s390/pkey: Introduce pkey kernel module

This patch introcudes a new kernel module pkey which is providing
protected key handling and management functions. The pkey API is
available within the kernel for other s390 specific code to create
and manage protected keys. Additionally the functions are exported
to user space via IOCTL calls. The implementation makes extensive
use of functions provided by the zcrypt device driver. For
generating protected keys from secure keys there is also a CEX
coprocessor card needed.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 113 insertions, 0 deletions

diff --git a/arch/s390/include/uapi/asm/Kbuild b/arch/s390/include/uapi/asm/Kbuild
index bf736e764cb4..6848ba5c1454 100644
--- a/arch/s390/include/uapi/asm/Kbuild
+++ b/arch/s390/include/uapi/asm/Kbuild
@@ -24,6 +24,7 @@ header-y += mman.h
 header-y += monwriter.h
 header-y += msgbuf.h
 header-y += param.h
+header-y += pkey.h
 header-y += poll.h
 header-y += posix_types.h
 header-y += ptrace.h
diff --git a/arch/s390/include/uapi/asm/pkey.h b/arch/s390/include/uapi/asm/pkey.h
new file mode 100644
index 000000000000..ed7f19c27ce5
--- /dev/null
+++ b/arch/s390/include/uapi/asm/pkey.h
@@ -0,0 +1,112 @@
+/*
+ * Userspace interface to the pkey device driver
+ *
+ * Copyright IBM Corp. 2017
+ *
+ * Author: Harald Freudenberger <freude@de.ibm.com>
+ *
+ */
+
+#ifndef _UAPI_PKEY_H
+#define _UAPI_PKEY_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/*
+ * Ioctl calls supported by the pkey device driver
+ */
+
+#define PKEY_IOCTL_MAGIC 'p'
+
+#define SECKEYBLOBSIZE	64     /* secure key blob size is always 64 bytes */
+#define MAXPROTKEYSIZE	64  /* a protected key blob may be up to 64 bytes */
+#define MAXCLRKEYSIZE	32     /* a clear key value may be up to 32 bytes */
+
+/* defines for the type field within the pkey_protkey struct */
+#define PKEY_KEYTYPE_AES_128  1
+#define PKEY_KEYTYPE_AES_192  2
+#define PKEY_KEYTYPE_AES_256  3
+
+/* Struct to hold a secure key blob */
+struct pkey_seckey {
+	__u8  seckey[SECKEYBLOBSIZE];		  /* the secure key blob */
+};
+
+/* Struct to hold protected key and length info */
+struct pkey_protkey {
+	__u32 type;	     /* key type, one of the PKEY_KEYTYPE values */
+	__u32 len;		/* bytes actually stored in protkey[]	 */
+	__u8  protkey[MAXPROTKEYSIZE];	       /* the protected key blob */
+};
+
+/* Struct to hold a clear key value */
+struct pkey_clrkey {
+	__u8  clrkey[MAXCLRKEYSIZE]; /* 16, 24, or 32 byte clear key value */
+};
+
+/*
+ * Generate secure key
+ */
+struct pkey_genseck {
+	__u16 cardnr;		    /* in: card to use or FFFF for any	 */
+	__u16 domain;		    /* in: domain or FFFF for any	 */
+	__u32 keytype;		    /* in: key type to generate		 */
+	struct pkey_seckey seckey;  /* out: the secure key blob		 */
+};
+#define PKEY_GENSECK _IOWR(PKEY_IOCTL_MAGIC, 0x01, struct pkey_genseck)
+
+/*
+ * Construct secure key from clear key value
+ */
+struct pkey_clr2seck {
+	__u16 cardnr;		    /* in: card to use or FFFF for any	 */
+	__u16 domain;		    /* in: domain or FFFF for any	 */
+	__u32 keytype;		    /* in: key type to generate		 */
+	struct pkey_clrkey clrkey;  /* in: the clear key value		 */
+	struct pkey_seckey seckey;  /* out: the secure key blob		 */
+};
+#define PKEY_CLR2SECK _IOWR(PKEY_IOCTL_MAGIC, 0x02, struct pkey_clr2seck)
+
+/*
+ * Fabricate protected key from a secure key
+ */
+struct pkey_sec2protk {
+	__u16 cardnr;		     /* in: card to use or FFFF for any   */
+	__u16 domain;		     /* in: domain or FFFF for any	  */
+	struct pkey_seckey seckey;   /* in: the secure key blob		  */
+	struct pkey_protkey protkey; /* out: the protected key		  */
+};
+#define PKEY_SEC2PROTK _IOWR(PKEY_IOCTL_MAGIC, 0x03, struct pkey_sec2protk)
+
+/*
+ * Fabricate protected key from an clear key value
+ */
+struct pkey_clr2protk {
+	__u32 keytype;		     /* in: key type to generate	  */
+	struct pkey_clrkey clrkey;   /* in: the clear key value		  */
+	struct pkey_protkey protkey; /* out: the protected key		  */
+};
+#define PKEY_CLR2PROTK _IOWR(PKEY_IOCTL_MAGIC, 0x04, struct pkey_clr2protk)
+
+/*
+ * Search for matching crypto card based on the Master Key
+ * Verification Pattern provided inside a secure key.
+ */
+struct pkey_findcard {
+	struct pkey_seckey seckey;	       /* in: the secure key blob */
+	__u16  cardnr;			       /* out: card number	  */
+	__u16  domain;			       /* out: domain number	  */
+};
+#define PKEY_FINDCARD _IOWR(PKEY_IOCTL_MAGIC, 0x05, struct pkey_findcard)
+
+/*
+ * Combined together: findcard + sec2prot
+ */
+struct pkey_skey2pkey {
+	struct pkey_seckey seckey;   /* in: the secure key blob		  */
+	struct pkey_protkey protkey; /* out: the protected key		  */
+};
+#define PKEY_SKEY2PKEY _IOWR(PKEY_IOCTL_MAGIC, 0x06, struct pkey_skey2pkey)
+
+#endif /* _UAPI_PKEY_H */