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author | Roland Shoemaker <roland@golang.org> | 2022-04-25 19:02:35 -0700 |
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committer | Alex Rakoczy <alex@golang.org> | 2022-05-25 19:26:16 +0000 |
commit | 2be03d789de905a4b050ff5f3a51b724e1b09494 (patch) | |
tree | c7b85c81b9cf6aa0fa9c3de63ae5bb36b5919137 /src/crypto/rand/rand.go | |
parent | 65701ad2b430466dd4bd6e1df107f81c0f8ee9cb (diff) | |
download | go-2be03d789de905a4b050ff5f3a51b724e1b09494.tar.gz go-2be03d789de905a4b050ff5f3a51b724e1b09494.zip |
[release-branch.go1.17] crypto/rand: properly handle large Read on windows
Use the batched reader to chunk large Read calls on windows to a max of
1 << 31 - 1 bytes. This prevents an infinite loop when trying to read
more than 1 << 32 -1 bytes, due to how RtlGenRandom works.
This change moves the batched function from rand_unix.go to rand.go,
since it is now needed for both windows and unix implementations.
Updates #52561
Fixes #52932
Fixes CVE-2022-30634
Change-Id: Id98fc4b1427e5cb2132762a445b2aed646a37473
Reviewed-on: https://go-review.googlesource.com/c/go/+/402257
Run-TryBot: Roland Shoemaker <roland@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Filippo Valsorda <valsorda@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
(cherry picked from commit bb1f4416180511231de6d17a1f2f55c82aafc863)
Reviewed-on: https://go-review.googlesource.com/c/go/+/406635
Reviewed-by: Damien Neil <dneil@google.com>
Diffstat (limited to 'src/crypto/rand/rand.go')
-rw-r--r-- | src/crypto/rand/rand.go | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/src/crypto/rand/rand.go b/src/crypto/rand/rand.go index fddd1147e6e..f2c276008d7 100644 --- a/src/crypto/rand/rand.go +++ b/src/crypto/rand/rand.go @@ -23,3 +23,21 @@ var Reader io.Reader func Read(b []byte) (n int, err error) { return io.ReadFull(Reader, b) } + +// batched returns a function that calls f to populate a []byte by chunking it +// into subslices of, at most, readMax bytes. +func batched(f func([]byte) error, readMax int) func([]byte) error { + return func(out []byte) error { + for len(out) > 0 { + read := len(out) + if read > readMax { + read = readMax + } + if err := f(out[:read]); err != nil { + return err + } + out = out[read:] + } + return nil + } +} |