Two extensions are added:

 (1) Support for SHA1 digestion of in-kernel buffers directly without the use
     of scatter-gather lists.

 (2) Allocation of crypto algorithm instances without resort to fallback module
     loading.

SHA1 is used by module signature checking, and so must not itself require
loading as a module when the module signature checking is enabled.

Signed-Off-By: David Howells <[EMAIL PROTECTED]>
---

 crypto/api.c           |   46 +++++++++++++++++++++++++++++++++++++++++++++-
 crypto/digest.c        |    9 +++++++++
 include/linux/crypto.h |   11 +++++++++++
 3 files changed, 65 insertions(+), 1 deletions(-)

diff --git a/crypto/api.c b/crypto/api.c
index 55af8bb..3138d7c 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -341,6 +341,45 @@ out:
 EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
 
 /*
+ *     crypto_alloc_tfm2 - Find or load crypto module
+ *     @name: Name of algorithm
+ *     @flags: Flags to control algorithm instance
+ *     @nomodload: True to suppress resort to module loading
+ *
+ *     Attempt to find or load a crypto algorithm module and create an
+ *     instance of it.
+ */
+struct crypto_tfm *crypto_alloc_tfm2(const char *name, u32 flags,
+                                    int nomodload)
+{
+       struct crypto_tfm *tfm = NULL;
+       int err;
+
+       do {
+               struct crypto_alg *alg;
+
+               if (!nomodload)
+                       alg = crypto_alg_mod_lookup(name, 0, CRYPTO_ALG_ASYNC);
+               else
+                       alg = crypto_alg_lookup(name, 0, CRYPTO_ALG_ASYNC);
+
+               err = PTR_ERR(alg);
+               if (IS_ERR(alg))
+                       continue;
+
+               tfm = __crypto_alloc_tfm(alg, flags, 0);
+               err = 0;
+               if (IS_ERR(tfm)) {
+                       crypto_mod_put(alg);
+                       err = PTR_ERR(tfm);
+                       tfm = NULL;
+               }
+       } while (err == -EAGAIN && !signal_pending(current));
+
+       return tfm;
+}
+
+/*
  *     crypto_alloc_base - Locate algorithm and allocate transform
  *     @alg_name: Name of algorithm
  *     @type: Type of algorithm
@@ -392,7 +431,12 @@ err:
        return ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(crypto_alloc_base);
- 
+
+struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
+{
+       return crypto_alloc_tfm2(name, flags, 0);
+}
+
 /*
  *     crypto_free_tfm - Free crypto transform
  *     @tfm: Transform to free
diff --git a/crypto/digest.c b/crypto/digest.c
index 1bf7414..d03a4e1 100644
--- a/crypto/digest.c
+++ b/crypto/digest.c
@@ -91,6 +91,14 @@ static int update(struct hash_desc *desc,
        return update2(desc, sg, nbytes);
 }
 
+static void update_kernel(struct hash_desc *desc,
+                         const void *data, size_t count)
+{
+       struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
+       tfm->__crt_alg->cra_digest.dia_update(tfm, data, count);
+       crypto_yield(desc->flags);
+}
+
 static int final(struct hash_desc *desc, u8 *out)
 {
        struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
@@ -146,6 +154,7 @@ int crypto_init_digest_ops(struct crypto_tfm *tfm)
        
        ops->init       = init;
        ops->update     = update;
+       ops->update_kernel = update_kernel;
        ops->final      = final;
        ops->digest     = digest;
        ops->setkey     = dalg->dia_setkey ? setkey : nosetkey;
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 779aa78..d960ec1 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -273,6 +273,8 @@ struct hash_tfm {
        int (*init)(struct hash_desc *desc);
        int (*update)(struct hash_desc *desc,
                      struct scatterlist *sg, unsigned int nsg);
+       void (*update_kernel)(struct hash_desc *desc,
+                             const void *data, size_t count);
        int (*final)(struct hash_desc *desc, u8 *out);
        int (*digest)(struct hash_desc *desc, struct scatterlist *sg,
                      unsigned int nsg, u8 *out);
@@ -341,6 +343,8 @@ struct crypto_attr_alg {
  */
  
 struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, u32 tfm_flags);
+struct crypto_tfm *crypto_alloc_tfm2(const char *alg_name, u32 tfm_flags,
+               int nomodload);
 struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask);
 void crypto_free_tfm(struct crypto_tfm *tfm);
 
@@ -739,6 +743,13 @@ static inline int crypto_hash_update(struct hash_desc 
*desc,
        return crypto_hash_crt(desc->tfm)->update(desc, sg, nbytes);
 }
 
+static inline void crypto_hash_update_kernel(struct hash_desc *desc,
+                                            const void *data,
+                                            size_t count)
+{
+       return crypto_hash_crt(desc->tfm)->update_kernel(desc, data, count);
+}
+
 static inline int crypto_hash_final(struct hash_desc *desc, u8 *out)
 {
        return crypto_hash_crt(desc->tfm)->final(desc, out);
-
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