1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3 * Copyright (C) 2018, ARM Limited
4 * Copyright (C) 2019, Linaro Limited
5 */
6
7 #include <assert.h>
8 #include <crypto/crypto.h>
9 #include <kernel/panic.h>
10 #include <mbedtls/bignum.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <util.h>
14
15 #define ciL (sizeof(mbedtls_mpi_uint)) /* chars in limb */
16 #define biL (ciL << 3) /* bits in limb */
17 #define BITS_TO_LIMBS(i) ((i) / biL + ((i) % biL != 0))
18
crypto_bignum_num_bytes(struct bignum * a)19 size_t crypto_bignum_num_bytes(struct bignum *a)
20 {
21 assert(a != NULL);
22 return mbedtls_mpi_size((const mbedtls_mpi *)a);
23 }
24
crypto_bignum_num_bits(struct bignum * a)25 size_t crypto_bignum_num_bits(struct bignum *a)
26 {
27 assert(a != NULL);
28 return mbedtls_mpi_bitlen((const mbedtls_mpi *)a);
29 }
30
crypto_bignum_compare(struct bignum * a,struct bignum * b)31 int32_t crypto_bignum_compare(struct bignum *a, struct bignum *b)
32 {
33 int ret = 0;
34
35 assert(a != NULL);
36 assert(b != NULL);
37 ret = mbedtls_mpi_cmp_mpi((const mbedtls_mpi *)a,
38 (const mbedtls_mpi *)b);
39 return CMP_TRILEAN(ret, 0);
40 }
41
crypto_bignum_bn2bin(const struct bignum * from,uint8_t * to)42 void crypto_bignum_bn2bin(const struct bignum *from, uint8_t *to)
43 {
44 size_t len = 0;
45
46 assert(from != NULL);
47 assert(to != NULL);
48 len = crypto_bignum_num_bytes((struct bignum *)from);
49 if (mbedtls_mpi_write_binary((mbedtls_mpi *)from, to, len))
50 panic();
51 }
52
crypto_bignum_bin2bn(const uint8_t * from,size_t fromsize,struct bignum * to)53 TEE_Result crypto_bignum_bin2bn(const uint8_t *from, size_t fromsize,
54 struct bignum *to)
55 {
56 assert(from != NULL);
57 assert(to != NULL);
58 if (mbedtls_mpi_read_binary((mbedtls_mpi *)to, from, fromsize))
59 return TEE_ERROR_BAD_PARAMETERS;
60 return TEE_SUCCESS;
61 }
62
crypto_bignum_copy(struct bignum * to,const struct bignum * from)63 void crypto_bignum_copy(struct bignum *to, const struct bignum *from)
64 {
65 assert(from != NULL);
66 assert(to != NULL);
67 if (mbedtls_mpi_copy((mbedtls_mpi *)to, (const mbedtls_mpi *)from))
68 panic();
69 }
70
crypto_bignum_allocate(size_t size_bits)71 struct bignum *crypto_bignum_allocate(size_t size_bits)
72 {
73 mbedtls_mpi *bn = NULL;
74
75 if (size_bits > CFG_CORE_BIGNUM_MAX_BITS)
76 size_bits = CFG_CORE_BIGNUM_MAX_BITS;
77
78 bn = calloc(1, sizeof(mbedtls_mpi));
79 if (!bn)
80 return NULL;
81 mbedtls_mpi_init(bn);
82 if (mbedtls_mpi_grow(bn, BITS_TO_LIMBS(size_bits)) != 0) {
83 free(bn);
84 return NULL;
85 }
86
87 return (struct bignum *)bn;
88 }
89
crypto_bignum_free(struct bignum * s)90 void crypto_bignum_free(struct bignum *s)
91 {
92 mbedtls_mpi_free((mbedtls_mpi *)s);
93 free(s);
94 }
95
crypto_bignum_clear(struct bignum * s)96 void crypto_bignum_clear(struct bignum *s)
97 {
98 mbedtls_mpi *bn = (mbedtls_mpi *)s;
99
100 memset(bn->p, 0, mbedtls_mpi_size((const mbedtls_mpi *)bn));
101 }
102