diff options
Diffstat (limited to 'internal/stupidgcm/stupidchacha.go')
-rw-r--r-- | internal/stupidgcm/stupidchacha.go | 156 |
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 - } -} |