1 files changed, 401 insertions, 0 deletions
diff --git a/lib/libsecureboot/brf.c b/lib/libsecureboot/brf.c
new file mode 100644
index 000000000000..fbd24f322bee
--- /dev/null
+++ b/lib/libsecureboot/brf.c
@@ -0,0 +1,401 @@
+// The functions here are derrived from BearSSL/tools/*.c
+// When that is refactored suitably we can use them directly.
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <sys/cdefs.h>
+#define NEED_BRSSL_H
+#include "libsecureboot-priv.h"
+#include <brssl.h>
+
+
+static int
+is_ign(int c)
+{
+	if (c == 0) {
+		return (0);
+	}
+	if (c <= 32 || c == '-' || c == '_' || c == '.'
+		|| c == '/' || c == '+' || c == ':')
+	{
+		return (1);
+	}
+	return (0);
+}
+
+/*
+ * Get next non-ignored character, normalised:
+ *    ASCII letters are converted to lowercase
+ *    control characters, space, '-', '_', '.', '/', '+' and ':' are ignored
+ * A terminating zero is returned as 0.
+ */
+static int
+next_char(const char **ps, const char *limit)
+{
+	for (;;) {
+		int c;
+
+		if (*ps == limit) {
+			return (0);
+		}
+		c = *(*ps) ++;
+		if (c == 0) {
+			return (0);
+		}
+		if (c >= 'A' && c <= 'Z') {
+			c += 'a' - 'A';
+		}
+		if (!is_ign(c)) {
+			return (c);
+		}
+	}
+}
+
+/*
+ * Partial string equality comparison, with normalisation.
+ */
+static int
+eqstr_chunk(const char *s1, size_t s1_len, const char *s2, size_t s2_len)
+{
+	const char *lim1, *lim2;
+
+	lim1 = s1 + s1_len;
+	lim2 = s2 + s2_len;
+	for (;;) {
+		int c1, c2;
+
+		c1 = next_char(&s1, lim1);
+		c2 = next_char(&s2, lim2);
+		if (c1 != c2) {
+			return (0);
+		}
+		if (c1 == 0) {
+			return (1);
+		}
+	}
+}
+
+/* see brssl.h */
+int
+eqstr(const char *s1, const char *s2)
+{
+	return (eqstr_chunk(s1, strlen(s1), s2, strlen(s2)));
+}
+
+int
+looks_like_DER(const unsigned char *buf, size_t len)
+{
+	int fb;
+	size_t dlen;
+
+	if (len < 2) {
+		return (0);
+	}
+	if (*buf ++ != 0x30) {
+		return (0);
+	}
+	fb = *buf ++;
+	len -= 2;
+	if (fb < 0x80) {
+		return ((size_t)fb == len);
+	} else if (fb == 0x80) {
+		return (0);
+	} else {
+		fb -= 0x80;
+		if (len < (size_t)fb + 2) {
+			return (0);
+		}
+		len -= (size_t)fb;
+		dlen = 0;
+		while (fb -- > 0) {
+			if (dlen > (len >> 8)) {
+				return (0);
+			}
+			dlen = (dlen << 8) + (size_t)*buf ++;
+		}
+		return (dlen == len);
+	}
+}
+
+static void
+vblob_append(void *cc, const void *data, size_t len)
+{
+	bvector *bv;
+
+	bv = cc;
+	VEC_ADDMANY(*bv, data, len);
+}
+
+void
+free_pem_object_contents(pem_object *po)
+{
+	if (po != NULL) {
+		xfree(po->name);
+		xfree(po->data);
+	}
+}
+
+pem_object *
+decode_pem(const void *src, size_t len, size_t *num)
+{
+	VECTOR(pem_object) pem_list = VEC_INIT;
+	br_pem_decoder_context pc;
+	pem_object po, *pos;
+	const unsigned char *buf;
+	bvector bv = VEC_INIT;
+	int inobj;
+	int extra_nl;
+
+	*num = 0;
+	br_pem_decoder_init(&pc);
+	buf = src;
+	inobj = 0;
+	po.name = NULL;
+	po.data = NULL;
+	po.data_len = 0;
+	extra_nl = 1;
+	while (len > 0) {
+		size_t tlen;
+
+		tlen = br_pem_decoder_push(&pc, buf, len);
+		buf += tlen;
+		len -= tlen;
+		switch (br_pem_decoder_event(&pc)) {
+
+		case BR_PEM_BEGIN_OBJ:
+			po.name = xstrdup(br_pem_decoder_name(&pc));
+			br_pem_decoder_setdest(&pc, vblob_append, &bv);
+			inobj = 1;
+			break;
+
+		case BR_PEM_END_OBJ:
+			if (inobj) {
+				po.data = VEC_TOARRAY(bv);
+				po.data_len = VEC_LEN(bv);
+				VEC_ADD(pem_list, po);
+				VEC_CLEAR(bv);
+				po.name = NULL;
+				po.data = NULL;
+				po.data_len = 0;
+				inobj = 0;
+			}
+			break;
+
+		case BR_PEM_ERROR:
+			xfree(po.name);
+			VEC_CLEAR(bv);
+			ve_error_set("ERROR: invalid PEM encoding");
+			VEC_CLEAREXT(pem_list, &free_pem_object_contents);
+			return (NULL);
+		}
+
+		/*
+		 * We add an extra newline at the end, in order to
+		 * support PEM files that lack the newline on their last
+		 * line (this is somwehat invalid, but PEM format is not
+		 * standardised and such files do exist in the wild, so
+		 * we'd better accept them).
+		 */
+		if (len == 0 && extra_nl) {
+			extra_nl = 0;
+			buf = (const unsigned char *)"\n";
+			len = 1;
+		}
+	}
+	if (inobj) {
+	    ve_error_set("ERROR: unfinished PEM object");
+		xfree(po.name);
+		VEC_CLEAR(bv);
+		VEC_CLEAREXT(pem_list, &free_pem_object_contents);
+		return (NULL);
+	}
+
+	*num = VEC_LEN(pem_list);
+	VEC_ADD(pem_list, po);
+	pos = VEC_TOARRAY(pem_list);
+	VEC_CLEAR(pem_list);
+	return (pos);
+}
+
+br_x509_certificate *
+parse_certificates(unsigned char *buf, size_t len, size_t *num)
+{
+	VECTOR(br_x509_certificate) cert_list = VEC_INIT;
+	pem_object *pos;
+	size_t u, num_pos;
+	br_x509_certificate *xcs;
+	br_x509_certificate dummy;
+
+	*num = 0;
+
+	/*
+	 * Check for a DER-encoded certificate.
+	 */
+	if (looks_like_DER(buf, len)) {
+		xcs = xmalloc(2 * sizeof *xcs);
+		xcs[0].data = buf;
+		xcs[0].data_len = len;
+		xcs[1].data = NULL;
+		xcs[1].data_len = 0;
+		*num = 1;
+		return (xcs);
+	}
+
+	pos = decode_pem(buf, len, &num_pos);
+	if (pos == NULL) {
+		return (NULL);
+	}
+	for (u = 0; u < num_pos; u ++) {
+		if (eqstr(pos[u].name, "CERTIFICATE")
+			|| eqstr(pos[u].name, "X509 CERTIFICATE"))
+		{
+			br_x509_certificate xc;
+
+			xc.data = pos[u].data;
+			xc.data_len = pos[u].data_len;
+			pos[u].data = NULL;
+			VEC_ADD(cert_list, xc);
+		}
+	}
+	for (u = 0; u < num_pos; u ++) {
+		free_pem_object_contents(&pos[u]);
+	}
+	xfree(pos);
+
+	if (VEC_LEN(cert_list) == 0) {
+		return (NULL);
+	}
+	*num = VEC_LEN(cert_list);
+	dummy.data = NULL;
+	dummy.data_len = 0;
+	VEC_ADD(cert_list, dummy);
+	xcs = VEC_TOARRAY(cert_list);
+	VEC_CLEAR(cert_list);
+	return (xcs);
+}
+
+br_x509_certificate *
+read_certificates(const char *fname, size_t *num)
+{
+	br_x509_certificate *xcs;
+	unsigned char *buf;
+	size_t len;
+
+	*num = 0;
+
+	/*
+	 * TODO: reading the whole file is crude; we could parse them
+	 * in a streamed fashion. But it does not matter much in practice.
+	 */
+	buf = read_file(fname, &len);
+	if (buf == NULL) {
+		return (NULL);
+	}
+	xcs = parse_certificates(buf, len, num);
+	if (xcs == NULL) {
+	    ve_error_set("ERROR: no certificate in file '%s'\n", fname);
+	}
+	xfree(buf);
+	return (xcs);
+}
+
+/* see brssl.h */
+void
+free_certificates(br_x509_certificate *certs, size_t num)
+{
+	size_t u;
+
+	for (u = 0; u < num; u ++) {
+		xfree(certs[u].data);
+	}
+	xfree(certs);
+}
+
+
+static void
+dn_append(void *ctx, const void *buf, size_t len)
+{
+	VEC_ADDMANY(*(bvector *)ctx, buf, len);
+}
+
+int
+certificate_to_trust_anchor_inner(br_x509_trust_anchor *ta,
+	br_x509_certificate *xc)
+{
+	br_x509_decoder_context dc;
+	bvector vdn = VEC_INIT;
+	br_x509_pkey *pk;
+
+	br_x509_decoder_init(&dc, dn_append, &vdn);
+	br_x509_decoder_push(&dc, xc->data, xc->data_len);
+	pk = br_x509_decoder_get_pkey(&dc);
+	if (pk == NULL) {
+	    ve_error_set("ERROR: CA decoding failed with error %d\n",
+		      br_x509_decoder_last_error(&dc));
+	    VEC_CLEAR(vdn);
+	    return (-1);
+	}
+	ta->dn.data = VEC_TOARRAY(vdn);
+	ta->dn.len = VEC_LEN(vdn);
+	VEC_CLEAR(vdn);
+	ta->flags = 0;
+	if (br_x509_decoder_isCA(&dc)) {
+		ta->flags |= BR_X509_TA_CA;
+	}
+	switch (pk->key_type) {
+	case BR_KEYTYPE_RSA:
+		ta->pkey.key_type = BR_KEYTYPE_RSA;
+		ta->pkey.key.rsa.n = xblobdup(pk->key.rsa.n, pk->key.rsa.nlen);
+		ta->pkey.key.rsa.nlen = pk->key.rsa.nlen;
+		ta->pkey.key.rsa.e = xblobdup(pk->key.rsa.e, pk->key.rsa.elen);
+		ta->pkey.key.rsa.elen = pk->key.rsa.elen;
+		break;
+	case BR_KEYTYPE_EC:
+		ta->pkey.key_type = BR_KEYTYPE_EC;
+		ta->pkey.key.ec.curve = pk->key.ec.curve;
+		ta->pkey.key.ec.q = xblobdup(pk->key.ec.q, pk->key.ec.qlen);
+		ta->pkey.key.ec.qlen = pk->key.ec.qlen;
+		break;
+	default:
+	    ve_error_set("ERROR: unsupported public key type in CA\n");
+		xfree(ta->dn.data);
+		return (-1);
+	}
+	return (0);
+}
+
+/* see brssl.h */
+void
+free_ta_contents(br_x509_trust_anchor *ta)
+{
+	xfree(ta->dn.data);
+	switch (ta->pkey.key_type) {
+	case BR_KEYTYPE_RSA:
+		xfree(ta->pkey.key.rsa.n);
+		xfree(ta->pkey.key.rsa.e);
+		break;
+	case BR_KEYTYPE_EC:
+		xfree(ta->pkey.key.ec.q);
+		break;
+	}
+}