diff --git a/src/config/config_crypto.c b/src/config/config_crypto.c
index c9d04a890..47b35371b 100644
--- a/src/config/config_crypto.c
+++ b/src/config/config_crypto.c
@@ -169,6 +169,16 @@ REQUIRE_OBJECT ( rsa_sha384 );
 REQUIRE_OBJECT ( rsa_sha512 );
 #endif
 
+/* RSA and SHA-512/224 */
+#if defined ( CRYPTO_PUBKEY_RSA ) && defined ( CRYPTO_DIGEST_SHA512_224 )
+REQUIRE_OBJECT ( rsa_sha512_224 );
+#endif
+
+/* RSA and SHA-512/256 */
+#if defined ( CRYPTO_PUBKEY_RSA ) && defined ( CRYPTO_DIGEST_SHA512_256 )
+REQUIRE_OBJECT ( rsa_sha512_256 );
+#endif
+
 /* RSA, AES-CBC, and SHA-1 */
 #if defined ( CRYPTO_EXCHANGE_PUBKEY ) && defined ( CRYPTO_PUBKEY_RSA ) && \
     defined ( CRYPTO_CIPHER_AES_CBC ) && defined ( CRYPTO_DIGEST_SHA1 )
diff --git a/src/crypto/mishmash/rsa_sha512_224.c b/src/crypto/mishmash/rsa_sha512_224.c
new file mode 100644
index 000000000..ce54a52cf
--- /dev/null
+++ b/src/crypto/mishmash/rsa_sha512_224.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2026 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( PERMITTED );
+
+#include <byteswap.h>
+#include <ipxe/rsa.h>
+#include <ipxe/sha512.h>
+
+/** "sha512-224WithRSAEncryption" object identifier */
+static uint8_t oid_sha512_224_with_rsa_encryption[] =
+	{ ASN1_OID_SHA512_224WITHRSAENCRYPTION };
+
+/** "sha512-224WithRSAEncryption" OID-identified algorithm */
+struct asn1_algorithm
+sha512_224_with_rsa_encryption_algorithm __asn1_algorithm = {
+	.name = "sha512-224WithRSAEncryption",
+	.pubkey = &rsa_algorithm,
+	.digest = &sha512_224_algorithm,
+	.oid = ASN1_CURSOR ( oid_sha512_224_with_rsa_encryption ),
+};
+
+/** SHA-512/224 digestInfo prefix */
+static const uint8_t rsa_sha512_224_prefix_data[] =
+	{ RSA_DIGESTINFO_PREFIX ( SHA512_224_DIGEST_SIZE,
+				  ASN1_OID_SHA512_224 ) };
+
+/** SHA-512/224 digestInfo prefix */
+struct rsa_digestinfo_prefix rsa_sha512_224_prefix __rsa_digestinfo_prefix = {
+	.digest = &sha512_224_algorithm,
+	.data = rsa_sha512_224_prefix_data,
+	.len = sizeof ( rsa_sha512_224_prefix_data ),
+};
diff --git a/src/crypto/mishmash/rsa_sha512_256.c b/src/crypto/mishmash/rsa_sha512_256.c
new file mode 100644
index 000000000..a8cf3cdbc
--- /dev/null
+++ b/src/crypto/mishmash/rsa_sha512_256.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2026 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( PERMITTED );
+
+#include <byteswap.h>
+#include <ipxe/rsa.h>
+#include <ipxe/sha512.h>
+
+/** "sha512-256WithRSAEncryption" object identifier */
+static uint8_t oid_sha512_256_with_rsa_encryption[] =
+	{ ASN1_OID_SHA512_256WITHRSAENCRYPTION };
+
+/** "sha512-256WithRSAEncryption" OID-identified algorithm */
+struct asn1_algorithm
+sha512_256_with_rsa_encryption_algorithm __asn1_algorithm = {
+	.name = "sha512-256WithRSAEncryption",
+	.pubkey = &rsa_algorithm,
+	.digest = &sha512_256_algorithm,
+	.oid = ASN1_CURSOR ( oid_sha512_256_with_rsa_encryption ),
+};
+
+/** SHA-512/256 digestInfo prefix */
+static const uint8_t rsa_sha512_256_prefix_data[] =
+	{ RSA_DIGESTINFO_PREFIX ( SHA512_256_DIGEST_SIZE,
+				  ASN1_OID_SHA512_256 ) };
+
+/** SHA-512/256 digestInfo prefix */
+struct rsa_digestinfo_prefix rsa_sha512_256_prefix __rsa_digestinfo_prefix = {
+	.digest = &sha512_256_algorithm,
+	.data = rsa_sha512_256_prefix_data,
+	.len = sizeof ( rsa_sha512_256_prefix_data ),
+};
diff --git a/src/include/ipxe/asn1.h b/src/include/ipxe/asn1.h
index 649b059d7..0c4854afe 100644
--- a/src/include/ipxe/asn1.h
+++ b/src/include/ipxe/asn1.h
@@ -212,6 +212,18 @@ struct asn1_builder_header {
 	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
 	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 14 )
 
+/** ASN.1 OID for sha512-224WithRSAEncryption (1.2.840.113549.1.1.15) */
+#define ASN1_OID_SHA512_224WITHRSAENCRYPTION			\
+	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
+	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
+	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 15 )
+
+/** ASN.1 OID for sha512-256WithRSAEncryption (1.2.840.113549.1.1.16) */
+#define ASN1_OID_SHA512_256WITHRSAENCRYPTION			\
+	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
+	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
+	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 16 )
+
 /** ASN.1 OID for id-md4 (1.2.840.113549.2.4) */
 #define ASN1_OID_MD4						\
 	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
@@ -448,13 +460,17 @@ extern struct asn1_algorithm md5_with_rsa_encryption_algorithm __asn1_algorithm;
 extern struct asn1_algorithm
 sha1_with_rsa_encryption_algorithm __asn1_algorithm;
 extern struct asn1_algorithm
+sha224_with_rsa_encryption_algorithm __asn1_algorithm;
+extern struct asn1_algorithm
 sha256_with_rsa_encryption_algorithm __asn1_algorithm;
 extern struct asn1_algorithm
 sha384_with_rsa_encryption_algorithm __asn1_algorithm;
 extern struct asn1_algorithm
 sha512_with_rsa_encryption_algorithm __asn1_algorithm;
 extern struct asn1_algorithm
-sha224_with_rsa_encryption_algorithm __asn1_algorithm;
+sha512_224_with_rsa_encryption_algorithm __asn1_algorithm;
+extern struct asn1_algorithm
+sha512_256_with_rsa_encryption_algorithm __asn1_algorithm;
 extern struct asn1_algorithm oid_md4_algorithm __asn1_algorithm;
 extern struct asn1_algorithm oid_md5_algorithm __asn1_algorithm;
 extern struct asn1_algorithm oid_sha1_algorithm __asn1_algorithm;