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Diffstat (limited to 'internal/stupidgcm/stupidchacha.go')
-rw-r--r--internal/stupidgcm/stupidchacha.go156
1 files changed, 0 insertions, 156 deletions
diff --git a/internal/stupidgcm/stupidchacha.go b/internal/stupidgcm/stupidchacha.go
deleted file mode 100644
index 5073aa3..0000000
--- a/internal/stupidgcm/stupidchacha.go
+++ /dev/null
@@ -1,156 +0,0 @@
-// +build !without_openssl
-
-package stupidgcm
-
-import (
- "crypto/cipher"
- "fmt"
- "log"
-
- "golang.org/x/crypto/chacha20poly1305"
-)
-
-/*
-#include <openssl/evp.h>
-#include "chacha.h"
-#cgo pkg-config: libcrypto
-*/
-import "C"
-
-type stupidChacha20poly1305 struct {
- key [chacha20poly1305.KeySize]byte
- wiped bool
-}
-
-// Verify that we satisfy the cipher.AEAD interface
-var _ cipher.AEAD = &stupidChacha20poly1305{}
-
-func newChacha20poly1305(key []byte) cipher.AEAD {
- if len(key) != chacha20poly1305.KeySize {
- log.Panicf("Only %d-byte keys are supported, you passed %d bytes", chacha20poly1305.KeySize, len(key))
- }
- ret := new(stupidChacha20poly1305)
- copy(ret.key[:], key)
- return ret
-}
-
-// NonceSize returns the required size of the nonce / IV.
-func (g *stupidChacha20poly1305) NonceSize() int {
- return chacha20poly1305.NonceSize
-}
-
-// Overhead returns the number of bytes that are added for authentication.
-func (g *stupidChacha20poly1305) Overhead() int {
- return tagLen
-}
-
-// Seal encrypts "in" using "iv" and "authData" and append the result to "dst"
-func (g *stupidChacha20poly1305) Seal(dst, iv, in, authData []byte) []byte {
- if g.wiped {
- panic("BUG: tried to use wiped key")
- }
- if len(iv) != g.NonceSize() {
- log.Panicf("Only %d-byte IVs are supported, you passed %d bytes", g.NonceSize(), len(iv))
- }
- if len(in) == 0 {
- log.Panic("Zero-length input data is not supported")
- }
- if len(g.key) != chacha20poly1305.KeySize {
- log.Panicf("Wrong key length: %d. Key has been wiped?", len(g.key))
- }
-
- // If the "dst" slice is large enough we can use it as our output buffer
- outLen := len(in) + tagLen
- var buf []byte
- inplace := false
- if cap(dst)-len(dst) >= outLen {
- inplace = true
- buf = dst[len(dst) : len(dst)+outLen]
- } else {
- buf = make([]byte, outLen)
- }
-
- C.aead_seal(C.aeadTypeChacha,
- (*C.uchar)(&in[0]),
- C.int(len(in)),
- (*C.uchar)(&authData[0]),
- C.int(len(authData)),
- (*C.uchar)(&g.key[0]),
- C.int(len(g.key)),
- (*C.uchar)(&iv[0]),
- C.int(len(iv)),
- (*C.uchar)(&buf[0]),
- C.int(len(buf)))
-
- if inplace {
- return dst[:len(dst)+outLen]
- }
- return append(dst, buf...)
-}
-
-// Open decrypts "in" using "iv" and "authData" and append the result to "dst"
-func (g *stupidChacha20poly1305) Open(dst, iv, in, authData []byte) ([]byte, error) {
- if g.wiped {
- panic("BUG: tried to use wiped key")
- }
- if len(iv) != g.NonceSize() {
- log.Panicf("Only %d-byte IVs are supported", g.NonceSize())
- }
- if len(g.key) != chacha20poly1305.KeySize {
- log.Panicf("Wrong key length: %d. Key has been wiped?", len(g.key))
- }
- if len(in) <= tagLen {
- return nil, fmt.Errorf("stupidChacha20poly1305: input data too short (%d bytes)", len(in))
- }
-
- // If the "dst" slice is large enough we can use it as our output buffer
- outLen := len(in) - tagLen
- var buf []byte
- inplace := false
- if cap(dst)-len(dst) >= outLen {
- inplace = true
- buf = dst[len(dst) : len(dst)+outLen]
- } else {
- buf = make([]byte, len(in)-tagLen)
- }
-
- ciphertext := in[:len(in)-tagLen]
- tag := in[len(in)-tagLen:]
-
- res := int(C.aead_open(C.aeadTypeChacha,
- (*C.uchar)(&ciphertext[0]),
- C.int(len(ciphertext)),
- (*C.uchar)(&authData[0]),
- C.int(len(authData)),
- (*C.uchar)(&tag[0]),
- C.int(len(tag)),
- (*C.uchar)(&g.key[0]),
- C.int(len(g.key)),
- (*C.uchar)(&iv[0]),
- C.int(len(iv)),
- (*C.uchar)(&buf[0]),
- C.int(len(buf))))
-
- if res < 0 {
- return nil, ErrAuth
- }
- if res != outLen {
- log.Panicf("unexpected length %d", res)
- }
-
- if inplace {
- return dst[:len(dst)+outLen], nil
- }
- return append(dst, buf...), nil
-}
-
-// Wipe tries to wipe the key from memory by overwriting it with zeros.
-//
-// This is not bulletproof due to possible GC copies, but
-// still raises the bar for extracting the key.
-func (g *stupidChacha20poly1305) Wipe() {
- g.wiped = true
- for i := range g.key {
- g.key[i] = 0
- }
-}