diff options
Diffstat (limited to 'src/crypto/evp/scrypt.c')
| -rw-r--r-- | src/crypto/evp/scrypt.c | 82 |
1 files changed, 41 insertions, 41 deletions
diff --git a/src/crypto/evp/scrypt.c b/src/crypto/evp/scrypt.c index 3f102145..ed186eed 100644 --- a/src/crypto/evp/scrypt.c +++ b/src/crypto/evp/scrypt.c @@ -18,25 +18,25 @@ #include "../internal.h" -/* This file implements scrypt, described in RFC 7914. - * - * Note scrypt refers to both "blocks" and a "block size" parameter, r. These - * are two different notions of blocks. A Salsa20 block is 64 bytes long, - * represented in this implementation by 16 |uint32_t|s. |r| determines the - * number of 64-byte Salsa20 blocks in a scryptBlockMix block, which is 2 * |r| - * Salsa20 blocks. This implementation refers to them as Salsa20 blocks and - * scrypt blocks, respectively. */ - -/* A block_t is a Salsa20 block. */ +// This file implements scrypt, described in RFC 7914. +// +// Note scrypt refers to both "blocks" and a "block size" parameter, r. These +// are two different notions of blocks. A Salsa20 block is 64 bytes long, +// represented in this implementation by 16 |uint32_t|s. |r| determines the +// number of 64-byte Salsa20 blocks in a scryptBlockMix block, which is 2 * |r| +// Salsa20 blocks. This implementation refers to them as Salsa20 blocks and +// scrypt blocks, respectively. + +// A block_t is a Salsa20 block. typedef struct { uint32_t words[16]; } block_t; OPENSSL_COMPILE_ASSERT(sizeof(block_t) == 64, block_t_has_padding); #define R(a, b) (((a) << (b)) | ((a) >> (32 - (b)))) -/* salsa208_word_specification implements the Salsa20/8 core function, also - * described in RFC 7914, section 3. It modifies the block at |inout| - * in-place. */ +// salsa208_word_specification implements the Salsa20/8 core function, also +// described in RFC 7914, section 3. It modifies the block at |inout| +// in-place. static void salsa208_word_specification(block_t *inout) { block_t x; OPENSSL_memcpy(&x, inout, sizeof(x)); @@ -81,16 +81,16 @@ static void salsa208_word_specification(block_t *inout) { } } -/* xor_block sets |*out| to be |*a| XOR |*b|. */ +// xor_block sets |*out| to be |*a| XOR |*b|. static void xor_block(block_t *out, const block_t *a, const block_t *b) { for (size_t i = 0; i < 16; i++) { out->words[i] = a->words[i] ^ b->words[i]; } } -/* scryptBlockMix implements the function described in RFC 7914, section 4. B' - * is written to |out|. |out| and |B| may not alias and must be each one scrypt - * block (2 * |r| Salsa20 blocks) long. */ +// scryptBlockMix implements the function described in RFC 7914, section 4. B' +// is written to |out|. |out| and |B| may not alias and must be each one scrypt +// block (2 * |r| Salsa20 blocks) long. static void scryptBlockMix(block_t *out, const block_t *B, uint64_t r) { assert(out != B); @@ -100,19 +100,19 @@ static void scryptBlockMix(block_t *out, const block_t *B, uint64_t r) { xor_block(&X, &X, &B[i]); salsa208_word_specification(&X); - /* This implements the permutation in step 3. */ + // This implements the permutation in step 3. OPENSSL_memcpy(&out[i / 2 + (i & 1) * r], &X, sizeof(X)); } } -/* scryptROMix implements the function described in RFC 7914, section 5. |B| is - * an scrypt block (2 * |r| Salsa20 blocks) and is modified in-place. |T| and - * |V| are scratch space allocated by the caller. |T| must have space for one - * scrypt block (2 * |r| Salsa20 blocks). |V| must have space for |N| scrypt - * blocks (2 * |r| * |N| Salsa20 blocks). */ +// scryptROMix implements the function described in RFC 7914, section 5. |B| is +// an scrypt block (2 * |r| Salsa20 blocks) and is modified in-place. |T| and +// |V| are scratch space allocated by the caller. |T| must have space for one +// scrypt block (2 * |r| Salsa20 blocks). |V| must have space for |N| scrypt +// blocks (2 * |r| * |N| Salsa20 blocks). static void scryptROMix(block_t *B, uint64_t r, uint64_t N, block_t *T, block_t *V) { - /* Steps 1 and 2. */ + // Steps 1 and 2. OPENSSL_memcpy(V, B, 2 * r * sizeof(block_t)); for (uint64_t i = 1; i < N; i++) { scryptBlockMix(&V[2 * r * i /* scrypt block i */], @@ -120,9 +120,9 @@ static void scryptROMix(block_t *B, uint64_t r, uint64_t N, block_t *T, } scryptBlockMix(B, &V[2 * r * (N - 1) /* scrypt block N-1 */], r); - /* Step 3. */ + // Step 3. for (uint64_t i = 0; i < N; i++) { - /* Note this assumes |N| <= 2^32 and is a power of 2. */ + // Note this assumes |N| <= 2^32 and is a power of 2. uint32_t j = B[2 * r - 1].words[0] & (N - 1); for (size_t k = 0; k < 2 * r; k++) { xor_block(&T[k], &B[k], &V[2 * r * j + k]); @@ -131,16 +131,16 @@ static void scryptROMix(block_t *B, uint64_t r, uint64_t N, block_t *T, } } -/* SCRYPT_PR_MAX is the maximum value of p * r. This is equivalent to the - * bounds on p in section 6: - * - * p <= ((2^32-1) * hLen) / MFLen iff - * p <= ((2^32-1) * 32) / (128 * r) iff - * p * r <= (2^30-1) */ +// SCRYPT_PR_MAX is the maximum value of p * r. This is equivalent to the +// bounds on p in section 6: +// +// p <= ((2^32-1) * hLen) / MFLen iff +// p <= ((2^32-1) * 32) / (128 * r) iff +// p * r <= (2^30-1) #define SCRYPT_PR_MAX ((1 << 30) - 1) -/* SCRYPT_MAX_MEM is the default maximum memory that may be allocated by - * |EVP_PBE_scrypt|. */ +// SCRYPT_MAX_MEM is the default maximum memory that may be allocated by +// |EVP_PBE_scrypt|. #define SCRYPT_MAX_MEM (1024 * 1024 * 32) int EVP_PBE_scrypt(const char *password, size_t password_len, @@ -148,18 +148,18 @@ int EVP_PBE_scrypt(const char *password, size_t password_len, uint64_t p, size_t max_mem, uint8_t *out_key, size_t key_len) { if (r == 0 || p == 0 || p > SCRYPT_PR_MAX / r || - /* |N| must be a power of two. */ + // |N| must be a power of two. N < 2 || (N & (N - 1)) || - /* We only support |N| <= 2^32 in |scryptROMix|. */ + // We only support |N| <= 2^32 in |scryptROMix|. N > UINT64_C(1) << 32 || - /* Check that |N| < 2^(128×r / 8). */ + // Check that |N| < 2^(128×r / 8). (16 * r <= 63 && N >= UINT64_C(1) << (16 * r))) { OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_PARAMETERS); return 0; } - /* Determine the amount of memory needed. B, T, and V are |p|, 1, and |N| - * scrypt blocks, respectively. Each scrypt block is 2*|r| |block_t|s. */ + // Determine the amount of memory needed. B, T, and V are |p|, 1, and |N| + // scrypt blocks, respectively. Each scrypt block is 2*|r| |block_t|s. if (max_mem == 0) { max_mem = SCRYPT_MAX_MEM; } @@ -171,8 +171,8 @@ int EVP_PBE_scrypt(const char *password, size_t password_len, return 0; } - /* Allocate and divide up the scratch space. |max_mem| fits in a size_t, which - * is no bigger than uint64_t, so none of these operations may overflow. */ + // Allocate and divide up the scratch space. |max_mem| fits in a size_t, which + // is no bigger than uint64_t, so none of these operations may overflow. OPENSSL_COMPILE_ASSERT(UINT64_MAX >= ((size_t)-1), size_t_exceeds_u64); size_t B_blocks = p * 2 * r; size_t B_bytes = B_blocks * sizeof(block_t); |