# define SRP_RANDOM_SALT_LEN 20
# define MAX_LEN 2500
+/*
+ * Note that SRP uses its own variant of base 64 encoding. A different base64
+ * alphabet is used and no padding '=' characters are added. Instead we pad to
+ * the front with 0 bytes and subsequently strip off leading encoded padding.
+ * This variant is used for compatibility with other SRP implementations -
+ * notably libsrp, but also others. It is also required for backwards
+ * compatibility in order to load verifier files from other OpenSSL versions.
+ */
+
/*
* Convert a base64 string into raw byte array representation.
* Returns the length of the decoded data, or -1 on error.
{
EVP_ENCODE_CTX *ctx;
int outl = 0, outl2 = 0;
- size_t size = strlen(src);
+ size_t size, padsize;
+ const unsigned char *pad = (const unsigned char *)"00";
- if (size > INT_MAX)
+ while (*src == ' ' || *src == '\t' || *src == '\n')
+ ++src;
+ size = strlen(src);
+ padsize = 4 - (size & 3);
+ padsize &= 3;
+
+ /* Four bytes in src become three bytes output. */
+ if (size > INT_MAX || ((size + padsize) / 4) * 3 > alen)
return -1;
ctx = EVP_ENCODE_CTX_new();
if (ctx == NULL)
return -1;
+ /*
+ * This should never occur because 1 byte of data always requires 2 bytes of
+ * encoding, i.e.
+ * 0 bytes unencoded = 0 bytes encoded
+ * 1 byte unencoded = 2 bytes encoded
+ * 2 bytes unencoded = 3 bytes encoded
+ * 3 bytes unencoded = 4 bytes encoded
+ * 4 bytes unencoded = 6 bytes encoded
+ * etc
+ */
+ if (padsize == 3) {
+ outl = -1;
+ goto err;
+ }
+
+ /* Valid padsize values are now 0, 1 or 2 */
+
EVP_DecodeInit(ctx);
- if (EVP_DecodeUpdate(ctx, a, &outl, (const unsigned char *)src, size) < 0) {
- EVP_ENCODE_CTX_free(ctx);
- return -1;
+ evp_encode_ctx_set_flags(ctx, EVP_ENCODE_CTX_USE_SRP_ALPHABET);
+
+ /* Add any encoded padding that is required */
+ if (padsize != 0
+ && EVP_DecodeUpdate(ctx, a, &outl, pad, padsize) < 0) {
+ outl = -1;
+ goto err;
}
+ if (EVP_DecodeUpdate(ctx, a, &outl2, (const unsigned char *)src, size) < 0) {
+ outl = -1;
+ goto err;
+ }
+ outl += outl2;
EVP_DecodeFinal(ctx, a + outl, &outl2);
+ outl += outl2;
+
+ /* Strip off the leading padding */
+ if (padsize != 0) {
+ if ((int)padsize >= outl) {
+ outl = -1;
+ goto err;
+ }
+ /*
+ * If we added 1 byte of padding prior to encoding then we have 2 bytes
+ * of "real" data which gets spread across 4 encoded bytes like this:
+ * (6 bits pad)(2 bits pad | 4 bits data)(6 bits data)(6 bits data)
+ * So 1 byte of pre-encoding padding results in 1 full byte of encoded
+ * padding.
+ * If we added 2 bytes of padding prior to encoding this gets encoded
+ * as:
+ * (6 bits pad)(6 bits pad)(4 bits pad | 2 bits data)(6 bits data)
+ * So 2 bytes of pre-encoding padding results in 2 full bytes of encoded
+ * padding, i.e. we have to strip the same number of bytes of padding
+ * from the encoded data as we added to the pre-encoded data.
+ */
+ memmove(a, a + padsize, outl - padsize);
+ outl -= padsize;
+ }
+
+ err:
EVP_ENCODE_CTX_free(ctx);
- return outl + outl2;
+
+ return outl;
}
/*
{
EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
int outl = 0, outl2 = 0;
+ unsigned char pad[2] = {0, 0};
+ size_t leadz = 0;
if (ctx == NULL)
return 0;
EVP_EncodeInit(ctx);
- evp_encode_ctx_set_flags(ctx, EVP_ENCODE_CTX_NO_NEWLINES);
+ evp_encode_ctx_set_flags(ctx, EVP_ENCODE_CTX_NO_NEWLINES
+ | EVP_ENCODE_CTX_USE_SRP_ALPHABET);
+
+ /*
+ * We pad at the front with zero bytes until the length is a multiple of 3
+ * so that EVP_EncodeUpdate/EVP_EncodeFinal does not add any of its own "="
+ * padding
+ */
+ leadz = 3 - (size % 3);
+ if (leadz != 3
+ && !EVP_EncodeUpdate(ctx, (unsigned char *)dst, &outl, pad,
+ leadz)) {
+ EVP_ENCODE_CTX_free(ctx);
+ return 0;
+ }
- if (!EVP_EncodeUpdate(ctx, (unsigned char *)dst, &outl, src, size)) {
+ if (!EVP_EncodeUpdate(ctx, (unsigned char *)dst + outl, &outl2, src,
+ size)) {
EVP_ENCODE_CTX_free(ctx);
return 0;
}
+ outl += outl2;
EVP_EncodeFinal(ctx, (unsigned char *)dst + outl, &outl2);
+ outl += outl2;
+
+ /* Strip the encoded padding at the front */
+ if (leadz != 3) {
+ memmove(dst, dst + leadz, outl - leadz);
+ dst[outl - leadz] = '\0';
+ }
EVP_ENCODE_CTX_free(ctx);
return 1;
SRP_user_pwd *ret;
if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) {
- /* SRPerr(SRP_F_SRP_USER_PWD_NEW, ERR_R_MALLOC_FAILURE); */
+ /* SRPerr(SRP_F_SRP_USER_PWD_NEW, ERR_R_MALLOC_FAILURE); */ /*ckerr_ignore*/
return NULL;
}
ret->N = NULL;
int i;
SRP_gN *gN;
- if (gN_tab != NULL)
+ if (gN_tab != NULL) {
for (i = 0; i < sk_SRP_gN_num(gN_tab); i++) {
gN = sk_SRP_gN_value(gN_tab, i);
if (gN && (id == NULL || strcmp(gN->id, id) == 0))
return gN;
}
+ }
return SRP_get_default_gN(id);
}
}
/*
- * this function parses verifier file. Format is:
- * string(index):base64(N):base64(g):0
- * string(username):base64(v):base64(salt):int(index)
+ * This function parses the verifier file generated by the srp app.
+ * The format for each entry is:
+ * V base64(verifier) base64(salt) username gNid userinfo(optional)
+ * or
+ * I base64(N) base64(g)
+ * Note that base64 is the SRP variant of base64 encoding described
+ * in t_fromb64().
*/
int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file)
return NULL;
}
+int SRP_VBASE_add0_user(SRP_VBASE *vb, SRP_user_pwd *user_pwd)
+{
+ if (sk_SRP_user_pwd_push(vb->users_pwd, user_pwd) <= 0)
+ return 0;
+ return 1;
+}
+
# if OPENSSL_API_COMPAT < 0x10100000L
/*
* DEPRECATED: use SRP_VBASE_get1_by_user instead.
g_bn = g_bn_alloc;
defgNid = "*";
} else {
- SRP_gN *gN = SRP_get_gN_by_id(g, NULL);
+ SRP_gN *gN = SRP_get_default_gN(g);
if (gN == NULL)
goto err;
N_bn = gN->N;