From 456bee986e0a372ad4beed5d3cedb3622633d9df Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 20 Sep 2016 20:35:55 +0800 Subject: [PATCH 1/2] KEYS: Fix skcipher IV clobbering The IV must not be modified by the skcipher operation so we need to duplicate it. Fixes: c3917fd9dfbc ("KEYS: Use skcipher") Cc: stable@vger.kernel.org Reported-by: Mimi Zohar Signed-off-by: Herbert Xu --- security/keys/encrypted-keys/encrypted.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c index 5adbfc32242f..17a06105ccb6 100644 --- a/security/keys/encrypted-keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -478,6 +479,7 @@ static int derived_key_encrypt(struct encrypted_key_payload *epayload, struct crypto_skcipher *tfm; struct skcipher_request *req; unsigned int encrypted_datalen; + u8 iv[AES_BLOCK_SIZE]; unsigned int padlen; char pad[16]; int ret; @@ -500,8 +502,8 @@ static int derived_key_encrypt(struct encrypted_key_payload *epayload, sg_init_table(sg_out, 1); sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen); - skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, - epayload->iv); + memcpy(iv, epayload->iv, sizeof(iv)); + skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, iv); ret = crypto_skcipher_encrypt(req); tfm = crypto_skcipher_reqtfm(req); skcipher_request_free(req); @@ -581,6 +583,7 @@ static int derived_key_decrypt(struct encrypted_key_payload *epayload, struct crypto_skcipher *tfm; struct skcipher_request *req; unsigned int encrypted_datalen; + u8 iv[AES_BLOCK_SIZE]; char pad[16]; int ret; @@ -599,8 +602,8 @@ static int derived_key_decrypt(struct encrypted_key_payload *epayload, epayload->decrypted_datalen); sg_set_buf(&sg_out[1], pad, sizeof pad); - skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, - epayload->iv); + memcpy(iv, epayload->iv, sizeof(iv)); + skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, iv); ret = crypto_skcipher_decrypt(req); tfm = crypto_skcipher_reqtfm(req); skcipher_request_free(req); From 0cf43f509f72128196e23f5ade7e512a72152cc6 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 22 Sep 2016 17:04:57 +0800 Subject: [PATCH 2/2] crypto: rsa-pkcs1pad - Handle leading zero for decryption As the software RSA implementation now produces fixed-length output, we need to eliminate leading zeros in the calling code instead. This patch does just that for pkcs1pad decryption while signature verification was fixed in an earlier patch. Fixes: 9b45b7bba3d2 ("crypto: rsa - Generate fixed-length output") Reported-by: Mat Martineau Signed-off-by: Herbert Xu --- crypto/rsa-pkcs1pad.c | 41 ++++++++++++++++++++++++----------------- 1 file changed, 24 insertions(+), 17 deletions(-) diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c index 877019a6d3ea..8baab4307f7b 100644 --- a/crypto/rsa-pkcs1pad.c +++ b/crypto/rsa-pkcs1pad.c @@ -298,41 +298,48 @@ static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err) struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); + unsigned int dst_len; unsigned int pos; - - if (err == -EOVERFLOW) - /* Decrypted value had no leading 0 byte */ - err = -EINVAL; + u8 *out_buf; if (err) goto done; - if (req_ctx->child_req.dst_len != ctx->key_size - 1) { - err = -EINVAL; + err = -EINVAL; + dst_len = req_ctx->child_req.dst_len; + if (dst_len < ctx->key_size - 1) goto done; + + out_buf = req_ctx->out_buf; + if (dst_len == ctx->key_size) { + if (out_buf[0] != 0x00) + /* Decrypted value had no leading 0 byte */ + goto done; + + dst_len--; + out_buf++; } - if (req_ctx->out_buf[0] != 0x02) { - err = -EINVAL; + if (out_buf[0] != 0x02) goto done; - } - for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) - if (req_ctx->out_buf[pos] == 0x00) + + for (pos = 1; pos < dst_len; pos++) + if (out_buf[pos] == 0x00) break; - if (pos < 9 || pos == req_ctx->child_req.dst_len) { - err = -EINVAL; + if (pos < 9 || pos == dst_len) goto done; - } pos++; - if (req->dst_len < req_ctx->child_req.dst_len - pos) + err = 0; + + if (req->dst_len < dst_len - pos) err = -EOVERFLOW; - req->dst_len = req_ctx->child_req.dst_len - pos; + req->dst_len = dst_len - pos; if (!err) sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst, req->dst_len), - req_ctx->out_buf + pos, req->dst_len); + out_buf + pos, req->dst_len); done: kzfree(req_ctx->out_buf);