1 #include <string.h>
2 
3 #include "crypto_box_curve25519xsalsa20poly1305.h"
4 #include "crypto_core_hsalsa20.h"
5 #include "crypto_hash_sha512.h"
6 #include "crypto_scalarmult_curve25519.h"
7 #include "crypto_secretbox_xsalsa20poly1305.h"
8 #include "randombytes.h"
9 #include "utils.h"
10 
11 int
12 crypto_box_curve25519xsalsa20poly1305_seed_keypair(unsigned char *pk,
13                                                    unsigned char *sk,
14                                                    const unsigned char *seed)
15 {
16     unsigned char hash[64];
17 
18     crypto_hash_sha512(hash, seed, 32);
19     memcpy(sk, hash, 32);
20     sodium_memzero(hash, sizeof hash);
21 
22     return crypto_scalarmult_curve25519_base(pk, sk);
23 }
24 
25 int
26 crypto_box_curve25519xsalsa20poly1305_keypair(unsigned char *pk,
27                                               unsigned char *sk)
28 {
29     randombytes_buf(sk, 32);
30 
31     return crypto_scalarmult_curve25519_base(pk, sk);
32 }
33 
34 int
35 crypto_box_curve25519xsalsa20poly1305_beforenm(unsigned char *k,
36                                                const unsigned char *pk,
37                                                const unsigned char *sk)
38 {
39     static const unsigned char zero[16] = { 0 };
40     unsigned char s[32];
41 
42     if (crypto_scalarmult_curve25519(s, sk, pk) != 0) {
43         return -1;
44     }
45     return crypto_core_hsalsa20(k, zero, s, NULL);
46 }
47 
48 int
49 crypto_box_curve25519xsalsa20poly1305_afternm(unsigned char *c,
50                                               const unsigned char *m,
51                                               unsigned long long mlen,
52                                               const unsigned char *n,
53                                               const unsigned char *k)
54 {
55     return crypto_secretbox_xsalsa20poly1305(c, m, mlen, n, k);
56 }
57 
58 int
59 crypto_box_curve25519xsalsa20poly1305_open_afternm(unsigned char *m,
60                                                    const unsigned char *c,
61                                                    unsigned long long clen,
62                                                    const unsigned char *n,
63                                                    const unsigned char *k)
64 {
65     return crypto_secretbox_xsalsa20poly1305_open(m, c, clen, n, k);
66 }
67 
68 int
69 crypto_box_curve25519xsalsa20poly1305(unsigned char *c, const unsigned char *m,
70                                       unsigned long long   mlen,
71                                       const unsigned char *n,
72                                       const unsigned char *pk,
73                                       const unsigned char *sk)
74 {
75     unsigned char k[crypto_box_curve25519xsalsa20poly1305_BEFORENMBYTES];
76     int           ret;
77 
78     if (crypto_box_curve25519xsalsa20poly1305_beforenm(k, pk, sk) != 0) {
79         return -1;
80     }
81     ret = crypto_box_curve25519xsalsa20poly1305_afternm(c, m, mlen, n, k);
82     sodium_memzero(k, sizeof k);
83 
84     return ret;
85 }
86 
87 int
88 crypto_box_curve25519xsalsa20poly1305_open(
89     unsigned char *m, const unsigned char *c, unsigned long long clen,
90     const unsigned char *n, const unsigned char *pk, const unsigned char *sk)
91 {
92     unsigned char k[crypto_box_curve25519xsalsa20poly1305_BEFORENMBYTES];
93     int           ret;
94 
95     if (crypto_box_curve25519xsalsa20poly1305_beforenm(k, pk, sk) != 0) {
96         return -1;
97     }
98     ret = crypto_box_curve25519xsalsa20poly1305_open_afternm(m, c, clen, n, k);
99     sodium_memzero(k, sizeof k);
100 
101     return ret;
102 }
103 
104 size_t
105 crypto_box_curve25519xsalsa20poly1305_seedbytes(void)
106 {
107     return crypto_box_curve25519xsalsa20poly1305_SEEDBYTES;
108 }
109 
110 size_t
111 crypto_box_curve25519xsalsa20poly1305_publickeybytes(void)
112 {
113     return crypto_box_curve25519xsalsa20poly1305_PUBLICKEYBYTES;
114 }
115 
116 size_t
117 crypto_box_curve25519xsalsa20poly1305_secretkeybytes(void)
118 {
119     return crypto_box_curve25519xsalsa20poly1305_SECRETKEYBYTES;
120 }
121 
122 size_t
123 crypto_box_curve25519xsalsa20poly1305_beforenmbytes(void)
124 {
125     return crypto_box_curve25519xsalsa20poly1305_BEFORENMBYTES;
126 }
127 
128 size_t
129 crypto_box_curve25519xsalsa20poly1305_noncebytes(void)
130 {
131     return crypto_box_curve25519xsalsa20poly1305_NONCEBYTES;
132 }
133 
134 size_t
135 crypto_box_curve25519xsalsa20poly1305_zerobytes(void)
136 {
137     return crypto_box_curve25519xsalsa20poly1305_ZEROBYTES;
138 }
139 
140 size_t
141 crypto_box_curve25519xsalsa20poly1305_boxzerobytes(void)
142 {
143     return crypto_box_curve25519xsalsa20poly1305_BOXZEROBYTES;
144 }
145 
146 size_t
147 crypto_box_curve25519xsalsa20poly1305_macbytes(void)
148 {
149     return crypto_box_curve25519xsalsa20poly1305_MACBYTES;
150 }
151 
152 size_t
153 crypto_box_curve25519xsalsa20poly1305_messagebytes_max(void)
154 {
155     return crypto_box_curve25519xsalsa20poly1305_MESSAGEBYTES_MAX;
156 }
157