diff options
Diffstat (limited to 'src/crypto/internal/boring/aes.go')
-rw-r--r-- | src/crypto/internal/boring/aes.go | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/src/crypto/internal/boring/aes.go b/src/crypto/internal/boring/aes.go new file mode 100644 index 0000000000..8ca03b3f3e --- /dev/null +++ b/src/crypto/internal/boring/aes.go @@ -0,0 +1,357 @@ +// Copyright 2017 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build linux,amd64 +// +build !android +// +build !cmd_go_bootstrap +// +build !msan + +package boring + +// #include "goboringcrypto.h" +import "C" +import ( + "crypto/cipher" + "errors" + "runtime" + "strconv" + "unsafe" +) + +type aesKeySizeError int + +func (k aesKeySizeError) Error() string { + return "crypto/aes: invalid key size " + strconv.Itoa(int(k)) +} + +const aesBlockSize = 16 + +type aesCipher struct { + key []byte + enc C.GO_AES_KEY + dec C.GO_AES_KEY +} + +type extraModes interface { + // Copied out of crypto/aes/modes.go. + NewCBCEncrypter(iv []byte) cipher.BlockMode + NewCBCDecrypter(iv []byte) cipher.BlockMode + NewCTR(iv []byte) cipher.Stream + NewGCM(nonceSize int) (cipher.AEAD, error) + + // Invented for BoringCrypto. + NewGCMTLS() (cipher.AEAD, error) +} + +var _ extraModes = (*aesCipher)(nil) + +func NewAESCipher(key []byte) (cipher.Block, error) { + c := &aesCipher{key: make([]byte, len(key))} + copy(c.key, key) + // Note: 0 is success, contradicting the usual BoringCrypto convention. + if C._goboringcrypto_AES_set_decrypt_key((*C.uint8_t)(unsafe.Pointer(&c.key[0])), C.uint(8*len(c.key)), &c.dec) != 0 || + C._goboringcrypto_AES_set_encrypt_key((*C.uint8_t)(unsafe.Pointer(&c.key[0])), C.uint(8*len(c.key)), &c.enc) != 0 { + return nil, aesKeySizeError(len(key)) + } + return c, nil +} + +func (c *aesCipher) BlockSize() int { return aesBlockSize } + +func (c *aesCipher) Encrypt(dst, src []byte) { + if inexactOverlap(dst, src) { + panic("crypto/cipher: invalid buffer overlap") + } + if len(src) < aesBlockSize { + panic("crypto/aes: input not full block") + } + if len(dst) < aesBlockSize { + panic("crypto/aes: output not full block") + } + C._goboringcrypto_AES_encrypt( + (*C.uint8_t)(unsafe.Pointer(&src[0])), + (*C.uint8_t)(unsafe.Pointer(&dst[0])), + &c.enc) +} + +func (c *aesCipher) Decrypt(dst, src []byte) { + if inexactOverlap(dst, src) { + panic("crypto/cipher: invalid buffer overlap") + } + if len(src) < aesBlockSize { + panic("crypto/aes: input not full block") + } + if len(dst) < aesBlockSize { + panic("crypto/aes: output not full block") + } + C._goboringcrypto_AES_decrypt( + (*C.uint8_t)(unsafe.Pointer(&src[0])), + (*C.uint8_t)(unsafe.Pointer(&dst[0])), + &c.dec) +} + +type aesCBC struct { + key *C.GO_AES_KEY + mode C.int + iv [aesBlockSize]byte +} + +func (x *aesCBC) BlockSize() int { return aesBlockSize } + +func (x *aesCBC) CryptBlocks(dst, src []byte) { + if inexactOverlap(dst, src) { + panic("crypto/cipher: invalid buffer overlap") + } + if len(src)%aesBlockSize != 0 { + panic("crypto/cipher: input not full blocks") + } + if len(dst) < len(src) { + panic("crypto/cipher: output smaller than input") + } + if len(src) > 0 { + C._goboringcrypto_AES_cbc_encrypt( + (*C.uint8_t)(unsafe.Pointer(&src[0])), + (*C.uint8_t)(unsafe.Pointer(&dst[0])), + C.size_t(len(src)), x.key, + (*C.uint8_t)(unsafe.Pointer(&x.iv[0])), x.mode) + } +} + +func (x *aesCBC) SetIV(iv []byte) { + if len(iv) != aesBlockSize { + panic("cipher: incorrect length IV") + } + copy(x.iv[:], iv) +} + +func (c *aesCipher) NewCBCEncrypter(iv []byte) cipher.BlockMode { + x := &aesCBC{key: &c.enc, mode: C.GO_AES_ENCRYPT} + copy(x.iv[:], iv) + return x +} + +func (c *aesCipher) NewCBCDecrypter(iv []byte) cipher.BlockMode { + x := &aesCBC{key: &c.dec, mode: C.GO_AES_DECRYPT} + copy(x.iv[:], iv) + return x +} + +type aesCTR struct { + key *C.GO_AES_KEY + iv [aesBlockSize]byte + num C.uint + ecount_buf [16]C.uint8_t +} + +func (x *aesCTR) XORKeyStream(dst, src []byte) { + if inexactOverlap(dst, src) { + panic("crypto/cipher: invalid buffer overlap") + } + if len(dst) < len(src) { + panic("crypto/cipher: output smaller than input") + } + if len(src) == 0 { + return + } + C._goboringcrypto_AES_ctr128_encrypt( + (*C.uint8_t)(unsafe.Pointer(&src[0])), + (*C.uint8_t)(unsafe.Pointer(&dst[0])), + C.size_t(len(src)), x.key, (*C.uint8_t)(unsafe.Pointer(&x.iv[0])), + &x.ecount_buf[0], &x.num) +} + +func (c *aesCipher) NewCTR(iv []byte) cipher.Stream { + x := &aesCTR{key: &c.enc} + copy(x.iv[:], iv) + return x +} + +type aesGCM struct { + ctx C.GO_EVP_AEAD_CTX + aead *C.GO_EVP_AEAD +} + +const ( + gcmBlockSize = 16 + gcmTagSize = 16 + gcmStandardNonceSize = 12 +) + +type aesNonceSizeError int + +func (n aesNonceSizeError) Error() string { + return "crypto/aes: invalid GCM nonce size " + strconv.Itoa(int(n)) +} + +type noGCM struct { + cipher.Block +} + +func (c *aesCipher) NewGCM(nonceSize int) (cipher.AEAD, error) { + return c.newGCM(nonceSize, false) +} + +func (c *aesCipher) NewGCMTLS() (cipher.AEAD, error) { + return c.newGCM(gcmStandardNonceSize, true) +} + +func (c *aesCipher) newGCM(nonceSize int, tls bool) (cipher.AEAD, error) { + if nonceSize != gcmStandardNonceSize { + // Fall back to standard library for GCM with non-standard nonce size. + return cipher.NewGCMWithNonceSize(&noGCM{c}, nonceSize) + } + + var aead *C.GO_EVP_AEAD + switch len(c.key) * 8 { + case 128: + if tls { + aead = C._goboringcrypto_EVP_aead_aes_128_gcm_tls12() + } else { + aead = C._goboringcrypto_EVP_aead_aes_128_gcm() + } + case 256: + if tls { + aead = C._goboringcrypto_EVP_aead_aes_256_gcm_tls12() + } else { + aead = C._goboringcrypto_EVP_aead_aes_256_gcm() + } + default: + // Fall back to standard library for GCM with non-standard key size. + return cipher.NewGCMWithNonceSize(&noGCM{c}, nonceSize) + } + + g := &aesGCM{aead: aead} + if C._goboringcrypto_EVP_AEAD_CTX_init(&g.ctx, aead, (*C.uint8_t)(unsafe.Pointer(&c.key[0])), C.size_t(len(c.key)), C.GO_EVP_AEAD_DEFAULT_TAG_LENGTH, nil) == 0 { + return nil, fail("EVP_AEAD_CTX_init") + } + // Note: Because of the finalizer, any time g.ctx is passed to cgo, + // that call must be followed by a call to runtime.KeepAlive(g), + // to make sure g is not collected (and finalized) before the cgo + // call returns. + runtime.SetFinalizer(g, (*aesGCM).finalize) + if g.NonceSize() != nonceSize { + panic("boringcrypto: internal confusion about nonce size") + } + if g.Overhead() != gcmTagSize { + panic("boringcrypto: internal confusion about tag size") + } + + return g, nil +} + +func (g *aesGCM) finalize() { + C._goboringcrypto_EVP_AEAD_CTX_cleanup(&g.ctx) +} + +func (g *aesGCM) NonceSize() int { + return int(C._goboringcrypto_EVP_AEAD_nonce_length(g.aead)) +} + +func (g *aesGCM) Overhead() int { + return int(C._goboringcrypto_EVP_AEAD_max_overhead(g.aead)) +} + +// base returns the address of the underlying array in b, +// being careful not to panic when b has zero length. +func base(b []byte) *C.uint8_t { + if len(b) == 0 { + return nil + } + return (*C.uint8_t)(unsafe.Pointer(&b[0])) +} + +func (g *aesGCM) Seal(dst, nonce, plaintext, additionalData []byte) []byte { + if len(nonce) != gcmStandardNonceSize { + panic("cipher: incorrect nonce length given to GCM") + } + if uint64(len(plaintext)) > ((1<<32)-2)*aesBlockSize || len(plaintext)+gcmTagSize < len(plaintext) { + panic("cipher: message too large for GCM") + } + if len(dst)+len(plaintext)+gcmTagSize < len(dst) { + panic("cipher: message too large for buffer") + } + + // Make room in dst to append plaintext+overhead. + n := len(dst) + for cap(dst) < n+len(plaintext)+gcmTagSize { + dst = append(dst[:cap(dst)], 0) + } + dst = dst[:n+len(plaintext)+gcmTagSize] + + // Check delayed until now to make sure len(dst) is accurate. + if inexactOverlap(dst[n:], plaintext) { + panic("cipher: invalid buffer overlap") + } + + var outLen C.size_t + ok := C._goboringcrypto_EVP_AEAD_CTX_seal( + &g.ctx, + (*C.uint8_t)(unsafe.Pointer(&dst[n])), &outLen, C.size_t(len(plaintext)+gcmTagSize), + base(nonce), C.size_t(len(nonce)), + base(plaintext), C.size_t(len(plaintext)), + base(additionalData), C.size_t(len(additionalData))) + runtime.KeepAlive(g) + if ok == 0 { + panic(fail("EVP_AEAD_CTX_seal")) + } + if outLen != C.size_t(len(plaintext)+gcmTagSize) { + panic("boringcrypto: internal confusion about GCM tag size") + } + return dst[:n+int(outLen)] +} + +var errOpen = errors.New("cipher: message authentication failed") + +func (g *aesGCM) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) { + if len(nonce) != gcmStandardNonceSize { + panic("cipher: incorrect nonce length given to GCM") + } + if len(ciphertext) < gcmTagSize { + return nil, errOpen + } + if uint64(len(ciphertext)) > ((1<<32)-2)*aesBlockSize+gcmTagSize { + return nil, errOpen + } + + // Make room in dst to append ciphertext without tag. + n := len(dst) + for cap(dst) < n+len(ciphertext)-gcmTagSize { + dst = append(dst[:cap(dst)], 0) + } + dst = dst[:n+len(ciphertext)-gcmTagSize] + + // Check delayed until now to make sure len(dst) is accurate. + if inexactOverlap(dst[n:], ciphertext) { + panic("cipher: invalid buffer overlap") + } + + var outLen C.size_t + ok := C._goboringcrypto_EVP_AEAD_CTX_open( + &g.ctx, + base(dst[n:]), &outLen, C.size_t(len(ciphertext)-gcmTagSize), + base(nonce), C.size_t(len(nonce)), + base(ciphertext), C.size_t(len(ciphertext)), + base(additionalData), C.size_t(len(additionalData))) + runtime.KeepAlive(g) + if ok == 0 { + return nil, errOpen + } + if outLen != C.size_t(len(ciphertext)-gcmTagSize) { + panic("boringcrypto: internal confusion about GCM tag size") + } + return dst[:n+int(outLen)], nil +} + +func anyOverlap(x, y []byte) bool { + return len(x) > 0 && len(y) > 0 && + uintptr(unsafe.Pointer(&x[0])) <= uintptr(unsafe.Pointer(&y[len(y)-1])) && + uintptr(unsafe.Pointer(&y[0])) <= uintptr(unsafe.Pointer(&x[len(x)-1])) +} + +func inexactOverlap(x, y []byte) bool { + if len(x) == 0 || len(y) == 0 || &x[0] == &y[0] { + return false + } + return anyOverlap(x, y) +} |