Commit ba1ee070 authored by Salman Qazi's avatar Salman Qazi Committed by Herbert Xu

crypto: vmac - Make VMAC work when blocks aren't aligned

VMAC implementation, as it is, does not work with blocks that
are not multiples of 128-bytes.  Furthermore, this is a problem
when using the implementation on scatterlists, even
when the complete plain text is 128-byte multiple, as the pieces
that get passed to vmac_update can be pretty much any size.

I also added test cases for unaligned blocks.
Signed-off-by: default avatarSalman Qazi <sqazi@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 7291a932
......@@ -1707,7 +1707,7 @@ static struct hash_testvec aes_xcbc128_tv_template[] = {
}
};
#define VMAC_AES_TEST_VECTORS 8
#define VMAC_AES_TEST_VECTORS 11
static char vmac_string1[128] = {'\x01', '\x01', '\x01', '\x01',
'\x02', '\x03', '\x02', '\x02',
'\x02', '\x04', '\x01', '\x07',
......@@ -1723,6 +1723,19 @@ static char vmac_string3[128] = {'a', 'b', 'c', 'a', 'b', 'c',
'a', 'b', 'c', 'a', 'b', 'c',
};
static char vmac_string4[17] = {'b', 'c', 'e', 'f',
'i', 'j', 'l', 'm',
'o', 'p', 'r', 's',
't', 'u', 'w', 'x', 'z'};
static char vmac_string5[127] = {'r', 'm', 'b', 't', 'c',
'o', 'l', 'k', ']', '%',
'9', '2', '7', '!', 'A'};
static char vmac_string6[129] = {'p', 't', '*', '7', 'l',
'i', '!', '#', 'w', '0',
'z', '/', '4', 'A', 'n'};
static struct hash_testvec aes_vmac128_tv_template[] = {
{
.key = "\x00\x01\x02\x03\x04\x05\x06\x07"
......@@ -1776,6 +1789,24 @@ static struct hash_testvec aes_vmac128_tv_template[] = {
.digest = "\x8b\x32\x8f\xe1\xed\x8f\xfa\xd4",
.psize = 128,
.ksize = 16,
}, {
.key = "a09b5cd!f#07K\x00\x00\x00",
.plaintext = vmac_string4,
.digest = "\xab\xa5\x0f\xea\x42\x4e\xa1\x5f",
.psize = sizeof(vmac_string4),
.ksize = 16,
}, {
.key = "a09b5cd!f#07K\x00\x00\x00",
.plaintext = vmac_string5,
.digest = "\x25\x31\x98\xbc\x1d\xe8\x67\x60",
.psize = sizeof(vmac_string5),
.ksize = 16,
}, {
.key = "a09b5cd!f#07K\x00\x00\x00",
.plaintext = vmac_string6,
.digest = "\xc4\xae\x9b\x47\x95\x65\xeb\x41",
.psize = sizeof(vmac_string6),
.ksize = 16,
},
};
......
......@@ -375,6 +375,11 @@ static void vhash_update(const unsigned char *m,
u64 pkh = ctx->polykey[0];
u64 pkl = ctx->polykey[1];
if (!mbytes)
return;
BUG_ON(mbytes % VMAC_NHBYTES);
mptr = (u64 *)m;
i = mbytes / VMAC_NHBYTES; /* Must be non-zero */
......@@ -454,7 +459,7 @@ static u64 vhash(unsigned char m[], unsigned int mbytes,
}
static u64 vmac(unsigned char m[], unsigned int mbytes,
unsigned char n[16], u64 *tagl,
const unsigned char n[16], u64 *tagl,
struct vmac_ctx_t *ctx)
{
u64 *in_n, *out_p;
......@@ -559,8 +564,33 @@ static int vmac_update(struct shash_desc *pdesc, const u8 *p,
{
struct crypto_shash *parent = pdesc->tfm;
struct vmac_ctx_t *ctx = crypto_shash_ctx(parent);
int expand;
int min;
expand = VMAC_NHBYTES - ctx->partial_size > 0 ?
VMAC_NHBYTES - ctx->partial_size : 0;
min = len < expand ? len : expand;
memcpy(ctx->partial + ctx->partial_size, p, min);
ctx->partial_size += min;
if (len < expand)
return 0;
vhash_update(p, len, &ctx->__vmac_ctx);
vhash_update(ctx->partial, VMAC_NHBYTES, &ctx->__vmac_ctx);
ctx->partial_size = 0;
len -= expand;
p += expand;
if (len % VMAC_NHBYTES) {
memcpy(ctx->partial, p + len - (len % VMAC_NHBYTES),
len % VMAC_NHBYTES);
ctx->partial_size = len % VMAC_NHBYTES;
}
vhash_update(p, len - len % VMAC_NHBYTES, &ctx->__vmac_ctx);
return 0;
}
......@@ -572,10 +602,20 @@ static int vmac_final(struct shash_desc *pdesc, u8 *out)
vmac_t mac;
u8 nonce[16] = {};
mac = vmac(NULL, 0, nonce, NULL, ctx);
/* vmac() ends up accessing outside the array bounds that
* we specify. In appears to access up to the next 2-word
* boundary. We'll just be uber cautious and zero the
* unwritten bytes in the buffer.
*/
if (ctx->partial_size) {
memset(ctx->partial + ctx->partial_size, 0,
VMAC_NHBYTES - ctx->partial_size);
}
mac = vmac(ctx->partial, ctx->partial_size, nonce, NULL, ctx);
memcpy(out, &mac, sizeof(vmac_t));
memset(&mac, 0, sizeof(vmac_t));
memset(&ctx->__vmac_ctx, 0, sizeof(struct vmac_ctx));
ctx->partial_size = 0;
return 0;
}
......@@ -673,4 +713,3 @@ module_exit(vmac_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("VMAC hash algorithm");
......@@ -56,6 +56,8 @@ typedef u64 vmac_t;
struct vmac_ctx_t {
struct crypto_cipher *child;
struct vmac_ctx __vmac_ctx;
u8 partial[VMAC_NHBYTES]; /* partial block */
int partial_size; /* size of the partial block */
};
#endif /* __CRYPTO_VMAC_H */
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