commit b688945dfbc8b0a27f510db259ec7c1aaa4bfb34 Author: Nick Mathewson nickm@torproject.org Date: Wed May 4 09:53:10 2016 -0400

Refactor digest allocation backend code

I'm doing this to simplify crypto_digest_smartlist_prefix, and make it better covered by our tests. --- src/common/crypto.c | 82 +++++++++++++++++++++++++---------------------------- 1 file changed, 38 insertions(+), 44 deletions(-)

diff --git a/src/common/crypto.c b/src/common/crypto.c index 9551435..8fdcfc1 100644 --- a/src/common/crypto.c +++ b/src/common/crypto.c @@ -1786,16 +1786,46 @@ crypto_digest_alloc_bytes(digest_algorithm_t alg) #undef STRUCT_FIELD_SIZE }

+/** + * Internal function: create and return a new digest object for 'algorithm'. + * Does not typecheck the algorithm. + */ +static crypto_digest_t * +crypto_digest_new_internal(digest_algorithm_t algorithm) +{ + crypto_digest_t *r = tor_malloc(crypto_digest_alloc_bytes(algorithm)); + r->algorithm = algorithm; + + switch (algorithm) + { + case DIGEST_SHA1: + SHA1_Init(&r->d.sha1); + break; + case DIGEST_SHA256: + SHA256_Init(&r->d.sha2); + break; + case DIGEST_SHA512: + SHA512_Init(&r->d.sha512); + break; + case DIGEST_SHA3_256: + keccak_digest_init(&r->d.sha3, 256); + break; + case DIGEST_SHA3_512: + keccak_digest_init(&r->d.sha3, 512); + break; + default: + tor_assert_unreached(); + } + + return r; +} + /** Allocate and return a new digest object to compute SHA1 digests. */ crypto_digest_t * crypto_digest_new(void) { - crypto_digest_t *r; - r = tor_malloc(crypto_digest_alloc_bytes(DIGEST_SHA1)); - SHA1_Init(&r->d.sha1); - r->algorithm = DIGEST_SHA1; - return r; + return crypto_digest_new_internal(DIGEST_SHA1); }

/** Allocate and return a new digest object to compute 256-bit digests @@ -1803,15 +1833,8 @@ crypto_digest_new(void) crypto_digest_t * crypto_digest256_new(digest_algorithm_t algorithm) { - crypto_digest_t *r; tor_assert(algorithm == DIGEST_SHA256 || algorithm == DIGEST_SHA3_256); - r = tor_malloc(crypto_digest_alloc_bytes(algorithm)); - if (algorithm == DIGEST_SHA256) - SHA256_Init(&r->d.sha2); - else - keccak_digest_init(&r->d.sha3, 256); - r->algorithm = algorithm; - return r; + return crypto_digest_new_internal(algorithm); }

/** Allocate and return a new digest object to compute 512-bit digests @@ -1819,15 +1842,8 @@ crypto_digest256_new(digest_algorithm_t algorithm) crypto_digest_t * crypto_digest512_new(digest_algorithm_t algorithm) { - crypto_digest_t *r; tor_assert(algorithm == DIGEST_SHA512 || algorithm == DIGEST_SHA3_512); - r = tor_malloc(crypto_digest_alloc_bytes(algorithm)); - if (algorithm == DIGEST_SHA512) - SHA512_Init(&r->d.sha512); - else - keccak_digest_init(&r->d.sha3, 512); - r->algorithm = algorithm; - return r; + return crypto_digest_new_internal(algorithm); }

/** Deallocate a digest object. @@ -1977,27 +1993,7 @@ crypto_digest_smartlist_prefix(char *digest_out, size_t len_out, const char *append, digest_algorithm_t alg) { - crypto_digest_t *d = NULL; - switch (alg) { - case DIGEST_SHA1: - d = crypto_digest_new(); - break; - case DIGEST_SHA256: /* FALLSTHROUGH */ - case DIGEST_SHA3_256: - d = crypto_digest256_new(alg); - break; - case DIGEST_SHA512: /* FALLSTHROUGH */ - case DIGEST_SHA3_512: - d = crypto_digest512_new(alg); - break; - default: - log_warn(LD_BUG, "Called with unknown algorithm %d", alg); - /* If fragile_assert is not enabled, wipe output and return - * without running any calculations */ - memwipe(digest_out, 0xff, len_out); - tor_fragile_assert(); - goto free; - } + crypto_digest_t *d = crypto_digest_new_internal(alg); if (prepend) crypto_digest_add_bytes(d, prepend, strlen(prepend)); SMARTLIST_FOREACH(lst, const char *, cp, @@ -2005,8 +2001,6 @@ crypto_digest_smartlist_prefix(char *digest_out, size_t len_out, if (append) crypto_digest_add_bytes(d, append, strlen(append)); crypto_digest_get_digest(d, digest_out, len_out); - - free: crypto_digest_free(d); }