diff options
Diffstat (limited to 'crypto/cmac')
| -rw-r--r-- | crypto/cmac/cmac.c | 37 |
1 files changed, 32 insertions, 5 deletions
diff --git a/crypto/cmac/cmac.c b/crypto/cmac/cmac.c index b7cbba90c0..961df0d719 100644 --- a/crypto/cmac/cmac.c +++ b/crypto/cmac/cmac.c @@ -20,6 +20,7 @@ #include <openssl/cmac.h> #include <openssl/err.h> +#define LOCAL_BUF_SIZE 2048 struct CMAC_CTX_st { /* Cipher context to use */ EVP_CIPHER_CTX *cctx; @@ -162,6 +163,8 @@ int CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen) { const unsigned char *data = in; int bl; + size_t max_burst_blocks, cipher_blocks; + unsigned char buf[LOCAL_BUF_SIZE]; if (ctx->nlast_block == -1) return 0; @@ -188,11 +191,35 @@ int CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen) return 0; } /* Encrypt all but one of the complete blocks left */ - while (dlen > (size_t)bl) { - if (EVP_Cipher(ctx->cctx, ctx->tbl, data, bl) <= 0) - return 0; - dlen -= bl; - data += bl; + + max_burst_blocks = LOCAL_BUF_SIZE / bl; + cipher_blocks = (dlen - 1) / bl; + if (max_burst_blocks == 0) { + /* + * In case block length is greater than local buffer size, + * use ctx->tbl as cipher output. + */ + while (dlen > (size_t)bl) { + if (EVP_Cipher(ctx->cctx, ctx->tbl, data, bl) <= 0) + return 0; + dlen -= bl; + data += bl; + } + } else { + while (cipher_blocks > max_burst_blocks) { + if (EVP_Cipher(ctx->cctx, buf, data, max_burst_blocks * bl) <= 0) + return 0; + dlen -= max_burst_blocks * bl; + data += max_burst_blocks * bl; + cipher_blocks -= max_burst_blocks; + } + if (cipher_blocks > 0) { + if (EVP_Cipher(ctx->cctx, buf, data, cipher_blocks * bl) <= 0) + return 0; + dlen -= cipher_blocks * bl; + data += cipher_blocks * bl; + memcpy(ctx->tbl, &buf[(cipher_blocks - 1) * bl], bl); + } } /* Copy any data left to last block buffer */ memcpy(ctx->last_block, data, dlen); |