdsplit-jdk len=40
41 			@0xffe04000
42 */
43 int gen_split_key(struct device *jrdev, u8 *key_out,
44 		  struct alginfo * const adata, const u8 *key_in, u32 keylen,
45 		  int max_keylen)
46 {
47 	u32 *desc;
48 	struct split_key_result result;
49 	dma_addr_t dma_addr;
50 	int ret = -ENOMEM;
51 
52 	adata->keylen = split_key_len(adata->algtype & OP_ALG_ALGSEL_MASK);
53 	adata->keylen_pad = split_key_pad_len(adata->algtype &
54 					      OP_ALG_ALGSEL_MASK);
55 
56 	dev_dbg(jrdev, "split keylen %d split keylen padded %d\n",
57 		adata->keylen, adata->keylen_pad);
58 	print_hex_dump_debug("ctx.key@" __stringify(__LINE__)": ",
59 			     DUMP_PREFIX_ADDRESS, 16, 4, key_in, keylen, 1);
60 
61 	if (adata->keylen_pad > max_keylen)
62 		return -EINVAL;
63 
64 	desc = kmalloc(CAAM_CMD_SZ * 6 + CAAM_PTR_SZ * 2, GFP_KERNEL | GFP_DMA);
65 	if (!desc) {
66 		dev_err(jrdev, "unable to allocate key input memory\n");
67 		return ret;
68 	}
69 
70 	memcpy(key_out, key_in, keylen);
71 
72 	dma_addr = dma_map_single(jrdev, key_out, adata->keylen_pad,
73 				  DMA_BIDIRECTIONAL);
74 	if (dma_mapping_error(jrdev, dma_addr)) {
75 		dev_err(jrdev, "unable to map key memory\n");
76 		goto out_free;
77 	}
78 
79 	init_job_desc(desc, 0);
80 	append_key(desc, dma_addr, keylen, CLASS_2 | KEY_DEST_CLASS_REG);
81 
82 	/* Sets MDHA up into an HMAC-INIT */
83 	append_operation(desc, (adata->algtype & OP_ALG_ALGSEL_MASK) |
84 			 OP_ALG_AAI_HMAC | OP_TYPE_CLASS2_ALG | OP_ALG_DECRYPT |
85 			 OP_ALG_AS_INIT);
86 
87 	/*
88 	 * do a FIFO_LOAD of zero, this will trigger the internal key expansion
89 	 * into both pads inside MDHA
90 	 */
91 	append_fifo_load_as_imm(desc, NULL, 0, LDST_CLASS_2_CCB |
92 				FIFOLD_TYPE_MSG | FIFOLD_TYPE_LAST2);
93 
94 	/*
95 	 * FIFO_STORE with the explicit split-key content store
96 	 * (0x26 output type)
97 	 */
98 	append_fifo_store(desc, dma_addr, adata->keylen,
99 			  LDST_CLASS_2_CCB | FIFOST_TYPE_SPLIT_KEK);
100 
101 	print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
102 			     DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc),
103 			     1);
104 
105 	result.err = 0;
106 	init_completion(&result.completion);
107 
108 	ret = caam_jr_enqueue(jrdev, desc, split_key_done, &result);
109 	if (!ret) {
110 		/* in progress */
111 		wait_for_completion(&result.completion);
112 		ret = result.err;
113 
114 		print_hex_dump_debug("ctx.key@"__stringify(__LINE__)": ",
115 				     DUMP_PREFIX_ADDRESS, 16, 4, key_out,
116 				     adata->keylen_pad, 1);
117 	}
118 
119 	dma_unmap_single(jrdev, dma_addr, adata->keylen_pad, DMA_BIDIRECTIONAL);
120 out_free:
121 	kfree(desc);
122 	return ret;
123 }
124 EXPORT_SYMBOL(gen_split_key);
125