On Thu, Apr 28, 2022 at 09:59:38PM +0800, zhenwei pi wrote: > From: Lei He <helei.sig11@xxxxxxxxxxxxx> > > Add an ANS.1 DER decoder which is used to parse asymmetric > cipher keys > > Signed-off-by: zhenwei pi <pizhenwei@xxxxxxxxxxxxx> > Signed-off-by: lei he <helei.sig11@xxxxxxxxxxxxx> > --- > crypto/der.c | 190 +++++++++++++++++++++++ > crypto/der.h | 82 ++++++++++ > crypto/meson.build | 1 + > tests/unit/meson.build | 1 + > tests/unit/test-crypto-der.c | 290 +++++++++++++++++++++++++++++++++++ > 5 files changed, 564 insertions(+) > create mode 100644 crypto/der.c > create mode 100644 crypto/der.h > create mode 100644 tests/unit/test-crypto-der.c > > diff --git a/crypto/der.c b/crypto/der.c > new file mode 100644 > index 0000000000..7907bcfd51 > --- /dev/null > +++ b/crypto/der.c > @@ -0,0 +1,190 @@ > +/* > + * QEMU Crypto ASN.1 DER decoder > + * > + * Copyright (c) 2022 Bytedance > + * Author: lei he <helei.sig11@xxxxxxxxxxxxx> > + * > + * This library is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; either > + * version 2.1 of the License, or (at your option) any later version. > + * > + * This library is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with this library; if not, see <http://www.gnu.org/licenses/>. > + * > + */ > + > +#include <stdint.h> > +#include <stddef.h> These should both be replaced by #include "qemu/osdep.h" otherwise this fails to build for Mingw targets > +static int qcrypto_der_invoke_callback(DERDecodeCb cb, void *ctx, > + const uint8_t *value, size_t vlen, > + Error **errp) > +{ > + if (!cb) { > + return 0; > + } > + > + return cb(ctx, value, vlen, errp); > +} > + > +static int qcrypto_der_extract_definite_data(const uint8_t **data, size_t *dlen, > + DERDecodeCb cb, void *ctx, > + Error **errp) > +{ > + const uint8_t *value; > + size_t vlen = 0; > + uint8_t byte_count = qcrypto_der_cut_byte(data, dlen); > + > + /* short format of definite-length */ > + if (!(byte_count & QCRYPTO_DER_SHORT_LEN_MASK)) { > + if (byte_count > *dlen) { > + error_setg(errp, "Invalid content length: %u", byte_count); > + return -1; > + } > + > + value = *data; > + vlen = byte_count; > + qcrypto_der_cut_nbytes(data, dlen, vlen); > + > + if (qcrypto_der_invoke_callback(cb, ctx, value, vlen, errp) != 0) { > + return -1; > + } > + return vlen; > + } > + > + /* Ignore highest bit */ > + byte_count &= ~QCRYPTO_DER_SHORT_LEN_MASK; > + > + /* > + * size_t is enough to store the value of length, although the DER > + * encoding standard supports larger length. > + */ > + if (byte_count > sizeof(size_t)) { > + error_setg(errp, "Invalid byte count of content length: %u", > + byte_count); > + return -1; > + } > + > + if (*dlen < byte_count) { Can you flip this to 'byte_count > *dlen' so that the ordering is consistent with the rest of the checks in this method. > + error_setg(errp, "Invalid content length: %u", byte_count); > + return -1; > + } > + while (byte_count--) { > + vlen <<= 8; > + vlen += qcrypto_der_cut_byte(data, dlen); > + } > + > + if (vlen > *dlen) { > + error_setg(errp, "Invalid content length: %lu", vlen); > + return -1; > + } > + > + value = *data; > + qcrypto_der_cut_nbytes(data, dlen, vlen); > + > + if (qcrypto_der_invoke_callback(cb, ctx, value, vlen, errp) != 0) { > + return -1; > + } > + return vlen; > +} > diff --git a/crypto/der.h b/crypto/der.h > new file mode 100644 > index 0000000000..aaa0e01969 > --- /dev/null > +++ b/crypto/der.h > @@ -0,0 +1,82 @@ > +#ifndef QCRYPTO_ASN1_DECODER_H > +#define QCRYPTO_ASN1_DECODER_H > + > +#include "qemu/osdep.h" osdep.h should always be in the .c file > +#include "qapi/error.h" > + > +/* Simple decoder used to parse DER encoded rsa keys. */ > + > +/** > + * @opaque: user context. > + * @value: the starting address of |value| part of 'Tag-Length-Value' pattern. > + * @vlen: length of the |value|. > + * Returns: 0 for success, any other value is considered an error. > + */ > +typedef int (*DERDecodeCb) (void *opaque, const uint8_t *value, > + size_t vlen, Error **errp); Could you call this one 'QCryptoDERDecodeCb)' > + > +/** > + * der_decode_int: Needs updating for the new func name > + * @data: pointer to address of input data > + * @dlen: pointer to length of input data > + * @cb: callback invoked when decode succeed, if cb equals NULL, no > + * callback will be invoked > + * @opaque: parameter passed to cb > + * > + * Decode integer from DER-encoded data. > + * > + * Returns: On success, *data points to rest data, and *dlen > + * will be set to the rest length of data, if cb is not NULL, must > + * return 0 to make decode success, at last, the length of the data > + * part of the decoded INTEGER will be returned. Otherwise, -1 is > + * returned. > + */ > +int qcrypto_der_decode_int(const uint8_t **data, > + size_t *dlen, > + DERDecodeCb cb, > + void *opaque, > + Error **errp); > + > +/** > + * der_decode_seq: Likewise needs updating > + * > + * Decode sequence from DER-encoded data, similar with der_decode_int. > + * > + * @data: pointer to address of input data > + * @dlen: pointer to length of input data > + * @cb: callback invoked when decode succeed, if cb equals NULL, no > + * callback will be invoked > + * @opaque: parameter passed to cb > + * > + * Returns: On success, *data points to rest data, and *dlen > + * will be set to the rest length of data, if cb is not NULL, must > + * return 0 to make decode success, at last, the length of the data > + * part of the decoded SEQUENCE will be returned. Otherwise, -1 is > + * returned. > + */ > +int qcrypto_der_decode_seq(const uint8_t **data, > + size_t *dlen, > + DERDecodeCb cb, > + void *opaque, > + Error **errp); > + > +#endif /* QCRYPTO_ASN1_DECODER_H */ With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
