drivers/crypto/caam/key_gen.c

   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);