12 files changed, 802 insertions, 34 deletions

diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index 2b221b915a..6369bafac0 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -49,4 +49,7 @@ config PKCS7_MESSAGE_PARSER
 	  This option provides support for parsing PKCS#7 format messages for
 	  signature data and provides the ability to verify the signature.
 
+config PKCS7_VERIFY
+	bool
+
 endif # ASYMMETRIC_KEY_TYPE
diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index 8267fee0a7..f3a414525d 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_PKCS7_MESSAGE_PARSER) += pkcs7_message.o
 pkcs7_message-y := \
 	pkcs7.asn1.o \
 	pkcs7_parser.o
+obj-$(CONFIG_PKCS7_VERIFY) += pkcs7_verify.o
 
 $(obj)/pkcs7_parser.o: $(obj)/pkcs7.asn1.h
 $(obj)/pkcs7.asn1.o: $(obj)/pkcs7.asn1.c $(obj)/pkcs7.asn1.h
diff --git a/lib/crypto/pkcs7_verify.c b/lib/crypto/pkcs7_verify.c
new file mode 100644
index 0000000000..320ba49f79
--- /dev/null
+++ b/lib/crypto/pkcs7_verify.c
@@ -0,0 +1,657 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Verify the signature on a PKCS#7 message.
+ *
+ * Imported from crypto/asymmetric_keys/pkcs7_verify.c of linux 5.7
+ * with modification marked as __UBOOT__.
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) "PKCS7: "fmt
+#ifdef __UBOOT__
+#include <image.h>
+#include <string.h>
+#include <linux/bitops.h>
+#include <linux/compat.h>
+#include <linux/asn1.h>
+#include <u-boot/rsa-checksum.h>
+#include <crypto/public_key.h>
+#include <crypto/pkcs7_parser.h>
+#else
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/asn1.h>
+#include <crypto/hash.h>
+#include <crypto/hash_info.h>
+#include <crypto/public_key.h>
+#include "pkcs7_parser.h"
+#endif
+
+/*
+ * pkcs7_digest - Digest the relevant parts of the PKCS#7 data
+ * @pkcs7:	PKCS7 Signed Data
+ * @sinfo:	PKCS7 Signed Info
+ *
+ * Digest the relevant parts of the PKCS#7 data, @pkcs7, using signature
+ * information in @sinfo. But if there are authentication attributes,
+ * i.e. signed image case, the digest must be calculated against
+ * the authentication attributes.
+ *
+ * Return:	0 - on success, non-zero error code - otherwise
+ */
+#ifdef __UBOOT__
+static int pkcs7_digest(struct pkcs7_message *pkcs7,
+			struct pkcs7_signed_info *sinfo)
+{
+	struct public_key_signature *sig = sinfo->sig;
+	struct image_region regions[2];
+	int ret = 0;
+
+	/* The digest was calculated already. */
+	if (sig->digest)
+		return 0;
+
+	if (!sinfo->sig->hash_algo)
+		return -ENOPKG;
+	if (!strcmp(sinfo->sig->hash_algo, "sha256"))
+		sig->digest_size = SHA256_SUM_LEN;
+	else if (!strcmp(sinfo->sig->hash_algo, "sha1"))
+		sig->digest_size = SHA1_SUM_LEN;
+	else
+		return -ENOPKG;
+
+	sig->digest = calloc(1, sig->digest_size);
+	if (!sig->digest) {
+		pr_warn("Sig %u: Out of memory\n", sinfo->index);
+		return -ENOMEM;
+	}
+
+	regions[0].data = pkcs7->data;
+	regions[0].size = pkcs7->data_len;
+
+	/* Digest the message [RFC2315 9.3] */
+	hash_calculate(sinfo->sig->hash_algo, regions, 1, sig->digest);
+
+	/* However, if there are authenticated attributes, there must be a
+	 * message digest attribute amongst them which corresponds to the
+	 * digest we just calculated.
+	 */
+	if (sinfo->authattrs) {
+		u8 tag;
+
+		if (!sinfo->msgdigest) {
+			pr_warn("Sig %u: No messageDigest\n", sinfo->index);
+			ret = -EKEYREJECTED;
+			goto error;
+		}
+
+		if (sinfo->msgdigest_len != sig->digest_size) {
+			pr_debug("Sig %u: Invalid digest size (%u)\n",
+				 sinfo->index, sinfo->msgdigest_len);
+			ret = -EBADMSG;
+			goto error;
+		}
+
+		if (memcmp(sig->digest, sinfo->msgdigest,
+			   sinfo->msgdigest_len) != 0) {
+			pr_debug("Sig %u: Message digest doesn't match\n",
+				 sinfo->index);
+			ret = -EKEYREJECTED;
+			goto error;
+		}
+
+		/* We then calculate anew, using the authenticated attributes
+		 * as the contents of the digest instead.  Note that we need to
+		 * convert the attributes from a CONT.0 into a SET before we
+		 * hash it.
+		 */
+		memset(sig->digest, 0, sig->digest_size);
+
+		tag = 0x31;
+		regions[0].data = &tag;
+		regions[0].size = 1;
+		regions[1].data = sinfo->authattrs;
+		regions[1].size = sinfo->authattrs_len;
+
+		hash_calculate(sinfo->sig->hash_algo, regions, 2, sig->digest);
+
+		ret = 0;
+	}
+error:
+	return ret;
+}
+#else /* !__UBOOT__ */
+static int pkcs7_digest(struct pkcs7_message *pkcs7,
+			struct pkcs7_signed_info *sinfo)
+{
+	struct public_key_signature *sig = sinfo->sig;
+	struct crypto_shash *tfm;
+	struct shash_desc *desc;
+	size_t desc_size;
+	int ret;
+
+	kenter(",%u,%s", sinfo->index, sinfo->sig->hash_algo);
+
+	/* The digest was calculated already. */
+	if (sig->digest)
+		return 0;
+
+	if (!sinfo->sig->hash_algo)
+		return -ENOPKG;
+
+	/* Allocate the hashing algorithm we're going to need and find out how
+	 * big the hash operational data will be.
+	 */
+	tfm = crypto_alloc_shash(sinfo->sig->hash_algo, 0, 0);
+	if (IS_ERR(tfm))
+		return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm);
+
+	desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
+	sig->digest_size = crypto_shash_digestsize(tfm);
+
+	ret = -ENOMEM;
+	sig->digest = kmalloc(sig->digest_size, GFP_KERNEL);
+	if (!sig->digest)
+		goto error_no_desc;
+
+	desc = kzalloc(desc_size, GFP_KERNEL);
+	if (!desc)
+		goto error_no_desc;
+
+	desc->tfm   = tfm;
+
+	/* Digest the message [RFC2315 9.3] */
+	ret = crypto_shash_digest(desc, pkcs7->data, pkcs7->data_len,
+				  sig->digest);
+	if (ret < 0)
+		goto error;
+	pr_devel("MsgDigest = [%*ph]\n", 8, sig->digest);
+
+	/* However, if there are authenticated attributes, there must be a
+	 * message digest attribute amongst them which corresponds to the
+	 * digest we just calculated.
+	 */
+	if (sinfo->authattrs) {
+		u8 tag;
+
+		if (!sinfo->msgdigest) {
+			pr_warn("Sig %u: No messageDigest\n", sinfo->index);
+			ret = -EKEYREJECTED;
+			goto error;
+		}
+
+		if (sinfo->msgdigest_len != sig->digest_size) {
+			pr_debug("Sig %u: Invalid digest size (%u)\n",
+				 sinfo->index, sinfo->msgdigest_len);
+			ret = -EBADMSG;
+			goto error;
+		}
+
+		if (memcmp(sig->digest, sinfo->msgdigest,
+			   sinfo->msgdigest_len) != 0) {
+			pr_debug("Sig %u: Message digest doesn't match\n",
+				 sinfo->index);
+			ret = -EKEYREJECTED;
+			goto error;
+		}
+
+		/* We then calculate anew, using the authenticated attributes
+		 * as the contents of the digest instead.  Note that we need to
+		 * convert the attributes from a CONT.0 into a SET before we
+		 * hash it.
+		 */
+		memset(sig->digest, 0, sig->digest_size);
+
+		ret = crypto_shash_init(desc);
+		if (ret < 0)
+			goto error;
+		tag = ASN1_CONS_BIT | ASN1_SET;
+		ret = crypto_shash_update(desc, &tag, 1);
+		if (ret < 0)
+			goto error;
+		ret = crypto_shash_finup(desc, sinfo->authattrs,
+					 sinfo->authattrs_len, sig->digest);
+		if (ret < 0)
+			goto error;
+		pr_devel("AADigest = [%*ph]\n", 8, sig->digest);
+	}
+
+error:
+	kfree(desc);
+error_no_desc:
+	crypto_free_shash(tfm);
+	kleave(" = %d", ret);
+	return ret;
+}
+
+int pkcs7_get_digest(struct pkcs7_message *pkcs7, const u8 **buf, u32 *len,
+		     enum hash_algo *hash_algo)
+{
+	struct pkcs7_signed_info *sinfo = pkcs7->signed_infos;
+	int i, ret;
+
+	/*
+	 * This function doesn't support messages with more than one signature.
+	 */
+	if (sinfo == NULL || sinfo->next != NULL)
+		return -EBADMSG;
+
+	ret = pkcs7_digest(pkcs7, sinfo);
+	if (ret)
+		return ret;
+
+	*buf = sinfo->sig->digest;
+	*len = sinfo->sig->digest_size;
+
+	for (i = 0; i < HASH_ALGO__LAST; i++)
+		if (!strcmp(hash_algo_name[i], sinfo->sig->hash_algo)) {
+			*hash_algo = i;
+			break;
+		}
+
+	return 0;
+}
+#endif /* !__UBOOT__ */
+
+/*
+ * Find the key (X.509 certificate) to use to verify a PKCS#7 message.  PKCS#7
+ * uses the issuer's name and the issuing certificate serial number for
+ * matching purposes.  These must match the certificate issuer's name (not
+ * subject's name) and the certificate serial number [RFC 2315 6.7].
+ */
+static int pkcs7_find_key(struct pkcs7_message *pkcs7,
+			  struct pkcs7_signed_info *sinfo)
+{
+	struct x509_certificate *x509;
+	unsigned certix = 1;
+
+	kenter("%u", sinfo->index);
+
+	for (x509 = pkcs7->certs; x509; x509 = x509->next, certix++) {
+		/* I'm _assuming_ that the generator of the PKCS#7 message will
+		 * encode the fields from the X.509 cert in the same way in the
+		 * PKCS#7 message - but I can't be 100% sure of that.  It's
+		 * possible this will need element-by-element comparison.
+		 */
+		if (!asymmetric_key_id_same(x509->id, sinfo->sig->auth_ids[0]))
+			continue;
+		pr_devel("Sig %u: Found cert serial match X.509[%u]\n",
+			 sinfo->index, certix);
+
+		if (strcmp(x509->pub->pkey_algo, sinfo->sig->pkey_algo) != 0) {
+			pr_warn("Sig %u: X.509 algo and PKCS#7 sig algo don't match\n",
+				sinfo->index);
+			continue;
+		}
+
+		sinfo->signer = x509;
+		return 0;
+	}
+
+	/* The relevant X.509 cert isn't found here, but it might be found in
+	 * the trust keyring.
+	 */
+	pr_debug("Sig %u: Issuing X.509 cert not found (#%*phN)\n",
+		 sinfo->index,
+		 sinfo->sig->auth_ids[0]->len, sinfo->sig->auth_ids[0]->data);
+	return 0;
+}
+
+/*
+ * pkcs7_verify_sig_chain - Verify the internal certificate chain as best
+ *                          as we can.
+ * @pkcs7:	PKCS7 Signed Data
+ * @sinfo:	PKCS7 Signed Info
+ * @signer:	Singer's certificate
+ *
+ * Build up and verify the internal certificate chain against a signature
+ * in @sinfo, using certificates contained in @pkcs7 as best as we can.
+ * If the chain reaches the end, the last certificate will be returned
+ * in @signer.
+ *
+ * Return:	0 - on success, non-zero error code - otherwise
+ */
+#ifdef __UBOOT__
+static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
+				  struct pkcs7_signed_info *sinfo,
+				  struct x509_certificate **signer)
+#else
+static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
+				  struct pkcs7_signed_info *sinfo)
+#endif
+{
+	struct public_key_signature *sig;
+	struct x509_certificate *x509 = sinfo->signer, *p;
+	struct asymmetric_key_id *auth;
+	int ret;
+
+	kenter("");
+
+	*signer = NULL;
+
+	for (p = pkcs7->certs; p; p = p->next)
+		p->seen = false;
+
+	for (;;) {
+		pr_debug("verify %s: %*phN\n",
+			 x509->subject,
+			 x509->raw_serial_size, x509->raw_serial);
+		x509->seen = true;
+
+		if (x509->blacklisted) {
+			/* If this cert is blacklisted, then mark everything
+			 * that depends on this as blacklisted too.
+			 */
+			sinfo->blacklisted = true;
+			for (p = sinfo->signer; p != x509; p = p->signer)
+				p->blacklisted = true;
+			pr_debug("- blacklisted\n");
+#ifdef __UBOOT__
+			*signer = x509;
+#endif
+			return 0;
+		}
+
+		if (x509->unsupported_key)
+			goto unsupported_crypto_in_x509;
+
+		pr_debug("- issuer %s\n", x509->issuer);
+		sig = x509->sig;
+		if (sig->auth_ids[0])
+			pr_debug("- authkeyid.id %*phN\n",
+				 sig->auth_ids[0]->len, sig->auth_ids[0]->data);
+		if (sig->auth_ids[1])
+			pr_debug("- authkeyid.skid %*phN\n",
+				 sig->auth_ids[1]->len, sig->auth_ids[1]->data);
+
+		if (x509->self_signed) {
+			/* If there's no authority certificate specified, then
+			 * the certificate must be self-signed and is the root
+			 * of the chain.  Likewise if the cert is its own
+			 * authority.
+			 */
+			if (x509->unsupported_sig)
+				goto unsupported_crypto_in_x509;
+			x509->signer = x509;
+			pr_debug("- self-signed\n");
+#ifdef __UBOOT__
+			*signer = x509;
+#endif
+			return 0;
+		}
+
+		/* Look through the X.509 certificates in the PKCS#7 message's
+		 * list to see if the next one is there.
+		 */
+		auth = sig->auth_ids[0];
+		if (auth) {
+			pr_debug("- want %*phN\n", auth->len, auth->data);
+			for (p = pkcs7->certs; p; p = p->next) {
+				pr_debug("- cmp [%u] %*phN\n",
+					 p->index, p->id->len, p->id->data);
+				if (asymmetric_key_id_same(p->id, auth))
+					goto found_issuer_check_skid;
+			}
+		} else if (sig->auth_ids[1]) {
+			auth = sig->auth_ids[1];
+			pr_debug("- want %*phN\n", auth->len, auth->data);
+			for (p = pkcs7->certs; p; p = p->next) {
+				if (!p->skid)
+					continue;
+				pr_debug("- cmp [%u] %*phN\n",
+					 p->index, p->skid->len, p->skid->data);
+				if (asymmetric_key_id_same(p->skid, auth))
+					goto found_issuer;
+			}
+		}
+
+		/* We didn't find the root of this chain */
+		pr_debug("- top\n");
+#ifdef __UBOOT__
+		*signer = x509;
+#endif
+		return 0;
+
+	found_issuer_check_skid:
+		/* We matched issuer + serialNumber, but if there's an
+		 * authKeyId.keyId, that must match the CA subjKeyId also.
+		 */
+		if (sig->auth_ids[1] &&
+		    !asymmetric_key_id_same(p->skid, sig->auth_ids[1])) {
+			pr_warn("Sig %u: X.509 chain contains auth-skid nonmatch (%u->%u)\n",
+				sinfo->index, x509->index, p->index);
+			return -EKEYREJECTED;
+		}
+	found_issuer:
+		pr_debug("- subject %s\n", p->subject);
+		if (p->seen) {
+			pr_warn("Sig %u: X.509 chain contains loop\n",
+				sinfo->index);
+#ifdef __UBOOT__
+			*signer = p;
+#endif
+			return 0;
+		}
+		ret = public_key_verify_signature(p->pub, x509->sig);
+		if (ret < 0)
+			return ret;
+		x509->signer = p;
+		if (x509 == p) {
+			pr_debug("- self-signed\n");
+#ifdef __UBOOT__
+			*signer = p;
+#endif
+			return 0;
+		}
+		x509 = p;
+#ifndef __UBOOT__
+		might_sleep();
+#endif
+	}
+
+unsupported_crypto_in_x509:
+	/* Just prune the certificate chain at this point if we lack some
+	 * crypto module to go further.  Note, however, we don't want to set
+	 * sinfo->unsupported_crypto as the signed info block may still be
+	 * validatable against an X.509 cert lower in the chain that we have a
+	 * trusted copy of.
+	 */
+	return 0;
+}
+
+/*
+ * pkcs7_verify_one - Verify one signed information block from a PKCS#7
+ *                    message.
+ * @pkcs7:	PKCS7 Signed Data
+ * @sinfo:	PKCS7 Signed Info
+ * @signer:	Signer's certificate
+ *
+ * Verify one signature in @sinfo and follow the certificate chain.
+ * If the chain reaches the end, the last certificate will be returned
+ * in @signer.
+ *
+ * Return:	0 - on success, non-zero error code - otherwise
+ */
+#ifdef __UBOOT__
+int pkcs7_verify_one(struct pkcs7_message *pkcs7,
+		     struct pkcs7_signed_info *sinfo,
+		     struct x509_certificate **signer)
+#else
+static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
+			    struct pkcs7_signed_info *sinfo)
+#endif
+{
+	int ret;
+
+	kenter(",%u", sinfo->index);
+
+	/* First of all, digest the data in the PKCS#7 message and the
+	 * signed information block
+	 */
+	ret = pkcs7_digest(pkcs7, sinfo);
+	if (ret < 0)
+		return ret;
+
+	/* Find the key for the signature if there is one */
+	ret = pkcs7_find_key(pkcs7, sinfo);
+	if (ret < 0)
+		return ret;
+
+	if (!sinfo->signer)
+		return 0;
+
+	pr_devel("Using X.509[%u] for sig %u\n",
+		 sinfo->signer->index, sinfo->index);
+
+	/* Check that the PKCS#7 signing time is valid according to the X.509
+	 * certificate.  We can't, however, check against the system clock
+	 * since that may not have been set yet and may be wrong.
+	 */
+	if (test_bit(sinfo_has_signing_time, &sinfo->aa_set)) {
+		if (sinfo->signing_time < sinfo->signer->valid_from ||
+		    sinfo->signing_time > sinfo->signer->valid_to) {
+			pr_warn("Message signed outside of X.509 validity window\n");
+			return -EKEYREJECTED;
+		}
+	}
+
+	/* Verify the PKCS#7 binary against the key */
+	ret = public_key_verify_signature(sinfo->signer->pub, sinfo->sig);
+	if (ret < 0)
+		return ret;
+
+	pr_devel("Verified signature %u\n", sinfo->index);
+
+	/* Verify the internal certificate chain */
+	return pkcs7_verify_sig_chain(pkcs7, sinfo, signer);
+}
+
+#ifndef __UBOOT__
+/**
+ * pkcs7_verify - Verify a PKCS#7 message
+ * @pkcs7: The PKCS#7 message to be verified
+ * @usage: The use to which the key is being put
+ *
+ * Verify a PKCS#7 message is internally consistent - that is, the data digest
+ * matches the digest in the AuthAttrs and any signature in the message or one
+ * of the X.509 certificates it carries that matches another X.509 cert in the
+ * message can be verified.
+ *
+ * This does not look to match the contents of the PKCS#7 message against any
+ * external public keys.
+ *
+ * Returns, in order of descending priority:
+ *
+ *  (*) -EKEYREJECTED if a key was selected that had a usage restriction at
+ *      odds with the specified usage, or:
+ *
+ *  (*) -EKEYREJECTED if a signature failed to match for which we found an
+ *	appropriate X.509 certificate, or:
+ *
+ *  (*) -EBADMSG if some part of the message was invalid, or:
+ *
+ *  (*) 0 if a signature chain passed verification, or:
+ *
+ *  (*) -EKEYREJECTED if a blacklisted key was encountered, or:
+ *
+ *  (*) -ENOPKG if none of the signature chains are verifiable because suitable
+ *	crypto modules couldn't be found.
+ */
+int pkcs7_verify(struct pkcs7_message *pkcs7,
+		 enum key_being_used_for usage)
+{
+	struct pkcs7_signed_info *sinfo;
+	int actual_ret = -ENOPKG;
+	int ret;
+
+	kenter("");
+
+	switch (usage) {
+	case VERIFYING_MODULE_SIGNATURE:
+		if (pkcs7->data_type != OID_data) {
+			pr_warn("Invalid module sig (not pkcs7-data)\n");
+			return -EKEYREJECTED;
+		}
+		if (pkcs7->have_authattrs) {
+			pr_warn("Invalid module sig (has authattrs)\n");
+			return -EKEYREJECTED;
+		}
+		break;
+	case VERIFYING_FIRMWARE_SIGNATURE:
+		if (pkcs7->data_type != OID_data) {
+			pr_warn("Invalid firmware sig (not pkcs7-data)\n");
+			return -EKEYREJECTED;
+		}
+		if (!pkcs7->have_authattrs) {
+			pr_warn("Invalid firmware sig (missing authattrs)\n");
+			return -EKEYREJECTED;
+		}
+		break;
+	case VERIFYING_KEXEC_PE_SIGNATURE:
+		if (pkcs7->data_type != OID_msIndirectData) {
+			pr_warn("Invalid kexec sig (not Authenticode)\n");
+			return -EKEYREJECTED;
+		}
+		/* Authattr presence checked in parser */
+		break;
+	case VERIFYING_UNSPECIFIED_SIGNATURE:
+		if (pkcs7->data_type != OID_data) {
+			pr_warn("Invalid unspecified sig (not pkcs7-data)\n");
+			return -EKEYREJECTED;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) {
+		ret = pkcs7_verify_one(pkcs7, sinfo);
+		if (sinfo->blacklisted) {
+			if (actual_ret == -ENOPKG)
+				actual_ret = -EKEYREJECTED;
+			continue;
+		}
+		if (ret < 0) {
+			if (ret == -ENOPKG) {
+				sinfo->unsupported_crypto = true;
+				continue;
+			}
+			kleave(" = %d", ret);
+			return ret;
+		}
+		actual_ret = 0;
+	}
+
+	kleave(" = %d", actual_ret);
+	return actual_ret;
+}
+EXPORT_SYMBOL_GPL(pkcs7_verify);
+
+/**
+ * pkcs7_supply_detached_data - Supply the data needed to verify a PKCS#7 message
+ * @pkcs7: The PKCS#7 message
+ * @data: The data to be verified
+ * @datalen: The amount of data
+ *
+ * Supply the detached data needed to verify a PKCS#7 message.  Note that no
+ * attempt to retain/pin the data is made.  That is left to the caller.  The
+ * data will not be modified by pkcs7_verify() and will not be freed when the
+ * PKCS#7 message is freed.
+ *
+ * Returns -EINVAL if data is already supplied in the message, 0 otherwise.
+ */
+int pkcs7_supply_detached_data(struct pkcs7_message *pkcs7,
+			       const void *data, size_t datalen)
+{
+	if (pkcs7->data) {
+		pr_debug("Data already supplied\n");
+		return -EINVAL;
+	}
+	pkcs7->data = data;
+	pkcs7->data_len = datalen;
+	return 0;
+}
+#endif /* __UBOOT__ */
diff --git a/lib/crypto/public_key.c b/lib/crypto/public_key.c
index e12ebbb3d0..a8f7fbed45 100644
--- a/lib/crypto/public_key.c
+++ b/lib/crypto/public_key.c
@@ -25,7 +25,10 @@
 #include <keys/asymmetric-subtype.h>
 #endif
 #include <crypto/public_key.h>
-#ifndef __UBOOT__
+#ifdef __UBOOT__
+#include <image.h>
+#include <u-boot/rsa.h>
+#else
 #include <crypto/akcipher.h>
 #endif
 
@@ -80,6 +83,71 @@ void public_key_signature_free(struct public_key_signature *sig)
 }
 EXPORT_SYMBOL_GPL(public_key_signature_free);
 
+/**
+ * public_key_verify_signature - Verify a signature using a public key.
+ *
+ * @pkey:	Public key
+ * @sig:	Signature
+ *
+ * Verify a signature, @sig, using a RSA public key, @pkey.
+ *
+ * Return:	0 - verified, non-zero error code - otherwise
+ */
+int public_key_verify_signature(const struct public_key *pkey,
+				const struct public_key_signature *sig)
+{
+	struct image_sign_info info;
+	struct image_region region;
+	int ret;
+
+	pr_devel("==>%s()\n", __func__);
+
+	if (!pkey || !sig)
+		return -EINVAL;
+
+	if (pkey->key_is_private)
+		return -EINVAL;
+
+	memset(&info, '\0', sizeof(info));
+	info.padding = image_get_padding_algo("pkcs-1.5");
+	/*
+	 * Note: image_get_[checksum|crypto]_algo takes a string
+	 * argument like "<checksum>,<crypto>"
+	 * TODO: support other hash algorithms
+	 */
+	if (strcmp(sig->pkey_algo, "rsa") || (sig->s_size * 8) != 2048) {
+		pr_warn("Encryption is not RSA2048: %s%d\n",
+			sig->pkey_algo, sig->s_size * 8);
+		return -ENOPKG;
+	}
+	if (!strcmp(sig->hash_algo, "sha1")) {
+		info.checksum = image_get_checksum_algo("sha1,rsa2048");
+		info.name = "sha1,rsa2048";
+	} else if (!strcmp(sig->hash_algo, "sha256")) {
+		info.checksum = image_get_checksum_algo("sha256,rsa2048");
+		info.name = "sha256,rsa2048";
+	} else {
+		pr_warn("unknown msg digest algo: %s\n", sig->hash_algo);
+		return -ENOPKG;
+	}
+	info.crypto = image_get_crypto_algo(info.name);
+	if (IS_ERR(info.checksum) || IS_ERR(info.crypto))
+		return -ENOPKG;
+
+	info.key = pkey->key;
+	info.keylen = pkey->keylen;
+
+	region.data = sig->digest;
+	region.size = sig->digest_size;
+
+	if (rsa_verify_with_pkey(&info, sig->digest, sig->s, sig->s_size))
+		ret = -EKEYREJECTED;
+	else
+		ret = 0;
+
+	pr_devel("<==%s() = %d\n", __func__, ret);
+	return ret;
+}
 #else
 /*
  * Destroy a public key algorithm key.
diff --git a/lib/crypto/x509_cert_parser.c b/lib/crypto/x509_cert_parser.c
index 5f984b9dfd..eb24349460 100644
--- a/lib/crypto/x509_cert_parser.c
+++ b/lib/crypto/x509_cert_parser.c
@@ -142,12 +142,10 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
 	}
 	cert->id = kid;
 
-#ifndef __UBOOT__
 	/* Detect self-signed certificates */
 	ret = x509_check_for_self_signed(cert);
 	if (ret < 0)
 		goto error_decode;
-#endif
 
 	kfree(ctx);
 	return cert;
diff --git a/lib/crypto/x509_public_key.c b/lib/crypto/x509_public_key.c
index 571af9a0ad..91810a8640 100644
--- a/lib/crypto/x509_public_key.c
+++ b/lib/crypto/x509_public_key.c
@@ -8,6 +8,7 @@
 #define pr_fmt(fmt) "X.509: "fmt
 #ifdef __UBOOT__
 #include <common.h>
+#include <image.h>
 #include <dm/devres.h>
 #include <linux/compat.h>
 #include <linux/err.h>
@@ -18,6 +19,7 @@
 #include <linux/kernel.h>
 #ifdef __UBOOT__
 #include <crypto/x509_parser.h>
+#include <u-boot/rsa-checksum.h>
 #else
 #include <linux/slab.h>
 #include <keys/asymmetric-subtype.h>
@@ -35,7 +37,9 @@
 int x509_get_sig_params(struct x509_certificate *cert)
 {
 	struct public_key_signature *sig = cert->sig;
-#ifndef __UBOOT__
+#ifdef __UBOOT__
+	struct image_region region;
+#else
 	struct crypto_shash *tfm;
 	struct shash_desc *desc;
 	size_t desc_size;
@@ -63,12 +67,25 @@ int x509_get_sig_params(struct x509_certificate *cert)
 	sig->s_size = cert->raw_sig_size;
 
 #ifdef __UBOOT__
-	/*
-	 * Note:
-	 * This part (filling sig->digest) should be implemented if
-	 * x509_check_for_self_signed() is enabled x509_cert_parse().
-	 * Currently, this check won't affect UEFI secure boot.
-	 */
+	if (!sig->hash_algo)
+		return -ENOPKG;
+	if (!strcmp(sig->hash_algo, "sha256"))
+		sig->digest_size = SHA256_SUM_LEN;
+	else if (!strcmp(sig->hash_algo, "sha1"))
+		sig->digest_size = SHA1_SUM_LEN;
+	else
+		return -ENOPKG;
+
+	sig->digest = calloc(1, sig->digest_size);
+	if (!sig->digest)
+		return -ENOMEM;
+
+	region.data = cert->tbs;
+	region.size = cert->tbs_size;
+	hash_calculate(sig->hash_algo, &region, 1, sig->digest);
+
+	/* TODO: is_hash_blacklisted()? */
+
 	ret = 0;
 #else
 	/* Allocate the hashing algorithm we're going to need and find out how
@@ -118,7 +135,6 @@ error:
 	return ret;
 }
 
-#ifndef __UBOOT__
 /*
  * Check for self-signedness in an X.509 cert and if found, check the signature
  * immediately if we can.
@@ -175,6 +191,7 @@ not_self_signed:
 	return 0;
 }
 
+#ifndef __UBOOT__
 /*
  * Attempt to parse a data blob for a key as an X509 certificate.
  */
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 0b16554ba2..d49145fc76 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -104,7 +104,15 @@ int __efi_exit_check(void)
 	return ret;
 }
 
-/* Called from do_bootefi_exec() */
+/**
+ * efi_save_gd() - save global data register
+ *
+ * On the ARM architecture gd is mapped to a fixed register (r9 or x18).
+ * As this register may be overwritten by an EFI payload we save it here
+ * and restore it on every callback entered.
+ *
+ * This function is called after relocation from initr_reloc_global_data().
+ */
 void efi_save_gd(void)
 {
 #ifdef CONFIG_ARM
@@ -112,10 +120,12 @@ void efi_save_gd(void)
 #endif
 }
 
-/*
- * Special case handler for error/abort that just forces things back to u-boot
- * world so we can dump out an abort message, without any care about returning
- * back to UEFI world.
+/**
+ * efi_restore_gd() - restore global data register
+ *
+ * On the ARM architecture gd is mapped to a fixed register (r9 or x18).
+ * Restore it after returning from the UEFI world to the value saved via
+ * efi_save_gd().
  */
 void efi_restore_gd(void)
 {
diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index 670bf2b8ef..7bd1ccec45 100644
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -5,11 +5,14 @@
  *  Copyright (c) 2016 Alexander Graf
  */
 
+#define LOG_CATEGORY LOGC_EFI
+
 #include <common.h>
 #include <blk.h>
 #include <dm.h>
 #include <efi_loader.h>
 #include <fs.h>
+#include <log.h>
 #include <part.h>
 #include <malloc.h>
 
@@ -490,7 +493,7 @@ int efi_disk_create_partitions(efi_handle_t parent, struct blk_desc *desc,
 		ret = efi_disk_add_dev(parent, dp, if_typename, desc, diskid,
 				       info.start, part, NULL);
 		if (ret != EFI_SUCCESS) {
-			printf("Adding partition %s failed\n", pdevname);
+			log_err("Adding partition %s failed\n", pdevname);
 			continue;
 		}
 		disks++;
@@ -528,16 +531,16 @@ efi_status_t efi_disk_register(void)
 		const char *if_typename = blk_get_if_type_name(desc->if_type);
 
 		/* Add block device for the full device */
-		printf("Scanning disk %s...\n", dev->name);
+		log_info("Scanning disk %s...\n", dev->name);
 		ret = efi_disk_add_dev(NULL, NULL, if_typename,
 					desc, desc->devnum, 0, 0, &disk);
 		if (ret == EFI_NOT_READY) {
-			printf("Disk %s not ready\n", dev->name);
+			log_notice("Disk %s not ready\n", dev->name);
 			continue;
 		}
 		if (ret) {
-			printf("ERROR: failure to add disk device %s, r = %lu\n",
-			       dev->name, ret & ~EFI_ERROR_MASK);
+			log_err("ERROR: failure to add disk device %s, r = %lu\n",
+				dev->name, ret & ~EFI_ERROR_MASK);
 			return ret;
 		}
 		disks++;
@@ -560,7 +563,7 @@ efi_status_t efi_disk_register(void)
 			continue;
 
 		if_typename = cur_drvr->if_typename;
-		printf("Scanning disks on %s...\n", if_typename);
+		log_info("Scanning disks on %s...\n", if_typename);
 		for (i = 0; i < 4; i++) {
 			struct blk_desc *desc;
 			char devname[32] = { 0 }; /* dp->str is u16[32] long */
@@ -578,12 +581,12 @@ efi_status_t efi_disk_register(void)
 			ret = efi_disk_add_dev(NULL, NULL, if_typename, desc,
 					       i, 0, 0, &disk);
 			if (ret == EFI_NOT_READY) {
-				printf("Disk %s not ready\n", devname);
+				log_notice("Disk %s not ready\n", devname);
 				continue;
 			}
 			if (ret) {
-				printf("ERROR: failure to add disk device %s, r = %lu\n",
-				       devname, ret & ~EFI_ERROR_MASK);
+				log_err("ERROR: failure to add disk device %s, r = %lu\n",
+					devname, ret & ~EFI_ERROR_MASK);
 				return ret;
 			}
 			disks++;
@@ -595,7 +598,7 @@ efi_status_t efi_disk_register(void)
 		}
 	}
 #endif
-	printf("Found %d disks\n", disks);
+	log_info("Found %d disks\n", disks);
 
 	return EFI_SUCCESS;
 }
diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c
index 19afa69f53..44fafae058 100644
--- a/lib/efi_loader/efi_file.c
+++ b/lib/efi_loader/efi_file.c
@@ -349,6 +349,11 @@ static efi_status_t file_read(struct file_handle *fh, u64 *buffer_size,
 	efi_status_t ret;
 	loff_t file_size;
 
+	if (!buffer) {
+		ret = EFI_INVALID_PARAMETER;
+		return ret;
+	}
+
 	ret = efi_get_file_size(fh, &file_size);
 	if (ret != EFI_SUCCESS)
 		return ret;
@@ -414,6 +419,8 @@ static efi_status_t dir_read(struct file_handle *fh, u64 *buffer_size,
 		fh->dent = dent;
 		return EFI_BUFFER_TOO_SMALL;
 	}
+	if (!buffer)
+		return EFI_INVALID_PARAMETER;
 	fh->dent = NULL;
 
 	*buffer_size = required_size;
@@ -443,7 +450,7 @@ static efi_status_t EFIAPI efi_file_read(struct efi_file_handle *file,
 
 	EFI_ENTRY("%p, %p, %p", file, buffer_size, buffer);
 
-	if (!buffer_size || !buffer) {
+	if (!buffer_size) {
 		ret = EFI_INVALID_PARAMETER;
 		goto error;
 	}
diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
index 91a4551448..78fd8014d9 100644
--- a/lib/efi_loader/efi_runtime.c
+++ b/lib/efi_loader/efi_runtime.c
@@ -144,6 +144,8 @@ efi_status_t efi_init_runtime_supported(void)
  *
  * At runtime memcpy() is not available.
  *
+ * Overlapping memory areas can be copied safely if src >= dest.
+ *
  * @dest:	destination buffer
  * @src:	source buffer
  * @n:		number of bytes to copy
diff --git a/lib/efi_loader/efi_var_mem.c b/lib/efi_loader/efi_var_mem.c
index 7a2dba7dc2..bfa8a56a8f 100644
--- a/lib/efi_loader/efi_var_mem.c
+++ b/lib/efi_loader/efi_var_mem.c
@@ -120,7 +120,8 @@ void __efi_runtime efi_var_mem_del(struct efi_var_entry *var)
 	       ALIGN((uintptr_t)data + var->length, 8);
 	efi_var_buf->length -= (uintptr_t)next - (uintptr_t)var;
 
-	memmove(var, next, (uintptr_t)last - (uintptr_t)next);
+	/* efi_memcpy_runtime() can be used because next >= var. */
+	efi_memcpy_runtime(var, next, (uintptr_t)last - (uintptr_t)next);
 	efi_var_buf->crc32 = crc32(0, (u8 *)efi_var_buf->var,
 				   efi_var_buf->length -
 				   sizeof(struct efi_var_file));
@@ -231,6 +232,7 @@ static void EFIAPI __efi_runtime
 efi_var_mem_notify_virtual_address_map(struct efi_event *event, void *context)
 {
 	efi_convert_pointer(0, (void **)&efi_var_buf);
+	efi_current_var = NULL;
 }
 
 efi_status_t efi_var_mem_init(void)
diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
index c042348938..94c4de8703 100644
--- a/lib/efi_loader/efi_variable_tee.c
+++ b/lib/efi_loader/efi_variable_tee.c
@@ -100,25 +100,25 @@ static efi_status_t optee_mm_communicate(void *comm_buf, ulong dsize)
 	param[1].attr = TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT;
 
 	rc = tee_invoke_func(conn.tee, &arg, 2, param);
-	if (rc)
-		return EFI_INVALID_PARAMETER;
 	tee_shm_free(shm);
 	tee_close_session(conn.tee, conn.session);
+	if (rc || arg.ret != TEE_SUCCESS)
+		return EFI_DEVICE_ERROR;
 
 	switch (param[1].u.value.a) {
-	case ARM_SMC_MM_RET_SUCCESS:
+	case ARM_SVC_SPM_RET_SUCCESS:
 		ret = EFI_SUCCESS;
 		break;
 
-	case ARM_SMC_MM_RET_INVALID_PARAMS:
+	case ARM_SVC_SPM_RET_INVALID_PARAMS:
 		ret = EFI_INVALID_PARAMETER;
 		break;
 
-	case ARM_SMC_MM_RET_DENIED:
+	case ARM_SVC_SPM_RET_DENIED:
 		ret = EFI_ACCESS_DENIED;
 		break;
 
-	case ARM_SMC_MM_RET_NO_MEMORY:
+	case ARM_SVC_SPM_RET_NO_MEMORY:
 		ret = EFI_OUT_OF_RESOURCES;
 		break;