include/sodium/crypto_aead_aes256gcm.h

0001 #ifndef crypto_aead_aes256gcm_H
0002 #define crypto_aead_aes256gcm_H
0003
0004 /*
0005  * WARNING: Despite being the most popular AEAD construction due to its
0006  * use in TLS, safely using AES-GCM in a different context is tricky.
0007  *
0008  * No more than ~ 350 GB of input data should be encrypted with a given key.
0009  * This is for ~ 16 KB messages -- Actual figures vary according to
0010  * message sizes.
0011  *
0012  * In addition, nonces are short and repeated nonces would totally destroy
0013  * the security of this scheme.
0014  *
0015  * Nonces should thus come from atomic counters, which can be difficult to
0016  * set up in a distributed environment.
0017  *
0018  * Unless you absolutely need AES-GCM, use crypto_aead_xchacha20poly1305_ietf_*()
0019  * instead. It doesn't have any of these limitations.
0020  * Or, if you don't need to authenticate additional data, just stick to
0021  * crypto_secretbox().
0022  */
0023
0024 #include <stddef.h>
0025 #include "export.h"
0026
0027 #ifdef __cplusplus
0028 # ifdef __GNUC__
0029 #  pragma GCC diagnostic ignored "-Wlong-long"
0030 # endif
0031 extern "C" {
0032 #endif
0033
0034 SODIUM_EXPORT
0035 int crypto_aead_aes256gcm_is_available(void);
0036
0037 #define crypto_aead_aes256gcm_KEYBYTES  32U
0038 SODIUM_EXPORT
0039 size_t crypto_aead_aes256gcm_keybytes(void);
0040
0041 #define crypto_aead_aes256gcm_NSECBYTES 0U
0042 SODIUM_EXPORT
0043 size_t crypto_aead_aes256gcm_nsecbytes(void);
0044
0045 #define crypto_aead_aes256gcm_NPUBBYTES 12U
0046 SODIUM_EXPORT
0047 size_t crypto_aead_aes256gcm_npubbytes(void);
0048
0049 #define crypto_aead_aes256gcm_ABYTES    16U
0050 SODIUM_EXPORT
0051 size_t crypto_aead_aes256gcm_abytes(void);
0052
0053 #define crypto_aead_aes256gcm_MESSAGEBYTES_MAX \
0054     SODIUM_MIN(SODIUM_SIZE_MAX - crypto_aead_aes256gcm_ABYTES, \
0055                (16ULL * ((1ULL << 32) - 2ULL)))
0056 SODIUM_EXPORT
0057 size_t crypto_aead_aes256gcm_messagebytes_max(void);
0058
0059 typedef struct CRYPTO_ALIGN(16) crypto_aead_aes256gcm_state_ {
0060     unsigned char opaque[512];
0061 } crypto_aead_aes256gcm_state;
0062
0063 SODIUM_EXPORT
0064 size_t crypto_aead_aes256gcm_statebytes(void);
0065
0066 SODIUM_EXPORT
0067 int crypto_aead_aes256gcm_encrypt(unsigned char *c,
0068                                   unsigned long long *clen_p,
0069                                   const unsigned char *m,
0070                                   unsigned long long mlen,
0071                                   const unsigned char *ad,
0072                                   unsigned long long adlen,
0073                                   const unsigned char *nsec,
0074                                   const unsigned char *npub,
0075                                   const unsigned char *k)
0076             __attribute__ ((nonnull(1, 8, 9)));
0077
0078 SODIUM_EXPORT
0079 int crypto_aead_aes256gcm_decrypt(unsigned char *m,
0080                                   unsigned long long *mlen_p,
0081                                   unsigned char *nsec,
0082                                   const unsigned char *c,
0083                                   unsigned long long clen,
0084                                   const unsigned char *ad,
0085                                   unsigned long long adlen,
0086                                   const unsigned char *npub,
0087                                   const unsigned char *k)
0088             __attribute__ ((warn_unused_result)) __attribute__ ((nonnull(4, 8, 9)));
0089
0090 SODIUM_EXPORT
0091 int crypto_aead_aes256gcm_encrypt_detached(unsigned char *c,
0092                                            unsigned char *mac,
0093                                            unsigned long long *maclen_p,
0094                                            const unsigned char *m,
0095                                            unsigned long long mlen,
0096                                            const unsigned char *ad,
0097                                            unsigned long long adlen,
0098                                            const unsigned char *nsec,
0099                                            const unsigned char *npub,
0100                                            const unsigned char *k)
0101             __attribute__ ((nonnull(1, 2, 9, 10)));
0102
0103 SODIUM_EXPORT
0104 int crypto_aead_aes256gcm_decrypt_detached(unsigned char *m,
0105                                            unsigned char *nsec,
0106                                            const unsigned char *c,
0107                                            unsigned long long clen,
0108                                            const unsigned char *mac,
0109                                            const unsigned char *ad,
0110                                            unsigned long long adlen,
0111                                            const unsigned char *npub,
0112                                            const unsigned char *k)
0113             __attribute__ ((warn_unused_result)) __attribute__ ((nonnull(3, 5, 8, 9)));
0114
0115 /* -- Precomputation interface -- */
0116
0117 SODIUM_EXPORT
0118 int crypto_aead_aes256gcm_beforenm(crypto_aead_aes256gcm_state *ctx_,
0119                                    const unsigned char *k)
0120             __attribute__ ((nonnull));
0121
0122 SODIUM_EXPORT
0123 int crypto_aead_aes256gcm_encrypt_afternm(unsigned char *c,
0124                                           unsigned long long *clen_p,
0125                                           const unsigned char *m,
0126                                           unsigned long long mlen,
0127                                           const unsigned char *ad,
0128                                           unsigned long long adlen,
0129                                           const unsigned char *nsec,
0130                                           const unsigned char *npub,
0131                                           const crypto_aead_aes256gcm_state *ctx_)
0132             __attribute__ ((nonnull(1, 8, 9)));
0133
0134 SODIUM_EXPORT
0135 int crypto_aead_aes256gcm_decrypt_afternm(unsigned char *m,
0136                                           unsigned long long *mlen_p,
0137                                           unsigned char *nsec,
0138                                           const unsigned char *c,
0139                                           unsigned long long clen,
0140                                           const unsigned char *ad,
0141                                           unsigned long long adlen,
0142                                           const unsigned char *npub,
0143                                           const crypto_aead_aes256gcm_state *ctx_)
0144             __attribute__ ((warn_unused_result)) __attribute__ ((nonnull(4, 8, 9)));
0145
0146 SODIUM_EXPORT
0147 int crypto_aead_aes256gcm_encrypt_detached_afternm(unsigned char *c,
0148                                                    unsigned char *mac,
0149                                                    unsigned long long *maclen_p,
0150                                                    const unsigned char *m,
0151                                                    unsigned long long mlen,
0152                                                    const unsigned char *ad,
0153                                                    unsigned long long adlen,
0154                                                    const unsigned char *nsec,
0155                                                    const unsigned char *npub,
0156                                                    const crypto_aead_aes256gcm_state *ctx_)
0157             __attribute__ ((nonnull(1, 2, 9, 10)));
0158
0159 SODIUM_EXPORT
0160 int crypto_aead_aes256gcm_decrypt_detached_afternm(unsigned char *m,
0161                                                    unsigned char *nsec,
0162                                                    const unsigned char *c,
0163                                                    unsigned long long clen,
0164                                                    const unsigned char *mac,
0165                                                    const unsigned char *ad,
0166                                                    unsigned long long adlen,
0167                                                    const unsigned char *npub,
0168                                                    const crypto_aead_aes256gcm_state *ctx_)
0169             __attribute__ ((warn_unused_result)) __attribute__ ((nonnull(3, 5, 8, 9)));
0170
0171 SODIUM_EXPORT
0172 void crypto_aead_aes256gcm_keygen(unsigned char k[crypto_aead_aes256gcm_KEYBYTES])
0173             __attribute__ ((nonnull));
0174
0175 #ifdef __cplusplus
0176 }
0177 #endif
0178
0179 #endif