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);