1 /* 2 * Copyright (c) 2019 Google LLC 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17 #ifndef SSHSIG_H 18 #define SSHSIG_H 19 20 struct sshbuf; 21 struct sshkey; 22 struct sshsigopt; 23 struct sshkey_sig_details; 24 25 typedef int sshsig_signer(struct sshkey *, u_char **, size_t *, 26 const u_char *, size_t, const char *, const char *, u_int, void *); 27 28 /* Buffer-oriented API */ 29 30 /* 31 * Creates a detached SSH signature for a given buffer. 32 * Returns 0 on success or a negative SSH_ERR_* error code on failure. 33 * out is populated with the detached signature, or NULL on failure. 34 */ 35 int sshsig_signb(struct sshkey *key, const char *hashalg, 36 const char *sk_provider, const struct sshbuf *message, 37 const char *sig_namespace, struct sshbuf **out, 38 sshsig_signer *signer, void *signer_ctx); 39 40 /* 41 * Verifies that a detached signature is valid and optionally returns key 42 * used to sign via argument. 43 * Returns 0 on success or a negative SSH_ERR_* error code on failure. 44 */ 45 int sshsig_verifyb(struct sshbuf *signature, 46 const struct sshbuf *message, const char *sig_namespace, 47 struct sshkey **sign_keyp, struct sshkey_sig_details **sig_details); 48 49 /* File/FD-oriented API */ 50 51 /* 52 * Creates a detached SSH signature for a given file. 53 * Returns 0 on success or a negative SSH_ERR_* error code on failure. 54 * out is populated with the detached signature, or NULL on failure. 55 */ 56 int sshsig_sign_fd(struct sshkey *key, const char *hashalg, 57 const char *sk_provider, int fd, const char *sig_namespace, 58 struct sshbuf **out, sshsig_signer *signer, void *signer_ctx); 59 60 /* 61 * Verifies that a detached signature over a file is valid and optionally 62 * returns key used to sign via argument. 63 * Returns 0 on success or a negative SSH_ERR_* error code on failure. 64 */ 65 int sshsig_verify_fd(struct sshbuf *signature, int fd, 66 const char *sig_namespace, struct sshkey **sign_keyp, 67 struct sshkey_sig_details **sig_details); 68 69 /* Utility functions */ 70 71 /* 72 * Return a base64 encoded "ASCII armoured" version of a raw signature. 73 */ 74 int sshsig_armor(const struct sshbuf *blob, struct sshbuf **out); 75 76 /* 77 * Decode a base64 encoded armoured signature to a raw signature. 78 */ 79 int sshsig_dearmor(struct sshbuf *sig, struct sshbuf **out); 80 81 /* 82 * Checks whether a particular key/principal/namespace is permitted by 83 * an allowed_keys file. Returns 0 on success. 84 */ 85 int sshsig_check_allowed_keys(const char *path, const struct sshkey *sign_key, 86 const char *principal, const char *ns); 87 88 /* Parse zero or more allowed_keys signature options */ 89 struct sshsigopt *sshsigopt_parse(const char *opts, 90 const char *path, u_long linenum, const char **errstrp); 91 92 /* Free signature options */ 93 void sshsigopt_free(struct sshsigopt *opts); 94 95 /* Get public key from signature */ 96 int sshsig_get_pubkey(struct sshbuf *signature, struct sshkey **pubkey); 97 98 /* Find principal in allowed_keys file, given a sshkey. Returns 99 * 0 on success. 100 */ 101 int sshsig_find_principals(const char *path, const struct sshkey *sign_key, 102 char **principal); 103 104 #endif /* SSHSIG_H */ 105