crypto.h

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#ifndef _IPXE_CRYPTO_H
#define _IPXE_CRYPTO_H

/** @file
 *
 * Cryptographic API
 *
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <stdint.h>
#include <stddef.h>
#include <assert.h>
#include <ipxe/asn1.h>

/** A message digest algorithm */
struct digest_algorithm {
        /** Algorithm name */
        const char *name;
        /** Context size */
        size_t ctxsize;
        /** Block size */
        size_t blocksize;
        /** Digest size */
        size_t digestsize;
        /** Initialise digest
         *
         * @v ctx               Context
         */
        void ( * init ) ( void *ctx );
        /** Update digest with new data
         *
         * @v ctx               Context
         * @v src               Data to digest
         * @v len               Length of data
         *
         * @v len is not necessarily a multiple of @c blocksize.
         */
        void ( * update ) ( void *ctx, const void *src, size_t len );
        /** Finalise digest
         *
         * @v ctx               Context
         * @v out               Buffer for digest output
         */
        void ( * final ) ( void *ctx, void *out );
};

/** A cipher algorithm */
struct cipher_algorithm {
        /** Algorithm name */
        const char *name;
        /** Context size */
        size_t ctxsize;
        /** Block size
         *
         * Every call to encrypt() or decrypt() must be for a multiple
         * of this size.
         */
        size_t blocksize;
        /** Alignment size
         *
         * Every call to encrypt() or decrypt() must begin at a
         * multiple of this offset from the start of the stream.
         * (Equivalently: all but the last call to encrypt() or
         * decrypt() must be for a multiple of this size.)
         *
         * For ciphers supporting additional data, the main data
         * stream and additional data stream are both considered to
         * begin at offset zero.
         */
        size_t alignsize;
        /** Authentication tag size */
        size_t authsize;
        /** Set key
         *
         * @v ctx       Context
         * @v key       Key
         * @v keylen    Key length
         * @ret rc      Return status code
         */
        int ( * setkey ) ( void *ctx, const void *key, size_t keylen );
        /** Set initialisation vector
         *
         * @v ctx       Context
         * @v iv        Initialisation vector
         * @v ivlen     Initialisation vector length
         */
        void ( * setiv ) ( void *ctx, const void *iv, size_t ivlen );
        /** Encrypt data
         *
         * @v ctx       Context
         * @v src       Data to encrypt
         * @v dst       Buffer for encrypted data, or NULL for additional data
         * @v len       Length of data
         *
         * @v len is guaranteed to be a multiple of @c blocksize.
         */
        void ( * encrypt ) ( void *ctx, const void *src, void *dst,
                             size_t len );
        /** Decrypt data
         *
         * @v ctx       Context
         * @v src       Data to decrypt
         * @v dst       Buffer for decrypted data, or NULL for additional data
         * @v len       Length of data
         *
         * @v len is guaranteed to be a multiple of @c blocksize.
         */
        void ( * decrypt ) ( void *ctx, const void *src, void *dst,
                             size_t len );
        /** Generate authentication tag
         *
         * @v ctx       Context
         * @v auth      Authentication tag
         */
        void ( * auth ) ( void *ctx, void *auth );
};

/** A public key algorithm */
struct pubkey_algorithm {
        /** Algorithm name */
        const char *name;
        /** Encrypt
         *
         * @v key               Key
         * @v plaintext         Plaintext
         * @v ciphertext        Ciphertext
         * @ret rc              Return status code
         */
        int ( * encrypt ) ( const struct asn1_cursor *key,
                            const struct asn1_cursor *plaintext,
                            struct asn1_builder *ciphertext );
        /** Decrypt
         *
         * @v key               Key
         * @v ciphertext        Ciphertext
         * @v plaintext         Plaintext
         * @ret rc              Return status code
         */
        int ( * decrypt ) ( const struct asn1_cursor *key,
                            const struct asn1_cursor *ciphertext,
                            struct asn1_builder *plaintext );
        /** Sign digest value
         *
         * @v key               Key
         * @v digest            Digest algorithm
         * @v value             Digest value
         * @v signature         Signature
         * @ret rc              Return status code
         */
        int ( * sign ) ( const struct asn1_cursor *key,
                         struct digest_algorithm *digest, const void *value,
                         struct asn1_builder *builder );
        /** Verify signed digest value
         *
         * @v key               Key
         * @v digest            Digest algorithm
         * @v value             Digest value
         * @v signature         Signature
         * @ret rc              Return status code
         */
        int ( * verify ) ( const struct asn1_cursor *key,
                           struct digest_algorithm *digest, const void *value,
                           const struct asn1_cursor *signature );
        /** Check that public key matches private key
         *
         * @v private_key       Private key
         * @v public_key        Public key
         * @ret rc              Return status code
         */
        int ( * match ) ( const struct asn1_cursor *private_key,
                          const struct asn1_cursor *public_key );
};

/** An elliptic curve */
struct elliptic_curve {
        /** Curve name */
        const char *name;
        /** Point (and public key) size */
        size_t pointsize;
        /** Scalar (and private key) size */
        size_t keysize;
        /** Generator base point */
        const void *base;
        /** Order of the generator (if prime) */
        const void *order;
        /** Check if this is the point at infinity
         *
         * @v point             Curve point
         * @ret is_infinity     This is the point at infinity
         *
         * The point at infinity cannot be represented in affine
         * coordinates.  Each curve must choose a representation of
         * the point at infinity (e.g. all zeroes).
         */
        int ( * is_infinity ) ( const void *point );
        /** Multiply scalar by curve point
         *
         * @v base              Base point
         * @v scalar            Scalar multiple
         * @v result            Result point to fill in
         * @ret rc              Return status code
         */
        int ( * multiply ) ( const void *base, const void *scalar,
                             void *result );
        /** Add curve points (as a one-off operation)
         *
         * @v addend            Curve point to add
         * @v augend            Curve point to add
         * @v result            Curve point to hold result
         * @ret rc              Return status code
         */
        int ( * add ) ( const void *addend, const void *augend, void *result );
};

static inline __attribute__ (( always_inline )) void
digest_init ( struct digest_algorithm *digest, void *ctx ) {
        digest->init ( ctx );
}

static inline __attribute__ (( always_inline )) void
digest_update ( struct digest_algorithm *digest, void *ctx,
                const void *data, size_t len ) {
        digest->update ( ctx, data, len );
}

static inline __attribute__ (( always_inline )) void
digest_final ( struct digest_algorithm *digest, void *ctx, void *out ) {
        digest->final ( ctx, out );
}

static inline __attribute__ (( always_inline )) int
cipher_setkey ( struct cipher_algorithm *cipher, void *ctx,
                const void *key, size_t keylen ) {
        return cipher->setkey ( ctx, key, keylen );
}

static inline __attribute__ (( always_inline )) void
cipher_setiv ( struct cipher_algorithm *cipher, void *ctx,
               const void *iv, size_t ivlen ) {
        cipher->setiv ( ctx, iv, ivlen );
}

static inline __attribute__ (( always_inline )) void
cipher_encrypt ( struct cipher_algorithm *cipher, void *ctx,
                 const void *src, void *dst, size_t len ) {
        cipher->encrypt ( ctx, src, dst, len );
}
#define cipher_encrypt( cipher, ctx, src, dst, len ) do {               \
        assert ( ( (len) & ( (cipher)->blocksize - 1 ) ) == 0 );        \
        cipher_encrypt ( (cipher), (ctx), (src), (dst), (len) );        \
        } while ( 0 )

static inline __attribute__ (( always_inline )) void
cipher_decrypt ( struct cipher_algorithm *cipher, void *ctx,
                 const void *src, void *dst, size_t len ) {
        cipher->decrypt ( ctx, src, dst, len );
}
#define cipher_decrypt( cipher, ctx, src, dst, len ) do {               \
        assert ( ( (len) & ( (cipher)->blocksize - 1 ) ) == 0 );        \
        cipher_decrypt ( (cipher), (ctx), (src), (dst), (len) );        \
        } while ( 0 )

static inline __attribute__ (( always_inline )) void
cipher_auth ( struct cipher_algorithm *cipher, void *ctx, void *auth ) {
        cipher->auth ( ctx, auth );
}

static inline __attribute__ (( always_inline )) int
is_stream_cipher ( struct cipher_algorithm *cipher ) {
        return ( cipher->blocksize == 1 );
}

static inline __attribute__ (( always_inline )) int
is_block_cipher ( struct cipher_algorithm *cipher ) {
        return ( cipher->blocksize > 1 );
}

static inline __attribute__ (( always_inline )) int
is_auth_cipher ( struct cipher_algorithm *cipher ) {
        return cipher->authsize;
}

static inline __attribute__ (( always_inline )) int
pubkey_encrypt ( struct pubkey_algorithm *pubkey, const struct asn1_cursor *key,
                 const struct asn1_cursor *plaintext,
                 struct asn1_builder *ciphertext ) {
        return pubkey->encrypt ( key, plaintext, ciphertext );
}

static inline __attribute__ (( always_inline )) int
pubkey_decrypt ( struct pubkey_algorithm *pubkey, const struct asn1_cursor *key,
                 const struct asn1_cursor *ciphertext,
                 struct asn1_builder *plaintext ) {
        return pubkey->decrypt ( key, ciphertext, plaintext );
}

static inline __attribute__ (( always_inline )) int
pubkey_sign ( struct pubkey_algorithm *pubkey, const struct asn1_cursor *key,
              struct digest_algorithm *digest, const void *value,
              struct asn1_builder *signature ) {
        return pubkey->sign ( key, digest, value, signature );
}

static inline __attribute__ (( always_inline )) int
pubkey_verify ( struct pubkey_algorithm *pubkey, const struct asn1_cursor *key,
                struct digest_algorithm *digest, const void *value,
                const struct asn1_cursor *signature ) {
        return pubkey->verify ( key, digest, value, signature );
}

static inline __attribute__ (( always_inline )) int
pubkey_match ( struct pubkey_algorithm *pubkey,
               const struct asn1_cursor *private_key,
               const struct asn1_cursor *public_key ) {
        return pubkey->match ( private_key, public_key );
}

static inline __attribute__ (( always_inline )) int
elliptic_is_infinity ( struct elliptic_curve *curve, const void *point ) {
        return curve->is_infinity ( point );
}

static inline __attribute__ (( always_inline )) int
elliptic_multiply ( struct elliptic_curve *curve,
                    const void *base, const void *scalar, void *result ) {
        return curve->multiply ( base, scalar, result );
}

static inline __attribute__ (( always_inline )) int
elliptic_add ( struct elliptic_curve *curve, const void *addend,
               const void *augend, void *result ) {
        return curve->add ( addend, augend, result );
}

extern void digest_null_init ( void *ctx );
extern void digest_null_update ( void *ctx, const void *src, size_t len );
extern void digest_null_final ( void *ctx, void *out );

extern int cipher_null_setkey ( void *ctx, const void *key, size_t keylen );
extern void cipher_null_setiv ( void *ctx, const void *iv, size_t ivlen );
extern void cipher_null_encrypt ( void *ctx, const void *src, void *dst,
                                  size_t len );
extern void cipher_null_decrypt ( void *ctx, const void *src, void *dst,
                                  size_t len );
extern void cipher_null_auth ( void *ctx, void *auth );

extern int pubkey_null_encrypt ( const struct asn1_cursor *key,
                                 const struct asn1_cursor *plaintext,
                                 struct asn1_builder *ciphertext );
extern int pubkey_null_decrypt ( const struct asn1_cursor *key,
                                 const struct asn1_cursor *ciphertext,
                                 struct asn1_builder *plaintext );
extern int pubkey_null_sign ( const struct asn1_cursor *key,
                              struct digest_algorithm *digest,
                              const void *value,
                              struct asn1_builder *signature );
extern int pubkey_null_verify ( const struct asn1_cursor *key,
                                struct digest_algorithm *digest,
                                const void *value,
                                const struct asn1_cursor *signature );

extern struct digest_algorithm digest_null;
extern struct cipher_algorithm cipher_null;
extern struct pubkey_algorithm pubkey_null;

#endif /* _IPXE_CRYPTO_H */