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lib/crypto.c: add minisign ed25519 public-key cryptography api
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‎include/Makefile‎

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@@ -10,7 +10,7 @@ all:
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install:
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install -d $(DESTDIR)$(INCLUDEDIR)/xbps
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install -m 644 $(INCS) $(DESTDIR)$(INCLUDEDIR)
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for f in array bool data dictionary number object string; do \
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for f in array bool data dictionary number object string crypto; do \
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install -m 644 xbps/xbps_$${f}.h $(DESTDIR)$(INCLUDEDIR)/xbps; \
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done
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‎include/xbps/crypto.h‎

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#ifndef XBPS_CRYPTO_H
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#define XBPS_CRYPTO_H
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#include <sodium.h>
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/** @addtogroup crypto */
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/**@{*/
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#define B64_ENCODED_LEN(BIN_LEN) \
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sodium_base64_ENCODED_LEN(BIN_LEN, sodium_base64_VARIANT_ORIGINAL)
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/**
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*/
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struct xbps_hash_state {
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crypto_generichash_state hs;
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};
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/**
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* @struct xbps_hash
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* @brief BLAKE2b hash.
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*/
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struct xbps_hash {
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unsigned char mem[crypto_generichash_BYTES_MAX];
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};
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/**
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* @brief Initialize hash state.
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*/
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static inline int
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xbps_hash_init(struct xbps_hash_state *state)
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{
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return crypto_generichash_init(&state->hs, NULL, 0U, crypto_generichash_BYTES_MAX);
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}
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/**
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* @brief Update the hash state with new data.
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*/
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static inline int
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xbps_hash_update(struct xbps_hash_state *state,
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const unsigned char *in, unsigned long long inlen)
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{
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return crypto_generichash_update(&state->hs, in, inlen);
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}
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/**
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* @brief Finalize the hash state and return the final hash.
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*/
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static inline int
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xbps_hash_final(struct xbps_hash_state *state, struct xbps_hash *hash)
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{
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return crypto_generichash_final(&state->hs, hash->mem, sizeof(hash->mem));
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}
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/**
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* @brief Hash a file.
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*
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* @param[out] hash ::xbps_hash struct to store the hash.
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* @param[in] path Path of the file to hash.
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*
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* @return 0 on success or a negative \c errno from \c open(3) or \c read(3).
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*/
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int xbps_hash_file(struct xbps_hash *hash, const char *path);
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/**
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* @def SIGALG_HASHED
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* @brief Ed25519 public-key signature of the BLAKE2b hash of the message.
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*/
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/**
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* @def SIGALG
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* @brief Ed25519 public-key signature of the message.
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*/
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/**
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* @def KEYNUMBYTES
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* @brief Number of bytes used for keynum.
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*/
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#define KEYNUMBYTES 8
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/**
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* @def COMMENTMAXBYTES
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* @brief Maximum bytes of untristed comments including trailing `\0`.
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*/
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#define COMMENTMAXBYTES 1024
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/**
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* @def TRUSTEDCOMMENTMAXBYTES
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* @brief Maximum bytes of trusted comments including trailing `\0`.
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*/
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#define TRUSTEDCOMMENTMAXBYTES 8192
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/**
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* @def SIGBYTES
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* @brief Number of bytes of the Ed25519 public-key signature.
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*/
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#define SIGBYTES crypto_sign_BYTES
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/**
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* @def PUBLICKEYBYTES
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* @brief Number of bytes of the Ed25519 public-key.
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*/
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#define PUBLICKEYBYTES crypto_sign_PUBLICKEYBYTES
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/**
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* @def SECRETKEYBYTES
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* @brief Number of bytes of the Ed25519 secret-key.
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*/
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#define SECRETKEYBYTES crypto_sign_SECRETKEYBYTES
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/**
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* @def HASHBYTES
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* @brief Number of bytes for the BLAKE2b hash.
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*/
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#define HASHBYTES crypto_generichash_BYTES
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/**
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* @struct xbps_pubkey
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* @brief minisign public-key.
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*
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* Algorithm id, keynum and Ed25519 public-key.
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*/
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struct xbps_pubkey {
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/**
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* @var sig_alg
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* @brief Algorithm identifier.
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*/
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unsigned char sig_alg[2];
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/**
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* @var keynum_pk
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* @brief wtf
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*/
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struct {
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/**
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* @var keynum
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* @brief key identifier
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*/
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unsigned char keynum[KEYNUMBYTES];
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/**
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* @var pk
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* @brief Ed25519 public-key
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*/
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unsigned char pk[PUBLICKEYBYTES];
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} keynum_pk;
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};
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#define PUBKEY_ENCODED_LEN (B64_ENCODED_LEN(sizeof(struct xbps_pubkey)))
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/**
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* @brief Decode a base64 encoded minisign public-key.
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* @param[out] pubkey Structure to decode the public-key to.
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* @param[in] pubkey_s Encoded public-key.
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* @returns \c 0 on success or a negative \c errno.
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* @retval -ENOTSUP Public-key specifies a signature algorithm that is not supported.
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* @retval -EINVAL Public-key is invalid.
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*/
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int xbps_pubkey_decode(struct xbps_pubkey *pubkey, const char *pubkey_s);
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/**
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* @brief Encode a minising public-key using base64.
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* @param[in] pubkey Public-key to encode.
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* @param[out] pubkey_s Buffer to store the encoded public-key.
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* @param[in] pubkey_s_len Size of the \p pubkey_s buffer.
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* @returns \c 0 on success or a negative \c errno.
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* @retval -ENOBUFS Encoded public-key would exceed the \p pubkey_s buffer.
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*/
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int xbps_pubkey_encode(const struct xbps_pubkey *pubkey, char *pubkey_s, size_t pubkey_s_len);
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/**
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* @brief Read a minisign public-key file
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* @param[out] pubkey Structure to store the public-key to.
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* @param[in] fd File descriptor to read from
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* @returns \c 0 on success or a negative \c errno from ::xbps_pubkey_decode, \c open(3) or \c read(3).
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* @retval -ENOBUFS Comment or the encoded public-key exceed the maximum size.
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*/
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int xbps_pubkey_read(struct xbps_pubkey *pubkey, int fd);
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int xbps_pubkey_write(const struct xbps_pubkey *pubkey, const char *path);
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/**
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* @struct xbps_seckey
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* @brief minisign secret-key.
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*
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* Ed25519 secret-key, algorithm id and encryption data.
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*/
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struct xbps_seckey {
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unsigned char sig_alg[2];
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unsigned char kdf_alg[2];
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unsigned char chk_alg[2];
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unsigned char kdf_salt[crypto_pwhash_scryptsalsa208sha256_SALTBYTES];
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unsigned char kdf_opslimit_le[8];
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unsigned char kdf_memlimit_le[8];
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struct {
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unsigned char keynum[KEYNUMBYTES];
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unsigned char sk[SECRETKEYBYTES];
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/**
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* @var chk
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* @brief BLAKE2b hash of the secret-key.
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*
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* BLAKE2b hash of the secret-key used to check if the secret-key
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* was successfully decrypted.
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*/
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unsigned char chk[HASHBYTES];
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} keynum_sk;
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};
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/**
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* @brief Read and decrypt a secret-key.
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* @param[out] seckey Structure to store the read secret-key in.
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* @param[in] passphrase Optional passphrase to encrypt the secret-key.
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* @param[in] path File descriptor to read from.
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* @returns \c 0 on success or a negative \c errno.
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* @retval -ENOBUFS Comment or encoded secret-key exceed the maximum size.
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* @retval -ENOTSUP Secret-key used an algorithm or encryption that is not supported.
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* @retval -EINVAL Secret-key is invalid.
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* @retval -ERANGE Secret-key is encrypted but no passphrase was supplied or decryption failed.
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* @retval -ENOMEM Secret-key decryption failed due to resource limits.
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*/
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int xbps_seckey_read(struct xbps_seckey *seckey, const char *passphrase, const char *path);
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/**
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* @brief Write secret-key to file.
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* @param[in] seckey Secret-key to write.
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* @param[in] passphrase Optional passphrase to encrypt the secret-key with.
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* @param[in] path Path to the file.
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* @returns \c 0 on success or a negative \c errno from \c open(3) or \c write(3).
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*/
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int xbps_seckey_write(const struct xbps_seckey *seckey, const char *passphrase, const char *path);
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/**
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* @struct xbps_sig
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* @brief Ed25519 signature.
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*/
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struct xbps_sig {
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/**
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* @var sig_alg
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* @brief Signature algorithm.
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*
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* The signature algorithm, currently only ::SIGALG_HASHED.
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*/
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unsigned char sig_alg[2];
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/**
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* @var keynum
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* @brief Key identifier.
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*
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* Cryptographically insecure. This should not be presented to users
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* and is just used as a fastpath to check if a signature was signed
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* by a different key.
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*/
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unsigned char keynum[KEYNUMBYTES];
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/**
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* @var sig
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* @brief Ed25519 public-key signature.
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*
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* Detached Ed25519 pubkey-key signature.
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*
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* The signature depends on the used ::xbps_sig.sig_alg:
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* - ::SIGALG_HASHED: Signed BLAKE2b hash of the message.
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* - ::SIGALG: Signature of the message itself, not supported.
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*/
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unsigned char sig[SIGBYTES];
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};
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/**
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* @struct xbps_minisig
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* @brief minisig signature
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*/
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struct xbps_minisig {
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/**
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* @var comment
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* @brief Untrusted comment in the .minisig file.
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*/
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char comment[COMMENTMAXBYTES];
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/**
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* @var sig
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* @brief Algorithm, keynum and signature of the signed data.
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*/
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struct xbps_sig sig;
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/**
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* @var trusted_comment
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* @brief Trusted comment in the .minisig file.
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*/
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char trusted_comment[TRUSTEDCOMMENTMAXBYTES];
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/**
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* @var global_sig
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* @brief Signature of ::xbps_minisig.sig and ::xbps_minisig.trusted_comment.
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*
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* The global signature signs the signature and the trusted comment.
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*/
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unsigned char global_sig[SIGBYTES];
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};
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/**
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* @brief Read a minisig file.
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* @param[out] minisig ::xbps_minisig struct to store the read data.
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* @param[in] path Path to the .minisig file.
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* @returns \c 0 on success or a negative \c errno from \c open(3), \c read(3).
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* @retval -ENOBUFS Comments or the encoded signature exceed the maximum size.
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*/
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int xbps_minisig_read(struct xbps_minisig *minisig, const char *path);
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/**
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* @brief Write a minisig file.
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* @param[in] minisig The ::xbps_minisig structure that is written
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* @param[in] path Path to write to
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* @returns \c 0 on success or a negative \c errno from \c open(3), \c write(3).
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*/
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int xbps_minisig_write(const struct xbps_minisig *minisig, const char *path);
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/**
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* @brief Sign a minisig ::xbps_minisig.
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* @param[out] minisig The ::xbps_minisig that is being signed and stores the signatures.
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* @param[in] seckey Secret-key used to sign.
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* @param[in] hash The hash of the message that is begin signed.
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* @returns \c 0 on success or a negative \c errno.
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* @retval -EINVAL Signing failed.
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*/
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int xbps_minisig_sign(struct xbps_minisig *minisig, const struct xbps_seckey *seckey,
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const struct xbps_hash *hash);
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/**
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* @brief Verify a minisig ::xbps_minisig.
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* @param[in] minisig The ::xbps_minisig that is being verified.
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* @param[in] pubkey Public-key used to verify the ::xbps_minisig.
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* @param[in] hash The hash of the message that is being verified.
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* @returns \c 0 on success or a negative \c errno.
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* @retval -EINVAL \c keynum of \p pubkey does not match signature.
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* @retval -ERANGE Signature verification failed.
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*/
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int xbps_minisig_verify(const struct xbps_minisig *minisig, const struct xbps_pubkey *pubkey,
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const struct xbps_hash *hash);
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/**
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* @brief Generate a new key pair.
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*
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* Generates a new public- and secret-key pair.
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*
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* @param[out] seckey ::xbps_seckey to store the generated secret-key.
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* @param[out] pubkey ::xbps_pubkey to store the generated public-key.
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*
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* @return 0 on success or a negative \c errno.
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* @retval -EINVAL Failure during keypair generation.
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*/
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int xbps_generate_keypair(struct xbps_seckey *seckey, struct xbps_pubkey *pubkey);
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/**@}*/
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#endif

‎lib/Makefile‎

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@@ -52,6 +52,7 @@ OBJS += repo.o repo_sync.o
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OBJS += rpool.o cb_util.o proplib_wrapper.o
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OBJS += package_alternatives.o
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OBJS += conf.o log.o
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OBJS += crypto.o
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OBJS += $(EXTOBJS) $(COMPAT_OBJS)
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# unnecessary unless pkgdb format changes
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# OBJS += pkgdb_conversion.o

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