1 files changed, 302 insertions, 0 deletions
diff --git a/lib/libsecureboot/openpgp/decode.c b/lib/libsecureboot/openpgp/decode.c
new file mode 100644
index 000000000000..c59b5722c29e
--- /dev/null
+++ b/lib/libsecureboot/openpgp/decode.c
@@ -0,0 +1,302 @@
+/*-
+ * Copyright (c) 2018, Juniper Networks, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#include <libsecureboot.h>
+
+#include "decode.h"
+
+char *
+octets2hex(unsigned char *ptr, size_t n)
+{
+	char *hex;
+	char *cp;
+	size_t i;
+
+	hex = malloc(2 * n + 1);
+	if (hex != NULL) {
+		for (i = 0, cp = hex; i < n; i++) {
+			snprintf(&cp[i*2], 3, "%02X", ptr[i]);
+		}
+	}
+	return (hex);
+}
+
+unsigned char *
+i2octets(int n, size_t i)
+{
+	static unsigned char o[16];
+	int x, j;
+
+	if (n > 15)
+		return (NULL);
+	for (j = 0, x = n - 1; x >= 0; x--, j++) {
+		o[j] = (unsigned char)((i & (0xff << x * 8)) >> x * 8);
+	}
+	return (o);
+}
+
+int
+octets2i(unsigned char *ptr, size_t n)
+{
+	size_t i;
+	int val;
+
+	for (val = i = 0; i < n; i++) {
+		val |= (*ptr++ << ((n - i - 1) * 8));
+	}
+	return (val);
+}
+
+/**
+ * @brief decode packet tag
+ *
+ * Also indicate if new/old and in the later case
+ * the length type
+ *
+ * @sa rfc4880:4.2
+ */
+int
+decode_tag(unsigned char *ptr, int *isnew, int *ltype)
+{
+	int tag;
+
+	if (!ptr || !isnew || !ltype)
+		return (-1);
+	tag = *ptr;
+
+	if (!(tag & OPENPGP_TAG_ISTAG))
+		return (-1);		/* we are lost! */
+	*isnew = tag & OPENPGP_TAG_ISNEW;
+	if (*isnew) {
+		*ltype = -1;		/* irrelevant */
+		tag &= OPENPGP_TAG_NEW_MASK;
+	} else {
+		*ltype = tag & OPENPGP_TAG_OLD_TYPE;
+		tag = (tag & OPENPGP_TAG_OLD_MASK) >> 2;
+	}
+	return (tag);
+}
+
+/**
+ * @brief return packet length
+ *
+ * @sa rfc4880:4.2.2
+ */
+static int
+decode_new_len(unsigned char **pptr)
+{
+	unsigned char *ptr;
+	int len = -1;
+
+	if (pptr == NULL)
+		return (-1);
+	ptr = *pptr;
+
+	if (!(*ptr < 224 || *ptr == 255))
+		return (-1);		/* not supported */
+
+	if (*ptr < 192)
+		len = *ptr++;
+	else if (*ptr < 224) {
+		len = ((*ptr - 192) << 8) + *(ptr+1) + 192;
+		ptr++;
+	} else if (*ptr == 255) {
+		len = (*ptr++ << 24);
+		len |= (*ptr++ << 16);
+		len |= (*ptr++ < 8);
+		len |= *ptr++;
+	}
+
+	*pptr = ptr;
+	return (len);
+}
+
+/**
+ * @brief return packet length
+ *
+ * @sa rfc4880:4.2.1
+ */
+static int
+decode_len(unsigned char **pptr, int ltype)
+{
+	unsigned char *ptr;
+	int len;
+
+	if (ltype < 0)
+		return (decode_new_len(pptr));
+
+	if (pptr == NULL)
+		return (-1);
+
+	ptr = *pptr;
+
+	switch (ltype) {
+	case 0:
+		len = *ptr++;
+		break;
+	case 1:
+		len = (*ptr++ << 8);
+		len |= *ptr++;
+		break;
+	case 2:
+		len =  *ptr++ << 24;
+		len |= *ptr++ << 16;
+		len |= *ptr++ << 8;
+		len |= *ptr++;
+		break;
+	case 3:
+	default:
+		/* Not supported */
+		len = -1;
+	}
+
+	*pptr = ptr;
+	return (len);
+}
+
+/**
+ * @brief return pointer and length of an mpi
+ *
+ * @sa rfc4880:3.2
+ */
+unsigned char *
+decode_mpi(unsigned char **pptr, size_t *sz)
+{
+	unsigned char *data;
+	unsigned char *ptr;
+	size_t mlen;
+
+	if (pptr == NULL || sz == NULL)
+		return (NULL);
+
+	ptr = *pptr;
+
+	mlen = (size_t)(*ptr++ << 8);
+	mlen |= (size_t)*ptr++;		/* number of bits */
+	mlen = (mlen + 7) / 8;		/* number of bytes */
+	*sz = mlen;
+	data = ptr;
+	ptr += mlen;
+	*pptr = ptr;
+	return (data);
+}
+
+/**
+ * @brief return an OpenSSL BIGNUM from mpi
+ *
+ * @sa rfc4880:3.2
+ */
+#ifdef USE_BEARSSL
+unsigned char *
+mpi2bn(unsigned char **pptr, size_t *sz)
+{
+	return (decode_mpi(pptr, sz));
+}
+#else
+BIGNUM *
+mpi2bn(unsigned char **pptr)
+{
+	BIGNUM *bn = NULL;
+	unsigned char *ptr;
+	int mlen;
+
+	if (pptr == NULL)
+		return (NULL);
+
+	ptr = *pptr;
+
+	mlen = (*ptr++ << 8);
+	mlen |= *ptr++;			/* number of bits */
+	mlen = (mlen + 7) / 8;		/* number of bytes */
+	bn = BN_bin2bn(ptr, mlen, NULL);
+	ptr += mlen;
+	*pptr = ptr;
+
+	return (bn);
+}
+#endif
+
+/**
+ * @brief decode a packet
+ *
+ * If want is set, check that the packet tag matches
+ * if all good, call the provided decoder with its arg
+ *
+ * @return count of unconsumed data
+ *
+ * @sa rfc4880:4.2
+ */
+int
+decode_packet(int want, unsigned char **pptr, size_t nbytes,
+    decoder_t decoder, void *decoder_arg)
+{
+	int tag;
+	unsigned char *ptr;
+	unsigned char *nptr;
+	int isnew, ltype;
+	int len;
+	int hlen;
+	int rc = 0;
+
+	nptr = ptr = *pptr;
+
+	tag = decode_tag(ptr, &isnew, &ltype);
+
+	if (want > 0 && tag != want)
+		return (-1);
+	ptr++;
+
+	len = rc = decode_len(&ptr, ltype);
+	hlen = (int)(ptr - nptr);
+	nptr = ptr + len;		/* consume it */
+
+	if (decoder)
+		rc = decoder(tag, &ptr, len, decoder_arg);
+	*pptr = nptr;
+	nbytes -= (size_t)(hlen + len);
+	if (rc < 0)
+		return (rc);		/* error */
+	return ((int)nbytes);		/* unconsumed data */
+}
+
+/**
+ * @brief decode a sub packet
+ *
+ * @sa rfc4880:5.2.3.1
+ */
+unsigned char *
+decode_subpacket(unsigned char **pptr, int *stag, int *sz)
+{
+	unsigned char *ptr;
+	int len;
+
+	ptr = *pptr;
+	len = decode_len(&ptr, -1);
+	*sz = (int)(len + ptr - *pptr);
+	*pptr = ptr + len;
+	*stag = *ptr++;
+	return (ptr);
+}