From 14bb100b6cc4c875473af6659c8368198e898050 Mon Sep 17 00:00:00 2001 From: Andy Polyakov Date: Thu, 25 May 2017 18:08:09 +0200 Subject: [PATCH] modes/ocb128.c: address undefined behaviour warning. Reviewed-by: Rich Salz (Merged from https://github.com/openssl/openssl/pull/3526) --- crypto/modes/ocb128.c | 116 +++++++++++++++++++++--------------------- 1 file changed, 58 insertions(+), 58 deletions(-) diff --git a/crypto/modes/ocb128.c b/crypto/modes/ocb128.c index f6f8da7ab7..db794d0854 100644 --- a/crypto/modes/ocb128.c +++ b/crypto/modes/ocb128.c @@ -274,8 +274,7 @@ int CRYPTO_ocb128_aad(OCB128_CONTEXT *ctx, const unsigned char *aad, { u64 i, all_num_blocks; size_t num_blocks, last_len; - OCB_BLOCK tmp1; - OCB_BLOCK tmp2; + OCB_BLOCK tmp; /* Calculate the number of blocks of AAD provided now, and so far */ num_blocks = len / 16; @@ -284,7 +283,6 @@ int CRYPTO_ocb128_aad(OCB128_CONTEXT *ctx, const unsigned char *aad, /* Loop through all full blocks of AAD */ for (i = ctx->blocks_hashed + 1; i <= all_num_blocks; i++) { OCB_BLOCK *lookup; - OCB_BLOCK *aad_block; /* Offset_i = Offset_{i-1} xor L_{ntz(i)} */ lookup = ocb_lookup_l(ctx, ocb_ntz(i)); @@ -292,11 +290,13 @@ int CRYPTO_ocb128_aad(OCB128_CONTEXT *ctx, const unsigned char *aad, return 0; ocb_block16_xor(&ctx->offset_aad, lookup, &ctx->offset_aad); + memcpy(tmp.c, aad, 16); + aad += 16; + /* Sum_i = Sum_{i-1} xor ENCIPHER(K, A_i xor Offset_i) */ - aad_block = (OCB_BLOCK *)(aad + ((i - ctx->blocks_hashed - 1) * 16)); - ocb_block16_xor_misaligned(&ctx->offset_aad, aad_block, &tmp1); - ctx->encrypt(tmp1.c, tmp2.c, ctx->keyenc); - ocb_block16_xor(&ctx->sum, &tmp2, &ctx->sum); + ocb_block16_xor(&ctx->offset_aad, &tmp, &tmp); + ctx->encrypt(tmp.c, tmp.c, ctx->keyenc); + ocb_block16_xor(&tmp, &ctx->sum, &ctx->sum); } /* @@ -310,14 +310,14 @@ int CRYPTO_ocb128_aad(OCB128_CONTEXT *ctx, const unsigned char *aad, ocb_block16_xor(&ctx->offset_aad, &ctx->l_star, &ctx->offset_aad); /* CipherInput = (A_* || 1 || zeros(127-bitlen(A_*))) xor Offset_* */ - memset(&tmp1, 0, 16); - memcpy(&tmp1, aad + (num_blocks * 16), last_len); - ((unsigned char *)&tmp1)[last_len] = 0x80; - ocb_block16_xor(&ctx->offset_aad, &tmp1, &tmp2); + memset(tmp.c, 0, 16); + memcpy(tmp.c, aad, last_len); + tmp.c[last_len] = 0x80; + ocb_block16_xor(&ctx->offset_aad, &tmp, &tmp); /* Sum = Sum_m xor ENCIPHER(K, CipherInput) */ - ctx->encrypt(tmp2.c, tmp1.c, ctx->keyenc); - ocb_block16_xor(&ctx->sum, &tmp1, &ctx->sum); + ctx->encrypt(tmp.c, tmp.c, ctx->keyenc); + ocb_block16_xor(&tmp, &ctx->sum, &ctx->sum); } ctx->blocks_hashed = all_num_blocks; @@ -335,9 +335,6 @@ int CRYPTO_ocb128_encrypt(OCB128_CONTEXT *ctx, { u64 i, all_num_blocks; size_t num_blocks, last_len; - OCB_BLOCK tmp1; - OCB_BLOCK tmp2; - OCB_BLOCK pad; /* * Calculate the number of blocks of data to be encrypted provided now, and @@ -366,8 +363,7 @@ int CRYPTO_ocb128_encrypt(OCB128_CONTEXT *ctx, /* Loop through all full blocks to be encrypted */ for (i = ctx->blocks_processed + 1; i <= all_num_blocks; i++) { OCB_BLOCK *lookup; - OCB_BLOCK *inblock; - OCB_BLOCK *outblock; + OCB_BLOCK tmp; /* Offset_i = Offset_{i-1} xor L_{ntz(i)} */ lookup = ocb_lookup_l(ctx, ocb_ntz(i)); @@ -375,16 +371,19 @@ int CRYPTO_ocb128_encrypt(OCB128_CONTEXT *ctx, return 0; ocb_block16_xor(&ctx->offset, lookup, &ctx->offset); - /* C_i = Offset_i xor ENCIPHER(K, P_i xor Offset_i) */ - inblock = - (OCB_BLOCK *)(in + ((i - ctx->blocks_processed - 1) * 16)); - ocb_block16_xor_misaligned(&ctx->offset, inblock, &tmp1); + memcpy(tmp.c, in, 16); + in += 16; + /* Checksum_i = Checksum_{i-1} xor P_i */ - ocb_block16_xor_misaligned(&ctx->checksum, inblock, &ctx->checksum); - ctx->encrypt(tmp1.c, tmp2.c, ctx->keyenc); - outblock = - (OCB_BLOCK *)(out + ((i - ctx->blocks_processed - 1) * 16)); - ocb_block16_xor_misaligned(&ctx->offset, &tmp2, outblock); + ocb_block16_xor(&tmp, &ctx->checksum, &ctx->checksum); + + /* C_i = Offset_i xor ENCIPHER(K, P_i xor Offset_i) */ + ocb_block16_xor(&ctx->offset, &tmp, &tmp); + ctx->encrypt(tmp.c, tmp.c, ctx->keyenc); + ocb_block16_xor(&ctx->offset, &tmp, &tmp); + + memcpy(out, tmp.c, 16); + out += 16; } } @@ -395,6 +394,8 @@ int CRYPTO_ocb128_encrypt(OCB128_CONTEXT *ctx, last_len = len % 16; if (last_len > 0) { + OCB_BLOCK pad; + /* Offset_* = Offset_m xor L_* */ ocb_block16_xor(&ctx->offset, &ctx->l_star, &ctx->offset); @@ -402,14 +403,13 @@ int CRYPTO_ocb128_encrypt(OCB128_CONTEXT *ctx, ctx->encrypt(ctx->offset.c, pad.c, ctx->keyenc); /* C_* = P_* xor Pad[1..bitlen(P_*)] */ - ocb_block_xor(in + (len / 16) * 16, (unsigned char *)&pad, last_len, - out + (num_blocks * 16)); + ocb_block_xor(in, pad.c, last_len, out); /* Checksum_* = Checksum_m xor (P_* || 1 || zeros(127-bitlen(P_*))) */ - memset(&tmp1, 0, 16); - memcpy(&tmp1, in + (len / 16) * 16, last_len); - ((unsigned char *)(&tmp1))[last_len] = 0x80; - ocb_block16_xor(&ctx->checksum, &tmp1, &ctx->checksum); + memset(pad.c, 0, 16); /* borrow pad */ + memcpy(pad.c, in, last_len); + pad.c[last_len] = 0x80; + ocb_block16_xor(&pad, &ctx->checksum, &ctx->checksum); } ctx->blocks_processed = all_num_blocks; @@ -427,9 +427,6 @@ int CRYPTO_ocb128_decrypt(OCB128_CONTEXT *ctx, { u64 i, all_num_blocks; size_t num_blocks, last_len; - OCB_BLOCK tmp1; - OCB_BLOCK tmp2; - OCB_BLOCK pad; /* * Calculate the number of blocks of data to be decrypted provided now, and @@ -455,10 +452,10 @@ int CRYPTO_ocb128_decrypt(OCB128_CONTEXT *ctx, (size_t)ctx->blocks_processed + 1, ctx->offset.c, (const unsigned char (*)[16])ctx->l, ctx->checksum.c); } else { + OCB_BLOCK tmp; + /* Loop through all full blocks to be decrypted */ for (i = ctx->blocks_processed + 1; i <= all_num_blocks; i++) { - OCB_BLOCK *inblock; - OCB_BLOCK *outblock; /* Offset_i = Offset_{i-1} xor L_{ntz(i)} */ OCB_BLOCK *lookup = ocb_lookup_l(ctx, ocb_ntz(i)); @@ -466,17 +463,19 @@ int CRYPTO_ocb128_decrypt(OCB128_CONTEXT *ctx, return 0; ocb_block16_xor(&ctx->offset, lookup, &ctx->offset); + memcpy(tmp.c, in, 16); + in += 16; + /* P_i = Offset_i xor DECIPHER(K, C_i xor Offset_i) */ - inblock = - (OCB_BLOCK *)(in + ((i - ctx->blocks_processed - 1) * 16)); - ocb_block16_xor_misaligned(&ctx->offset, inblock, &tmp1); - ctx->decrypt(tmp1.c, tmp2.c, ctx->keydec); - outblock = - (OCB_BLOCK *)(out + ((i - ctx->blocks_processed - 1) * 16)); - ocb_block16_xor_misaligned(&ctx->offset, &tmp2, outblock); + ocb_block16_xor(&ctx->offset, &tmp, &tmp); + ctx->decrypt(tmp.c, tmp.c, ctx->keydec); + ocb_block16_xor(&ctx->offset, &tmp, &tmp); /* Checksum_i = Checksum_{i-1} xor P_i */ - ocb_block16_xor_misaligned(&ctx->checksum, outblock, &ctx->checksum); + ocb_block16_xor(&tmp, &ctx->checksum, &ctx->checksum); + + memcpy(out, tmp.c, 16); + out += 16; } } @@ -487,6 +486,8 @@ int CRYPTO_ocb128_decrypt(OCB128_CONTEXT *ctx, last_len = len % 16; if (last_len > 0) { + OCB_BLOCK pad; + /* Offset_* = Offset_m xor L_* */ ocb_block16_xor(&ctx->offset, &ctx->l_star, &ctx->offset); @@ -494,14 +495,13 @@ int CRYPTO_ocb128_decrypt(OCB128_CONTEXT *ctx, ctx->encrypt(ctx->offset.c, pad.c, ctx->keyenc); /* P_* = C_* xor Pad[1..bitlen(C_*)] */ - ocb_block_xor(in + (len / 16) * 16, (unsigned char *)&pad, last_len, - out + (num_blocks * 16)); + ocb_block_xor(in, pad.c, last_len, out); /* Checksum_* = Checksum_m xor (P_* || 1 || zeros(127-bitlen(P_*))) */ - memset(&tmp1, 0, 16); - memcpy(&tmp1, out + (len / 16) * 16, last_len); - ((unsigned char *)(&tmp1))[last_len] = 0x80; - ocb_block16_xor(&ctx->checksum, &tmp1, &ctx->checksum); + memset(pad.c, 0, 16); /* borrow pad */ + memcpy(pad.c, out, last_len); + pad.c[last_len] = 0x80; + ocb_block16_xor(&pad, &ctx->checksum, &ctx->checksum); } ctx->blocks_processed = all_num_blocks; @@ -515,15 +515,15 @@ int CRYPTO_ocb128_decrypt(OCB128_CONTEXT *ctx, int CRYPTO_ocb128_finish(OCB128_CONTEXT *ctx, const unsigned char *tag, size_t len) { - OCB_BLOCK tmp1, tmp2; + OCB_BLOCK tmp; /* * Tag = ENCIPHER(K, Checksum_* xor Offset_* xor L_$) xor HASH(K,A) */ - ocb_block16_xor(&ctx->checksum, &ctx->offset, &tmp1); - ocb_block16_xor(&tmp1, &ctx->l_dollar, &tmp2); - ctx->encrypt(tmp2.c, tmp1.c, ctx->keyenc); - ocb_block16_xor(&tmp1, &ctx->sum, &ctx->tag); + ocb_block16_xor(&ctx->checksum, &ctx->offset, &tmp); + ocb_block16_xor(&ctx->l_dollar, &tmp, &tmp); + ctx->encrypt(tmp.c, tmp.c, ctx->keyenc); + ocb_block16_xor(&tmp, &ctx->sum, &ctx->tag); if (len > 16 || len < 1) { return -1; @@ -549,7 +549,7 @@ int CRYPTO_ocb128_tag(OCB128_CONTEXT *ctx, unsigned char *tag, size_t len) CRYPTO_ocb128_finish(ctx, NULL, 0); /* Copy the tag into the supplied buffer */ - memcpy(tag, &ctx->tag, len); + memcpy(tag, ctx->tag.c, len); return 1; } -- 2.25.1