core-lightning/common/hsm_encryption.h
Antoine Poinsot d2a903992c hsmd: regroup hsm_secret decryption logic
Signed-off-by: Antoine Poinsot <darosior@protonmail.com>
2021-01-06 13:50:01 +01:00

65 lines
2.3 KiB
C

#ifndef LIGHTNING_COMMON_HSM_ENCRYPTION_H
#define LIGHTNING_COMMON_HSM_ENCRYPTION_H
#include "config.h"
#include <bitcoin/privkey.h>
#include <ccan/short_types/short_types.h>
#include <ccan/tal/tal.h>
#include <sodium.h>
/* Length of the encrypted hsm secret header. */
#define HS_HEADER_LEN crypto_secretstream_xchacha20poly1305_HEADERBYTES
/* From libsodium: "The ciphertext length is guaranteed to always be message
* length + ABYTES" */
#define HS_CIPHERTEXT_LEN \
(sizeof(struct secret) + crypto_secretstream_xchacha20poly1305_ABYTES)
/* Total length of an encrypted hsm_secret */
#define ENCRYPTED_HSM_SECRET_LEN (HS_HEADER_LEN + HS_CIPHERTEXT_LEN)
struct encrypted_hsm_secret {
u8 data[ENCRYPTED_HSM_SECRET_LEN];
};
/** Derive the hsm_secret encryption key from a passphrase.
* @pass: the passphrase string.
* @encryption_key: the output key derived from the passphrase.
*
* On success, NULL is returned. On error, a human-readable error is.
*/
char *hsm_secret_encryption_key(const char *pass, struct secret *encryption_key);
/** Encrypt the hsm_secret using a previously derived encryption key.
* @encryption_key: the key derived from the passphrase.
* @hsm_secret: the plaintext hsm_secret to encrypt.
* @output: the resulting encrypted hsm_secret.
*
* Return false on encryption failure.
*/
bool encrypt_hsm_secret(const struct secret *encryption_key,
const struct secret *hsm_secret,
struct encrypted_hsm_secret *output);
/** Decrypt the hsm_secret using a previously derived encryption key.
* @encryption_key: the key derived from the passphrase.
* @cipher: the encrypted hsm_secret to decrypt.
* @output: the resulting hsm_secret.
*
* Return false on decryption failure.
*/
bool decrypt_hsm_secret(const struct secret *encryption_key,
const struct encrypted_hsm_secret *cipher,
struct secret *output);
/** Unlock and zeroize the encryption key memory after use.
* @key: the encryption key. If taken, it will be tal_free'd
*/
void discard_key(struct secret *key TAKES);
/** Read hsm_secret encryption pass from stdin, disabling echoing.
* @reason: if NULL is returned, will point to the human-readable error.
*
* Caller must free the string as it does tal-reallocate getline's output.
*/
char *read_stdin_pass(char **reason);
#endif /* LIGHTNING_COMMON_HSM_ENCRYPTION_H */