Commit 6cb8815f41a9 ("crypto: sig - Add interface for sign/verify")
began a transition of asymmetric sign/verify operations from
crypto_akcipher to a new crypto_sig frontend.
Internally, the crypto_sig frontend still uses akcipher_alg as backend,
however:
"The link between sig and akcipher is meant to be temporary. The
plan is to create a new low-level API for sig and then migrate
the signature code over to that from akcipher."
https://lore.kernel.org/r/ZrG6w9wsb-iiLZIF@xxxxxxxxxxxxxxxxxxx/
"having a separate alg for sig is definitely where we want to
be since there is very little that the two types actually share."
https://lore.kernel.org/r/ZrHlpz4qnre0zWJO@xxxxxxxxxxxxxxxxxxx/
Take the next step of that migration and augment the crypto_sig frontend
with a sig_alg backend to which all algorithms can be moved.
During the migration, there will briefly be signature algorithms that
are still based on crypto_akcipher, whilst others are already based on
crypto_sig. Allow for that by building a fork into crypto_sig_*() API
calls (i.e. crypto_sig_maxsize() and friends) such that one of the two
backends is selected based on the transform's cra_type.
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
---
Documentation/crypto/api-sig.rst | 15 +++
Documentation/crypto/api.rst | 1 +
Documentation/crypto/architecture.rst | 2 +
crypto/sig.c | 143 +++++++++++++++++++++++++-
crypto/testmgr.c | 115 +++++++++++++++++++++
crypto/testmgr.h | 13 +++
include/crypto/internal/sig.h | 80 ++++++++++++++
include/crypto/sig.h | 61 +++++++++++
include/uapi/linux/cryptouser.h | 5 +
9 files changed, 433 insertions(+), 2 deletions(-)
create mode 100644 Documentation/crypto/api-sig.rst
diff --git a/Documentation/crypto/api-sig.rst b/Documentation/crypto/api-sig.rst
new file mode 100644
index 000000000000..e5e87e106884
--- /dev/null
+++ b/Documentation/crypto/api-sig.rst
@@ -0,0 +1,15 @@
+Asymmetric Signature Algorithm Definitions
+------------------------------------------
+
+.. kernel-doc:: include/crypto/sig.h
+ :functions: sig_alg
+
+Asymmetric Signature API
+------------------------
+
+.. kernel-doc:: include/crypto/sig.h
+ :doc: Generic Public Key Signature API
+
+.. kernel-doc:: include/crypto/sig.h
+ :functions: crypto_alloc_sig crypto_free_sig crypto_sig_set_pubkey crypto_sig_set_privkey crypto_sig_maxsize crypto_sig_sign crypto_sig_verify
+
diff --git a/Documentation/crypto/api.rst b/Documentation/crypto/api.rst
index ff31c30561d4..8b2a90521886 100644
--- a/Documentation/crypto/api.rst
+++ b/Documentation/crypto/api.rst
@@ -10,4 +10,5 @@ Programming Interface
api-digest
api-rng
api-akcipher
+ api-sig
api-kpp
diff --git a/Documentation/crypto/architecture.rst b/Documentation/crypto/architecture.rst
index 646c3380a7ed..15dcd62fd22f 100644
--- a/Documentation/crypto/architecture.rst
+++ b/Documentation/crypto/architecture.rst
@@ -214,6 +214,8 @@ the aforementioned cipher types:
- CRYPTO_ALG_TYPE_AKCIPHER Asymmetric cipher
+- CRYPTO_ALG_TYPE_SIG Asymmetric signature
+
- CRYPTO_ALG_TYPE_PCOMPRESS Enhanced version of
CRYPTO_ALG_TYPE_COMPRESS allowing for segmented compression /
decompression instead of performing the operation on one segment
diff --git a/crypto/sig.c b/crypto/sig.c
index 7645bedf3a1f..4f36ceb7a90b 100644
--- a/crypto/sig.c
+++ b/crypto/sig.c
@@ -21,14 +21,38 @@
static const struct crypto_type crypto_sig_type;
+static void crypto_sig_exit_tfm(struct crypto_tfm *tfm)
+{
+ struct crypto_sig *sig = __crypto_sig_tfm(tfm);
+ struct sig_alg *alg = crypto_sig_alg(sig);
+
+ alg->exit(sig);
+}
+
static int crypto_sig_init_tfm(struct crypto_tfm *tfm)
{
if (tfm->__crt_alg->cra_type != &crypto_sig_type)
return crypto_init_akcipher_ops_sig(tfm);
+ struct crypto_sig *sig = __crypto_sig_tfm(tfm);
+ struct sig_alg *alg = crypto_sig_alg(sig);
+
+ if (alg->exit)
+ sig->base.exit = crypto_sig_exit_tfm;
+
+ if (alg->init)
+ return alg->init(sig);
+
return 0;
}
+static void crypto_sig_free_instance(struct crypto_instance *inst)
+{
+ struct sig_instance *sig = sig_instance(inst);
+
+ sig->free(sig);
+}
+
static void __maybe_unused crypto_sig_show(struct seq_file *m,
struct crypto_alg *alg)
{
@@ -38,16 +62,17 @@ static void __maybe_unused crypto_sig_show(struct seq_file *m,
static int __maybe_unused crypto_sig_report(struct sk_buff *skb,
struct crypto_alg *alg)
{
- struct crypto_report_akcipher rsig = {};
+ struct crypto_report_sig rsig = {};
strscpy(rsig.type, "sig", sizeof(rsig.type));
- return nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER, sizeof(rsig), &rsig);
+ return nla_put(skb, CRYPTOCFGA_REPORT_SIG, sizeof(rsig), &rsig);
}
static const struct crypto_type crypto_sig_type = {
.extsize = crypto_alg_extsize,
.init_tfm = crypto_sig_init_tfm,
+ .free = crypto_sig_free_instance,
#ifdef CONFIG_PROC_FS
.show = crypto_sig_show,
#endif
@@ -68,6 +93,14 @@ EXPORT_SYMBOL_GPL(crypto_alloc_sig);
int crypto_sig_maxsize(struct crypto_sig *tfm)
{
+ if (crypto_sig_tfm(tfm)->__crt_alg->cra_type != &crypto_sig_type)
+ goto akcipher;
+
+ struct sig_alg *alg = crypto_sig_alg(tfm);
+
+ return alg->max_size(tfm);
+
+akcipher:
struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
return crypto_akcipher_maxsize(*ctx);
@@ -78,6 +111,14 @@ int crypto_sig_sign(struct crypto_sig *tfm,
const void *src, unsigned int slen,
void *dst, unsigned int dlen)
{
+ if (crypto_sig_tfm(tfm)->__crt_alg->cra_type != &crypto_sig_type)
+ goto akcipher;
+
+ struct sig_alg *alg = crypto_sig_alg(tfm);
+
+ return alg->sign(tfm, src, slen, dst, dlen);
+
+akcipher:
struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
struct crypto_akcipher_sync_data data = {
.tfm = *ctx,
@@ -97,6 +138,14 @@ int crypto_sig_verify(struct crypto_sig *tfm,
const void *src, unsigned int slen,
const void *digest, unsigned int dlen)
{
+ if (crypto_sig_tfm(tfm)->__crt_alg->cra_type != &crypto_sig_type)
+ goto akcipher;
+
+ struct sig_alg *alg = crypto_sig_alg(tfm);
+
+ return alg->verify(tfm, src, slen, digest, dlen);
+
+akcipher:
struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
struct crypto_akcipher_sync_data data = {
.tfm = *ctx,
@@ -120,6 +169,14 @@ EXPORT_SYMBOL_GPL(crypto_sig_verify);
int crypto_sig_set_pubkey(struct crypto_sig *tfm,
const void *key, unsigned int keylen)
{
+ if (crypto_sig_tfm(tfm)->__crt_alg->cra_type != &crypto_sig_type)
+ goto akcipher;
+
+ struct sig_alg *alg = crypto_sig_alg(tfm);
+
+ return alg->set_pub_key(tfm, key, keylen);
+
+akcipher:
struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
return crypto_akcipher_set_pub_key(*ctx, key, keylen);
@@ -129,11 +186,93 @@ EXPORT_SYMBOL_GPL(crypto_sig_set_pubkey);
int crypto_sig_set_privkey(struct crypto_sig *tfm,
const void *key, unsigned int keylen)
{
+ if (crypto_sig_tfm(tfm)->__crt_alg->cra_type != &crypto_sig_type)
+ goto akcipher;
+
+ struct sig_alg *alg = crypto_sig_alg(tfm);
+
+ return alg->set_priv_key(tfm, key, keylen);
+
+akcipher:
struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
return crypto_akcipher_set_priv_key(*ctx, key, keylen);
}
EXPORT_SYMBOL_GPL(crypto_sig_set_privkey);
+static void sig_prepare_alg(struct sig_alg *alg)
+{
+ struct crypto_alg *base = &alg->base;
+
+ base->cra_type = &crypto_sig_type;
+ base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
+ base->cra_flags |= CRYPTO_ALG_TYPE_SIG;
+}
+
+static int sig_default_sign(struct crypto_sig *tfm,
+ const void *src, unsigned int slen,
+ void *dst, unsigned int dlen)
+{
+ return -ENOSYS;
+}
+
+static int sig_default_verify(struct crypto_sig *tfm,
+ const void *src, unsigned int slen,
+ const void *dst, unsigned int dlen)
+{
+ return -ENOSYS;
+}
+
+static int sig_default_set_key(struct crypto_sig *tfm,
+ const void *key, unsigned int keylen)
+{
+ return -ENOSYS;
+}
+
+int crypto_register_sig(struct sig_alg *alg)
+{
+ struct crypto_alg *base = &alg->base;
+
+ if (!alg->sign)
+ alg->sign = sig_default_sign;
+ if (!alg->verify)
+ alg->verify = sig_default_verify;
+ if (!alg->set_priv_key)
+ alg->set_priv_key = sig_default_set_key;
+ if (!alg->set_pub_key)
+ return -EINVAL;
+ if (!alg->max_size)
+ return -EINVAL;
+
+ sig_prepare_alg(alg);
+ return crypto_register_alg(base);
+}
+EXPORT_SYMBOL_GPL(crypto_register_sig);
+
+void crypto_unregister_sig(struct sig_alg *alg)
+{
+ crypto_unregister_alg(&alg->base);
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_sig);
+
+int sig_register_instance(struct crypto_template *tmpl,
+ struct sig_instance *inst)
+{
+ if (WARN_ON(!inst->free))
+ return -EINVAL;
+ sig_prepare_alg(&inst->alg);
+ return crypto_register_instance(tmpl, sig_crypto_instance(inst));
+}
+EXPORT_SYMBOL_GPL(sig_register_instance);
+
+int crypto_grab_sig(struct crypto_sig_spawn *spawn,
+ struct crypto_instance *inst,
+ const char *name, u32 type, u32 mask)
+{
+ spawn->base.frontend = &crypto_sig_type;
+ return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_grab_sig);
+
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Public Key Signature Algorithms");
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index f02cb075bd68..bb21378aa510 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -33,6 +33,7 @@
#include <crypto/akcipher.h>
#include <crypto/kpp.h>
#include <crypto/acompress.h>
+#include <crypto/sig.h>
#include <crypto/internal/cipher.h>
#include <crypto/internal/simd.h>
@@ -131,6 +132,11 @@ struct akcipher_test_suite {
unsigned int count;
};
+struct sig_test_suite {
+ const struct sig_testvec *vecs;
+ unsigned int count;
+};
+
struct kpp_test_suite {
const struct kpp_testvec *vecs;
unsigned int count;
@@ -151,6 +157,7 @@ struct alg_test_desc {
struct cprng_test_suite cprng;
struct drbg_test_suite drbg;
struct akcipher_test_suite akcipher;
+ struct sig_test_suite sig;
struct kpp_test_suite kpp;
} suite;
};
@@ -4317,6 +4324,114 @@ static int alg_test_akcipher(const struct alg_test_desc *desc,
return err;
}
+static int test_sig_one(struct crypto_sig *tfm, const struct sig_testvec *vecs)
+{
+ u8 *ptr, *key __free(kfree);
+ int err, sig_size;
+
+ key = kmalloc(vecs->key_len + 2 * sizeof(u32) + vecs->param_len,
+ GFP_KERNEL);
+ if (!key)
+ return -ENOMEM;
+
+ /* ecrdsa expects additional parameters appended to the key */
+ memcpy(key, vecs->key, vecs->key_len);
+ ptr = key + vecs->key_len;
+ ptr = test_pack_u32(ptr, vecs->algo);
+ ptr = test_pack_u32(ptr, vecs->param_len);
+ memcpy(ptr, vecs->params, vecs->param_len);
+
+ if (vecs->public_key_vec)
+ err = crypto_sig_set_pubkey(tfm, key, vecs->key_len);
+ else
+ err = crypto_sig_set_privkey(tfm, key, vecs->key_len);
+ if (err)
+ return err;
+
+ /*
+ * Run asymmetric signature verification first
+ * (which does not require a private key)
+ */
+ err = crypto_sig_verify(tfm, vecs->c, vecs->c_size,
+ vecs->m, vecs->m_size);
+ if (err) {
+ pr_err("alg: sig: verify test failed: err %d\n", err);
+ return err;
+ }
+
+ /*
+ * Don't invoke sign test (which requires a private key)
+ * for vectors with only a public key.
+ */
+ if (vecs->public_key_vec)
+ return 0;
+
+ sig_size = crypto_sig_maxsize(tfm);
+ if (sig_size < vecs->c_size) {
+ pr_err("alg: sig: invalid maxsize %u\n", sig_size);
+ return -EINVAL;
+ }
+
+ u8 *sig __free(kfree) = kzalloc(sig_size, GFP_KERNEL);
+ if (!sig)
+ return -ENOMEM;
+
+ /* Run asymmetric signature generation */
+ err = crypto_sig_sign(tfm, vecs->m, vecs->m_size, sig, sig_size);
+ if (err) {
+ pr_err("alg: sig: sign test failed: err %d\n", err);
+ return err;
+ }
+
+ /* Verify that generated signature equals cooked signature */
+ if (memcmp(sig, vecs->c, vecs->c_size) ||
+ memchr_inv(sig + vecs->c_size, 0, sig_size - vecs->c_size)) {
+ pr_err("alg: sig: sign test failed: invalid output\n");
+ hexdump(sig, sig_size);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int test_sig(struct crypto_sig *tfm, const char *alg,
+ const struct sig_testvec *vecs, unsigned int tcount)
+{
+ const char *algo = crypto_tfm_alg_driver_name(crypto_sig_tfm(tfm));
+ int ret, i;
+
+ for (i = 0; i < tcount; i++) {
+ ret = test_sig_one(tfm, vecs++);
+ if (ret) {
+ pr_err("alg: sig: test %d failed for %s: err %d\n",
+ i + 1, algo, ret);
+ return ret;
+ }
+ }
+ return 0;
+}
+
+__maybe_unused
+static int alg_test_sig(const struct alg_test_desc *desc, const char *driver,
+ u32 type, u32 mask)
+{
+ struct crypto_sig *tfm;
+ int err = 0;
+
+ tfm = crypto_alloc_sig(driver, type, mask);
+ if (IS_ERR(tfm)) {
+ pr_err("alg: sig: Failed to load tfm for %s: %ld\n",
+ driver, PTR_ERR(tfm));
+ return PTR_ERR(tfm);
+ }
+ if (desc->suite.sig.vecs)
+ err = test_sig(tfm, desc->alg, desc->suite.sig.vecs,
+ desc->suite.sig.count);
+
+ crypto_free_sig(tfm);
+ return err;
+}
+
static int alg_test_null(const struct alg_test_desc *desc,
const char *driver, u32 type, u32 mask)
{
diff --git a/crypto/testmgr.h b/crypto/testmgr.h
index ed1640f3e352..39dd1d558883 100644
--- a/crypto/testmgr.h
+++ b/crypto/testmgr.h
@@ -162,6 +162,19 @@ struct akcipher_testvec {
enum OID algo;
};
+struct sig_testvec {
+ const unsigned char *key;
+ const unsigned char *params;
+ const unsigned char *m;
+ const unsigned char *c;
+ unsigned int key_len;
+ unsigned int param_len;
+ unsigned int m_size;
+ unsigned int c_size;
+ bool public_key_vec;
+ enum OID algo;
+};
+
struct kpp_testvec {
const unsigned char *secret;
const unsigned char *b_secret;
diff --git a/include/crypto/internal/sig.h b/include/crypto/internal/sig.h
index 97cb26ef8115..b16648c1a986 100644
--- a/include/crypto/internal/sig.h
+++ b/include/crypto/internal/sig.h
@@ -10,8 +10,88 @@
#include <crypto/algapi.h>
#include <crypto/sig.h>
+struct sig_instance {
+ void (*free)(struct sig_instance *inst);
+ union {
+ struct {
+ char head[offsetof(struct sig_alg, base)];
+ struct crypto_instance base;
+ };
+ struct sig_alg alg;
+ };
+};
+
+struct crypto_sig_spawn {
+ struct crypto_spawn base;
+};
+
static inline void *crypto_sig_ctx(struct crypto_sig *tfm)
{
return crypto_tfm_ctx(&tfm->base);
}
+
+/**
+ * crypto_register_sig() -- Register public key signature algorithm
+ *
+ * Function registers an implementation of a public key signature algorithm
+ *
+ * @alg: algorithm definition
+ *
+ * Return: zero on success; error code in case of error
+ */
+int crypto_register_sig(struct sig_alg *alg);
+
+/**
+ * crypto_unregister_sig() -- Unregister public key signature algorithm
+ *
+ * Function unregisters an implementation of a public key signature algorithm
+ *
+ * @alg: algorithm definition
+ */
+void crypto_unregister_sig(struct sig_alg *alg);
+
+int sig_register_instance(struct crypto_template *tmpl,
+ struct sig_instance *inst);
+
+static inline struct sig_instance *sig_instance(struct crypto_instance *inst)
+{
+ return container_of(&inst->alg, struct sig_instance, alg.base);
+}
+
+static inline struct sig_instance *sig_alg_instance(struct crypto_sig *tfm)
+{
+ return sig_instance(crypto_tfm_alg_instance(&tfm->base));
+}
+
+static inline struct crypto_instance *sig_crypto_instance(struct sig_instance
+ *inst)
+{
+ return container_of(&inst->alg.base, struct crypto_instance, alg);
+}
+
+static inline void *sig_instance_ctx(struct sig_instance *inst)
+{
+ return crypto_instance_ctx(sig_crypto_instance(inst));
+}
+
+int crypto_grab_sig(struct crypto_sig_spawn *spawn,
+ struct crypto_instance *inst,
+ const char *name, u32 type, u32 mask);
+
+static inline struct crypto_sig *crypto_spawn_sig(struct crypto_sig_spawn
+ *spawn)
+{
+ return crypto_spawn_tfm2(&spawn->base);
+}
+
+static inline void crypto_drop_sig(struct crypto_sig_spawn *spawn)
+{
+ crypto_drop_spawn(&spawn->base);
+}
+
+static inline struct sig_alg *crypto_spawn_sig_alg(struct crypto_sig_spawn
+ *spawn)
+{
+ return container_of(spawn->base.alg, struct sig_alg, base);
+}
#endif
diff --git a/include/crypto/sig.h b/include/crypto/sig.h
index d25186bb2be3..f0f52a7c5ae7 100644
--- a/include/crypto/sig.h
+++ b/include/crypto/sig.h
@@ -19,6 +19,52 @@ struct crypto_sig {
struct crypto_tfm base;
};
+/**
+ * struct sig_alg - generic public key signature algorithm
+ *
+ * @sign: Function performs a sign operation as defined by public key
+ * algorithm. Optional.
+ * @verify: Function performs a complete verify operation as defined by
+ * public key algorithm, returning verification status. Optional.
+ * @set_pub_key: Function invokes the algorithm specific set public key
+ * function, which knows how to decode and interpret
+ * the BER encoded public key and parameters. Mandatory.
+ * @set_priv_key: Function invokes the algorithm specific set private key
+ * function, which knows how to decode and interpret
+ * the BER encoded private key and parameters. Optional.
+ * @max_size: Function returns key size. Mandatory.
+ * @init: Initialize the cryptographic transformation object.
+ * This function is used to initialize the cryptographic
+ * transformation object. This function is called only once at
+ * the instantiation time, right after the transformation context
+ * was allocated. In case the cryptographic hardware has some
+ * special requirements which need to be handled by software, this
+ * function shall check for the precise requirement of the
+ * transformation and put any software fallbacks in place.
+ * @exit: Deinitialize the cryptographic transformation object. This is a
+ * counterpart to @init, used to remove various changes set in
+ * @init.
+ *
+ * @base: Common crypto API algorithm data structure
+ */
+struct sig_alg {
+ int (*sign)(struct crypto_sig *tfm,
+ const void *src, unsigned int slen,
+ void *dst, unsigned int dlen);
+ int (*verify)(struct crypto_sig *tfm,
+ const void *src, unsigned int slen,
+ const void *digest, unsigned int dlen);
+ int (*set_pub_key)(struct crypto_sig *tfm,
+ const void *key, unsigned int keylen);
+ int (*set_priv_key)(struct crypto_sig *tfm,
+ const void *key, unsigned int keylen);
+ unsigned int (*max_size)(struct crypto_sig *tfm);
+ int (*init)(struct crypto_sig *tfm);
+ void (*exit)(struct crypto_sig *tfm);
+
+ struct crypto_alg base;
+};
+
/**
* DOC: Generic Public Key Signature API
*
@@ -47,6 +93,21 @@ static inline struct crypto_tfm *crypto_sig_tfm(struct crypto_sig *tfm)
return &tfm->base;
}
+static inline struct crypto_sig *__crypto_sig_tfm(struct crypto_tfm *tfm)
+{
+ return container_of(tfm, struct crypto_sig, base);
+}
+
+static inline struct sig_alg *__crypto_sig_alg(struct crypto_alg *alg)
+{
+ return container_of(alg, struct sig_alg, base);
+}
+
+static inline struct sig_alg *crypto_sig_alg(struct crypto_sig *tfm)
+{
+ return __crypto_sig_alg(crypto_sig_tfm(tfm)->__crt_alg);
+}
+
/**
* crypto_free_sig() - free signature tfm handle
*
diff --git a/include/uapi/linux/cryptouser.h b/include/uapi/linux/cryptouser.h
index 20a6c0fc149e..db05e0419972 100644
--- a/include/uapi/linux/cryptouser.h
+++ b/include/uapi/linux/cryptouser.h
@@ -64,6 +64,7 @@ enum crypto_attr_type_t {
CRYPTOCFGA_STAT_AKCIPHER, /* No longer supported, do not use. */
CRYPTOCFGA_STAT_KPP, /* No longer supported, do not use. */
CRYPTOCFGA_STAT_ACOMP, /* No longer supported, do not use. */
+ CRYPTOCFGA_REPORT_SIG, /* struct crypto_report_sig */
__CRYPTOCFGA_MAX
#define CRYPTOCFGA_MAX (__CRYPTOCFGA_MAX - 1)
@@ -207,6 +208,10 @@ struct crypto_report_acomp {
char type[CRYPTO_MAX_NAME];
};
+struct crypto_report_sig {
+ char type[CRYPTO_MAX_NAME];
+};
+
#define CRYPTO_REPORT_MAXSIZE (sizeof(struct crypto_user_alg) + \
sizeof(struct crypto_report_blkcipher))
--
2.43.0
