openssl: Use EVP API for AES.

opensssl-1.1 no longer exports AES_set_encrypt_key() and
AES_ctr128_encrypt(). Applications are supposed to use the high-level
EVP interface instead.

Fortunately, the EVP library functions necessary for our use of
the AES_ctr128 stream cipher are available in openssl version 1.0.1
and above, so switching to the EVP API makes the code work with all
versions >= 1.0.1.

diff --git a/crypt.c b/crypt.c
index 610d2057947dba6757526127a317f8b87bf7eebc..06ae6265010a946bd51a1e64b1c620f0e4c89fc3 100644 (file)
--- a/crypt.c
+++ b/crypt.c
@@ -260,27 +260,18 @@ int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
        return ret < 0? -E_ENCRYPT : ret;
 }
 
-struct aes_ctr_128_context {
-       AES_KEY key;
-       unsigned char ivec[AES_CRT128_BLOCK_SIZE];
-       unsigned char ecount[AES_CRT128_BLOCK_SIZE];
-       unsigned int num;
-};
-
 struct stream_cipher {
        bool use_aes;
        union {
                RC4_KEY rc4_key;
-               struct aes_ctr_128_context aes;
+               EVP_CIPHER_CTX *aes;
        } context;
 };
 
 struct stream_cipher *sc_new(const unsigned char *data, int len,
                bool use_aes)
 {
-       int ret;
        struct stream_cipher *sc = para_malloc(sizeof(*sc));
-       struct aes_ctr_128_context *aes;
 
        sc->use_aes = use_aes;
        if (!use_aes) {
@@ -288,17 +279,17 @@ struct stream_cipher *sc_new(const unsigned char *data, int len,
                return sc;
        }
        assert(len >= 2 * AES_CRT128_BLOCK_SIZE);
-       aes = &sc->context.aes;
-       ret = AES_set_encrypt_key(data, AES_CRT128_BLOCK_SIZE * 8 /* bits */,
-               &aes->key);
-       assert(ret == 0);
-       memcpy(aes->ivec, data + AES_CRT128_BLOCK_SIZE, AES_CRT128_BLOCK_SIZE);
-       aes->num = 0;
+       sc->context.aes = EVP_CIPHER_CTX_new();
+       EVP_EncryptInit_ex(sc->context.aes, EVP_aes_128_ctr(), NULL, data,
+               data + AES_CRT128_BLOCK_SIZE);
        return sc;
 }
 
 void sc_free(struct stream_cipher *sc)
 {
+       if (!sc)
+               return;
+       EVP_CIPHER_CTX_free(sc->context.aes);
        free(sc);
 }
 
@@ -332,25 +323,29 @@ static void rc4_crypt(RC4_KEY *key, struct iovec *src, struct iovec *dst)
        ((char *)dst->iov_base)[len] = '\0';
 }
 
-static void aes_ctr128_crypt(struct aes_ctr_128_context *aes, struct iovec *src,
+static void aes_ctr128_crypt(EVP_CIPHER_CTX *ctx, struct iovec *src,
                struct iovec *dst)
 {
-       size_t len = src->iov_len;
+       int ret, inlen = src->iov_len, outlen, tmplen;
 
        *dst = (typeof(*dst)) {
                /* Add one for the terminating zero byte. */
-               .iov_base = para_malloc(len + 1),
-               .iov_len = len
+               .iov_base = para_malloc(inlen + 1),
+               .iov_len = inlen
        };
-       AES_ctr128_encrypt(src->iov_base, dst->iov_base, len,
-               &aes->key, aes->ivec, aes->ecount, &aes->num);
-       ((char *)dst->iov_base)[len] = '\0';
+       ret = EVP_EncryptUpdate(ctx, dst->iov_base, &outlen, src->iov_base, inlen);
+       assert(ret != 0);
+       ret = EVP_EncryptFinal_ex(ctx, dst->iov_base + outlen, &tmplen);
+       assert(ret != 0);
+       outlen += tmplen;
+       ((char *)dst->iov_base)[outlen] = '\0';
+       dst->iov_len = outlen;
 }
 
 void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
 {
        if (sc->use_aes)
-               return aes_ctr128_crypt(&sc->context.aes, src, dst);
+               return aes_ctr128_crypt(sc->context.aes, src, dst);
        return rc4_crypt(&sc->context.rc4_key, src, dst);
 }