crypto: aead - Add common IV generation code
[deliverable/linux.git] / crypto / seqiv.c
index 2680e94b00f598698dd63c63602470fa905ca15c..127970a69ecfcc58082a8377864506a8e7d040dd 100644 (file)
 #include <linux/spinlock.h>
 #include <linux/string.h>
 
+struct seqniv_request_ctx {
+       struct scatterlist dst[2];
+       struct aead_request subreq;
+};
+
 struct seqiv_ctx {
        spinlock_t lock;
        u8 salt[] __attribute__ ((aligned(__alignof__(u32))));
@@ -135,6 +140,50 @@ static void seqiv_aead_encrypt_complete(struct crypto_async_request *base,
        aead_request_complete(req, err);
 }
 
+static void seqniv_aead_encrypt_complete2(struct aead_request *req, int err)
+{
+       unsigned int ivsize = 8;
+       u8 data[20];
+
+       if (err == -EINPROGRESS)
+               return;
+
+       /* Swap IV and ESP header back to correct order. */
+       scatterwalk_map_and_copy(data, req->dst, 0, req->assoclen + ivsize, 0);
+       scatterwalk_map_and_copy(data + ivsize, req->dst, 0, req->assoclen, 1);
+       scatterwalk_map_and_copy(data, req->dst, req->assoclen, ivsize, 1);
+}
+
+static void seqniv_aead_encrypt_complete(struct crypto_async_request *base,
+                                       int err)
+{
+       struct aead_request *req = base->data;
+
+       seqniv_aead_encrypt_complete2(req, err);
+       aead_request_complete(req, err);
+}
+
+static void seqniv_aead_decrypt_complete2(struct aead_request *req, int err)
+{
+       u8 data[4];
+
+       if (err == -EINPROGRESS)
+               return;
+
+       /* Move ESP header back to correct location. */
+       scatterwalk_map_and_copy(data, req->dst, 16, req->assoclen - 8, 0);
+       scatterwalk_map_and_copy(data, req->dst, 8, req->assoclen - 8, 1);
+}
+
+static void seqniv_aead_decrypt_complete(struct crypto_async_request *base,
+                                        int err)
+{
+       struct aead_request *req = base->data;
+
+       seqniv_aead_decrypt_complete2(req, err);
+       aead_request_complete(req, err);
+}
+
 static void seqiv_geniv(struct seqiv_ctx *ctx, u8 *info, u64 seq,
                        unsigned int ivsize)
 {
@@ -244,45 +293,62 @@ static int seqiv_aead_encrypt_compat(struct aead_request *req)
 {
        struct crypto_aead *geniv = crypto_aead_reqtfm(req);
        struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
-       struct aead_request *subreq = aead_request_ctx(req);
+       struct seqniv_request_ctx *rctx = aead_request_ctx(req);
+       struct aead_request *subreq = &rctx->subreq;
+       struct scatterlist *dst;
        crypto_completion_t compl;
        void *data;
-       u8 *info;
-       unsigned int ivsize;
+       unsigned int ivsize = 8;
+       u8 buf[20] __attribute__ ((aligned(__alignof__(u32))));
        int err;
 
-       aead_request_set_tfm(subreq, ctx->child);
+       if (req->cryptlen < ivsize)
+               return -EINVAL;
 
-       compl = req->base.complete;
-       data = req->base.data;
-       info = req->iv;
+       /* ESP AD is at most 12 bytes (ESN). */
+       if (req->assoclen > 12)
+               return -EINVAL;
 
-       ivsize = crypto_aead_ivsize(geniv);
+       aead_request_set_tfm(subreq, ctx->child);
 
-       if (unlikely(!IS_ALIGNED((unsigned long)info,
-                                crypto_aead_alignmask(geniv) + 1))) {
-               info = kmalloc(ivsize, req->base.flags &
-                                      CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
-                                                                 GFP_ATOMIC);
-               if (!info)
-                       return -ENOMEM;
+       compl = seqniv_aead_encrypt_complete;
+       data = req;
 
-               memcpy(info, req->iv, ivsize);
-               compl = seqiv_aead_encrypt_complete;
-               data = req;
+       if (req->src != req->dst) {
+               struct scatterlist srcbuf[2];
+               struct scatterlist dstbuf[2];
+               struct blkcipher_desc desc = {
+                       .tfm = ctx->null,
+               };
+
+               err = crypto_blkcipher_encrypt(
+                       &desc,
+                       scatterwalk_ffwd(dstbuf, req->dst,
+                                        req->assoclen + ivsize),
+                       scatterwalk_ffwd(srcbuf, req->src,
+                                        req->assoclen + ivsize),
+                       req->cryptlen - ivsize);
+               if (err)
+                       return err;
        }
 
+       dst = scatterwalk_ffwd(rctx->dst, req->dst, ivsize);
+
        aead_request_set_callback(subreq, req->base.flags, compl, data);
-       aead_request_set_crypt(subreq, req->src, req->dst,
-                              req->cryptlen - ivsize, info);
-       aead_request_set_ad(subreq, req->assoclen, ivsize);
+       aead_request_set_crypt(subreq, dst, dst,
+                              req->cryptlen - ivsize, req->iv);
+       aead_request_set_ad(subreq, req->assoclen);
 
-       crypto_xor(info, ctx->salt, ivsize);
-       scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
+       memcpy(buf, req->iv, ivsize);
+       crypto_xor(buf, ctx->salt, ivsize);
+       memcpy(req->iv, buf, ivsize);
+
+       /* Swap order of IV and ESP AD for ICV generation. */
+       scatterwalk_map_and_copy(buf + ivsize, req->dst, 0, req->assoclen, 0);
+       scatterwalk_map_and_copy(buf, req->dst, 0, req->assoclen + ivsize, 1);
 
        err = crypto_aead_encrypt(subreq);
-       if (unlikely(info != req->iv))
-               seqiv_aead_encrypt_complete2(req, err);
+       seqniv_aead_encrypt_complete2(req, err);
        return err;
 }
 
@@ -294,17 +360,18 @@ static int seqiv_aead_encrypt(struct aead_request *req)
        crypto_completion_t compl;
        void *data;
        u8 *info;
-       unsigned int ivsize;
+       unsigned int ivsize = 8;
        int err;
 
+       if (req->cryptlen < ivsize)
+               return -EINVAL;
+
        aead_request_set_tfm(subreq, ctx->child);
 
        compl = req->base.complete;
        data = req->base.data;
        info = req->iv;
 
-       ivsize = crypto_aead_ivsize(geniv);
-
        if (req->src != req->dst) {
                struct scatterlist src[2];
                struct scatterlist dst[2];
@@ -339,7 +406,7 @@ static int seqiv_aead_encrypt(struct aead_request *req)
        aead_request_set_callback(subreq, req->base.flags, compl, data);
        aead_request_set_crypt(subreq, req->dst, req->dst,
                               req->cryptlen - ivsize, info);
-       aead_request_set_ad(subreq, req->assoclen + ivsize, 0);
+       aead_request_set_ad(subreq, req->assoclen + ivsize);
 
        crypto_xor(info, ctx->salt, ivsize);
        scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
@@ -354,26 +421,64 @@ static int seqiv_aead_decrypt_compat(struct aead_request *req)
 {
        struct crypto_aead *geniv = crypto_aead_reqtfm(req);
        struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
-       struct aead_request *subreq = aead_request_ctx(req);
+       struct seqniv_request_ctx *rctx = aead_request_ctx(req);
+       struct aead_request *subreq = &rctx->subreq;
+       struct scatterlist *dst;
        crypto_completion_t compl;
        void *data;
-       unsigned int ivsize;
+       unsigned int ivsize = 8;
+       u8 buf[20];
+       int err;
+
+       if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
+               return -EINVAL;
 
        aead_request_set_tfm(subreq, ctx->child);
 
        compl = req->base.complete;
        data = req->base.data;
 
-       ivsize = crypto_aead_ivsize(geniv);
+       if (req->assoclen > 12)
+               return -EINVAL;
+       else if (req->assoclen > 8) {
+               compl = seqniv_aead_decrypt_complete;
+               data = req;
+       }
+
+       if (req->src != req->dst) {
+               struct scatterlist srcbuf[2];
+               struct scatterlist dstbuf[2];
+               struct blkcipher_desc desc = {
+                       .tfm = ctx->null,
+               };
+
+               err = crypto_blkcipher_encrypt(
+                       &desc,
+                       scatterwalk_ffwd(dstbuf, req->dst,
+                                        req->assoclen + ivsize),
+                       scatterwalk_ffwd(srcbuf, req->src,
+                                        req->assoclen + ivsize),
+                       req->cryptlen - ivsize);
+               if (err)
+                       return err;
+       }
+
+       /* Move ESP AD forward for ICV generation. */
+       scatterwalk_map_and_copy(buf, req->dst, 0, req->assoclen + ivsize, 0);
+       memcpy(req->iv, buf + req->assoclen, ivsize);
+       scatterwalk_map_and_copy(buf, req->dst, ivsize, req->assoclen, 1);
+
+       dst = scatterwalk_ffwd(rctx->dst, req->dst, ivsize);
 
        aead_request_set_callback(subreq, req->base.flags, compl, data);
-       aead_request_set_crypt(subreq, req->src, req->dst,
+       aead_request_set_crypt(subreq, dst, dst,
                               req->cryptlen - ivsize, req->iv);
-       aead_request_set_ad(subreq, req->assoclen, ivsize);
+       aead_request_set_ad(subreq, req->assoclen);
 
-       scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
-
-       return crypto_aead_decrypt(subreq);
+       err = crypto_aead_decrypt(subreq);
+       if (req->assoclen > 8)
+               seqniv_aead_decrypt_complete2(req, err);
+       return err;
 }
 
 static int seqiv_aead_decrypt(struct aead_request *req)
@@ -383,19 +488,20 @@ static int seqiv_aead_decrypt(struct aead_request *req)
        struct aead_request *subreq = aead_request_ctx(req);
        crypto_completion_t compl;
        void *data;
-       unsigned int ivsize;
+       unsigned int ivsize = 8;
+
+       if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
+               return -EINVAL;
 
        aead_request_set_tfm(subreq, ctx->child);
 
        compl = req->base.complete;
        data = req->base.data;
 
-       ivsize = crypto_aead_ivsize(geniv);
-
        aead_request_set_callback(subreq, req->base.flags, compl, data);
        aead_request_set_crypt(subreq, req->src, req->dst,
                               req->cryptlen - ivsize, req->iv);
-       aead_request_set_ad(subreq, req->assoclen + ivsize, 0);
+       aead_request_set_ad(subreq, req->assoclen + ivsize);
 
        scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
        if (req->src != req->dst)
@@ -522,25 +628,7 @@ static int seqiv_old_aead_init(struct crypto_tfm *tfm)
        return aead_geniv_init(tfm);
 }
 
-static int seqiv_aead_compat_init(struct crypto_tfm *tfm)
-{
-       struct crypto_aead *geniv = __crypto_aead_cast(tfm);
-       struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
-       int err;
-
-       spin_lock_init(&ctx->lock);
-
-       crypto_aead_set_reqsize(geniv, sizeof(struct aead_request));
-
-       err = aead_geniv_init(tfm);
-
-       ctx->child = geniv->child;
-       geniv->child = geniv;
-
-       return err;
-}
-
-static int seqiv_aead_init(struct crypto_tfm *tfm)
+static int seqiv_aead_init_common(struct crypto_tfm *tfm, unsigned int reqsize)
 {
        struct crypto_aead *geniv = __crypto_aead_cast(tfm);
        struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
@@ -570,11 +658,14 @@ drop_null:
        goto out;
 }
 
-static void seqiv_aead_compat_exit(struct crypto_tfm *tfm)
+static int seqiv_aead_init(struct crypto_tfm *tfm)
 {
-       struct seqiv_aead_ctx *ctx = crypto_tfm_ctx(tfm);
+       return seqiv_aead_init_common(tfm, sizeof(struct aead_request));
+}
 
-       crypto_free_aead(ctx->child);
+static int seqniv_aead_init(struct crypto_tfm *tfm)
+{
+       return seqiv_aead_init_common(tfm, sizeof(struct seqniv_request_ctx));
 }
 
 static void seqiv_aead_exit(struct crypto_tfm *tfm)
@@ -669,7 +760,7 @@ static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb)
                return seqiv_old_aead_create(tmpl, inst);
 
        err = -EINVAL;
-       if (inst->alg.ivsize < sizeof(u64))
+       if (inst->alg.ivsize != sizeof(u64))
                goto free_inst;
 
        spawn = aead_instance_ctx(inst);
@@ -690,8 +781,8 @@ static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb)
                inst->alg.encrypt = seqiv_aead_encrypt_compat_first;
                inst->alg.decrypt = seqiv_aead_decrypt_compat;
 
-               inst->alg.base.cra_init = seqiv_aead_compat_init;
-               inst->alg.base.cra_exit = seqiv_aead_compat_exit;
+               inst->alg.base.cra_init = seqniv_aead_init;
+               inst->alg.base.cra_exit = seqiv_aead_exit;
        }
 
        err = aead_register_instance(tmpl, inst);
@@ -747,7 +838,7 @@ static int seqniv_create(struct crypto_template *tmpl, struct rtattr **tb)
                goto put_rng;
 
        err = -EINVAL;
-       if (inst->alg.ivsize < sizeof(u64))
+       if (inst->alg.ivsize != sizeof(u64))
                goto free_inst;
 
        spawn = aead_instance_ctx(inst);
@@ -758,8 +849,8 @@ static int seqniv_create(struct crypto_template *tmpl, struct rtattr **tb)
        inst->alg.encrypt = seqiv_aead_encrypt_compat_first;
        inst->alg.decrypt = seqiv_aead_decrypt_compat;
 
-       inst->alg.base.cra_init = seqiv_aead_compat_init;
-       inst->alg.base.cra_exit = seqiv_aead_compat_exit;
+       inst->alg.base.cra_init = seqniv_aead_init;
+       inst->alg.base.cra_exit = seqiv_aead_exit;
 
        inst->alg.base.cra_alignmask |= __alignof__(u32) - 1;
        inst->alg.base.cra_ctxsize = sizeof(struct seqiv_aead_ctx);
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