1 files changed, 291 insertions, 0 deletions

diff --git a/lib/libsecureboot/vectx.c b/lib/libsecureboot/vectx.c
new file mode 100644
index 000000000000..879cecac188d
--- /dev/null
+++ b/lib/libsecureboot/vectx.c
@@ -0,0 +1,291 @@
+/*-
+ * 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>
+__FBSDID("$FreeBSD$");
+
+#ifndef _STANDALONE
+/* Avoid unwanted userlandish components */
+#define _KERNEL
+#include <sys/errno.h>
+#undef _KERNEL
+#endif
+
+#include "libsecureboot-priv.h"
+
+/**
+ * @file vectx.c
+ * @brief api to verify file while reading
+ *
+ * This API allows the hash of a file to be computed as it is read.
+ * Key to this is seeking by reading.
+ *
+ * On close an indication of the verification result is returned.
+ */
+
+struct vectx {
+	br_hash_compat_context vec_ctx;	/* hash ctx */
+	const br_hash_class *vec_md;	/* hash method */
+	const char	*vec_path;	/* path we are verifying */
+	const char	*vec_want;	/* hash value we want */
+	off_t		vec_off;	/* current offset */
+	size_t		vec_size;	/* size of path */
+	size_t		vec_hashsz;	/* size of hash */
+	int		vec_fd;		/* file descriptor */
+	int		vec_status;	/* verification status */
+};
+
+/**
+ * @brief
+ * verify an open file as we read it
+ *
+ * If the file has no fingerprint to match, we will still return a
+ * verification context containing little more than the file
+ * descriptor, and an error code in @c error.
+ *
+ * @param[in] fd
+ *	open descriptor
+ *
+ * @param[in] path
+ *	pathname to open
+ *
+ * @param[in] off
+ *	current offset
+ *
+ * @param[in] stp
+ *	pointer to struct stat
+ *
+ * @param[out] error
+ *	@li 0 all is good
+ *	@li ENOMEM out of memory
+ *	@li VE_FINGERPRINT_NONE	no entry found
+ *	@li VE_FINGERPRINT_UNKNOWN no fingerprint in entry
+ *
+ * @return ctx or NULL on error.
+ *	NULL is only returned for non-files or out-of-memory.
+ */
+struct vectx *
+vectx_open(int fd, const char *path, off_t off, struct stat *stp, int *error)
+{
+	struct vectx *ctx;
+	struct stat st;
+	size_t hashsz;
+	char *cp;
+
+	if (!stp) {
+		if (fstat(fd, &st) == 0)
+			stp = &st;
+	}
+
+	/* we *should* only get called for files */
+	if (stp && !S_ISREG(stp->st_mode)) {
+		*error = 0;
+		return (NULL);
+	}
+
+	ctx = malloc(sizeof(struct vectx));
+	if (!ctx)
+		goto enomem;
+	ctx->vec_fd = fd;
+	ctx->vec_path = path;
+	ctx->vec_size = stp->st_size;
+	ctx->vec_off = 0;
+	ctx->vec_want = NULL;
+	ctx->vec_status = 0;
+	hashsz = 0;
+
+	cp = fingerprint_info_lookup(fd, path);
+	if (!cp) {
+		ctx->vec_status = VE_FINGERPRINT_NONE;
+		ve_error_set("%s: no entry", path);
+	} else {
+		if (strncmp(cp, "sha256=", 7) == 0) {
+			ctx->vec_md = &br_sha256_vtable;
+			hashsz = br_sha256_SIZE;
+			cp += 7;
+#ifdef VE_SHA1_SUPPORT
+		} else if (strncmp(cp, "sha1=", 5) == 0) {
+			ctx->vec_md = &br_sha1_vtable;
+			hashsz = br_sha1_SIZE;
+			cp += 5;
+#endif
+#ifdef VE_SHA384_SUPPORT
+		} else if (strncmp(cp, "sha384=", 7) == 0) {
+		    ctx->vec_md = &br_sha384_vtable;
+		    hashsz = br_sha384_SIZE;
+		    cp += 7;
+#endif
+#ifdef VE_SHA512_SUPPORT
+		} else if (strncmp(cp, "sha512=", 7) == 0) {
+		    ctx->vec_md = &br_sha512_vtable;
+		    hashsz = br_sha512_SIZE;
+		    cp += 7;
+#endif
+		} else {
+			ctx->vec_status = VE_FINGERPRINT_UNKNOWN;
+			ve_error_set("%s: no supported fingerprint", path);
+		}
+	}
+	*error = ctx->vec_status;
+	ctx->vec_hashsz = hashsz;
+	ctx->vec_want = cp;
+	ctx->vec_md->init(&ctx->vec_ctx.vtable);
+
+	if (hashsz > 0 && off > 0) {
+		lseek(fd, 0, SEEK_SET);
+		vectx_lseek(ctx, off, SEEK_SET);
+	}
+	return (ctx);
+
+enomem:					/* unlikely */
+	*error = ENOMEM;
+	free(ctx);
+	return (NULL);
+}
+
+/**
+ * @brief
+ * read bytes from file and update hash
+ *
+ * It is critical that all file I/O comes through here.
+ * We keep track of current offset.
+ *
+ * @param[in] pctx
+ *	pointer to ctx
+ *
+ * @param[in] buf
+ *
+ * @param[in] nbytes
+ *
+ * @return bytes read or error.
+ */
+ssize_t
+vectx_read(struct vectx *ctx, void *buf, size_t nbytes)
+{
+	unsigned char *bp = buf;
+	int n;
+	size_t off;
+
+	if (ctx->vec_hashsz == 0)	/* nothing to do */
+		return (read(ctx->vec_fd, buf, nbytes));
+
+	off = 0;
+	do {
+		n = read(ctx->vec_fd, &bp[off], nbytes - off);
+		if (n < 0)
+			return (n);
+		if (n > 0) {
+			ctx->vec_md->update(&ctx->vec_ctx.vtable, &bp[off], n);
+			off += n;
+			ctx->vec_off += n;
+		}
+	} while (n > 0 && off < nbytes);
+	return (off);
+}
+
+/**
+ * @brief
+ * vectx equivalent of lseek
+ *
+ * We do not actually, seek, but call vectx_read
+ * to reach the desired offset.
+ *
+ * We do not support seeking backwards.
+ *
+ * @param[in] pctx
+ *	pointer to ctx
+ *
+ * @param[in] off
+ *	desired offset
+ *
+ * @param[in] whence
+ *
+ * @return offset or error.
+ */
+off_t
+vectx_lseek(struct vectx *ctx, off_t off, int whence)
+{
+	unsigned char buf[PAGE_SIZE];
+	size_t delta;
+	ssize_t n;
+
+	if (ctx->vec_hashsz == 0)	/* nothing to do */
+		return (lseek(ctx->vec_fd, off, whence));
+
+	/*
+	 * Try to convert whence to SEEK_SET
+	 * but we cannot support seeking backwards!
+	 * Nor beyond end of file.
+	 */
+	if (whence == SEEK_END && off <= 0) {
+		whence = SEEK_SET;
+		off += ctx->vec_size;
+	} else if (whence == SEEK_CUR && off >= 0) {
+		whence = SEEK_SET;
+		off += ctx->vec_off;
+	}
+	if (whence != SEEK_SET || off < ctx->vec_off ||
+	    (size_t)off > ctx->vec_size) {
+		printf("ERROR: %s: unsupported operation\n",  __func__);
+		return (-1);
+	}
+	n = 0;
+	do {
+		delta = off - ctx->vec_off;
+		if (delta > 0) {
+			delta = MIN(PAGE_SIZE, delta);
+			n = vectx_read(ctx, buf, delta);
+			if (n < 0)
+				return (n);
+		}
+	} while (ctx->vec_off < off && n > 0);
+	return (ctx->vec_off);
+}
+
+/**
+ * @brief
+ * check that hashes match and cleanup
+ *
+ * We have finished reading file, compare the hash with what
+ * we wanted.
+ *
+ * @param[in] pctx
+ *	pointer to ctx
+ *
+ * @return 0 or an error.
+ */
+int
+vectx_close(struct vectx *ctx)
+{
+	int rc;
+
+	if (ctx->vec_hashsz == 0) {
+		rc = ctx->vec_status;
+	} else {
+		rc = ve_check_hash(&ctx->vec_ctx, ctx->vec_md,
+		    ctx->vec_path, ctx->vec_want, ctx->vec_hashsz);
+	}
+	free(ctx);
+	return ((rc < 0) ? rc : 0);
+}